EPA/600/R-98/144

November 1998

Environmental Technology Verification

Report

Field-Portable Gas Chromatograph

Perkin-Elmer Photovac, Voyager

by

Wayne Einfeld

Sandia National Laboratories

Albuquerque, New Mexico 87185-0755

IAG DW89936700-01-0

Project Officer

Stephen Billets

National Exposure Research Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Las Vegas, Nevada 89193
ii

Notice

The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), funded

and managed, under Interagency Agreement No. DW89936700-01-0 with the U.S. Department of Energy=s Sandia

National Laboratory, the verification effort described in this document. This report has received both technical peer

and administrative policy reviews and has been approved for publication as an EPA document. Mention of

corporate names, trade names, or commercial products does not constitute endorsement or recommendation for use.
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

Office of Research and Development

Washington, D.C. 20460

EPA-VS-SCM-24 The accompanying notice is an integral part of this verification statement November 1998

iii

ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM

VERIFICATION STATEMENT

PROGRAM DESCRIPTION

The U.S. Environmental Protection Agency (EPA) created the Environmental Technology Verification Program

(ETV) to facilitate the deployment of innovative environmental technologies through verification of performance

and dissemination of information. The goal of the ETV program is to further environmental protection by

substantially accelerating the acceptance and use of improved and cost-effective technologies. The ETV program is

intended to assist and inform those involved in the design, distribution, permitting, and purchase of environmental

technologies.

Under this program, in partnership with recognized testing organizations, and with the full participation of the

technology developer, the EPA evaluates the performance of innovative technologies by developing demonstration

plans, conducting field tests, collecting and analyzing the demonstration results, and preparing reports. The testing

is conducted in accordance with rigorous quality assurance protocols to ensure that data of known and adequate

quality are generated and that the results are defensible. The EPA National Exposure Research Laboratory, in

cooperation with Sandia National Laboratories, the testing organization, evaluated field-portable systems for

monitoring chlorinated volatile organic compounds (VOCs) in water. This verification statement provides a

summary of the demonstration and results for the Perkin-Elmer Photovac, Voyager field-portable gas

chromatograph (GC).

DEMONSTRATION DESCRIPTION

The field demonstration of the Voyager portable GC was held in September 1997. The demonstration was designed

to assess the instrument’s ability to detect and measure chlorinated VOCs in groundwater at two contaminated sites:

the Department of Energy’s Savannah River Site, near Aiken, South Carolina, and the McClellan Air Force Base,

near Sacramento, California. Groundwater samples from each site were supplemented with performance evaluation

(PE) samples of known composition. Both sample types were used to assess instrument accuracy, precision, sample

throughput, and comparability to reference laboratory results. The primary target compounds at the Savannah River

Site were trichloroethene and tetrachloroethene. At McClellan Air Force Base, the target compounds were 

 TECHNOLOGY TYPE: FIELD-PORTABLE GAS CHROMATOGRAPH

 APPLICATION: MEASUREMENT OF CHLORINATED VOLATILE ORGANIC

COMPOUNDS IN WATER

 TECHNOLOGY NAME: Voyager

 COMPANY Perkin-Elmer Corporation - Photovac Monitoring Instruments

 ADDRESS: 50 Danbury Road

Wilton, CT 06897

 PHONE: (203) 761-2557
EPA-VS-SCM-24 The accompanying notice is an integral part of this verification statement November 1998

iv

trichloroethene, tetrachloroethene, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,2-dichloropropane, and trans-1,3-

dichloropropene. These sites were chosen because they contain varied concentrations of chlorinated VOCs and

exhibit different climatic and geological conditions. The conditions at these sites are typical, but not inclusive, of

those under which this technology would be expected to operate. A complete description of the demonstration,

including a data summary and discussion of results, may be found in the report entitled Environmental Technology

Verification Report, Field-Portable Gas Chromatograph, Perkin-Elmer Photovac, Voyager. (EPA/600/R98/144).

TECHNOLOGY DESCRIPTION

Gas chromatography with electron capture detection is a proven analytical technology that has been used in

environmental laboratories for many years. The gas chromatographic column separates the sample into individual

components. The electron capture detector measures a change in electron current from a sealed radioactive source as

compounds exit the chromatographic column, move through the detector, and capture electrons. The electron

capture detector is particularly sensitive to chlorinated compounds. Compounds are identified by matching the

column retention time of sample components, run under controlled temperature conditions, to those of standard

mixtures run under similar conditions. Quantitation is achieved by comparing the detector response intensity of the

sample component and the standard. A GC offers some potential for identification of unknown components in a

mixture; however, a confirmational analysis by an alternative method is often advisable. Portable GC is a versatile

technique that can be used to provide rapid screening data or routine monitoring of groundwater samples. In many

GC systems, the instrument configuration can also be quickly changed to accommodate different sample matrices

such as soil, soil gas, water, or air. As with all field analytical studies, it may be necessary to send a portion of the

samples to an independent laboratory for confirmatory analyses.

The Voyager includes an on-board processor and is encapsulated in a weather-resistant case. The GC unit weighs

about 15 pounds and the accessories for water analysis weigh about 33 pounds. Both units can be easily transported

and operated in the rear compartment of a minivan. The instrument utilizes an equilibrium headspace technique for

the analysis of VOCs in water. Instrument detection limits for many chlorinated VOCs in water are in the range of 5

to 10 μg/L. Sample processing and analysis can be accomplished by a chemical technician with 1 day of training;

however, instrument method development and initial calibration may require additional experience and training. At

the time of the demonstration, the baseline cost of the Voyager and headspace sampling accessories was $24,000. 

Operational costs, which take into account consumable supplies, are on the order of $25 per 8-hour day. 

VERIFICATION OF PERFORMANCE

The following performance characteristics of the Voyager were observed:

Sample Throughput: Throughput was one to three samples per hour. This rate includes the periodic analysis of

blanks and calibration check samples. The sample throughput rate is influenced by the complexity of the sample,

with less complex samples yielding higher throughput rates. 

Completeness: The Voyager reported results for all 166 PE evaluation and groundwater samples provided for

analysis at the two demonstration sites. 

Analytical Versatility: The Voyager was calibrated for and detected 75% (24 of 32) of the PE sample VOCs

provided for analysis at the demonstration. Three pairs of coeluting compounds were encountered in the GC

methods used during this demonstration. For the groundwater contaminant compounds for which it was calibrated,

the Voyager detected 39 of the 44 compounds reported by the reference laboratory at concentration levels in excess

of 1 μg/L. A total of 68 compounds were detected by the reference laboratory in all groundwater samples. 

Precision: Precision was determined by analyzing sets of four replicate samples from a variety of PE mixtures

containing known concentrations of chlorinated VOCs. The results are reported in terms of relative standard

deviations (RSD). The RSDs compiled for all reported compounds from both sites had a median value of 20% and

a 95th percentile value of 69%. By comparison, the compiled RSDs from the reference laboratory had a median
EPA-VS-SCM-24 The accompanying notice is an integral part of this verification statement November 1998

v

value of 7% and a 95th percentile value of 25%. The range of Voyager RSD values for specific target compounds

was as follows: trichloroethene, 7 to 71%; tetrachloroethene, <30% (limited data—-only one value was available);

1,2-dichloroethane and 1,2-dichloropropane (coeluting pair), 4 to 44%; 1,1,2-trichloroethane, 11 to 103%; and

trans-1,3-dichloropropene, 8 to 46%.

Accuracy: Instrument accuracy was evaluated by comparing Voyager results with the known concentrations of

chlorinated organic compounds in PE mixtures. Absolute percent difference (APD) values from both sites were

calculated for all reported compounds in the PE mixtures. The APDs from both sites had a median value of 41%

and a 95th percentile value of 170%. By comparison, the compiled APDs from the reference laboratory had a

median value of 7% and a 95th percentile value of 24%. The range of Voyager APD values for target compounds

was as follows: trichloroethene, 8 to 244%; tetrachloroethene, 24 to 99%; 1,2-dichloroethane and 1,2-

dichloropropane (coeluting pair), 14 to 70%; 1,1,2-trichloroethane, 16 to 50%; and trans-1,3-dichloropropene, 3 to

62%.

Comparability: A comparison of Voyager and reference laboratory data was based on 33 groundwater samples

analyzed at each site. The correlation coefficient (r) for all compounds detected by both the Voyager and the

laboratory at or below the 100 μg/L concentration level was 0.890 at Savannah River and 0.660 at McClellan. The

r values for compounds detected at concentration levels in excess of 100 μg/L were 0.830 for Savannah River and

0.999 for McClellan. These correlation coefficients reveal a moderately linear relationship between Voyager and

laboratory data. The median absolute percent difference between groundwater compounds mutually detected by the

Voyager and reference laboratory was 74%, with a 95th percentile value of 453%.

Deployment: The system was ready to analyze samples within 60 minutes of arrival at the site. At both sites, the

instrument was transported in and operated from the rear luggage compartment of a minivan. The instrument was

powered by self-contained batteries or from a small dc-to-ac inverter connected to the vehicle’s battery. 

The results of the demonstration revealed that sample handling methodologies may have adversely affected the

observed precision and accuracy of the instrument. Perkin-Elmer Photovac has developed an improved field method

for sample preparation and handling that includes the use of an internal standard. The new method is expected to

result in improved instrument precision and accuracy. The Voyager may be suitable for both field screening and

routine analysis applications. In the selection of a technology for use at a particular site, the user must determine

what is appropriate through consideration of instrument performance and the project’s data quality objectives.

Gary J. Foley, Ph. D. Samuel G. Varnado

Director Director

National Exposure Research Laboratory Energy and Critical Infrastructure Center

Office of Research and Development Sandia National Laboratories

NOTICE: EPA verifications are based on an evaluation of technology performance under specific, predetermined criteria

and the appropriate quality assurance procedures. EPA makes no expressed or implied warranties as to the performance of

the technology and does not certify that a technology will always, under circumstances other than those tested, operate at

the levels verified. The end user is solely responsible for complying with any and all applicable federal, state and local

requirements.
vi

Foreword

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the nation’s natural

resources. The National Exposure Research Laboratory (NERL) is the EPA center for the investigation of technical

and management approaches for identifying and quantifying risks to human health and the environment. The

NERL research goals are to (1) develop and evaluate technologies for the characterization and monitoring of air,

soil, and water; (2) support regulatory and policy decisions; and (3) provide the science support needed to ensure

effective implementation of environmental regulations and strategies.

The EPA created the Environmental Technology Verification (ETV) Program to facilitate the deployment of

innovative technologies through verification of performance and dissemination of information. The goal of the ETV

Program is to further environmental protection by substantially accelerating the acceptance and use of improved

and cost-effective technologies. It is intended to assist and inform those involved in the design, distribution,

permitting, and purchase of environmental technologies.

Candidate technologies for this program originate from the private sector and must be market ready. Through the

ETV Program, developers are given the opportunity to conduct rigorous demonstrations of their technologies under

realistic field conditions. By completing the evaluation and distributing the results, the EPA establishes a baseline

for acceptance and use of these technologies.

Gary J. Foley, Ph. D.

Director

National Exposure Research Laboratory

Office of Research and Development
vii

Executive Summary

The U.S. Environmental Protection Agency, through the Environmental Technology Verification Program, is

working to accelerate the acceptance and use of innovative technologies that improve the way the United States

manages its environmental problems. As part of this program, the Consortium for Site Characterization

Technology was established as a pilot program to test and verify field monitoring and site characterization

technologies. The Consortium is a partnership involving the U.S. Environmental Protection Agency, the

Department of Defense, and the Department of Energy. In 1997 the Consortium conducted a demonstration of five

systems designed for the analysis of chlorinated volatile organic compounds in groundwater. The developers

participating in this demonstration were Electronic Sensor Technology, Perkin-Elmer Photovac, and Sentex

Systems, Inc. (field-portable gas chromatographs); Inficon, Inc. (field-portable gas chromatograph/mass

spectrometer, GC/MS); and Innova AirTech Instruments (photoacoustic infrared analyzer). This report documents

demonstration activities, presents demonstration data, and verifies the performance of the Perkin-Elmer Photovac

Voyager field-portable gas chromatograph. Reports documenting the performance of the other technologies have

been published separately.

The demonstration was conducted at two geologically and climatologically different sites: the U.S. Department of

Energy’s Savannah River Site, near Aiken, South Carolina, and McClellan Air Force Base, near Sacramento,

California. Both sites have groundwater resources that are significantly contaminated with a variety of chlorinated

volatile organic compounds. The demonstrations designed to evaluate the capabilities of each field-transportable

system were conducted in September 1997 and were coordinated by Sandia National Laboratories.

The demonstration provided adequate analytical and operational data with which to evaluate the performance of the

Voyager gas chromatograph. Instrument precision and accuracy were determined from analyses of replicate samples

from 16 multicomponent standard mixtures of known composition. The relative standard deviations obtained from

analysis of 4 replicate samples from each of the 16 standard mixtures were used as measures of precision. The

distribution of relative standard deviations from all compounds had a median value of 20% and a 95th percentile value

of 69%. Accuracy was expressed as the absolute percent difference between the Voyager measured value and the

true value of the component in the standard mixtures. The distribution of absolute percent difference values for all

compounds in all standard mixtures had a median value of 41% and a 95th percentile value of 170%. A comparison

of Voyager and reference laboratory results from 33 groundwater samples at each site resulted in a median absolute

percent difference of 74%, with a 95th percentile value of 453%. A correlation analysis between Voyager and

laboratory groundwater yields correlation coefficients (r) greater than 0.66 at low (≤100 μg/L) contaminant

concentrations and greater than 0.83 at high (>100 μg/L) concentrations. The sample throughput rate of the Voyager

was determined to be between 1 and 3 samples per hour.

The results of this study suggest that the sample handling methodology used in this demonstration may have

adversely affected instrument precision and accuracy. A refinement of sample handling methods may improve

overall instrument performance. Under appropriate applications, the Voyager gas chromatograph can provide

useful, cost-effective data for environmental site characterization and routine monitoring. As with any technology

selection, the user must determine what is appropriate by taking into account instrument performance and the

project’s data quality objectives.
viii
ix

Contents

Notice .................................................................................................................................................................. ii

Verification Statement......................................................................................................................................... iii

Foreword ............................................................................................................................................................ vi

Executive Summary ........................................................................................................................................... vii

Figures.............................................................................................................................................................. xiii

Tables............................................................................................................................................................... xiv

Acronyms and Abbreviations.............................................................................................................................. xv

Acknowledgments ............................................................................................................................................ xvii

Chapter 1 Introduction.......................................................................................................................................... 1

Site Characterization Technology Challenge....................................................................................... 1

Technology Verification Process........................................................................................................ 2

Identification of Needs and Selection of Technology..................................................................... 2

Planning and Implementation of Demonstration............................................................................ 2

Preparation of Report.................................................................................................................. 3

Distribution of Information.......................................................................................................... 3

The Wellhead VOC Monitoring Demonstration.................................................................................. 3

Chapter 2 Technology Description........................................................................................................................ 5

Technology Overview........................................................................................................................ 5

Analytical Methods............................................................................................................................ 6

Advantages........................................................................................................................................ 6

Limitations........................................................................................................................................ 7

Applications...................................................................................................................................... 7

Operator Training.............................................................................................................................. 7

Performance Characteristics .............................................................................................................. 7

Method Detection Limits and Practical Quantitation Limit ........................................................... 7

Accuracy..................................................................................................................................... 7
x

Precision ..................................................................................................................................... 8

Comparison with Reference Laboratory Analyses ........................................................................ 8

Data Completeness...................................................................................................................... 9

Specificity................................................................................................................................... 9

Other Field Performance Characteristics............................................................................................ 9

Instrument Setup and Disassembly Time...................................................................................... 9

Instrument Calibration Frequency During Field Use..................................................................... 9

Ancillary Equipment Requirements............................................................................................ 11

Field Maintenance Requirements ............................................................................................... 11

Sample Throughput Rate........................................................................................................... 11

Ease of Operation...................................................................................................................... 11

Chapter 3 Demonstration Design and Description ............................................................................................... 12

Introduction..................................................................................................................................... 12

Overview of Demonstration Design.................................................................................................. 12

Quantitative Factors.................................................................................................................. 12

Qualitative Factors.................................................................................................................... 13

Site Selection and Description.......................................................................................................... 14

Savannah River Site .................................................................................................................. 14

McClellan Air Force Base ......................................................................................................... 16

Sample Set Descriptions.................................................................................................................. 18

PE Samples and Preparation Methods........................................................................................ 21

Groundwater Samples and Collection Methods .......................................................................... 23

Sample Handling and Distribution.................................................................................................... 23

Field Demonstration Schedule and Operations.................................................................................. 24

Site Operations and Environmental Conditions................................................................................. 24

Field Audits..................................................................................................................................... 25

Data Collection and Analysis........................................................................................................... 26

Demonstration Plan Deviations........................................................................................................ 26

Chapter 4 Laboratory Data Results and Evaluation............................................................................................. 27

Introduction..................................................................................................................................... 27

Reference Laboratory ...................................................................................................................... 27
xi

Laboratory Selection Criteria........................................................................................................... 27

Summary of Analytical Work by DataChem Laboratories................................................................ 28

Summary of Method 8260A............................................................................................................. 28

Method 8260A Quality Control Requirements.................................................................................. 28

Summary of Laboratory QC Performance ........................................................................................ 28

Target Compound List and Method Detection Limits ................................................................. 29

Sample Holding Conditions and Times....................................................................................... 29

System Calibration.................................................................................................................... 29

Daily Instrument Performance Checks....................................................................................... 31

Batch-Specific Instrument QC Checks....................................................................................... 31

Sample-Specific QC Checks...................................................................................................... 31

Summary of Analytical and QC Deviations................................................................................ 33

Other Data Quality Indicators.......................................................................................................... 33

PE Sample Precision ................................................................................................................. 34

PE Sample Accuracy................................................................................................................. 34

Groundwater Sample Precision.................................................................................................. 39

Summary of Reference Laboratory Data Quality.............................................................................. 40

Chapter 5 Demonstration Results........................................................................................................................ 41

Voyager Calibrated and Reported Compounds ................................................................................. 41

Preanalysis Sample Information....................................................................................................... 41

Sample Completion.......................................................................................................................... 42

Blank Sample Results...................................................................................................................... 42

Performance at Instrument Detection Limit ...................................................................................... 42

PE Sample Precision........................................................................................................................ 43

PE Sample Accuracy....................................................................................................................... 43

Comparison with Laboratory Results............................................................................................... 49

Sample Throughput ......................................................................................................................... 49

Performance Summary .................................................................................................................... 49

Chapter 6 Field Observations and Cost Summary ............................................................................................... 55

Introduction..................................................................................................................................... 55
xii

Method Summary...................................................................................................................... 55

Equipment................................................................................................................................. 55

Sample Preparation and Handling.............................................................................................. 55

Consumables............................................................................................................................. 56

Historical Use ........................................................................................................................... 56

Equipment Cost......................................................................................................................... 57

Operators and Training.............................................................................................................. 57

Data Processing and Output ...................................................................................................... 57

Compounds Detected................................................................................................................. 58

Initial and Daily Calibration ...................................................................................................... 58

QC Procedures and Corrective Actions...................................................................................... 58

Sample Throughput................................................................................................................... 58

Problems Observed During Audit .............................................................................................. 58

Data Availability and Changes................................................................................................... 58

Instrument Transport................................................................................................................. 59

Applications Assessment.................................................................................................................. 59

Chapter 7 Technology Update............................................................................................................................. 60

Introduction..................................................................................................................................... 60

Additional Performance Testing....................................................................................................... 60

Voyager Configuration and Method Improvements..................................................................... 60

Sample Preparation and Handling.............................................................................................. 61

Reference Laboratory................................................................................................................ 61

Test Results..................................................................................................................................... 61

Calculation of Concentrations.................................................................................................... 61

Precision and Accuracy ............................................................................................................. 61

Chapter 8 Previous Deployments........................................................................................................................ 65

References.......................................................................................................................................................... 66
xiii

Figures

2-1. A schematic diagram of the Voyager GC.................................................................................................. 5

3-1. The general location of the Savannah River Site in the southeast United States........................................ 14

3-2. A map of the A/M area at the Savannah River Site showing the subsurface TCE plume.......................... 15

3-3. A map of Sacramento and vicinity showing the location of McClellan Air Force Base............................. 17

3-4. Subsurface TCE plumes at McClellan Air Force Base in the shallowest (A) aquifer layer ....................... 19

4-1. Laboratory control standard recovery values for SRS analyses. .............................................................. 32

4-2. Laboratory control standard recovery values for MAFB analyses............................................................ 32

4-3. Laboratory precision on SRS PE samples containing mix 1 .................................................................... 35

4-4. Laboratory precision on SRS PE samples containing mix 2 .................................................................... 35

4-5. Laboratory precision on MAFB PE samples containing mix 2................................................................. 36

4-6. Laboratory precision on MAFB PE samples containing mix 3................................................................. 36

4-7. Laboratory mean recoveries for SRS PE samples containing mix 1......................................................... 37

4-8. Laboratory mean recoveries for SRS PE samples containing mix 2......................................................... 37

4-9. Laboratory mean recoveries for MAFB PE samples containing mix 2 ..................................................... 38

4-10. Laboratory mean recoveries for MAFB PE samples containing mix 3 ..................................................... 38

5-1. Voyager precision on PE mix 1 at the SRS............................................................................................. 44

5-2. Voyager precision on PE mix 2 at the SRS............................................................................................. 44

5-3. Voyager precision on PE mix 2 at MAFB............................................................................................... 45

5-4. Voyager precision on PE mix 3 at MAFB............................................................................................... 45

5-5. Voyager recovery on PE mix 1 at the SRS.............................................................................................. 46

5-6. Voyager recovery on PE mix 2 at the SRS.............................................................................................. 46

5-7. Voyager recovery on PE mix 2 at MAFB. .............................................................................................. 48

5-8. Voyager recovery on PE mix 3 at MAFB. .............................................................................................. 48

5-9. Voyager groundwater results at the SRS relative to laboratory results..................................................... 52

5-10. Voyager groundwater results at MAFB relative to laboratory results....................................................... 52

6-1. The Voyager GC.................................................................................................................................... 56
xiv

Tables

2-1. Voyager Specifications for MDL, PQL, and Upper Range for Selected Chlorinated Hydrocarbons............ 8

2-2. Voyager Retention Times and Resolution Factors................................................................................... 10

3-1. Quarterly Monitoring Results for SRS Wells Sampled in the Demonstration ........................................... 16

3-2. Groundwater Contaminants at MAFB.................................................................................................... 20

3-3. Quarterly Monitoring Results for MAFB Wells Sampled in the Demonstration ....................................... 20

3-4. Composition of PE Source Materials...................................................................................................... 22

3-5. PE Sample Composition and Count for SRS Demonstration ................................................................... 22

3-6. PE Sample Composition and Count for MAFB Demonstration ............................................................... 23

3-7. Weather Summary for SRS and MAFB During Demonstration Periods .................................................. 25

4-1. Method 8260A Quality Control Summary .............................................................................................. 29

4-2. Reference Laboratory Method Detection Limits for Target Compounds.................................................. 30

4-3. Summary of Reference Laboratory Quality Control and Analytical Deviations........................................ 33

4-4. Sources of Uncertainty in PE Sample Preparation................................................................................... 34

4-5. Summary of SRS Groundwater Analysis Precision................................................................................. 39

4-6. Summary of MAFB Groundwater Analysis Precision ............................................................................. 39

5-1. Voyager Calibrated and Reported Compounds........................................................................................ 41

5-2. False Positive Rates from Blank Sample Analysis................................................................................... 42

5-3. False Negative Rates from Very Low-Level PE Sample Analysis............................................................ 42

5-4. Target Compound Precision at Both Sites............................................................................................... 43

5-5. Summary of PE Sample Precision and Percent Difference Statistics for the SRS and MAFB................... 47

5-6. Target Compound Recovery for PE Mix 2 at Both Sites......................................................................... 47

5-7. Voyager and Reference Laboratory Results for SRS Groundwater Samples............................................ 50

5-8. Voyager and Reference Laboratory Results for MAFB Groundwater Samples........................................ 51

5-9. Voyager Absolute Percent Difference Summary for Pooled Groundwater Results.................................... 53

5-10. Correlation Coefficients for Laboratory and Voyager Groundwater Analyses.......................................... 53

5-11. Summary of Voyager Performance......................................................................................................... 53

6-1. Voyager GC Cost Summary................................................................................................................... 57

7-1. Blank Sample Results............................................................................................................................ 62

7-2. Very Low-Level Sample (7 μg/L) Results .............................................................................................. 62

7-3. Low-Level Sample (30 μg/L) Results..................................................................................................... 63

7-4. Midlevel Sample (700 μg/L) Results...................................................................................................... 63

7-5. Mid- to High-Level Sample (300 and 5000 μg/L) Results....................................................................... 64

7-6. Very High-Level Sample (3000 μg/L) Results........................................................................................ 64

7-7. Summary Mean Percent Recoveries........................................................................................................ 64
xv

Acronyms and Abbreviations

ac alternating current

APD absolute percent difference

BNZN benzene

BTEX xylene

°C degrees centigrade

CCC calibration check compounds

CCL4 carbon tetrachloride

CLFRM chloroform

dc direct current

11DCA 1,1-dichloroethane

12DCA 1,2-dichloroethane

DCE dichloroethene

11DCE 1,1-dichloroethene

c12DCE cis-1,2-dichloroethene

t12DCE trans-1,2-dichloroethene

DCL DataChem Laboratories

DOE Department of Energy

ECD electron capture detector

EPA Environmental Protection Agency

ETV Environmental Technology Verification Program

eV electron-volt

GC gas chromatograph

GW groundwater

GC/MS gas chromatograph/mass spectrometer

Hz hertz, cycles per second

L liter

m meter

mg milligram

mg/L milligrams per liter

mL milliliter

mm millimeter

MAFB McClellan Air Force Base

MCL maximum concentration level

MDL method detection limit

MS mass spectroscopy

NA not analyzed
xvi

ND not detected

NERL National Exposure Research Laboratory

ng/L nanograms per liter

NR not reported

PC personal computer

PCE tetrachloroethene (perchloroethene)

PE performance evaluation

PID photoionization detector

ppb parts per billion

ppm parts per million

ppt parts per trillion

PQL practical quantitation limit

PVC poly (vinyl chloride)

QA quality assurance

QC quality control

r correlation coefficient

RPD relative percent difference

RSD relative standard deviation

SPCC system performance check compounds

SRS Savannah River Site

TCE trichloroethene

V volts

V ac volts alternating current

VOA volatile organics analysis

VOC volatile organic compound

μg microgram

μg/L micrograms per liter

μL microliter

μm micrometer
xvii

Acknowledgments

The author wishes to acknowledge the support of all those who helped to plan and conduct the demonstrations,

analyze the data, and prepare this report. In particular, the technical expertise of Gary Brown, Robert Helgesen,

Michael Hightower, and Dr. Brian Rutherford of Sandia National Laboratories in the planning and conduct of the

study are recognized. The assistance of Dr. Timothy Jarosch and Joseph Rossabi of Westinghouse Savannah River

Co. in planning the demonstration and field activities at both Savannah River and McClellan is also recognized.

The willingness of Phillip Mook and Timothy Chapman of the Environmental Directorate at McClellan Air Force

Base to host the McClellan phase of the study is also greatly appreciated. The availability of funding from the

Department of Defense’s Strategic Environmental Research and Development Program helped to make the

McClellan phase of the study possible. The guidance and contributions of project technical leaders Dr. Stephen

Billets and Eric Koglin of the EPA National Exposure Research Laboratory, Environmental Sciences Division, in

Las Vegas, Nevada, during all phases of the project are also recognized.

The participation of personnel from Perkin-Elmer Photovac in this technology demonstration is also acknowledged.

Susan Johnke and Suzanne Moller operated the instrument during the demonstrations.

For more information on the Wellhead Monitoring demonstration, contact:

Stephen Billets, Project Technical Leader, U.S. Environmental Protection Agency

National Exposure Research Laboratory, Environmental Sciences Division

P.O. Box 93478, Las Vegas, Nevada 89193-3478

(702) 798-2232

For more information on the Perkin Elmer - Photovac, Voyager gas chromatograph, contact:

Dr. Mark Collins, Product Manager

Perkin-Elmer Corporation - Photovac Monitoring Instruments

50 Danbury Road, Wilton, CT 06897

(203) 761-2557
xviii
1

Chapter 1 

Introduction

Site Characterization Technology Challenge

The U.S. Environmental Protection Agency (EPA) created the Environmental Technology Verification (ETV)

Program to facilitate the deployment of innovative environmental technologies through verification of performance

and dissemination of information. The goal of the ETV Program is to further environmental protection by

substantially accelerating the acceptance and use of improved and cost-effective technologies. It is intended to

assist and inform those involved in the design, distribution, permitting, purchase, and use of environmental

technologies. The ETV Program capitalizes on and applies the lessons that were learned in the implementation of

the Superfund Innovative Technology Evaluation Program to twelve pilot programs: Drinking Water Systems,

Pollution Prevention for Waste Treatment, Pollution Prevention for Innovative Coatings and Coatings Equipment,

Indoor Air Products, Advanced Monitoring Systems, EvTEC (an independent, private-sector approach), Wet

Weather Flows Technologies, Pollution Prevention for Metal Finishing, Source Water Protection Technologies, Site

Characterization and Monitoring Technology, Climate Change Technologies, and Air Pollution Control.

For each pilot, the EPA utilizes the expertise of partner “verification organizations” to design efficient procedures

for performance tests of the technologies. The EPA selects its partners from both public and private sectors,

including federal laboratories, states, and private sector entities. Verification organizations oversee and report

activities based on testing and quality assurance protocols developed with input from all major stakeholder and

customer groups associated with the technology area. The U.S. Department of Energy’s (DOE’s) Sandia National

Laboratories in Albuquerque, New Mexico, served as the verification organization for the demonstration described

in this report.

The performance verification reported here is based on data collected during a demonstration of technologies for the

characterization and monitoring of chlorinated volatile organic compounds (VOCs) in groundwater. Rapid,

reliable, and cost-effective field screening and analysis technologies are needed to assist in the complex task of

characterizing and monitoring hazardous and chemical waste sites. Environmental regulators and site managers are

often reluctant to use new technologies that have not been validated in an objective EPA-sanctioned testing program

or other similar process. Until the field performance of a technology can be verified through objective evaluations,

users will remain skeptical of innovative technologies, despite the promise of better, less expensive, and faster

environmental analyses. This demonstration was administered by the Site Characterization and Monitoring

Technology Pilot Program, which is also known as the Consortium for Site Characterization Technology. The

mission of the Consortium is to identify, demonstrate, and verify the performance of innovative site characterization

and monitoring technologies. The Consortium also disseminates information about technology performance to

developers, environmental remediation site managers, consulting engineers, and regulators.
2

Technology Verification Process

The technology verification process consists of the four key steps shown here and discussed in more detail in the

following paragraphs:

1. identification of needs and selection of technology;

2. planning and implementation of demonstration;

3. preparation of report; and

4. distribution of information.

Identification of Needs and Selection of Technology

The first aspect of the verification process is to determine the technology needs of the EPA and the regulated

community. The EPA, the U.S. Department of Energy, the U.S. Department of Defense, industry, and state

agencies are asked to identify technology needs for site characterization and monitoring. Once a need is recognized,

a search is conducted to identify suitable technologies that will address this need. This search and identification

process consists of reviewing responses to Commerce Business Daily announcements, searching industry and trade

publications, attending related conferences, and following up on suggestions from technology developers and

experts in the field. Candidate characterization and monitoring technologies are evaluated against the following

criteria:

• may be used in the field or in a mobile laboratory;

• has a regulatory application;

• is applicable to a variety of environmentally affected sites;

• has a high potential for resolving problems for which current methods are unsatisfactory;

• has costs that are competitive with current methods;

• has performance as good or better than current methods in areas such as data quality, sample preparation, and/or

analytical turnaround time;

• uses techniques that are easier and safer than current methods; and

• is a commercially available, field-ready technology.

Planning and Implementation of Demonstration

After a technology has been selected, the EPA, the verification organization, and the developer(s) agree on a

strategy for conducting the demonstration and evaluating the technology. A conceptual plan for designing a

demonstration for a site characterization technology has been published by the Site Characterization and

Monitoring Technology Pilot Program (EPA, 1996a). During the planning process, the following steps are carried

out:

• identification of at least two demonstration sites that will provide the appropriate physical or chemical attributes

in the desired environmental media;

• identification and definition of the roles of demonstration participants, observers, and reviewers;

• determination of logistical and support requirements (for example, field equipment, power and water sources,

mobile laboratory, communications network);

• arranging for field sampling and reference analytical laboratory support; and
3

• preparation and implementation of a demonstration plan that addresses the experimental design, sampling design,

quality assurance and quality control (QA/QC), health and safety considerations, scheduling of field and

laboratory operations, data analysis procedures, and reporting requirements.

Preparation of Report

Each of the innovative technologies is evaluated independently and, when possible, against a reference technology.

The technologies are operated in the field by the developers in the presence of independent observers who are

provided by the EPA or the verification organization. Demonstration data are used to evaluate the capabilities,

limitations, and field applications of each technology. Following the demonstration, all raw and reduced data used

to evaluate each technology are compiled in a technology evaluation report, which is a record of the demonstration.

A data summary and detailed evaluation of each technology are published in an environmental technology

verification report. The report includes a verification statement, which is a concise summary of the instrument’s

performance during the demonstration.

Distribution of Information

The goal of the information distribution strategy is to ensure that environmental technology verification reports and

accompanying verification statements are readily available to interested parties through traditional data distribution

pathways, such as printed documents. Related documents and updates are also available on the World Wide Web

through the ETV Web site (http://www.epa.gov/etv) and through a Web site supported by the EPA Office of Solid

Waste and Emergency Response Technology Innovation Office (http://clu-in.com). Additional information at the

ETV Web site includes a summary of the demonstration plan, test protocols (where applicable), demonstration

schedule and participants, and in some cases a brief narrative and pictorial summary of the demonstrations.

The Wellhead VOC Monitoring Demonstration

In August 1996, the selection of a technology for monitoring chlorinated VOCs in water was initiated by

publication in the Commerce Business Daily of a solicitation and notice of intent to conduct such a technology

demonstration. Potential participants were also solicited through manufacturer and technical literature references.

The original demonstration scope was limited to market-ready in situ technologies; however, only a limited response

was obtained, so the demonstration scope was expanded to include technologies that could be used to measure

groundwater at or near the wellhead. The final selection of technologies was based on the readiness of the

technologies for field demonstration and their applicability to the measurement of chlorinated VOCs in groundwater

at environmentally affected sites.

For this demonstration, five instrument systems were selected. Three of them were field-portable gas

chromatographs with various detection systems: one with a surface acoustic wave detector from Electronic Sensor

Technology, one with dual electron capture and photoionization detectors from Perkin-Elmer Photovac, and one

with an argon ion/electron capture detector from Sentex Systems. The fourth instrument was a field-portable gas

chromatograph/mass spectrometer (GC/MS) from Inficon, and the fifth was a photoacoustic infrared spectrometer

from Innova AirTech Instruments. This report documents demonstration activities, presents demonstration data,

and verifies the performance of the Perkin-Elmer Photovac Voyager gas chromatograph. Reports documenting the

performance of the other four technologies have been published separately.

The demonstration was conducted in September 1997 at the DOE Savannah River Site (SRS) near Aiken, Georgia,

and at McClellan Air Force Base (MAFB), near Sacramento, California. Both sites have subsurface plumes of
4

chlorinated VOCs and extensive networks of groundwater monitoring wells. The demonstrations were coordinated

by Sandia National Laboratories with the assistance of personnel from the Savannah River Site.

The primary objective of this demonstration was to evaluate and verify the performance of field-portable

characterization and monitoring technologies for analysis of chlorinated VOCs in groundwater. Specific

demonstration objectives were to:

• verify instrument performance characteristics that can be directly quantified (such factors include response to

blank samples, measurement accuracy and precision, sample throughput, and data completeness);

• verify instrument characteristics and performance in various qualitative categories such as ease of operation,

required logistical support, operator training requirements, transportability, versatility, and other related

characteristics; and

• compare instrument performance with results from standard laboratory analytical techniques currently used to

analyze groundwater for chlorinated VOCs.

The goal of this and other ETV demonstrations is to verify the performance of each instrument as a separate entity.

Technologies are not compared with each other in this program. The demonstration results are summarized for

each technology independent of other participating technologies. In this demonstration, the capabilities of the five

instruments varied and in many cases were not directly comparable. Some of the instruments are best suited for

routine monitoring where compounds of concern are known and there is a maximum contaminant concentration

requirement for routine monitoring to determine regulatory compliance. Other instruments are best suited for

characterization or field-screening activities where groundwater samples of unknown composition can be analyzed

in the field to develop an improved understanding of the type of contamination at a particular site. This field

demonstration was designed so that both monitoring and characterization technologies could be verified.
5

Chapter 2 

Technology Description

This chapter was provided by the developer and was edited for format and relevance. The data presented include

performance claims that may not have been verified as part of the demonstration. Chapters 5 and 6 report

instrument features and performance observed in this demonstration. Publication of this material does not

represent the EPA’s approval or endorsement.

Technology Overview

The Voyager is a field-portable, computer-controlled, gas chromatograph that incorporates three columns and dual

detectors to achieve broadened analytical capabilities. The instrument’s triple column and dual detector

configuration is shown schematically in Figure 2-1.

Voyager G C Assay # 1

C o lumn A rrangemen t

Carrier 

Gas (N2)

Pre-Column

Column A

Column B

Column C Make-Up

Carrier Gas

PID

ECD

Precolumn: 4m x 0.53mm x 2.0 um SPB-35

Column A (HEAVY): 8m x 0.25mm BLANK Fused Silica 

Column B (MID-RANGE): 20m x 0.32mm x 1.0 um Supelcowax10 (PEG)

Column C (LIGHT): 15m x 0.32mm x 12 um Quadrex 007-1

80%

20%

Figure 2-1. A schematic diagram of the Voyager GC.

The Voyager has dimensions of 15.4 inches × 10.6 inches × 5.4 inches and weighs 15 pounds. It incorporates a

high-sensitivity photoionization detector (PID) and a miniature electron capture detector (ECD). The instrument is

the fourth generation in the evolutionary design of field-portable GCs from the Photovac division of the PerkinElmer Corporation. The Voyager was developed with consideration of ergonomic and analytical performance

demands in field environments. Previous generations of Perkin-Elmer Photovac field-portable GCs, such as the

10S50 and 10S70 GC, have been utilized by the EPA Emergency Response Team based in Edison, New Jersey.

This team has generated standard operating procedures for using these instruments to analyze water, soil, ambient

air, and soil gas.
6

A unique internal analytical engine includes a specially designed miniature stainless steel valve array to provide fast

sample delivery and minimize sample carryover (and contamination) caused by high VOC concentrations. The

instrument also incorporates a unique triple-column arrangement, with precolumn and backflush, and a syringe

injection port for headspace sampling of aqueous and soil extract media. The two detectors are configured in

parallel. Gas flow from the three internal columns is split to the detectors, with 80% going to the PID and 20%

going to the ECD. Columns A, B, and C, whose configurations are shown in Figure 2-1, are for heavy (C7 to C12),

midrange (C4 to C7), and light (C1 to C3) hydrocarbon compounds, respectively. The internal sampling train,

sample loop, GC columns, valves, and injection port are heated isothermally at temperatures from 55 to 80 °C. The

Voyager is also unique in that it is the only GC of its kind in the world that is classified as intrinsically safe (Class

1, Division I, Groups A, B, C, and D), rendering it useful in hazardous locations.

The instrument is powered by field-rechargeable and replaceable batteries that allow up to 9 hours of field use with

a 5-hour charge time. Alternatively, the Voyager can be operated from an external 10 to 18-V dc power supply

such as a vehicle battery using a cigarette lighter receptacle. The instrument can also be operated on ac power.

The Voyager can be effectively used to monitor many of the volatile organic compounds listed in EPA Method

8240A (EPA, 1996b), including chlorinated and aromatic hydrocarbons. Sample matrices of applicability include

soil, soil gas, water, and ambient air. Method detection limits (MDLs) for VOCs range from parts per trillion (ppt)

in water (ng/L) to about 500 parts per million (ppm) in ambient air, depending upon the type of compound and

detector used.

Analytical results are displayed on the built-in liquid crystal display and include a list of compounds detected, with

concentrations as well as chromatograms. Built-in data logging allows storage of up to 40 10-minute

chromatograms or 400 analyses obtained during operation in a total-VOC screening mode.

Analytical Methods

The Voyager GC can be configured with one analytical method (assay) at a time. The assay includes the

compound library, column temperature, carrier gas pressure (flow rate), and sampling method (internal variable

volume loop or syringe injection). The preferred method of setting up a new analytical method is by using a PC

interface and downloading files. A laptop computer is required for on-site operation if various types of samples are

to be analyzed that require the installation of different methods. The PC does not have to be connected

continuously to the instrument; however, for accurate quantification of trace concentrations of target compounds, it

is recommended that correct integration of chromatogram peak areas be visually verified on the computer screen.

Advantages

The instrument is lightweight and small. The triple-column configuration and dual PID and ECD give this

instrument sensitivity and selectivity (through confirmational analysis) for a wide cross-section of VOCs on site.

Furthermore, the ability to use the internal pump to draw air samples or to perform syringe injections from

headspace samples of soil and groundwater adds further analytical flexibility for different monitoring tasks. The

Voyager has the added advantage of multiple columns and dual detector systems, which can aid in identifying

unknown compounds.
7

Limitations

The instrument contains radioactive components in the electron capture detector and normally requires statespecific licensing and periodic inventory. As a gas chromatograph, the instrument is also somewhat limited in its

ability to identify unknown compounds. Column retention time is used as an indicator; however, as with most GC

systems, an additional data dimension such as mass spectra, provided by GC/MS systems, is not available.

The Voyager utilizes an equilibrium headspace method to determine VOCs in water. Thus it is only able to analyze

those compounds with solubilities and vapor pressures that promote the formation of a detectable equilibrium

headspace concentration.

Applications

The Voyager GC will detect chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (sometimes

identified as perchloroethene, PCE) at sub-parts-per-billion (ppb or μg/L) levels in aqueous media using the PID

and ECD. Benzene, toluene, ethyl benzene, and xylene isomers are also detected at these trace levels using the PID.

Operator Training

One full day of operator training is adequate. The training covers instrument operation, calibration, automatic

(pump) sampling, headspace syringe injection, data storage and retrieval, and method customization and

development, as well as routine maintenance and troubleshooting.

Performance Characteristics

Method Detection Limits and Practical Quantitation Limit

Voyager, in the Assay No. 1 configuration, which includes a PID and ECD and uses a 500-μL headspace injection,

will give the method detection limits for the chlorinated hydrocarbons shown in Table 2-1 with 95% confidence.

Assay No. 1 covers 40 of the compounds listed in EPA Methods 8260A (EPA, 1996b) and TO-14 (EPA, 1988).

Method detection limits are estimated by determining the Voyager’s average sensitivity for a particular compound

(e.g., parts per billion per millivolt × seconds) in its working range, and then multiplying this sensitivity factor by

the minimum detectable peak area (also in units of millivolts × seconds). The Voyager with the Assay No. 1

column-PID/ECD configuration will give a practical quantitation limit (PQL) at a level 5 to 10 times the standard

deviation of the instrument noise signal. Table 2-1 gives the MDLs, PQLs, and upper ranges for various

chlorinated hydrocarbons, including TCE and PCE.

Accuracy

Voyager will provide an accuracy within ±20% for each target compound, over its working range, 95% of the time

through the use of a three-point calibration.
8

Table 2-1. Voyager Specifications for MDL, PQL, and Upper Range for Selected

Chlorinated Hydrocarbons

Compounds MDL

(μg/L)

PQL

(μg/L)

Upper Range

(μg/L) PQL × 500

PID ECD PID ECD PID ECD

Column A (C7 – C12)

Bromoform 20.00 10.00 60.00 30 30,000 15,000

1,1,2,2-Tetrachloroethane 180.00 30.00 540.00 90 270,000 45,000

1,3-Dichlorobenzene 0.80 2.40 1200

1,4-Dichlorobenzene 0.60 1.80 900

1,2-Dichlorobenzene 1.60 4.80 2400

Column B (C4 – C7)

Trichloroethene 0.08 0.24 120

1,2-Dichloropropane 6.00 18.00 9000

Tetrachloroethene 0.06 0.03 0.18 0.10 90 48

2-Chloroethyl vinyl ether 10.00 30 15,000

cis-1,3-Dichloropropene 0.60 1.80 900

Bromodichloromethane 32.00 0.10 96.00 0.30 48,000 150

trans-1,3-Dichloropropene 1.40 1200 4.20 3600 2100

Chlorobenzene 0.12 0.36 180

1,1,2-Trichloroethane 280.00 840 420,000

Dibromochloromethane 6.00 18.00 9000

Column C (C1 – C3)

Bromomethane 0.12 0.36 180

1,1-Dichloroethene 0.08 0.06 0.24 0.18 120 90

Methylene chloride 1.80 5.40 2700

trans-1,2-Dichloroethene 0.04 0.12 60

Vinyl acetate 10.00 30 15,000

cis-1,2-Dichloroethene 0.60 1.80 900

Chloroform 1.20 3.60 1800

1,2-Dichloroethane 40.00 80.00 120 240 60,000 120,000

1,1,1-Trichloroethane 12.00 0.18 36.00 0.54 18,000 270

Carbon tetrachloride 0.40 1.20 600

Note: Blank cells indicate no determination.

Precision

The precision of the Voyager, as represented by the relative standard deviation (RSD)1 on six replicate

measurements, will be ≤ 20% over the working range of the instrument for each compound.

Comparison with Reference Laboratory Analyses

To date, comparison checks that follow EPA protocols have not been carried out on the Voyager against reference

analytical methods for chlorinated species in water.

 

1 The relative standard deviation is the sample standard deviation divided by the mean value and multiplied by 100.
9

Data Completeness

A complete analysis for TCE; PCE; and benzene, toluene, ethyl benzene, and xylene (BTEX) may take up to 20

minutes. Under these conditions, throughput will be approximately 20 samples and 1 calibration in an 8-hour day.

If there are only 2 analytes (e.g., TCE and PCE), the analysis time will be greatly reduced and sample throughput

will be significantly increased.

Specificity

Specificity is defined in this performance statement as the degree of separation in a mixture of analytes as indicated

by the chromatographic resolution (R).2 The Voyager’s resolution is provided in Table 2-2 and is within 20%

reproducibility 95% of the time. Compounds with R < 1 coelute with those immediately above or immediately

below them in the table.

Other Field Performance Characteristics

Instrument Setup and Disassembly Time

The daily operational procedure consists of the following steps:

1. Fill the built-in carrier gas cylinder with nitrogen (assuming portable field operation).

2. Turn the instrument on.

3. Allow stabilization for 60 minutes.

4. Download desired method (assuming a different method is to be used than in the previous day’s work).

5. Prepare standards and calibrate for the target compounds at a specified concentration.

6. Analyze samples.

If the carrier gas pressure drops below 200 pounds per square inch, as indicated on the Voyager’s internal cylinder

gauge, the cylinder can be recharged from an external supply cylinder. If the “battery voltage low” message is

displayed on the instrument’s display panel, the Voyager can be switched off and the battery replaced with a fully

charged one (assuming field operation). After the battery is replaced, the Voyager should be recalibrated in order to

meet specifications. If the Voyager was not connected to a computer before being switched off on the previous day,

the instrument should be connected to a PC running the Windows-based SiteChart software so that any logged data

files may be downloaded. Shutdown time for the Voyager is less than 5 minutes.

Instrument Calibration Frequency During Field Use

Multipoint calibration curves can be prepared for target compounds prior to field deployment. Accuracy

specifications assume that such curves have been established for each compound under headspace conditions. This

will increase sample throughput rather than utilizing a “generic environmental assay.” The Voyager requires daily

calibration checks with target analytes.

 

2 Chromatographic resolution, R, is defined as the time between the maximum values of two adjacent peaks divided by 4

times the standard deviation of the peak. The standard deviation of the peak is half the peak width at its inflection point.
10

Table 2-2. Voyager Retention Times and Resolution Factors

Compound Retention Time

(seconds)

Chromatographic

Resolution (R)

Column A

ortho-Xylene 472.8 0.73

Styrene 506 2.55

Bromoform 638.6 1.27

1,1,2,2-Tetrachloroethane 715.3 5.86

1,3-Dichlorobenzene 1199.5 1.07

1,4-Dichlorobenzene 1313.5 2.55

1,2-Dichlorobenzene 1629

Column B

Benzene 267.5 1.38

Trichloroethene 329.6 3.15

Methyl isobutyl ketone 381.3 1.84

1,2-Dichloropropane 413.7 2.94

Toluene 468.8 0.79

Tetrachloroethene 484.4 4.14

2-Hexanone 571.7 2.61

2-Chloroethyl vinyl ether 632 1.50

cis-1,3-Dichloropropene 668.6 1.57

Bromodichloromethane 708.7 4.53

Ethyl benzene 833.9 1.30

meta-Xylene 872.8 0

para-Xylene 872.8 4.25

trans-1,3-Dichloropropene 1010 3.73

ortho-Xylene 1144 0.47

Chlorobenzene 1162 5.00

1,1,2-Trichloroethane 1367 6.39

Dibromochloromethane 1673

Column C

Chloromethane 105.7 1.02

Vinyl chloride 118.4 2.08

Bromomethane 147.2 0.62

Chloroethane 156.6 2.03

Acetone 190.2 2.63

1,1-Dichloroethene 241.1 0.54

Dichloromethane 252.8 1.35

Carbon disulfide 283.7 1.31

trans-1,2-Dichloroethene 316.3 0.84

Vinyl acetate 339 1.09

Methyl ethyl ketone 370.3 1.49

cis-1,2-Dichloroethene 416.8 3.63

1,2-Dichloroethene 552.1 0.49

1,1,1-Trichloroethane 573.3 1.57

Benzene 645.2 0.62

Carbon tetrachloride 675.8

Note: Blank cells indicate no determination.
11

Ancillary Equipment Requirements

If the Voyager is used in a stationary (indoor) location, ac or dc power will be required for on-going analyses.

Sample handling accessories include such items as 40-mL volatile organics analysis (VOA) vials, gas-tight syringes

for headspace sampling, spare septa for the syringe injection port, and a small water bath for sample equilibration.

A cylinder of zero-grade nitrogen should be available with a two-stage regulator to run the Voyager in a stationary

location or to refill the internal carrier gas cylinder during field use.

Field Maintenance Requirements

Periodic refilling of the internal carrier gas cylinder is required. The Voyager’s on-board battery pack can be

replaced in the field as required. The 10.6-eV light source in the PID can also be cleaned or replaced in the field if

necessary.

Sample Throughput Rate

Depending upon the number and molecular weights of the analytes to be monitored, a typical GC column run for

TCE, PCE, and BTEX may take about 20 minutes in a complex sample background. Additional time is required

for sample preparation and headspace equilibration. For an 8-hour workday and a daily calibration (not including

blanks), the sample throughput would be about 20 per day. If only TCE and PCE are being monitored, the daily

sample throughput will be significantly higher.

Ease of Operation

Once the analytical method has been installed in the Voyager, the instrument can be disconnected from the PC for

field use and the start/stop key can be used to begin and end analyses as required. All Voyager data, including

chromatograms, are logged on an internal data logger and are automatically downloaded when a PC connection is

made.

The Voyager’s mode of operation in the field can also be set to a “user only” mode. In this mode, the field

operator can only access the method parameters by entering a password established during method development. In

this manner, the Voyager is used as a simple “point-and-press” instrument with no access to method parameters in

the field.
12

Chapter 3 

Demonstration Design and Description

Introduction

This chapter summarizes the demonstration objectives and describes related field activities. The material is

condensed from the Demonstration Plan for Wellhead Monitoring Technology Demonstration (Sandia, 1997),

which was reviewed and approved by all participants prior to the field demonstration.

Overview of Demonstration Design

The primary objective was to test and verify the performance of field-portable characterization and monitoring

technologies for the analysis of chlorinated VOCs in groundwater. Specific demonstration objectives are listed

below:

• verify instrument performance characteristics that can be directly quantified; such factors include response to

blank samples, measurement accuracy and precision, data completeness, sample throughput, etc.;

• verify instrument characteristics and performance in various qualitative categories such as ease of operation,

required logistical support, operator training requirements, transportability, versatility, and other considerations;

and

• compare instrument results with data from standard laboratory analytical methods currently used to analyze

groundwater for chlorinated VOCs.

The experimental design included a consideration of both quantitative and qualitative performance factors for each

participating technology.

Quantitative Factors

The primary quantitative performance factors that were verified included such instrument parameters as precision

and accuracy, blank sample response, instrument performance at sample concentrations near its limit of detection,

sample throughput, and comparability with reference methods. An overview of the procedures used to determine

quantitative evaluation factors is given below.

Precision

Measurement uncertainty was assessed over the instrument’s working range by the use of blind replicate samples

from a number of performance evaluation (PE) mixtures. Eight PE mixtures containing chlorinated VOCs at

concentrations ranging from 50 μg/L to over 1000 μg/L were prepared and distributed at each site. The mixtures

were prepared from certified standard mixes with accompanying documentation giving mixture content and purity.

The relative standard deviation was computed for each compound contained in each set of replicate PE samples and

was used as a measure of instrument precision.
13

Accuracy

Instrument accuracy was also evaluated by using results from the PE samples. A mean recovery was computed for

each reported compound in each PE mixture. The average instrument result for each compound, based on four

blind replicate sample analyses, was compared against the known concentration in the PE mixture and reported as

the average percent recovery and the absolute percent difference.

Blank Sample Response

At least two blank groundwater samples were analyzed with each instrument system per demonstration day. These

were distributed as blind samples in the daily set of samples provided to each instrument operator. The results from

these samples were used to assess the degree to which instrument contamination and sample-to-sample carryover

resulted in a false positive.

Low-Level Sample Response

The scope of this demonstration did not include an exhaustive determination of instrument detection limits.

However, 10 replicate spiked samples at concentrations near typical regulatory action limits were provided for

analysis at each site to validate the instrument performance at these low concentration levels. The results from

these analyses were compiled as detects and nondetects and were used to calculate the percentage of correct

determinations and false negatives.

Sample Throughput

Sample throughput takes into account all aspects of sample processing, including sample preparation, instrument

calibration, sample analysis, and data reduction. The multiday demonstration design permitted the determination of

sample throughput rates over an extended period. Thus the throughput rates are representative of those likely to be

observed in routine field use of the instrument.

Laboratory–Field Comparability

The degree to which the field measurements agree with reference laboratory measurements is a useful parameter in

instrument evaluation. In this demonstration, comparisons were made on groundwater samples by computing the

absolute percent difference between laboratory and field technology results for all groundwater contaminants

detected. Linear regression of the two data sets was also carried out to determine the strength of the linear

correlation between the two data sets.

Qualitative Factors

Key qualitative instrument performance factors observed during the demonstration were instrument portability,

logistical support requirements, operator training requirements, and ease of operation. Logistical requirements

include the technology’s power requirements, setup time, routine maintenance, and the need for other equipment or

supplies, such as a computers, reagent solutions, or gas mixtures. Qualitative factors were assessed during the

demonstration by review of vendor information and on-site audits. Vendors provided information concerning these

factors during preparation of the demonstration plan. Vendor claims regarding these specifications and

requirements are included in Chapter 2. During the field demonstration phase, auditors from the verification

organization observed instrument operation and documented the degree of compliance with the instrument

specifications and methodology. Audit results are included in Chapter 6.
14

Site Selection and Description

Two sites—the DOE Savannah River Site near Aiken, South Carolina, and McClellan Air Force Base near

Sacramento, California—were chosen for this demonstration. This section provides a brief history of each site, a

discussion of important geological features, and an outline of the nature and extent of contamination at each site.

The sites chosen met the following selection criteria:

• presence of chlorinated VOCs in groundwater;

• multiple wells at the site with a variety of contaminants and depths;

• documented well-sampling history with characterization and monitoring data;

• convenient access; and,

• support facilities and services at the site.

Savannah River Site

The Savannah River Site is operated under contract by the Westinghouse Savannah River Company. The complex

covers 310 square miles in western South Carolina, adjacent to the Savannah River, as shown in Figure 3-1. The

SRS was constructed during the early 1950s to produce the basic materials used in the fabrication of nuclear

weapons, primarily tritium and plutonium-239. Production of weapons material at the SRS also produced unusable

byproducts such as intensely radioactive waste. In addition to these high-level wastes, other wastes at the site

include low-level solid and liquid radioactive wastes, transuranic waste, hazardous chemical waste, and mixed

waste.

Figure 3-1. The general location of the Savannah River Site in

the southeast United States.

Geological Characteristics

The SRS is located on the upper Atlantic Coastal Plain. The site is underlain by a thick wedge (approximately

1000 feet) of unconsolidated Tertiary and Cretaceous sediments that overlie Precambrian and Paleozoic

metamorphic rocks and consolidated Triassic sediments (siltstone and sandstone). The younger sedimentary section

consists predominantly of sand and sandy clay. The depth to the water table from the surface ranges from 50 to

170 feet for the wells used in this demonstration.
15

Groundwater and Monitoring Wells

The wells selected for sampling in this demonstration were in the A/M area, located in the northwest section of the

site. This area encompasses an abandoned process transfer line that, beginning in 1958, carried wastewater for 27

years from M-area processing facilities to a settling basin. Site characterization data indicate that several leaks

occurred in the transfer line, which is buried about 20 feet below the surface, producing localized contamination.

Past industrial operations resulted in the release of chlorinated solvents, primarily trichloroethene (TCE),

tetrachloroethene (PCE), and 1,1,1-trichloroethane, to the subsurface.

The A/M area monitoring-well network, shown in Figure 3-2, consists of approximately 400 wells. The dark

squares in the figure indicate soil borings and the light squares indicate monitoring wells. The largest group of

wells, comprising approximately 70% of the total, are associated with the plume originating from the process

transfer lines and the settling basin. The majority of these wells are constructed of 4-inch poly(vinyl chloride)

(PVC) casing with wire-wrapped screens varying in length from 5 to 30 feet. The wells are screened either in the

water-table aquifer (M-area aquifer, well depths ranging from 30 to 170 feet), the underlying tertiary aquifer (Lost

Lake aquifer, well depths ranging from 170 feet to 205 feet), or a narrow permeable zone within the confining unit

above the cretaceous aquifer (Crouch Branch Middle Sand, well depths ranging from 215 to 260 feet). The wells

are all completed with approximately 2.5 feet of standpipe above ground and a protective housing. Most wells are

equipped with a dedicated single-speed centrifugal pump (1/2 hp Grundfos Model 10S05-9) that can be operated

with a control box and generator. Wellhead pump connections also contain a flow meter and totalizer for

monitoring pumped volumes.

All the wells are measured quarterly for water levels. On a semiannual basis, all point-of-compliance wells (41),

plume definition wells (236), and background wells (6) are sampled to assess compliance with groundwater

protection standards. Other water quality parameters such as conductivity, turbidity, temperature, and pH are

Figure 3-2. A map of the A/M area at the Savannah River Site

showing the subsurface TCE plume.
16

also measured. As a part of the monitoring program, VOCs are measured using EPA Method 8260A at an off-site

contract laboratory. The most recent (winter of 1996) quarterly water analysis results for the 10 wells used in this

demonstration are shown in Table 3-1. Well cluster numbers shown in the table include a letter designation (A

through D) that indicates the relative screening depth and aquifer zone. The A wells are the deepest of a cluster,

while the D wells mark the shallowest.

Table 3-1. Quarterly Monitoring Results for SRS Wells Sampled in the Demonstration

Sample Description Well Number Compound Qtrly. Resultsa(μg/L)

Very low 1 MSB 33B Trichloroethene

Tetrachloroethene

10

5

Very low 2 MSB 33C Trichloroethene

Tetrachloroethene

5

12

Low 1 MSB 18B Trichloroethene

Tetrachloroethene

1,1-Dichloroethene

12

12

3

Low 2 MSB 37B Trichloroethene

Tetrachloroethene

Carbon tetrachloride

28

2

2

Mid 1 MSB 4D Trichloroethene

Tetrachloroethene

219

178

Mid 2 MSB 64C Trichloroethene

Tetrachloroethene

1,1-Dichloroethene

51

337

13

Very high 1 MSB 4B Trichloroethene

Tetrachloroethene

830

43

Very high 2 MSB 70C Trichloroethene

Tetrachloroethene

1,1-Dichloroethane

1,1,1-Trichloroethane

1290

413

61

17

Very high 1 MSB 14A Trichloroethene

Tetrachloroethene

3240

2440

Very high 2 MSB 8C Trichloroethene

Tetrachloroethene

3620

2890

a

 Winter 1996.

McClellan Air Force Base

McClellan Air Force Base is located 7 miles northeast of downtown Sacramento, California, as shown in

Figure 3-3. The installation consists of about 3000 acres bounded by the city of Sacramento on the west and

southwest, the city of Antelope on the north, the unincorporated areas of Rio Linda on the northwest, and North

Highlands on the east.

McClellan has been an active industrial facility since its dedication in 1936, when it was called the Sacramento Air

Depot. Operations have changed from maintenance of bombers during World War II and the Korean War, to

maintenance of jet aircraft in the 1960s, and now include the maintenance and repair of communications equipment

and electronics. McClellan currently operates as an installation of the Air Force Materiel Command and employs

approximately 13,400 military and civilian personnel.
17

Figure 3-3. A map of Sacramento and vicinity showing the

location of McClellan Air Force Base.

Currently, most of the industrial facilities are located in the southeastern portion of the base. The southwestern

portion has both industrial and storage areas. In the far western part are vernal pools and wetland areas. Between

these wetlands and the engine test cells along the taxiways is an open area that was used for disposal pits.

McClellan Air Force Base is listed on the EPA Superfund National Priorities List of hazardous waste sites. The

most important environmental problem at MAFB is groundwater contamination caused by the disposal of

hazardous wastes, such as solvents and oils, into unlined pits. Approximately 990 acres beneath McClellan are

contaminated with volatile organic compounds. Remediation activities at MAFB include an extensive groundwater

pump-and-treat network, as well as soil-vapor extraction systems.

McClellan has been designated a Chlorinated Hydrocarbons Remedial Demonstration Site as part of the National

Environmental Technology Test Sites program. The Strategic Environmental Research and Development Program

is the parent organization that provides support staff for the environmental technologies undergoing development

and testing at MAFB.
18

Geological Characteristics

Surface features at MAFB include open grassland, creeks and drainages, and vernal pools, as well as industrial,

residential, and runway areas. The land surface is a relatively flat plain that slopes gently to the west. Surface

elevations range from about 75 feet above mean sea level on the eastern side of the base to about 50 feet above

mean sea level on the western side.

Surface soils at MAFB are variable, but are generally sediments that have formed from stream erosion of granite

rocks in the Sierra Nevada. Soil in the vadose zone—the unsaturated region between the surface and the

groundwater table—is composed of interbedded layers of sands, silts, and clays. The vadose zone ranges from 90

to 105 feet. Clays and hardpan layers in this zone slow, but do not halt, infiltration of liquids into the underlying

aquifer.

The groundwater beneath MAFB behaves as one hydrogeologic unit. This single aquifer has been divided into five

groundwater monitoring zones, designated A, B, C, D, and E, from shallowest to deepest.

Groundwater and Monitoring Wells

An estimated 14 billion gallons of contaminated water underlie MAFB. Trichloroethene is the most frequently

detected contaminant in the subsurface groundwater. Over 90% of the contaminant mass is located in the A zone,

the shallowest portion of the aquifer. An estimated surface area of approximately 664 acres is underlain by a

plume in the A zone that exceeds the 5-μg/L maximum contaminant level for TCE, as shown in Figure 3-4.

Groundwater contaminants consistently detected above federal maximum concentration limits (MCLs) are shown in

Table 3-2.

Other detected compounds that are either below regulatory levels or are not currently regulated are also shown in

the table.

Monitoring wells at McClellan range from 2 to 8 inches in diameter. Well casings are Schedule 5 stainless steel

(304) and the well screen is Johnson stainless steel (304) with a 0.01- or 0.02-inch screen slot size. The screen is

surrounded by either 16 × 40 or 8 × 20 mesh gravel pack to a level about 3 feet above the screen. An

approximately 3-foot sand bridge and 3-foot bentonite seal are placed above the gravel pack. A concrete sanitary

seal containing about 3% bentonite powder is used to seal the well casing between the bentonite seal and the ground

surface.

For this demonstration, monitoring wells that penetrate both A and B aquifer zones in operational units A and B

were selected for sample collection. Quarterly monitoring data exist for 354 wells at the A and B zone aquifer

levels in these operational units. Monitoring results for TCE were used to select ten wells. Groundwater TCE

concentrations in the selected wells ranged from very low (~10 μg/L) to very high (>5000 μg/L) levels.

Wells that had multiple contaminants or nonchlorinated contaminants were given selection preference over those

with only a few chlorinated hydrocarbons. The most recent (winter of 1996) monitoring results for the wells chosen

for this demonstration are shown in Table 3-3.

Sample Set Descriptions

The experimental design of the demonstration specified the preparation and collection of an approximately equal

number of PE samples and groundwater samples for distribution to the participants and reference laboratory.

Descriptions of the PE and groundwater samples and their preparation are given below.
19

Figure 3-4. Subsurface TCE plumes at McClellan Air Force Base in the

shallowest (A) aquifer layer. The circular lines enclose plume concentrations in

excess of 5 μg/L TCE. OU refers to operational units. Monitoring wells used in

the demonstration were primarily in OUs A and B. The demonstration setup area

was very near OU D (upper left in the figure).
20

Table 3-2. Groundwater Contaminants at MAFB

Detected above MCLa Detected below MCL Detected – Not Regulated

Benzene Bromodichloromethane Acetone

Carbon tetrachloride Trichlorofluoromethane 2-Butanone

Chloroform 1,1-Dichloroethane

1,2-Dichlorobenzene 4-Methyl-2-pentanone

1,2-Dichloroethane Toluene

1,1-Dichloroethene

1,2-Dichloroethene (cis and trans)

Tetrachloroethene

1,1,1-Trichloroethane

Trichloroethene

Vinyl chloride

a

 MCL = maximum concentration limit.

Table 3-3. Quarterly Monitoring Results for MAFB Wells Sampled in the Demonstration

Sample Description Well Number Compound Qtrly. Resultsa

 (μg/L)

Very low 1 EW-86 Trichloroethene

1,1-Dichloroethene

8

13

Very low 2 MW-349 Trichloroethene

Tetrachloroethene

Chloroform

Acetone

9

5

8

9

Low 1 MW-331 1,1-Dichloroethane

Carbon tetrachloride

Chloroform

Trichloroethene

cis-1,2-Dichloroethene

16

5

7

19

41

Low 2 MW-352 1,1-Dichloroethane

Tetrachloroethene

Freon11

6

5

115

Mid 1 EW-87 1,1,1-Trichloroethane

1,1-Dichloroethene

Trichloroethene

cis-1,2-Dichloroethene

17

334

220

5

Mid 2 MW-341 Trichloroethene

cis-1,2-Dichloroethene

350

18

High 1 MW-209 Chloroform

Trichloroethene

cis-1,2-Dichloroethene

trans-1,2-Dichloroethene

53

586

80

13

High 2 MW-330 Chloroform

Trichloroethene

cis-1,2-Dichloroethene

trans-1,2-Dichloroethene

44

437

64

9
21

Table 3-3. Quarterly Monitoring Results for MAFB Wells Sampled in the Demonstration

(Continued)

Sample Description Well Number Compound Qtrly. Resultsa

 (μg/L)

Very high 1 MW-334 1,1-Dichloroethene

Benzene

Carbon tetrachloride

Chloroform

Dichloromethane

Trichloroethene

cis-1,2-Dichloroethene

Xylene

1000

705

728

654

139

20,500

328

59

Very high 2 MW-369 1,2-Dichloroethane

Carbon tetrachloride

Chloroform

Tetrachloroethene

Trichloroethene

cis-1,2-Dichloroethene

13

91

84

6

10,200

246

a

 Winter 1996.

PE Samples and Preparation Methods

Three different commercially available (Supelco, Bellefonte, Pennsylvania) standard solutions of chlorinated VOCs

in methanol were used to prepare the PE mixtures. The standard solutions were supplied with quality control

documentation giving the purity and weight of the compounds in the mixture. The contents of the three mixtures,

termed mix 1, mix 2, and mix 3, are given in Table 3-4. VOC concentration levels in these standard solutions were

either 200 μg/L or 2000 μg/L. The PE mixtures were prepared by dilution of these standard solutions.

The number of replicate samples and the compound concentrations from each of the nine PE mixtures prepared at

each site are given in Table 3-5 for the SRS and Table 3-6 for MAFB. Ten replicates of the mixture with the

lowest concentration level were prepared so technology performance statistics near typical regulatory action levels

could be determined. Four replicates were prepared for each technology and the reference laboratory from the other

eight PE mixtures. The highest-level PE mixture, denoted “spike/low” in the tables, consisted of high-level (>1000 

μg/L) concentrations of TCE and PCE (and other compounds at MAFB as noted in the table) in the presence of a

low-level (50 or 100 μg/L) PE mixture background. Eight blank samples were also provided to each technology at

each site. The blank samples were prepared from the same batch of deionized, carbon-filtered water used to

prepare the PE mixtures.

Performance evaluation mixtures were prepared in either 8-L or 10-L glass carboys equipped with bottom spigots.

Stock PE solutions were dispensed with microsyringes into a known volume of deionized, carbon-filtered water in

the carboy. The mixture was gently stirred for 5 minutes with a Teflon-coated stir bar prior to dispensing samples

from the bottom of the carboy. A twofold excess volume of PE mixture was prepared in order to ensure a sample

volume well in excess of the required volume. The mixture was not stirred during sample dispensing to minimize

headspace losses in the lower half of the carboy. Headspace losses that did occur during dispensing were limited to

the top portion of the mixture, which was discarded after the samples were dispensed. Samples were dispensed into
22

Table 3-4. Composition of PE Source Materials

PE Mix 1 - Purgeable A

Supelco Cat. No. 4-8059

Lot LA68271

PE Mix 2 - VOC 3

Supelco Cat. No. 4-8779

Lot LA64701

PE Mix 3 - Purgeable B

Supelco Cat. No. 4-8058

Lot LA 63978

Trichlorofluoromethane 1,1-Dichloropropene 1,2-Dichloroethane

1,1-Dichloroethane 1,2-Dichloroethane 1,1,2,2-Tetrachloroethane

Dichloromethane Trichloroethene cis-1,3-Dichloropropene

1,1-Dichloroethene 1,2-Dichloropropane trans-1,3-Dichloropropene

Chloroform 1,1,2-Trichloroethane trans-1,2-Dichloroethene

Carbon tetrachloride 1,3-Dichloropropane 1,1,1-Trichloroethane

Trichloroethene 1,2-Dibromoethane Benzene

1,2-Dichloropropane 1,1,1,2-Tetrachloroethane Bromodichloromethane

1,1,2-Trichloroethane 1,1,2,2-Tetrachloroethane Toluene

Tetrachloroethene 1,2,3-Trichloropropane Ethyl benzene

Dibromochloromethane 1,2-Dibromo-3-chloropropane Bromoform

Chlorobenzene cis-1,3-Dichloropropene

1,2-Dichlorobenzene trans-1,3-Dichloropropene

2-Chloroethyl vinyl ether Hexachlorobutadiene

Table 3-5. PE Sample Composition and Count for SRS Demonstration

Sample Concentration Level PE Mixture - Mixture Concentrationa No. of Replicates

Very low level VOC Mix 1 - 10 μg/L 10

Low level VOC Mix 1 - 50 μg/L 4

VOC Mix 2 - 100 μg/L 4

Mid level VOC Mix 1 - 200 μg/L 4

VOC Mix 2 - 200 μg/L 4

High level VOC Mix 1 - 600 μg/L 4

VOC Mix 2 - 800 μg/L 4

Spike / low 1.02 mg/L TCE spike + 50 μg/L mix 1 4

1.28 mg/L TCE and 1.23 mg/L PCE

spike + 100 μg/L mix 2

4

Total number of samples 42

a

 TCE = trichloroethene; PCE = tetrachloroethene.

bottles specified by participants (40 mL, 250 mL, and 1 L) with zero headspace. The samples for field analysis

were not preserved with chemical additives since sterile, nutrient-free water was used in their preparation.

Reference laboratory samples were preserved by acidification as specified in Method 8260A. Following

preparation, all samples were kept under refrigeration until they were distributed to participants. All PE mixtures

were prepared and dispensed on the weekend before the demonstration week.
23

Table 3-6. PE Sample Composition and Count for MAFB Demonstration

Sample Concentration Level PE Mixture - Mixture Concentrationa No. of Replicates

Very low level VOC Mix 3 - 10 μg/L 10

Low level VOC Mix 3 - 50 μg/L 4

VOC Mix 2 - 100 μg/L 4

Mid level VOC Mix 3 - 200 μg/L 4

VOC Mix 2 - 300 μg/L 4

High level VOC Mix 1 - 600 μg/L 4

VOC Mix 2 - 800 μg/L 4

Spike / low 1.22 mg/L TCE, 1.00 mg/L PCE, 0.50 mg/L 11DCA,

and 0.50 mg/L BNZN spike + 100 μg/L mix 3

4

1.04 mg/L 11DCA, 0.86 mg/L BNZN, 0.57 mg/L

TCE, and 0.51 mg/L PCE spike + 50 μg/L mix 2

4

Total number of samples 42

a

 TCE = trichloroethene; PCE = tetrachloroethene; 11DCA = 1,1-dichloroethane; BNZN = benzene.

Groundwater Samples and Collection Methods

A total of 33 groundwater samples were provided to each participant and reference laboratory at each

demonstration site. These samples were collected from 10 wells selected to cover TCE concentrations ranging from

10 μg/L to >1000 μg/L. The presence of other groundwater contaminants was also considered in well selection, as

noted previously. Samples from each well were prepared in either triplicate or quadruplicate to allow statistical

evaluation of instrument precision and accuracy relative to the reference laboratory results.

Groundwater at both sites was sampled by the same contract personnel who conduct sampling for quarterly well

monitoring. Site-specific standard operational procedures, published in the demonstration plan, were followed at

both sites. The sampling procedure is briefly summarized in the next paragraph.

The wells were purged with three well volumes using a submersible pump. During the purge, pH, temperature, and

conductivity were monitored. Following well purge, pump flow was reduced and the purge line was used to fill a

10-L glass carboy. This initial carboy volume of groundwater was discarded. The carboy was filled to between 9

and 10 L a second time at a fill rate of 2 to 3 L/minute with the water stream directed down the side of the carboy

for minimal agitation. The filled carboy was gently mixed with a Teflon stir bar for 5 minutes. Zero-headspace

samples were immediately dispensed from the carboy while it was at the wellhead in the same manner as PE

samples. Either three or four replicate samples were prepared for each technology and the reference laboratory.

Following dispensing, the sample bottles were placed in a cooler and held under refrigeration until they were

distributed to the participants. Groundwater sampling was completed during the first 2 days of each demonstration.

Lists of the sampled wells and quarterly monitoring results are given in Tables 3-1 and 3-3 for the SRS and MAFB,

respectively.

Sample Handling and Distribution

The distribution and status of all samples were tracked with chain-of-custody forms. Samples were dispensed to

participants in small coolers containing a supply of blue ice. Normally, two sets of either 10 or 11 samples were

distributed to participants each day during the 4 days of the demonstration, for a total of 83 samples, including

blanks, at each site.
24

Some of the participants required information concerning the content of the samples prior to carrying out an

analysis. This information was noted on the chain-of-custody form for each PE and groundwater sample, and was

made available to the participants. Recorded information included:

• number of contaminants in the sample;

• list of contaminants in the sample;

• boiling point range of sample constituents; and

• approximate concentration range of contaminants in sample (low, mid, high).

The type of information provided during this demonstration would be required by the technology as a part of its

normal operational procedure and did not compromise the results of the test. The information provided to each of

the participants is documented in Chapter 5.

Field Demonstration Schedule and Operations

The following schedule was followed at both sites. The field team arrived on the Thursday prior to the

demonstration week. Performance evaluation samples were prepared on Friday, Saturday, and Sunday.

Technology participants arrived at the site on Monday morning and immediately began instrument setup. The first

set of PE samples was normally distributed to all participants by midday Monday. The groundwater sampling

crew, consisting of at least two on-site contractors and at least one ETV field-team member, carried out sampling of

the 10 wells on Monday and Tuesday. The first groundwater samples were distributed on Wednesday. Thursday

was reserved as a visitor day during which local and regional regulatory personnel and other potential instrument

users were invited to hear presentations about instrument capabilities as well as to view the instruments in

operation. Sample analysis was also performed on Thursday. On Friday, the final day of the demonstration,

participants finished sample analysis, packed up, and departed by midafternoon.

Site Operations and Environmental Conditions

Instruments were deployed in parking lots or open fields adjacent to the well networks sampled during each

demonstration. All participants came to the site self-equipped with power and shelter. Some came with fieldportable generators and staged under tent canopies; others operated their instruments inside vehicles and used dc-toac power inverters connected to the vehicle’s battery. Tables were provided for those participants who required a

work space. Each team provided its own instrument operators. Specifics regarding instrument setup and the

qualifications, training, and experience of the instrument operators are given in Chapter 6.

The SRS demonstration took place on September 8 through 12, 1997, and the MAFB demonstration on

September 22 through 26, 1997. The verification organization team staged its operations out of a tent at the SRS

and out of a mobile laboratory at MAFB. The PE mixtures at the SRS were prepared at a nearby SRS laboratory

facility and in the mobile laboratory at MAFB. Refrigerators at on-site facilities of the groundwater sampling

contractors were used to store the samples at both sites prior to their distribution.

Environmental conditions at both sites are summarized in Table 3-7. Conditions at SRS were generally hot and

humid. Sporadic rain showers were encountered on one of the test days, but did not impede demonstration

activities. Conditions at MAFB were initially hot and progressed to unseasonably hot. Moderately high winds

were also encountered during the last 2 days at MAFB.
25

Table 3-7. Weather Summary for SRS and MAFB During Demonstration Periods

Site/Parameters Mon Tue Wed Thu Fri

SRS

Temperature range (°C) 20 – 34 21 – 33 21 – 28 18 – 30 19 – 33

Relative humidity range (%) 25 – 68 28 – 67 51 – 71 40 – 70 26 – 70

MAFB

Temperature range (°C) 17 – 33 18 – 36 18 – 37 24 – 35 24 – 35

Relative humidity range (%) 17 – 72 25 – 47 15 – 59 17 – 67 31 – 83

Wind speed range (knots) 0 – 7 3 – 6 1 – 6 4 – 13 2 – 11

Note: Ranges are given for the 7 a.m. to 7 p.m. time interval.

Field Audits

Field auditors were used to observe and record specific features of technology operations. The demonstration goal

was to have at least two auditors observe each technology over the course of the two field demonstrations. Audit

results are documented in Chapter 6. The following checklist was used by the audit team as a guideline for

gathering information during the audit:

• description of equipment used;

• logistical considerations, including size and weight, shipping and power requirements, other required accessories;

• historical uses and applications of the technology;

• estimated cost of the equipment and its field operation;

• number of operators required;

• required operator qualifications;

• description of data produced;

• compounds that the equipment can detect;

• approximate detection limits for each compound, if available;

• initial calibration criteria;

• calibration check criteria;

• corrective actions for unacceptable calibrations;

• specific QC procedures followed;

• QC samples used;

• corrective action for QC samples;

• sample throughput rate;

• time requirements for data analysis and interpretation;

• data output format and description;

• specific problems or breakdowns occurring during the demonstration;

• possible sample matrix interference; and

• other auditor comments and observations.
26

Data Collection and Analysis

The analytical results were collected in hardcopy format at the end of each day. These results were used to

document sample completion and throughput. The participants also provided a compilation of their results on

computer disks at the conclusion of each demonstration week. No feedback on analytical results or performance

was given to the participants during the course of either demonstration week. Following the SRS demonstration,

and only after all results were submitted, was qualitative verbal feedback given to each participant concerning their

accuracy and precision on SRS PE sample results. This was reasonable since a well-defined monitoring plan would

use preliminary samples to determine control limits and to make system modifications or refinements prior to

advancing to the next phase of sampling and analysis. Three weeks following the MAFB demonstration, copies of

all submitted data were entered into spreadsheets by the verification organization and transmitted to participants for

final review. This gave each participant the opportunity to detect and change calculation or transcription errors. If

other more substantive changes were proposed, they were submitted to the verification organization, along with

documentation outlining the rationale for the change. Following this final data review opportunity, no other data

changes were permitted. The extent and nature of any changes are discussed in Chapter 6.

Demonstration Plan Deviations

The following deviations from the written demonstration plan were recorded during the field demonstration. The

impact of each deviation on the overall verification effort, if any, is also included.

• Five blank samples were submitted to the reference laboratory from the SRS demonstration instead of the

8 samples specified in the demonstration plan. The impact on the verification effort was minimal since a total of

13 blanks (8% of the total field sample count) were analyzed by the reference laboratory.

• During groundwater sampling of SRS well MSB 14A, two 250-mL sample bottles were not filled. Omission of

this sample resulted in a double replicate sample set instead of a triple replicate for Electronic Sensor Technology

and Sentex. The impact on the study was insignificant since this omission accounted for only 1 sample out of a

total groundwater sample count of 33.

• The demonstration plan specified that only two VOC mixtures would be used at each demonstration site. In fact,

three mixtures were used at the MAFB demonstration (Table 3-6) to add complexity to the sampling. This

change caused some minor confusion with one of the developers, who was not expecting this particular set of

compounds at MAFB. The most significant impact of this change was a loss of time for the affected developer as

a result of extended data review of the unanticipated mixture. The misunderstanding was verbally clarified and

no further problems were encountered. The results from the high-level VOC mix 1 were not used in the statistical

analyses.
27

Chapter 4 

Laboratory Data Results and Evaluation

Introduction

A reference laboratory was used to verify PE sample concentrations and to generate analytical results for all

groundwater samples using EPA Method 8260A. This chapter includes a brief description of the reference

laboratory and its data quality control program; the methodology and accompanying quality control procedures

employed during sample analysis; and laboratory results and associated measures of data quality for both

demonstration sites.

Reference Laboratory

DataChem Laboratories (DCL) in Salt Lake City, Utah, was chosen as the reference laboratory for both phases of

this demonstration. This is a full-service analytical laboratory with locations in Salt Lake City and Cincinnati,

Ohio. It provides analytical services in support of environmental, radiological, mixed-waste, and industrial hygiene

programs. DataChem’s qualifications include U.S. EPA Contract Laboratory Program participation in both

inorganic and organic analysis and American Industrial Hygiene Association accreditation, as well as U.S. Army

Environmental Center and U.S. Army Corps of Engineers (Missouri River Division) certification. State-specific

certifications for environmental analytical services include Utah, California, Washington, New Jersey, New York,

Florida, and others.

Laboratory Selection Criteria

Selection criteria for the reference laboratory included the following: relevant laboratory analytical experience,

adequacy of QC documentation, turnaround time for results, preselection audit results, and cost. Early discussions

with DCL revealed that the laboratory conducts a high number of water analyses using Method 8260A. Prior to

laboratory selection, a copy of the DataChem Quality Assurance Program Plan (DataChem, 1997) was carefully

reviewed. This document outlines the overall quality assurance program for the laboratory and provides specific

quality control measures for all the standard analytical methods used by the laboratory. Laboratory analysis and

reporting time for sample analysis was 21 days, with a per-sample cost of $95.

In June 1997, Sandia sent several PE water samples to DCL for evaluation. Laboratory performance on these

samples was reviewed during an audit in June 1997. The laboratory detected all compounds contained in the PE

mixtures. Reported concentration levels for all compounds in the mixtures were within acceptable error margins.

The audit also indicated that the laboratory conducted its operations in accordance with its QA plan. The results of

this preliminary investigation justified the selection of DCL as the reference laboratory and provided ample

evidence of the laboratory’s ability to correctly use Method 8260A for the analysis of demonstration samples.
28

Summary of Analytical Work by DataChem Laboratories

In addition to the preselection audit samples noted above, DCL also analyzed predemonstration groundwater

samples collected at SRS in August 1997. During the demonstration phase, DCL was sent split samples of all PE

and groundwater samples given to the demonstration participants from both the Savannah River and McClellan

sites. A total of 90 and 91 samples from the SRS and MAFB demonstrations, respectively, were received and

analyzed by the laboratory. Over the course of 1 month, demonstration samples were run in 9 batches of

approximately 20 samples per batch. The results were provided in both hardcopy and electronic format. The hard

copy included all paperwork associated with the analysis, including the mass spectral information for each

compound detected and complete quality control documentation. The electronic copy was provided in spreadsheet

format and included only the computed result for each target compound in each sample.

Preselection evaluation of DCL established their competence in the use of Method 8260A. In light of these findings

and in an effort to expedite laboratory analysis of demonstration samples, an estimate of the concentration levels of

target compounds in both PE and groundwater samples was provided to the laboratory with each batch of samples.

With a knowledge of the approximate concentration range of the target compounds, the analyst was able to dilute

the sample appropriately, thereby eliminating the need to do multiple dilutions in order to obtain a suitable result

within the calibrated range of the instrument.

Summary of Method 8260A

Method 8260A, which is included in the EPA SW-846 compendium of methods, is used to measure volatile organic

compounds in a variety of solid waste matrices, including groundwater (EPA, 1996b). The method can be used to

quantify most volatile organic compounds with boiling points below 200 °C that are either insoluble or only slightly

soluble in water. The method employs a chromatography/mass spectrometric procedure with purge-and-trap

sample introduction. An inert gas is bubbled through a vessel containing the water sample. The volatile organic

compounds partition into the gas phase and are carried to a sorbent trap, where they are adsorbed. Following the

purge cycle, the sorbent trap is heated and the volatile compounds are swept into the GC column, where they are

separated according to their boiling points. The gas chromatograph is interfaced directly to a mass spectrometer

that bombards the compounds with electrons as they sequentially exit the GC column. The resulting fragments,

which possess charge and mass characteristics that are unique for each compound, are detected by the

spectrometer’s mass detector. The signal from the mass detector is used to build a compound mass spectrum that is

used to identify the compound. The detector signal intensities for selected ions unique to each target compound are

used to quantify the amount of the compound in the sample.

Method 8260A Quality Control Requirements

Method 8260A specifies a number of quality control activities to be carried out in conjunction with routine sample

analysis. These activities are incorporated into DCL QA documentation and are summarized in Table 4-1

(DataChem, 1997). Corrective actions are specified in the event of failure to meet QC criteria; however, for the

sake of brevity they are not given in the table. In most cases the first corrective action is a calculation check. Other

corrective actions include system recalibration, sample rerun, batch rerun, or flag data.

Summary of Laboratory QC Performance

The following sections summarize the QC activities and results that accompanied the analysis of each sample batch.
29

Table 4-1. Method 8260A Quality Control Summary

Activity Frequency Data Acceptance Criteria

Spectrometer tune check Bromofluorobenzene

standard every 12 hours

Relative abundance; range of characteristic mass

fragments meets specifications.

System performance

check

SPCCa sample every 12

hours

Compound relative response factors must exceed

required minimums.

System calibration check CCCb sample every 12

hours

Response factor of CCC varies by no more than ±25%

from initial calibration.

Internal standard retention time within 30 seconds of last

check.

Internal standard area response within −50 to 100% of

last check.

Lab method blank One or more per batch

(approx. 20 samples)

≤ 3× Detection limit.

Field blank One or more per batch ≤ 3× Detection limit.

Laboratory control

standard

One or more per batch Compound recovery within established limits.c

Matrix spike One or more per batch Spike recovery within established limits. c

Matrix spike duplicate One or more per batch Relative percent difference of check compounds ≤50%.

Surrogate standards Included in every sample Recovery within established limits. c

Internal standards Included in every sample Recovery within established limits. c

a

SPCC = system performance check compounds.

b CCC = calibration check compounds.

c

The laboratory generates control limits that are based on 100 or more analyses of designated compounds. The upper and lower acceptable recovery limits

are based on a 3-standard-deviation-interval about the mean recovery from the multiple analyses. The result from a single analysis must fall within these

control limits in order to be considered valid.

Target Compound List and Method Detection Limits

The method detection limits and practical quantitation limits for the 34 target compounds used in this demonstration

are given in Table 4-2. The PQL marks the lower end of the calibrated working range of the instrument and

indicates the point at which detection and reported results carry a 99% certainty. Detects reported between the

MDL and PQL carry less certainty and are flagged accordingly in the tabulated results.

Sample Holding Conditions and Times

Method 8260A specifies a maximum 14-day holding time for refrigerated water samples. All samples prepared in

the field were kept under refrigeration before and during shipment to the laboratory. Upon receipt at the laboratory,

they were held under refrigeration until analysis. All samples were analyzed within the 14-day time period

following their preparation or collection.

System Calibration

Method 8260A stipulates that a five-point calibration be carried out using standard solutions for all target

compounds across the working range of the instrument. Each mix of compounds is run five times at each of the

five points in the instrument range. For an acceptable calibration, precision from these multiple analyses, as
30

Table 4-2. Reference Laboratory Method Detection Limits for Target Compounds

Target Compound Method Detection Limit

(μg/L)

Practical Quantitation

Limit (μg/L)

Trichlorofluoromethane 0.15 1

1,1-Dichloroethane 0.08 1

Methylene chloride 0.10 1

1,1-Dichloroethene 0.08 1

Chloroform 0.07 1

Carbon tetrachloride 0.10 1

1,1-Dichloropropene 0.10 1

1,2-Dichloroethane 0.04 1

Trichloroethene 0.14 1

1,2-Dichloropropane 0.04 1

1,1,2-Trichloroethane 0.09 1

Tetrachloroethene 0.10 1

1,3-Dichloropropane 0.06 1

Dibromochloromethane 0.08 1

1,2-Dibromoethane 0.09 1

Chlorobenzene 0.06 1

1,1,1,2-Tetrachloroethane 0.05 1

1,1,2,2-Tetrachloroethane 0.07 1

1,2,3-Trichloropropane 0.50 1

1,2-Dibromo-3-chloropropane 0.62 1

Hexachlorobutadiene 0.10 1

cis-1,3-Dichloropropene 0.17 1

trans-1,3-Dichloropropene 0.08 1

1,2-Dichlorobenzene 0.17 1

trans-1,2-Dichloroethene 0.17 1

1,1,1-Trichloroethane 0.26 1

Benzene 0.12 1

Bromodichloromethane 0.11 1

Toluene 0.15 1

Ethyl benzene 0.14 1

Bromoform 0.10 1

cis-1,2-Dichloroethene 0.14 1

ortho-Xylene 0.11 1

Acetone 2.9 5

Notes: Detection limits are given for an undiluted 5-mL sample volume. Detection limits are determined annually using the

method outlined in 40 CFR Part 136 Appendix B (seven replicates of deionized water spiked at 1 μg/L concentration

level). Dilutions of the original sample raise the MDL and PQL values accordingly. Surrogate standards used in the

analyses were 1,2-dichloroethane-d4, toluene-d8, and 4-bromofluorobenzene. Internal standards were fluorobenzene,

chlorobenzene-d5, and 1,4-dichlorobenzene-d4.
31

given by the relative standard deviation, must be 30% or less. A minimum instrument response factor1 is also

prescribed by the method for a designated subset of compounds termed system performance check compounds

(SPCC). The five-point calibration curve from the most recent instrument calibration met the specified precision

criteria. The system performance check compound response factors also met method criteria.

Daily Instrument Performance Checks

Daily mass spectrometer tune checks as well as other system performance and calibration checks noted in Table 4-1

were carried out for each of the nine sample batches and met Method 8260A on quality control criteria.

Batch-Specific Instrument QC Checks

Method Blanks

All method blank analyses met established criteria (Table 4-1), with one exception. Hexachlorobutadiene, one of

the demonstration target compounds, was detected in two of the method blanks at levels in excess of 3 times the

MDL. This compound was a component in one of the standard mixes used in preparing the PE samples because

reference laboratory data for this compound were not used in the study. Only one of the participating technologies

was calibrated to detect this particular compound. Occasional detection of this compound as a minor instrument

contaminant does not adversely affect the analytical results for other target compounds.

Laboratory Control Standard

At least one laboratory control standard was run with each of the nine batches of samples. Recovery values for

each component in the mixture are given in Figure 4-1 for SRS analyses and Figure 4-2 for MAFB analyses.

Recovery values were all within the laboratory-specific control criteria.

Matrix Spike and Matrix Spike Duplicate

The compounds in the matrix spike were the same as those in the laboratory control standard. Computed matrix

spike and matrix spike duplicate recoveries were all within the recovery ranges noted in Table 4-1. The relative

percent differences (RPDs)2 calculated for the matrix spike and matrix spike duplicate samples also met the

laboratory criteria of ≤50%. All RPD values from matrix spike analyses were less than 10% for the SRS samples

and less than 13% for MAFB samples.

Sample-Specific QC Checks

Internal Standard

All samples met internal standard acceptance criteria except one. All three internal standards in sample SP31 failed

to meet area response criteria and results from that sample were not included in the reference data set.

 

1 The response factor is the ratio of instrument response for a particular target compound to the instrument response for an

internal standard.

2 The relative percent difference between two samples is the absolute value of their difference divided by their mean and

multiplied by 100.
32

DCL Laboratory Control Standard Recoveries

Savannah River Data Set

80

90

100

110

120

Batch 1 Batch 2 Batch 3 Batch 4 Batch 5

Analysis Batch No. 

Recovery, %

11DCE

Benzene

Cl Benzene

Toluene

TCE

Figure 4-1. Laboratory control standard recovery values for SRS analyses.

DCL Laboratory Control Standard Recoveries

McClellan Data Set

80

90

100

110

120

Batch 1 Batch 2 Batch 3 Batch 4 Batch 5

Analysis Batch No. 

Recovery, %

11DCE

Benzene

Cl Benzene

Toluene

TCE

Figure 4-2. Laboratory control standard recovery values for MAFB analyses.
33

Surrogate Standard

With the following exceptions, surrogate standard recoveries met the criteria established by the laboratory, as noted

in Table 4-1. Six samples (SP12, SP16, SP26, SP29, SP33, and SP65) failed surrogate recovery criteria for 1,2-

dichloroethane-d4 and passed recovery criteria for 4-bromofluorobenzene and toluene-d8. The actions taken are

noted in Table 4-3.

Summary of Analytical and QC Deviations

A summary of QC deviations as well as other analytical errors or omissions is given in Table 4-3. The actions

taken with regard to the affected data and the reference data set are also tabulated, along with a brief rationale.

Table 4-3. Summary of Reference Laboratory Quality Control and Analytical Deviations

Deviation or QC Criteria Failure Action

Required dilution not made on two samples (SP20 and

SP21). Some compounds were present above

instrument linear range.

Data Included: Data values for affected samples fall in

the range of the other three replicate samples.

Three field blanks were not sent to DCL from SRS

demonstration.

No Action: Five field blanks and 10 method blanks were

run, yielding an adequate data set.

Calculation error in original DCL report. Dilution factors

applied incorrectly in two samples (SP55 and SP57).

Data Corrected and Included: The correct dilution

factors were applied following a teleconference with the

DCL analyst.

Sample SP31 failed internal standard recovery limits. Data Not Included.

The following samples failed one or more surrogate

standard recovery limits: SP12, SP16, SP26, SP29,

SP33, and SP65.

Data Not Included: SP12; results clearly fall outside of

the range of other three replicate samples.

Data Included: All others; nearly all target compounds

fall within the range of concentration reported for the

other three replicate samples.

Hexachlorobutadiene detected as a contaminant in

selected blanks and samples.

No Action: This compound was not a target compound

for any of the technologies. Its presence as a low-level

contaminant does not affect the results of other target

compounds.

Chloroethyl vinyl ether was not detected in PE samples

known to contain this compound.

No Action: The GC/MS was not calibrated for this

compound. None of the technologies included this

compound in their target compound lists.

Three sample results (MG20, MG51, and MG59) are

from a second withdrawal from the original zeroheadspace sample vial.

Data Included: The original volume withdrawn from the

vial was 0.05 mL, resulting in an insignificant headspace

volume and no expected impact on the composition of

the second sample.

Other Data Quality Indicators

The demonstration design incorporated nine PE mixtures of various target compounds at each site that were

prepared in the field and submitted in quadruplicate to each technology as well as to the laboratory. Laboratory

accuracy and precision checks on these samples were assessed. Precision on replicate analysis of groundwater

samples was also evaluated. The results of these assessments are summarized in the following sections.
34

PE Sample Precision

The relative standard deviation from quadruplicate laboratory analyses of each PE mixture prepared in the field

was computed for each target compound in the mixture. As noted in Chapter 3, care was taken to ensure the

preparation and distribution of homogeneous samples from each PE mixture. The RSD values represent an overall

estimate of precision that takes into account field handling, shipping, storage, and analysis of samples.

The precision data are shown in Figures 4-3 and 4-4 for SRS and Figures 4-5 and 4-6 for MAFB. (See Tables 3-5

and 3-6 for the composition and concentration level of each PE mixture.) The compiled RSDs for all PE sample

results had a median value of 7% and a 95th percentile value of 25%. In selected instances, precision in excess of

Method 8260A specifications (≤30% RSD) is observed for tetrachloroethene, trichloroethene, cis-1,3-

dichloropropene, 1,2,3-trichloropropane, and 1,1,2,2-tetrachloroethane. Precision well in excess of method

specifications is observed for 1,2-dibromo-3-chloropropane, trans-1,3-dichloropropene, and 1,1-dichloropropene.

The implications of these results with respect to evaluation of the technology performance are discussed, when

applicable, in Chapters 5 or 7.

PE Sample Accuracy

An error propagation analysis was carried out to estimate the degree of uncertainty in the stated “true”

concentration level of the PE samples prepared in the field. The sources of uncertainty and their magnitude

encountered during PE sample preparation are listed in Table 4-4. These errors are combined using the

methodology described by Bevington (1969) to arrive at a combined uncertainty in the PE sample value of ±5%.

Thus, for a 100-μg/L PE mix, the true value is known with 99% certainty to be within the range of 95 to 105 μg/L.

Table 4-4. Sources of Uncertainty in PE Sample Preparation

Type of Uncertainty Magnitude Source of Estimate

Weight of component in PE mix

ampule.

0.5 mg in 1200 mg Gravimetric balance uncertainty included

in PE mix certification documents

Volume of methanol solvent used

to dilute neat compounds.

0.2 mL in 600 mL Published tolerances for volumetric flasks

(Fisher Catalog)

Volume of PE solution (from

ampule) used in final PE solution.

±5% of microsyringe volume;

e.g., 25 μL for a 500-μL syringe

Published tolerances in certificates

shipped with microsyringes

Volume of water diluent in final

PE solution.

5 ml in 10 L Published tolerances for volumetric flasks

(Fisher Catalog)

The laboratory results for PE samples are compared with the “true” value of the mixture to provide an additional

measure of laboratory performance. A mean recovery3 was computed for each PE compound in each of the four

sample splits analyzed from each mixture. The SRS recovery values are shown in Figures 4-7 and 4-8, and MAFB

recoveries are shown in Figures 4-9 and 4-10. Acceptable mean percent recovery values, specified in Method

8260A, fall within the range of 70 to 130% with exceptions for a few compounds that pose analytical difficulties.

With the following exceptions, all PE compounds at all concentration ranges met the Method 8260A recovery

criteria. The exceptions are 1,2,3-trichloropropane, 1,1-dichloropropene, 1,2-dibromo-3-chloropropane,

 

3 Recovery is the ratio of the mean concentration level from analysis of the four sample splits to the reference or “true”

concentration levels of the target compounds in each PE mix.
35

DataChem PE Sample Precision

Site: Savannah River Mix 1

0 10 20 30 40 50

Trichlorofluoromethane

1,1-Dichloroethane

Methylene Chloride

1,1-Dichloroethene

Chloroform

Carbon Tetrachloride

Trichloroethene

1,2-Dichloropropane

1,1,2-Trichloroethane

Tetrachloroethene

Dibromochloromethane

Chlorobenzene

1,2-Dichlorobenzene

Target Compound

Relative Standard Deviation, %

Spike/Low

High

Mid

Low

Figure 4-3. Laboratory precision on SRS PE samples containing mix 1.

Trichloroethene was spiked into the spike/low samples.

DataChem PE Sample Precision

Site: Savannah River Mix 2

0 10 20 30 40 50

1,1-Dichloropropene

1,2-Dichloroethane

Trichloroethene

1,2-Dichloropropane

1,1,2-Trichloroethane

1,3-Dichloropropane

1,2-Dibromoethane

1,1,1,2-Tetrachloroethane

1,1,2,2-Tetrachloroethane

1,2,3-Trichloropropane

1,2-Dibromo-3-Chloropropane

cis-1,3-Dichloropropene

trans-1,3-Dichloropropene

Tetrachloroethene

Target Compound

Relative Standard Deviation, %

Spike/Low

High 

Mid

Low

85

66

Figure 4-4. Laboratory precision on SRS PE samples containing mix 2.

Tetrachloroethene was spiked into the mix 2 samples. Trichloroethene and

tetrachloroethene were spiked into the spike/low samples.

85

66
36

DataChem PE Sample Precision

Site: McClellan Mix 2

0 10 20 30 40 50

1,1-Dichloroethane

1,1-Dichloropropene

1,2-Dichloroethane

Trichloroethene

1,2-Dichloropropane

1,1,2-Trichloroethane

Tetrachloroethene

1,3-Dichloropropane

1,2-Dibromoethane

1,1,1,2-Tetrachloroethane

1,1,2,2-Tetrachloroethane

1,2,3-Trichloropropane

1,2-Dibromo-3-Chloropropane

cis-1,3-Dichloropropene

trans-1,3-Dichloropropene

Benzene

Target Compound

Relative Standard Deviation, %

Spike/Low

High

Mid

Low

Figure 4-5. Laboratory precision on MAFB PE samples containing mix 2.

Trichloroethene, tetrachloroethene, 1,1-dichloroethane, and benzene were

spiked into the spike/low samples.

DataChem PE Sample Precision

Site: McClellan Mix 3

0 10 20 30 40 50

1,1-Dichloroethane

1,2-Dichloroethane

Trichloroethene

Tetrachloroethene

1,1,2,2-Tetrachloroethane

cis-1,3-Dichloropropene

trans-1,3-Dichloropropene

trans-1,2-Dichloroethene

1,1,1-Trichloroethane

Benzene

Bromodichloromethane

Toluene

Ethylbenzene

Bromoform

Target Compound

Relative Standard Deviation, %

Spike/Low

Mid

Low

Figure 4-6. Laboratory precision on MAFB PE samples containing mix 3.

Trichloroethene, tetrachloroethene, 1,1-dichloroethane, and benzene were

spiked into the spike/low samples.

57
37

DataChem PE Sample Recovery

Site: Savannah River Mix 1

50 60 70 80 90 100 110 120 130 140 150

Trichlorofluoromethane

1,1-Dichloroethane

Methylene Chloride

1,1-Dichloroethene

Chloroform

Carbon Tetrachloride

Trichloroethene

1,2-Dichloropropane

1,1,2-Trichloroethane

Tetrachloroethene

Dibromochloromethane

Chlorobenzene

1,2-Dichlorobenzene

Target Compound

Average Percent Recovery

Spike/Low

High

Mid

Low

VLow

3

Figure 4-7. Laboratory mean recoveries for SRS PE samples containing mix 1.

Trichloroethane was spiked into the spike/low samples.

DataChem PE Sample Recovery

Site: Savannah River Mix 2

50 60 70 80 90 100 110 120 130 140 150

1,1-Dichloropropene

1,2-Dichloroethane

Trichloroethene

1,2-Dichloropropane

1,1,2-Trichloroethane

Tetrachloroethene

1,3-Dichloropropane

1,2-Dibromoethane

1,1,1,2-Tetrachloroethane

1,1,2,2-Tetrachloroethane

1,2,3-Trichloropropane

1,2-Dibromo-3-Chloropropane

cis-1,3-Dichloropropene

trans-1,3-Dichloropropene

Target Compound

Average Percent Recovery

Spike/Low

High

Mid

Low

Figure 4-8. Laboratory mean recoveries for SRS PE samples containing mix

2. Trichloroethane and tetrachloroethene were spiked into the spike/low

samples.
38

DataChem PE Sample Recovery

Site: McClellan Mix 2

50 60 70 80 90 100 110 120 130 140 150

1,1-Dichloroethane

1,1-Dichloropropene

1,2-Dichloroethane

Trichloroethene

1,2-Dichloropropane

1,1,2-Trichloroethane

Tetrachloroethene

1,3-Dichloropropane

1,2-Dibromoethane

1,1,1,2-Tetrachloroethane

1,1,2,2-Tetrachloroethane

1,2,3-Trichloropropane

1,2-Dibromo-3-Chloropropane

cis-1,3-Dichloropropene

trans-1,3-Dichloropropene

Benzene

Target Compound

Average Percent Recovery

Spike/Low

High

Mid

Low

Figure 4-9. Laboratory mean recoveries for MAFB PE samples containing

mix 2. Trichloroethene, tetrachloroethene, 1,1-dichloroethane, and benzene

were spiked into the spike/low samples.

DataChem PE Sample Recovery

Site: McClellan Mix 3

50 60 70 80 90 100 110 120 130 140 150

1,1-Dichloroethane

1,2-Dichloroethane

Trichloroethene

Tetrachloroethene

1,1,2,2-Tetrachloroethane

cis-1,3-Dichloropropene

trans-1,3-Dichloropropene

trans-1,2-Dichloroethene

1,1,1-Trichloroethane

Benzene

Bromodichloromethane

Toluene

Ethylbenzene

Bromoform

Target Compound

Average Percent Recovery

Spike/Low

Mid

Low

VLow

Figure 4-10. Laboratory mean recoveries for MAFB PE samples containing mix

3. Trichloroethene, tetrachloroethene, 1,1-dichloroethane, and benzene were

spiked into the spike/low samples.
39

and 1,2-dichlorobenzene at selected concentration levels. The implications of these exceptions for the technology

evaluation are further discussed, if applicable, in Chapter 5. The compiled absolute percent differences (APDs)4

for all PE sample results had a median value of 7% and a 95th percentile value of 25%.

Groundwater Sample Precision

Relative standard deviations are given in Table 4-5 for compound concentrations in excess of 1 μg/L in

groundwater samples from the SRS demonstration. Trichloroethene and tetrachloroethene were the only

contaminants detected in SRS groundwater samples. A similar compilation of RSD values from the MAFB

groundwater samples is included in Table 4-6. These values are based on analytical results from either three or four

replicate samples. With three exceptions, all tabulated values are less than 20%.

Table 4-5. Summary of SRS Groundwater Analysis Precision

Sample Description Relative Standard Deviation (%)

TCE PCE

Very low 1 10.6 14.3

Very low 2 34.4 12.4

Low 1 5.4 5.7

Low 2 7.1 8.7

Mid 1 9.4 11.6

Mid 2 7.3 4.2

High 1 0.8 1.8

High 2 11.8 7.9

Very high 1 8.4 5.7

Very high 2 6.2 6.3

Table 4-6. Summary of MAFB Groundwater Analysis Precision

Sample Relative Standard Deviation (%)

Description 11DCE TCE CLFRM CCL4 PCE 11DCA c12DCE t12DCE BNZN

Very low 1 9.1 5.0

Very low 2 2.6 <0.1 1.3 4.2 5.7

Low 1 6.8 3.7 2.0 1.9 <0.1

Low 2 11.5 5.2 4.0 22.3 4.1 3.8

Mid 1 12.0 10.5 13.9 9.4 12.6

Mid 2 3.6 4.9 3.8

High 1 2.4 20.9 4.1

High 2 5.3 5.3 5.1 3.8

Very high 1 2.5 5.4 5.2 6.5 4.9

Very high 2 8.0 6.4 4.9 10.1

Notes: 11DCE = 1,1-dichloroethene; TCE = trichloroethene; CLFRM = chloroform; CCL4 = carbon tetrachloride; PCE = tetrachloroethene; 11DCA =

1,1-dichloroethane; c12DCE = cis-1,2-dichloroethene; t12DCE = trans-1,2-dichloroethene; BNZN = benzene.

Blank cells indicate that the compound was not present.

 

4 The absolute percent difference is the absolute value of the percent difference between a measured value and a true value.
40

Summary of Reference Laboratory Data Quality

With the exceptions noted below, a review of DCL analytical data showed that all Method 8260A QC criteria were

met. Internal standard recovery limits were not met for one sample. The results for this sample were markedly

different from the other three samples in the replicate set and the sample was omitted from the data set. Six

samples failed one or more surrogate standard recovery criteria. These sample results were compared with

replicate sample results. Five of the six samples were comparable and were included in the reference data set.

The data for the remaining sample were not comparable and were omitted from the reference data set. Other

quality control deviations, which are summarized in Table 4-3, did not significantly affect the quality of the

laboratory data.

A review of DCL precision and accuracy on field-prepared PE mixtures corroborates laboratory internal QC

results. A similar precision evaluation on groundwater samples from both sites further supports these observations.

Overall, the internal and external QC data reveal appropriate application and use of Method 8260A by DataChem

Laboratories. The laboratory results for groundwater samples from both sites are considered suitable for use as a

reference data set.
41

Chapter 5 

Demonstration Results

Voyager Calibrated and Reported Compounds

Prior to the field demonstration, the participants were given a list of all compounds that were to be used in the PE

mixtures to facilitate preparations for predemonstration instrument calibration. The Voyager system was calibrated

for 24 compounds at the SRS and 17 compounds at the MAFB site (Table 5-1). The number of target analytes was

reduced at MAFB in order to increase sample throughput. A total of 32 chlorinated and nonchlorinated

hydrocarbon compounds were included in the PE mixtures noted in Table 3-4. The Voyager was also calibrated at

both sites for cis-1,2-dichloroethene, which was not a PE compound. Three pairs of compounds were reported as

coeluting pairs, as also noted in Table 5-1. The Voyager was not calibrated for the following nine PE compounds

at either site: trichlorofluoromethane, 1,1-dichloroethane, 1,2-dichlorobenzene, 2-chloroethyl vinyl ether, 1,1,2,2-

tetrachloroethane, 1,2,3-trichloropropane, 1,2-dibromo-3-chloropropane, hexachlorobutadiene, and bromoform.

Table 5-1. Voyager Calibrated and Reported Compounds

Calibrated Compounds at Both Sites

1,3-Dichloropropane 1,1,2-Trichloroethane(c)

1,2-Dichloroethane(a) 1,2-Dibromoethane(c)

1,2-Dichloropropane(a) Toluene

1,1-Dichloropropene Dibromochloromethane

Benzene Tetrachloroethene

Bromodichloromethane 1,1,1,2-Tetrachloroethane

Trichloroethene Chlorobenzene

cis-1,3-Dichloropropene Ethyl benzene

cis-1,2-Dichloroethene

Additional Calibrated Compounds at SRS

1,1-Dichloroethene(b) Carbon tetrachloride

Methylene chloride(b) trans-1,2-Dichloroethene

Chloroform 1,1,1-Trichloroethane

trans-1,3-Dichloropropene

Note: Superscripts denote coeluting compound pairs.

Preanalysis Sample Information

Samples were provided to the Voyager team without additional information on the number of compounds in the

sample or compound concentration levels.
42

Sample Completion

All 166 PE and groundwater samples submitted for analysis to the Voyager team were completed at both

demonstration sites. All Voyager PE and groundwater results are included in Appendix B.

Blank Sample Results

Eight blank samples were provided for analysis at each demonstration site. False positive detects were counted

only for compounds reported at concentration levels greater than 1 μg/L. A list of false positive detects is given for

both sites in Table 5-2.

Table 5-2. False Positive Rates from Blank Sample Analysis

SRS Blank Samples MAFB Blank Samples

Compound False Positive Compound False Positive

Trichloroethene 2 of 8 (25%) 1,1-Dichloropropene 1 of 8 (13%)

cis-1,3-Dichloropropene 1 of 8 (13%) Trichloroethene 1 of 8 (13%)

Chlorobenzene 1 0f 8 (13%) Tetrachloroethene 1 of 8 (13%)

trans-1,3-Dichloropropene 1 of 8 (13%)

Performance at Instrument Detection Limit

Ten replicate samples of a PE mixture at a concentration level of 10 μg/L were provided for analysis at each site.

Reported nondetects were compiled and are given as percent false negatives in Table 5-3. Vendor-provided

compound detection limits, where available, are also shown in the table for comparison.

Table 5-3. False Negative Rates from Very Low-Level PE Sample Analysis

SRS PE Mix 1 (10 μg/L) MAFB PE Mix 3 (10 μg/L)

Compound False Negative Compound False Negative

1,1-Dichloroethene (0.06) 0 of 10 trans-1,2-Dichloroethene (1) 10 of 10 (100%)

Dichloromethane (NA) 0 of 10 1,2-Dichloroethane (80) 10 of 10

Chloroform (11) 10 of 10 (100%) Benzene (1) 0 of 10

Carbon tetrachloride (1) 0 of 10 Bromodichloromethane (1) 5 of 10 (50%)

1,2-Dichloropropane (NA) 8 of 10 (80%) cis-1,3-Dichloropropene (1) 0 of 10

Trichloroethene (1) 0 of 10 trans-1,3-Dichloropropene (3) 0 of 10

1,1,2-Trichloroethane (NA) 10 of 10 (100%) Toluene (1) 1 of 10 (10%)

Dibromochloromethane (1) 9 of 10 (90%) Ethyl benzene (1) 6 of 10 (60%)

Tetrachloroethene (3) 0 of 10 Bromoform No calibration

Chlorobenzene (3) 0 of 10 1,1,2,2-Tetrachloroethane No calibration

2-Chloroethyl vinyl ether No calibration 1,1,1-Trichloroethane No calibration

Trichlorofluoromethane No calibration

1,1-Dichloroethane No calibration

1,2-Dichlorobenzene No calibration

Notes: Vendor-provided detection limits (in μg/L) are shown in parentheses after each compound.

NA = not available; the vendor provided no MDL for these compounds.
43

PE Sample Precision

Precision results from each of the four replicate sample sets provided to the participant from eight PE mixtures at

the SRS and seven mixtures at MAFB are shown in Figures 5-1 and 5-2 for the SRS and Figures 5-3 and 5-4 for

MAFB. In instances where no data are reported, no compound names or graph bars are shown. The figures show

the relative standard deviation for each compound in the PE mixtures at the four concentration levels used in the

study.1 (The compositions and concentrations of each of these mixtures were given in Table 3-5 for the SRS and

Table 3-6 for MAFB. Note that precision and accuracy were not determined for the “very low” concentration

level.) Relative standard deviations for coeluting compound pairs are also shown in the figures. Instrument

precision data for six target compounds which are all regulated under the Safe Drinking Water Act are shown in

Table 5-4. The relative standard deviations are given for each target compound at each of the four concentration

levels used in the study. The RSD range for each target compound is also given in the last column of the table.

Table 5-4. Target Compound Precision at Both Sites

Target Compound Site Relative Standard Deviation (%)

Low Mid High Spike/Low Range

Trichloroethene SRS 32 15 7 15 7 – 71

MAFB 7 71 14 3

1,2-Dichloroethane(a) SRS 37 19 25 4 4 – 44

MAFB 31 21 44 ND

1,2-Dichloropropane(a) SRS 37 19 25 4 4 – 44

MAFB 31 21 44 ND

1,1,2-Trichloroethane SRS ND ND ND ND 11 – 103

MAFB 19 30 11 103

Tetrachloroethene SRS ND ND ND 29 ≤ 29

MAFB ND ND ND ND

trans-1,3-Dichloropropene SRS 14 8 33 23 8 – 46

MAFB 46 30 37 18

Notes: 1,2-Dichloroethane and 1,2-dichloropropane are reported as a coeluting compound pair (a); the same results are reported for each

compound of the pair.

ND = not detected.

A summary of overall instrument precision is given in Table 5-5 for the PE mixtures used at both sites. For this

summary, RSD values from all PE sample analyses for all compounds at each site were pooled, and the median and

95th percentile values of the distribution were computed.

PE Sample Accuracy

The Voyager accuracy for PE sample analyses was determined by comparing the average value from each of the

four-sample replicate sets with the known concentration of the PE mixture (Tables 3-5 and 3-6 for the SRS and

MAFB, respectively). These comparisons are shown as percent recoveries2 in Figures 5-5 and 5-6 for the SRS

 

1

Precision data for the PE mix 1 sample set at MAFB are not shown in a figure. Precision results from this mixture were

comparable to those obtained from the same mixture at SRS.

2

Percent recovery is the Voyager value divided by the true value, multiplied by 100.
44

PE-Photovac Voyager PE Sample Precision

 SRS - PE Mix 1

0 10 20 30 40 50 60 70 80 90 100

Trichloroethene

1,2-Dichloropropane+ 1,2-

Dichloroethane

Tetrachlorethene

Chlorobenzene

Dibromochloromethane

1,1-Dichloroethene+ 

Dichloromethane

Chloroform

Carbon tetrachloride

Compound

Relative Standard Deviation, %

Low

Mid

High

Spike/Low

Figure 5-1. Voyager precision on PE mix 1 at the SRS.

PE-Photovac PE Sample Precision

SRS - PE Mix 2

0 10 20 30 40 50 60 70 80 90 100

Trichloroethene

1,2-Dichloropropane+ 1,2-

Dichloroethane

Tetrachlorethene

c-1,3-Dichloropropene

1,3-Dichloropropane

t-1,3-Dichloropropene

1,1-Dichloropropene

Compound

Relative Standard Deviation, %

Low

Mid

High

Spike/Low

123

Figure 5-2. Voyager precision on PE mix 2 at the SRS.
45

PE-Photovac Voyager PE Sample Precision

 MAFB - PE Mix 2

0 10 20 30 40 50 60 70 80 90 100

1,1-Dichloropropene

Benzene

Trichloroethene

1,2-Dichloropropane+ 1,2-

Dichloroethane

c-1,3-Dichloropropene

t-1,3-Dichloropropene

1,1,2-Trichloroethane+ 1,2-

Dibromoethane

1,1,1,2-Tetrachloroethane

Compound

Relative Standard Devation, %

Low

Mid

High

Spike/Low

103

Figure 5-3. Voyager precision on PE mix 2 at MAFB.

PE-Photovac Voyager PE Sample Precision

MAFB - PE Mix 3

0 10 20 30 40 50 60 70 80 90 100

Benzene

Trichloroethene

Toluene

Tetrachlorethene

Bromodichloromethane

Ethyl Benzene

t-1,3-Dichloropropene

Compound

Relative Standard Deviation, %

Low

Mid

Spike/Low

Figure 5-4. Voyager precision on PE mix 3 at MAFB.
46

PE-Photovac Voyager PE Sample Recovery

SRS - PE Mix 1

0 50 100 150 200 250 300

Trichloroethene

1,2-Dichloropropane+ 1,2-

Dichloroethane

Tetrachlorethene

Chlorobenzene

Dibromochloromethane

1,1-Dichloroethene+ 

Dichloromethane

Chloroform

Carbon tetrachloride

Compound

Average Percent Recovery

Low

Mid

High

Spike/Low

Figure 5-5. Voyager recovery on PE mix 1 at the SRS.

PE-Photovac Voyager PE Sample Recovery

SRS - PE Mix 2

0 50 100 150 200 250 300

Trichloroethene

1,2-Dichloropropane+ 1,2-

Dichloroethane

Tetrachlorethene

c-1,3-Dichloropropene

1,3-Dichloropropane

t-1,3-Dichloropropene

1,1-Dichloropropene

Compound

Average Percent Recovery

Low

Mid

High

Spike/Low

Figure 5-6. Voyager recovery on PE mix 2 at the SRS.
47

and Figures 5-7 and 5-8 for MAFB.3 In instances where no data were reported, no compound names or graph bars

are shown. To assist in assessing the sign of the difference, the percent recovery data are plotted as either a

positive or negative deviation from the 100% recovery line. Instrument recovery performance for the six target

compounds (in PE mix 2 at both sites) is shown in Table 5-6, which contains the average percent recoveries and

associated ranges for each compound.

A summary of overall Voyager recovery differences relative to PE mixture true values is given for both sites,

alongside the precision summary in Table 5-5. For this summary, percent recoveries were expressed as percent

difference (e.g., a 90% recovery is equivalent to a −10% difference; a 120% recovery is equivalent to a +20%

difference), and all data from PE mixtures were pooled. The median and 95th percentiles of the absolute values of

these pooled values were computed and are reported under the absolute percent difference (APD) category in

Table 5-5.4

Table 5-5. Summary of PE Sample Precision and Percent Difference Statistics for the SRS

and MAFB

Parameter Percentile SRS MAFB Combined Sites

PE Mix 1 PE Mix 2 PE Mix 2 PE Mix 3 Combined Mixes

RSD, % 50th 24 20 19 19 20

95th 77 59 61 56 69

Number in pool 29 28 29 25 111

Absolute percent 50th 20 48 50 77 41

difference 95th 47 156 219 170 170

Number in pool 29 28 29 25 111

Table 5-6. Target Compound Recovery for PE Mix 2 at Both Sites

Target Compound Site Average Recovery (%)

Low Mid High Spike/Low Range

Trichloroethene SRS 92 137 164 116

MAFB 231 246 333 344 92 – 344

1,2-Dichloroethane(a) SRS 55 86 85 34

MAFB 82 133 170 ND 34 – 170

1,2-Dichloropropane(a) SRS 55 86 85 34

MAFB 82 133 170 ND 34 – 170

1,1,2-Trichloroethane SRS ND ND ND ND

MAFB 116 54 50 116 50 – 116

Tetrachloroethene SRS ND ND 1 124

MAFB ND ND ND ND 1 – 124

trans-1,3-Dichloropropene SRS 106 154 162 122

MAFB 95 97 143 72 72 – 162

Notes: 1,2-Dichloroethane and 1,2-dichloropropane are reported as a coeluting compound pair (a); the same results are reported for each

compound of the pair.

ND = not detected.

 

3

Percent recovery data for the single PE mix 1 sample set at MAFB are not shown in a figure. Recovery results from this

mixture were comparable to those obtained from the same mixture at the SRS.

4 The absolute percent difference is the absolute value of the percent difference between a field and reference (in this case

the reference laboratory) measurement. As an example, the percent difference between a field measurement of 85 and a

laboratory measurement of 110 is −22.7% and the absolute percent difference is 22.7%.
48

PE-Photovac Voyager PE Sample Recovery

MAFB - PE Mix 2

0 50 100 150 200 250 300

1,1-Dichloropropene

Benzene

Trichloroethene

1,2-Dichloropropane+ 1,2-

Dichloroethane

c-1,3-Dichloropropene

t-1,3-Dichloropropene

1,1,2-Trichloroethane+ 1,2-

Dibromoethane

1,1,1,2-Tetrachloroethane

Compound

Average Percent Recovery

Low

Mid

High

Spike/Low

333

344

Figure 5-7. Voyager recovery on PE mix 2 at MAFB.

PE-Photovac Voyager PE Sample Recovery

 MAFB - PE Mix 3

0 50 100 150 200 250 300

Benzene

Trichloroethene

Toluene

Tetrachlorethene

Bromodichloromethane

Ethyl Benzene

t-1,3-Dichloropropene

Compound

Average Percent Recovery

Low

Mid

Spike/Low

367

Figure 5-8. Voyager recovery on PE mix 3 at MAFB.
49

Comparison with Laboratory Results

At each demonstration site, a total of 33 samples collected from 10 wells were provided to the participants and to

the reference laboratory. Replicate sample sets were composed of either 3 or 4 samples from each well. Average

laboratory results from each replicate set were used as the reference values for comparison with technology results.

A side-by-side comparison of laboratory and Voyager results for all groundwater samples is given in Table 5-7 for

the SRS and Table 5-8 for MAFB. The RSD values and their statistical summaries are included in the table. Well

designation (very low, low, mid, high, and very high) is based on TCE concentration levels; however, other

compounds were present in the groundwater samples at concentration levels noted in the tables. The precision of

the Voyager on replicate groundwater samples is also shown in the last column of the table.

The average percent difference between average Voyager and laboratory results for the compounds detected in each

set of groundwater samples is shown in Figures 5-9 and 5-10 for the SRS and MAFB, respectively. Average

laboratory results for groundwater contaminants reported at levels less than 1 μg/L are not included in the

comparison. The SRS groundwater comparison in Figure 5-9 includes only TCE and PCE. Two well samples

were also contaminated with 1,1-dichloroethene (11DCE) and one well contained chloroform (CLFRM) and carbon

tetrachloride (CCL4), as noted in Table 5-7. The groundwater samples at MAFB were by choice more complex, as

indicated by the additional compounds shown in Table 5-8 and Figure 5-10.

The median and 95th percentiles of the distribution of absolute percent differences between Voyager and laboratory

results for all groundwater samples are given in Table 5-9.

To assess the degree of linear correlation between the Voyager and laboratory groundwater data pairs shown in

Tables 5-7 and 5-8, correlation coefficients (r) were computed. The data pairs were divided into two subsets for

each site to reduce the likelihood of spuriously high r values caused by large differences in the data (e.g.,

concentrations ranging from 1 μg/L to those in excess of 1000 μg/L) (Havlicek and Crain, 1988). One subset

contained all data pairs with laboratory results less than or equal to 100 μg/L and the other subset included all data

pairs with laboratory values greater than 100 μg/L. The computed correlation coefficients are shown in Table 5-

10.

Sample Throughput

Voyager throughput rates ranged from one to three samples per hour. Throughput rates were assessed by using the

time lapsed between sample checkout in the morning and delivery of hardcopy results in the afternoon and the

number of samples completed. Voyager GC run times were influenced to some extent by sample complexity.

Groundwater samples with fewer and known components could be run relatively quickly, whereas multicomponent

PE mixtures required longer run times.

Performance Summary

Table 5-11 contains a summary of Voyager performance characteristics, including important instrument

performance parameters and operational features verified in this demonstration. For groundwater samples, the

results from the reference laboratory are given alongside Voyager performance results to facilitate comparison of

the two methodologies.
50

Table 5-7. Voyager and Reference Laboratory Results for SRS Groundwater Samples

Sample

Description

Well

Number

Compound Replicates Lab.

Avg.

(μg/L)

Lab.

RSD

(%)

Voyagera

Avg.

(μg/L)

Voyagera

RSD

(%)

Very low 1 MSB 33B Trichloroethene

Tetrachloroethene

3 9.0

3.5

11

14

18

18

22

28

Very low 2 MSB 33C Trichloroethene

Tetrachloroethene

3 2.4

0.7

34

12

7.0

5.3

100

93

Low 1 MSB 18B Trichloroethene

Tetrachloroethene

3 11

27

5

6

71

148

79

120

Low 2 MSB 37B Trichloroethene

Tetrachloroethene

Chloroform

Carbon tetrachloride

4 27

22

1.3

1.0

7

9

0

15

46

40

NR

NR

5

6

NR

NR

Mid 1 MSB 4D Trichloroethene

Tetrachloroethene

4 150

87

9

12

242

261

9

75

Mid 2 MSB 64C Trichloroethene

Tetrachloroethene

1,1-Dichloroethene

3 35

240

12

7

4

8

55

427

NR

19

15

NR

High 1 MSB 4B Trichloroethene

Tetrachloroethene

3 747

33

1

2

968

67

29

88

High 2 MSB 70C Trichloroethene

Tetrachloroethene

1,1-Dichloroethene

4 1875

520

32

12

8

8

1321

1016

NR

13

22

NR

Very high 1 MSB 14A Trichloroethene

Tetrachloroethene

3 1367

800

8

6

1378

1585

27

6

Very high 2 MSB 8C Trichloroethene

Tetrachloroethene

3 4933

3668

6

6

2231

3356

13

10

Range 0 – 34 5 – 120

Median 8 22

95th Percentile 15 101

a

 NR = Not reported.
51

Table 5-8. Voyager and Reference Laboratory Results for MAFB Groundwater Samples

Sample

Description

Well

Number

Replicates Compound Lab.

Avg.

(μg/L)

Lab.

RSD

(%)

Voyagera

Avg.

(μg/L)

Voyagera

RSD

(%)

Very low 1 EW-86 3 Trichloroethene

1,1-Dichloroethene

4.6

7.7

5

9

3.3

NR

17

NR

Very low 2 MW-349 3 Trichloroethene

Tetrachloroethene

Chloroform

1,1-Dichloroethene

Carbon tetrachloride

13

2.0

9.0

3.8

137

0

6

1

3

4

16

6

NR

NR

NR

9

0

NR

NR

NR

Low 1 MW-331 4 1,1-Dichloroethene

1,1-Dichloroethane

cis-1,2,dichloroethene

Carbon tetrachloride

Chloroform

Trichloroethene

2.5

15

NR

7.5

4.8

16

7

0

NR

2

2

4

NR

NR

45

NR

NR

25

NR

NR

3

NR

NR

4

Low 2 MW-352 3 Freon11

1,1-Dichloroethene

1,1-Dichloroethane

cis-1,2-Dichloroethene

Carbon tetrachloride

Trichloroethene

20

1.5

5.1

1.5

1.4

22

6

12

4

4

4

5

NR

NR

NR

1.3

NR

43

NR

NR

NR

43

NR

15

Mid 1 EW-87 4 1,1-Dichloroethene

1,1-Dichloroethane

cis-1,2-Dichloroethene

1,1,1-Trichloroethane

Trichloroethene

Tetrachloroethene

180

3.0

3.3

6.8

114

1.2

12

9

13

12

11

14

NR

NR

2.8

NR

214

5.0

NR

NR

18

NR

4

0

Mid 2 MW-341 3 cis-1,2-Dichloroethene

Chloroform

Trichloroethene

15

3.5

280

4

5

4

16

NR

463

16

NR

59

High 1 MW-209 3 cis-1,2-Dichloroethene

Chloroform

Trichloroethene

38

6.9

238

4

21

2

46

NR

497

1

NR

26

High 2 MW-330 4 trans-1,2-Dichloroethene

cis-1,2-dichloroethene

Chloroform

1,2-Dibromochloropropane

Trichloroethene

7.7

66

42

6.1

380

4

5

5

6

5

NR

86

NR

NR

946

NR

5

NR

NR

5

Very high 1 MW-334 3 1,1-Dichloroethene

cis-1,2-dichloroethene

Chloroform

Benzene

Trichloroethene

Carbon tetrachloride

690

237

397

283

10,667

350

3

7

5

5

5

5

NR

404

NR

468

27,300

NR

NR

4

NR

9

0

NR

Very high 2 MW-369 3 cis-1,2-Dichloroethene

Chloroform

Carbon tetrachloride

Trichloroethene

207

63

51

6167

10

6

5

8

261

NR

NR

17,433

15

NR

NR

7

Range 0 – 21 0 – 59

Median 5 7

95th Percentile 13 43

a

 NR = not reported.
52

PE-Photovac Voyager GW Sample Difference

Site: SRS Ref: Laboratory

-500 -400 -300 -200 -100 0 100 200 300 400 500

Trichloroethene

Tetrachlorethene

Compound

Average Difference, %

VLow1

VLow2

Low1

Low2

Mid1

Mid2

High1

High2

VHigh1

VHigh2

569

666

Figure 5-9. Voyager groundwater results at the SRS relative to laboratory results.

PE-Photovac Voyager GW Sample Difference

Site: MAFB Ref: Laboratory

-200 -150 -100 -50 0 50 100 150 200 250

Benzene

c-1,2-Dichloroethene

Trichloroethene

Tetrachlorethene

Compound

Average Difference, %

VLow1

VLow2

Low1

Low2

Mid1

Mid2

High1

High2

VHigh1

VHigh2

Figure 5-10. Voyager groundwater results at MAFB relative to laboratory results.
53

Table 5-9. Voyager Absolute Percent Difference Summary for

Pooled Groundwater Results

Percentile SRS MAFB Combined Sites

50thθ 89 65 74

95th 551 206 453

Number of samples in pool 20 20 40

Table 5-10. Correlation Coefficients for Laboratory and Voyager

Groundwater Analyses

Data Set Correlation

Coefficient

Number of

Data Pairs

SRS Laboratory (1 through 100 μg/L) 0.890 10

SRS Laboratory (> 100 μg/L) 0.830 9

MAFB Laboratory (1 through 100 μg/L) 0.660 15

MAFB Laboratory (> 100 μg/L) 0.999 9

Table 5-11. Summary of Voyager Performance

Instrument

Feature/Parameter

Performance Summary

Blank sample False positives detected at low (13 to 25%) rates for 6 of 24 reported compounds.

Detection limit sample False negatives reported at rates between 10 and 100% for 8 of 18 compounds at

concentration levels of 10 μg/L.

PE sample precision Target compounds, RSD range: 4 to 103%

All compounds, Voyager median RSD: 20%; 95th percentile RSD: 69%

All compounds, laboratory median RSD: 7%; 95th percentile RSD: 25%

(Target compounds: TCE, 1,2-dichloroethane, 1,1,2-trichloroethane,

1,2-dichloropropane, PCE, and trans-1,3-dichloropropene)

PE sample accuracy Target compounds: absolute percent difference range: 8 to 244%

All compounds, Voyager median APD: 41%; 95th percentile APD: 170%

All compounds, laboratory median APD: 7%; 95th percentile APD: 24%;

(Target compounds same as those for sample precision)

Voyager comparison

with laboratory results

for groundwater

samples

Voyager median RSD: 15% Laboratory median RSD: 6%

Voyager 95th percentile RSD: 93% Laboratory 95th percentile RSD: 14%

Voyager: laboratory median APD: 74%; 95th percentile APD: 453%

Voyager: laboratory correlation:

SRS low conc. (≤ 100 μg/L) r = 0.890

SRS high conc. (> 100 μg/L) r = 0.830

MAFB low conc. (≤ 100 μg/L) r = 0.660

MAFB high conc. (> 100 μg/L) r = 0.999
54

Table 5-11. Summary of Voyager Performance (Continued)

Instrument

Feature/Parameter

Performance Summary

Analytical versatility PE samples: calibrated for 24 of 32 PE compounds (75%)

Three pairs of coeluting compounds were reported.

GW samples: For the compounds for which it was calibrated, Voyager reported 39

of 44 compounds detected by the laboratory in all GW samples at or above the

1 μg/L concentration level. A total of 68 compounds were detected by the

laboratory in all groundwater samples.

Sample throughput 1 to 3 samples per hour

Support requirements Water bath

Radioactive detector permit/license

Operator requirements Sample processing: field technician with 1-day training

Data processing and review: B. S. chemist or equivalent

Total system weight 48 pounds

Portability GC is field-portable; accessories (water bath) are transportable

Total system cost $24,000 (with notebook computer and printer)

Shipping requirements Air freight, hand carry, luggage check (no compressed gas via commercial flight)

Recharge carrier gas cylinder requires drop shipment
55

Chapter 6 

Field Observations and Cost Summary

Introduction

The following subsections summarize the audit findings obtained while observing instrument operation at both field

sites. The purpose of the audits was to observe the instrument in operation as well as to verify that analytical

procedures used during the demonstration were consistent with written procedures submitted to the verification

organization prior to the field demonstration. An instrument cost summary and an applications assessment are

provided.

Method Summary

The Voyager uses a static equilibrium headspace method with temperature control. The headspace vapors from a

temperature-equilibrated sample are manually withdrawn with a gas-tight syringe and injected into the Voyager.

The instrument is a three-column GC with dual (photoionization and electron capture) detectors. Compounds are

identified by retention time and quantified by integrating the peak area of the compound and comparing it with that

of calibration standards. Internal and surrogate standards are not used. (See Chapter 7 for discussion of a revised

method that incorporates internal standards.)

Equipment

The Voyager dimensions are 15 inches × 11 inches × 5 inches and it weighs 15 pounds. A notebook computer

(8 pounds) and field-portable printer (10 pounds) were also used during the demonstration for data download,

review, and printing. Equipment weights include batteries and self-contained carrier gas. A small, ac-powered

water bath (15 pounds) was used for temperature equilibration of the sample vials. The system was deployed on

the folded-down middle seat of a minivan. The Voyager is field-portable and could be easily carried to a wellhead

(Figure 6-1); however, the accessory water bath requires ac power. The entire system is best regarded as

transportable in a vehicle to a site. A small cylinder of compressed nitrogen was used for periodic recharge of the

internal carrier gas cylinder. Battery lifetime is normally about 9 hours; however, for this demonstration, the

instrument and computer were powered by a dc-to-ac inverter that was connected to the vehicle’s battery.

Additional equipment used at the demonstration included 40-mL, screw-cap sample vials with septa; chemical

standards; 20-mL syringes and vent needles for sample transfer; and 500-μL gas-tight syringes for sample injection

into the GC.

Sample Preparation and Handling

For sample handling at the SRS, a zero-headspace, 40-mL sample vial was inverted and placed in a 30 °C water

bath. Following a 15-minute equilibration, the vial was uncapped and a 20-mL quantity poured into a second

40-mL vial and capped. The second vial was vigorously shaken for 2 minutes and then returned to the water bath
56

Figure 6-1. The Voyager GC.

and held for 5 minutes. The vial was removed from the bath and a 500-μL, gas-tight syringe was used to withdraw

a headspace sample from the vial through the cap septum. This syringe sample was then manually injected into the

Voyager.

The sampling procedures at MAFB were modified as follows: The zero-headspace, 40-mL sample vial was inverted

and placed into a 30 °C water bath. Following a 15-minute equilibration, the vial was removed from the bath for

withdrawal of a portion of the sample. The needle of a 20-mL syringe was inserted, along with a second vent

needle, through the septum and a 20-mL portion of the water sample was withdrawn. The withdrawn portion was

discarded and the original vial was returned to the water bath for an additional 5 minutes. A headspace vapor

sample was then withdrawn with a gas-tight syringe and injected into the Voyager, in the same manner as carried

out at the SRS.

Consumables

An internal gas bottle contains nitrogen carrier gas. An external cylinder is used to periodically refill the internal

cylinder.

Historical Use

This is the first demonstration of the Voyager GC for VOC analysis in water. The instrument and its predecessors

have been used extensively for air and soil gas analysis.
57

Equipment Cost

The Voyager, as equipped at the demonstration, has a purchase price of $20,000. This includes the proprietary

SiteChart software but does not include a notebook computer for data processing and instrument control. Ancillary

equipment costs are about $4000. Instrument costs are summarized in Table 6-1. Laboratory costs were $95 per

sample plus overnight Express Mail costs, which were about $30 per batch of 12 samples. Voyager sample

throughput is in the range of 1 to 3 samples per hour.

Table 6-1. Voyager GC Cost Summary

Instrument/Accessory Cost

Instrument

(Voyager three-column GC and dual PID, ECD;

SiteChart software)

$20,000

Instrument accessories

(notebook computer, field-portable printer)

Shipping case (option)

Thermally insulated soft case (option)

Water bath

$3000 (notebook computer)

$500 (printer)

$200

Sample handling accessories

(carrier gas, syringes, vials, standards)

$500 per 100 samples

Maintenance costs: periodic PID window cleaning,

column replacement, etc.

One-year parts and labor warranty

Service maintenance agreement ~$2000 per year

Operators and Training

The Voyager was operated by two sales and application technicians at the demonstration. Both of them had

bachelors’-level training in chemistry. Only one person is needed to operate the instrument. With 1 hour of

training, an experienced chemical technician could operate the system. A novice technician operator would require

1 day of training. Experience with GC data processing is required to do method development and analysis of

complex mixtures.

Data Processing and Output

A real-time chromatogram is displayed on the Voyager’s display panel and on the PC’s SiteChart software, if

connected. Hardcopy output is available immediately after analysis. The analysis report, available as a monitor

display or hard copy, includes the following:

• chromatogram;

• analysis parameters;

• analysis method;

• integration method; and

• peak report (compounds identified, compound concentration, peak area and height, retention time, and status).
58

Compounds Detected

The system was calibrated for 24 compounds at the SRS site and utilized two different methods and two columns.

To reduce analysis time and increase sample throughput, at the MAFB site the system was calibrated for 17

compounds on a single column. The calibrated compounds are given in Table 5-1.

Initial and Daily Calibration

A three-point calibration for each target compound was completed at Photovac facilities prior to the demonstration

period. The software will accommodate up to a five-point calibration, with the lowest point being a blank sample.

The user can choose a linear calibration curve or a quadratic fit curve. The linear curve selection produces a pointto-point line based on the calibration data. A standard mixture of target compounds at an intermediate

concentration (100 μg/L) was analyzed at the beginning of each demonstration day to update compound retention

times and detector response factors in the calibration file.

QC Procedures and Corrective Actions

Standard mixtures of chlorinated VOCs in methanol were used in a single daily calibration run. Injection syringes

were decontaminated between uses by heating them in sunlight. Carrier gas flow was controlled by an automatic

pressure regulator to permit analysis at varying atmospheric pressures with no mathematical data manipulation.

No internal standards or surrogate standards were used to monitor sample matrix effects.

Sample Throughput

Chromatographic analysis run time was observed to be approximately 60 minutes for a multicomponent PE sample,

and 10 minutes for a groundwater sample containing only TCE and PCE. Preliminary hardcopy data were

available at the end of the day and final data in spreadsheet format were available the following day. Typical

throughput rates were one to three samples per hour.

Problems Observed During Audit

The auditors observed that sample handling procedures used by the Voyager team at the SRS may have contributed

to imprecise or inaccurate results. The PE and groundwater samples were heated to 30 °C and then uncapped and

poured. Handling warm samples in this manner could result in volatile losses of target compounds, with resulting

degraded instrument recovery and precision. The method was changed at MAFB so that warm samples were never

opened. The precision data presented in Chapter 5 reveal improvement at MAFB compared with the SRS,

particularly for groundwater samples (see Tables 5-7 and 5-8). A moderate improvement in Voyager accuracy at

MAFB for groundwater samples was also noted (see Table 5-9).

The Voyager team encountered problems with the laptop computer during the latter portion of the MAFB

demonstration. This delayed delivery of hardcopy data until the computer could be repaired. The Voyager GC

performed acceptably throughout the demonstrations at both sites.

Data Availability and Changes

Preliminary data from the Voyager were obtained at the end of each demonstration day in hardcopy format. Data

were provided in spreadsheet format at the conclusion of each demonstration week. Several typographical and

transcription errors were corrected at the final data review. The concentration levels of several compounds were
59

reevaluated and changed after the final demonstration period when it was discovered that incorrect compound

response factors in the original calibration file were applied to several compounds. A software change has since

been made to remedy this situation in future use.

Instrument Transport

The Voyager can either be carried on or checked as luggage on airline flights provided that the internal carrier gas

cylinder is emptied. The GC is equipped with a purge valve so that the cylinder can be easily discharged. Drop

shipment is the preferred method for transporting the external carrier gas cylinder since carrying compressed gases

on commercial flights is not permitted. A hard-sided shipping case is available as an instrument option. When

shipping a Voyager equipped with an ECD, no special shipping papers are required since the radiation level of the

detector falls within the International Air Transportation Association level for exempt packages. A 2-week prior

notification is required to bring the Voyager to a particular state in the United States. There is usually no fee

associated with this notification and typically it is valid for 1 year.

Applications Assessment

This demonstration was intended to provide an assessment of the instrument’s suitability for analytical tasks in site

characterization and routine site monitoring. Site characterization refers to those instances where subsurface

contamination is suspected but information on specific compounds and their concentration level is not available.

The instrument best suited for this application is one that can screen a wide array of compounds in a timely and

cost-effective manner. Analytical precision and accuracy requirements may be relaxed in these instances since a

general description of the site characteristics is adequate for remediation planning. At the other end of the spectrum

is a monitoring application where contaminant compounds and their subsurface concentrations are known with

some certainty. Periodic monitoring requirements imposed by local regulatory agencies may specify that analyses

be carried out for specific contaminant compounds known to be present in the water. Quarterly well monitoring

programs fall into this category.

Based on its performance in this demonstration, the Voyager is most applicable to routine monitoring applications

where sample composition is known. It could also be successfully used in sample screening situations where the

contaminants and their approximate concentration in the water are known. Chromatographic methods utilized with

the Voyager may require specific tailoring for a given routine monitoring application.

The Voyager team has observed that their method of sample preparation could be improved. One suggested

improvement is to inject an internal standard in the water sample prior to temperature equilibration and withdrawal

of the headspace gas sample. The internal standard would yield a QC check on every sample and would reveal

such conditions as a plugged syringe or sample matrix effects. A low or high recovery of the internal standard

would prompt the analyst to flag the data and further investigate or reanalyze the sample. See Chapter 7 for a

vendor discussion of a modified method that incorporates an internal standard.
60

Chapter 7 

Technology Update

Note: The following comments were submitted by the technology developer. They have been edited for format

consistency with the rest of the report. The technical content in the following comments has not been verified by

the verification organization.

Introduction

Perkin-Elmer Photovac personnel reviewed the Environmental Technology Verification Report and found the

document to be written in a well-organized and objective manner. Since our participation in the ETV

demonstration, we have improved the method of sample preparation and handling. The revised method specifies the

injection of an internal standard into the water sample prior to temperature equilibration, headspace sampling, and

analysis with the Voyager GC. In addition, a heater block is now used instead of a water bath to provide more

uniform warming of the samples. In accordance with the applications assessment section in Chapter 6, the revised

data review process now includes a QC check based upon analytical results using an internal standard. These

results will help to identify abnormal conditions such as a plugged syringe or unusual sample matrix effects.

Additional Performance Testing

A summary of accuracy and precision results from limited additional testing using the improved methodology is

included in this chapter. This testing was carried out by Perkin-Elmer Photovac without verification organization

oversight and followed a design similar to that used during the field demonstrations.

Voyager Configuration and Method Improvements

Optimum separation of eight chlorinated and nonchlorinated VOC analytes examined in this test was achieved

utilizing two of the three columns in the Voyager’s analytical engine. The columns are described below:

Column B: 20 m × 0.32 mm × l μm Supelcowax 20 (PEG)

Column C: 25 m × 0.32 mm × 12 μm Quadrex 007-l

Improvements in the analytical protocol include:

• a modified headspace equilibration system using a heater block to ensure precise, uniform heating of samples at

30 °C;

• use of dibromomethane as an internal standard for both the PID and ECD; and
61

• a five-point calibration curve stored in the Voyager’s built-in assay library instead of the previous two-point (zero

and upscale value) calibration protocol.

Sample Preparation and Handling

For the postdemonstration test, standard solutions of the following compounds were prepared from certified stock

solutions at concentration levels of 7, 30, 700, and 3000 μg/L: benzene, toluene, ethyl benzene, meta-xylene,

trichloroethene, tetrachloroethene, bromodichloromethane, and dibromochloromethane. A two-level mixture was

also prepared with TCE and PCE at 5000 μg/L levels and the other compounds at 300 μg/L levels.

The standard samples were prepared by serial addition into organic-free water. Each solution was then transferred

to a 40-mL volatile organics analysis (VOA) vial with zero headspace. Twelve replicate vials of each concentration

were prepared in this manner. Four vials of each concentration were stored upside down in a refrigerator at 4 °C

for Voyager analysis. The remaining eight replicates (four samples of each concentration plus four extras in case

of breakage) were placed in a cooler with ice packs and shipped to Phoenix Environmental Laboratories, Inc., in

Manchester, Connecticut, for analysis using EPA Method 8260A. The sample preparation and handling procedures

were essentially the same as those used during the field demonstration.

Sample handling during Voyager analysis was conducted by withdrawing a 20-mL portion of the water sample

from the 40-mL VOA through the septum using a syringe. The withdrawn sample aliquot was discarded. A

100-μL volume of the dibromomethane internal standard was then injected through the septum to produce a final

solution concentration of 1000 μg/L. The vial was gently agitated for 30 seconds and placed in a heater block at

30 °C for 15 minutes. The vial was then removed from the heater block and a 100-μL volume of headspace gas

was manually withdrawn from the vial and injected into the Voyager with a gas-tight syringe.

Reference Laboratory

For consistency with the field demonstration design plan, Phoenix Environmental Laboratories was used as a

reference laboratory for verification of sample concentrations using EPA Method 8260A. A total of 24 samples (4

replicates of 5 different mixtures and 4 blanks) were analyzed by the reference laboratory for verification of

mixture composition and concentration.

Test Results

Calculation of Concentrations

Analytical results obtained using chromatograph column B were manually calculated from response factors derived

from peak area and weight ratios of earlier calibration runs of the dibromomethane internal standard and 500 μg/L

standards of each target analyte. The results for toluene and PCE on chromatograph column C were calculated

using Voyager internal software and a five-point calibration curve. The dibromomethane internal standard was not

used for these two compounds since it coelutes with toluene on this particular column.

Precision and Accuracy

Relative standard deviations for the nine compounds and six (five and a blank) concentration levels investigated in

this study are provided in Tables 7-1 to 7-6. The RSD values were computed from four replicate samples analyzed

at each concentration level. The average percent recovery of each compound, also computed from the replicate
62

samples, is also shown in Tables 7-1 to 7-6. In each table, three different recovery values are given: (1) the

percent ratio of the Voyager result to the laboratory result; (2) the percent ratio of the Voyager result to the “true”

value; and (3) the percent ratio of the laboratory value to the “true” value. The mean percent recoveries for each

target compound over all concentration ranges are given in Table 7-7.

Table 7-1. Blank Sample Results

Compound Voyager Avg.

(μg/L)

Voyager RSD

(%)

True Conc.

(μg/L)

Lab. Avg.

(μg/L)

Benzene No detect <0.5 No detect

Trichloroethene No detect <0.5 No detect

Toluene No detect <0.5 No detect

Tetrachloroethene 13 84.8 <0.5 No detect

Dibromomethane 1007 6.7 1000 NA

Ethyl benzene No detect <0.5 No detect

meta-Xylene No detect <0.5 No detect

Dibromochloromethane No detect <0.5 No detect

Bromodichloromethane No detect <0.5 No detect

Notes: In this table and the following five tables, average and RSD values are computed from four replicate samples.

NA = not analyzed.

Table 7-2. Very Low-Level Sample (7 μg/L) Results

Compound Voyager Voyager True Lab. Percent Recovery

Avg.

(μg/L)

RSD

(%)

Conc.

(μg/L)

Avg.

(μg/L)

Voyager

to Lab.

Voyager

to True

Lab. to

True

Benzene 6.0 32.9 7 15 38 82 214

Trichloroethene 6.0 27.3 7 12 52 89 171

Toluene 10.0 46.2 7 13 75 139 186

Tetrachloroethene 10.0 47.5 7 10 95 136 143

Dibromomethane 980 18.6 1000 NA NA 98 NA

Ethyl benzene 1.0 66.7 7 19 4 11 271

meta-Xylene 1.0 66.7 7 11 7 11 157

Dibromochloromethane 9.0 200.0 7 14 61 121 200

Bromodichloromethane 6.5 115.5 7 16 41 93 229

Note: NA = not analyzed.
63

Table 7-3. Low-Level Sample (30 μg/L) Results

Compound Voyager Voyager True Lab. Percent Recovery

Avg.

(μg/L)

RSD

(%)

Conc.

(μg/L)

Avg.

(μg/L)

Voyager

to Lab.

Voyager

to True

Lab. to

True

Benzene 42 10.2 30 40 104 139 133

Trichloroethene 44 4.8 30 44 99 145 147

Toluene 35 23.8 30 40 86 115 133

Tetrachloroethene 17 58.2 30 39 43 56 130

Dibromomethane 846 10.9 1000 NA NA 85 NA

Ethyl benzene 47 10.0 30 42 111 155 140

meta-Xylene 47 7.4 30 42 112 157 140

Dibromochloromethane 23 72.8 30 46 49 75 153

Bromodichloromethane 62 3.8 30 41 151 206 137

Note: NA = not analyzed.

Table 7-4. Midlevel Sample (700 μg/L) Results

Compound Voyager Voyager True Lab. Percent Recovery

Avg.

(μg/L)

RSD

(%)

Conc.

(μg/L)

Avg.

(μg/L)

Voyager

to Lab.

Voyager

to True

Lab. to

True

Benzene 787 4.1 700 585 134 112 84

Trichloroethene 717 1.0 700 633 113 102 90

Toluene 743 7.1 700 528 141 106 75

Tetrachloroethene 808 11.3 700 628 129 115 90

Dibromomethane 1058 3.6 1000 NA NA 106 NA

Ethyl benzene 686 6.3 700 648 106 98 93

meta-Xylene 520 2.2 700 403 129 74 58

Dibromochloromethane 705 10.1 700 733 96 101 105

Bromodichloromethane 680 7.5 700 655 104 97 94

Note: NA = not analyzed.
64

Table 7-5. Mid- to High-Level Sample (300 and 5000 μg/L) Results

Compound Voyager Voyager True Lab. Percent Recovery

Avg.

(μg/L)

RSD

(%)

Conc.

(μg/L)

Avg.

(μg/L)

Voyager

to Lab.

Voyager

to True

Lab. to

True

Benzene 197 12.6 300 135 146 66 45

Trichloroethene 3300 12.9 5000 3025 109 66 61

Toluene 254 11.4 300 95 267 85 32

Tetrachloroethene 4749 12.2 5000 2850 167 95 57

Dibromomethane 597 8.9 1000 NA NA 60 NA

Ethyl benzene 182 13.0 300 123 148 61 41

meta-Xylene 157 19.9 300 135 117 52 45

Dibromochloromethane 238 18.1 300 98 243 79 33

Bromodichloromethane 219 13.1 300 125 175 73 42

Note: NA = not analyzed.

Table 7-6. Very High-Level Sample (3000 μg/L) Results

Compound Voyager Voyager True Lab. Percent Recovery

Avg.

(μg/L)

RSD

(%)

Conc.

(μg/L)

Avg.

(μg/L)

Voyager

to Lab.

Voyager

to True

Lab. to

True

Benzene 2825 6.0 3000 2200 128 94 73

Trichloroethene 2675 16.3 3000 1625 165 89 54

Toluene 2765 16.1 3000 2175 127 92 73

Tetrachloroethene 2948 16.3 3000 1375 214 98 46

Dibromomethane 748 31.5 1000 NA NA 75 NA

Ethyl benzene 2775 16.5 3000 1950 142 93 65

meta-Xylene 2800 15.4 3000 1950 144 93 65

Dibromochloromethane 3050 1.9 3000 2375 128 102 79

Bromodichloromethane 3050 4.2 3000 2325 131 102 78

Note: NA = not analyzed.

Table 7-7. Summary Mean Percent Recoveries

Compound Mean Percent Recovery at Concentration Level (μg/L) Overall Mean

7 30 700 3000 300/5000 Percent Recovery

Benzene 82 139 112 94 66 99

Toluene 139 115 106 92 85 107

Ethyl benzene 11 155 98 93 60 83

meta-Xylene 11 157 74 93 52 77

Trichloroethene 89 145 102 89 66 98

Tetrachloroethene 136 56 115 98 95 100

Dibromochloromethane 121 75 101 102 79 96

Bromodichloromethane 93 206 97 102 73 114
65

Chapter 8 

Previous Deployments

Note from vendor: The names and companies listed below are current Perkin-Elmer Photovac Voyager users.

The individuals and/or companies are not endorsing the Voyager or its use for a specific application. Questions

about the Voyager and its use or application should be addressed to the Perkin-Elmer Photovac Applications group

at (203) 761-5040.

Vicky Bliss

Mobil Oil

Joliet, IL

(815) 423-7397

Application: Assay 2 - Petrochemical

Paulette Lane

PSE&G of New Jersey

(201) 761-1188

Application: Assay 2 - Petrochemical

Hilary Eustace

City of Somerville

Somerville, MA

(617) 625-6600

Application: Assay 1 - Environmental

Jan McChesney

Bayer Rubber

Sarnia, Ontario

(519) 337-8251

Application: Assay 4 - ABS Rubber
66

References

Bevington, P. R, 1969, Data Reduction and Error Analysis for the Physical Sciences, pp. 52–60. McGraw-Hill,

New York.

DataChem, 1997, “DataChem Laboratories Environmental Chemistry/Radiochemistry Quality Assurance Program

Plan,” 1997 Revision, DataChem Laboratories, Salt Lake City, UT.

EPA, 1986, “Test Methods for Evaluating Solid Waste,” 3rd ed., Vol. 1A (Test Method 3810). Office of Solid

Waste and Emergency Response, Washington, DC.

EPA, 1988, “Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air,”

Report No. EPA/600/4-89/017, Office of Research and Development, U.S. Environmental Protection Agency,

Research Triangle Park, NC.

EPA, 1996a, “A Guidance Manual for the Preparation of Site Characterization and Monitoring Technology

Demonstration Plans,” Office of Research and Development, National Exposure Research Laboratory, Las Vegas,

NV. (Available at the ETV Web Site [www.epa.gov/etv] in pdf format.)

EPA, 1996b, “Test Methods for Evaluating Solid Waste: Physical/Chemical Methods; Third Edition; Final Update

III,” Report No. EPA SW-846.3-3, Government Printing Office Order No. 955-001-00000-1, Office of Solid

Waste and Emergency Response, Washington, DC.

Havlicek, L. L., and R. D. Crain, 1988, Practical Statistics for the Physical Sciences, pp. 80–93. American

Chemical Society, Washington, DC.

Sandia, 1997, “Demonstration Plan for Wellhead Monitoring Technology Demonstration; Sandia National

Laboratories,” Albuquerque, NM. (Available at the ETV Web Site [www.epa.gov/etv] in pdf format.)