### QUALITY ASSURANCE PR OJECT PLAN

COMPREHENSIVE AIR EM ISSIONS TESTING

FOR
HYDROGEN CYANIDE
AT
THREE NEVADA GOLD MI NE SITES

USING THE
USEPA SURFACE ISOLAT ION FLUX CHAMBER TEC HNOLOGY

Prepared For:

NEVADA GOLD MINES

Prepared By:

MR. TOM CARD Environmental Management Consulting 41125 278 th 

### Way SE Enumclaw, Washington 98022

DR. C. E. SCHMIDT 19200 Live Oak Road Red Bluff, California 9608 0

October 7 , 2009

# TABLE OF CONTENTS

i

Section 1 Introduction

................................ ................................ ................................ ..... 1

- 1

Section 2 Project Description

................................ ................................ ......................... 2

- 1

2.1 Area Source Emissions Assessment

................................ ................................ ...... 2

- 3

Section 3 Project Organization and Responsibility

................................ ....................... 3

- 1

Section 4 Quality Assurance Objectives

................................ ................................ ........ 4

- 1

4.1 Precision

................................ ................................ ................................ ................ 4

- 2 4.2 Accuracy

................................ ................................ ................................ ................ 4

- 2 4.3 Completene ss

................................ ................................ ................................ ......... 4

- 3 4.4 Representativeness

................................ ................................ ................................ . 4

- 3 4.5 Comparability

................................ ................................ ................................ ........ 4

- 3

Section 5 Sampling Procedures

................................ ................................ ..................... 5

- 1

5.1 Air Sampling

................................ ................................ ................................ .......... 5

- 1 5.2 Liquid Sampling/Field Analysis

................................ ................................ ............ 5

- 7

Section 6 Sample Custody

................................ ................................ .............................. 6

- 1

6.1 Documentation Procedures

................................ ................................ .................... 6

- 1 6.2 Chain

- of

- Custody Procedures

................................ ................................ ................ 6

- 1 6.3 Sample Handling Procedures

................................ ................................ ................. 6

- 2 6.4 Sample Preservation

................................ ................................ .............................. 6

- 2

Section 7 Calibration Procedures and Frequency

................................ ........................ 7

- 1

7.1 Laboratory Instrument Calibration

................................ ................................ ........ 7

- 1 7.2 Sampling Equipment Calibration Procedures

................................ ........................ 7

- 1

Section 8 Data Reduction, Validation and Reporting

................................ .................... 8

- 1

8.1 Data Reduction

................................ ................................ ................................ ...... 8

- 1 8.2 Data Transfer and Verification

................................ ................................ .............. 8

- 1 8.3 Data Validation

................................ ................................ ................................ ...... 8

- 1 8.4 Anal ytical Data Reporting

................................ ................................ ..................... 8

- 2 8.5 Emissions Estimate

................................ ................................ ................................ 8

- 3 8.6 Process Data Needs

................................ ................................ ................................ 8

- 9

Section 9 Analytical Procedures and Calibration

................................ .......................... 9

- 1

9.1 Method Detection Limits

................................ ................................ ....................... 9

- 1 9.2 Laboratory Standards and Reagents

................................ ................................ ...... 9

- 1 9.3 Methods of Sorbent Analysis for Hydrogen Cyanide

................................ ............ 9

- 1

Section 10 Internal Quality Control

................................ ................................ ................ 10

- 1

# TABLE OF CONTENTS

ii 10.1 Analytical Laboratory Quality Control Samples

................................ ................. 10

- 1 10.2 Field Quality Control Samples

................................ ................................ ............ 10

- 2

Section 11 Performance and Systems Audits

................................ ............................... 11

- 1

11.1 Technical Systems Audit

................................ ................................ ..................... 11

- 1 11.2 Performance Audits and Data Quality Audits

................................ ..................... 11

- 1

Section 12 Preventative Maintenance

................................ ................................ ............ 12

- 1

12.1 Field Equipment/Instruments

................................ ................................ ............... 12

- 1 12.2 Laboratory Instruments

................................ ................................ ........................ 12

- 1

Section 13 Specific Routine Procedures Used to Access Data Precision, Accuracy, and

Completeness

................................ ................................ ............................... 13

- 1

13.1 Blank Data Assessment

................................ ................................ ....................... 13

- 2 13.2 Accuracy

................................ ................................ ................................ .............. 13

- 2 13.3 Precision

................................ ................................ ................................ .............. 13

- 3 13.4 Complet eness

................................ ................................ ................................ ....... 13

- 3 13.5 Corrective Action

................................ ................................ ................................ . 13

- 4

Section 14 Corrective Action

................................ ................................ .......................... 14

- 1

14.1 Reporting Malfunctions

................................ ................................ ....................... 14

- 1

Section 15 Quality Assurance Reports to Management

................................ ............... 15

- 1

Section 16 Health and Safety

................................ ................................ .......................... 16

- 1

## List of Tables, Figure s, and Appendices

iii Tables

Table 2

- 1 Summary of the Scope of Work for the Emissions Assessment Table 2

- 2 Summary of Analytical Species and Proposed Methods with Cost Information. Table 4

- 1 Sample Matrix and Parameters Table 4

- 2 Accuracy, Precision and Sensitivity of Analysis Table 6

- 1 Parameters fo r Sample Preservation Table 7

- 1 Calibration Frequency of Field Sampling Equipment Table 10

- 1 Summary of Internal Quality Control

Figures

Figure 5

- 1 Surface Flux Measurement Data Form

A ttachments

A ttachment 1 USEPA Flux Chamber User’s Guide A ttachment 2 NIOSH Method 6010 A ttachment 3 NIOSH Method 7904 A ttachment 4 Mackay and Matsugu, 1973.

## List of Acronyms and Abbreviations

iv μg/m 3 microgram per cubic meter CFR Code of Federal Regulations CLP contract laboratory program CSTR continuous stirred tank reactor DQO Data Quality Objectives EMSL Environmental Monitoring Systems Laboratory LIMS Laboratory Information System lpm liters per minute

m 2 meters squared MDL method detection limit NIST National Institute of Standards & Technology NIOSH National Institute of Occupational Safety and Health ppbv parts per billion, volume
ppmv parts per million, volume psig pounds per square inch gauge QA quality assurance QAPP Quality Assurance Project Plan QC quality control RPD relative percent difference SDG sample delivery group SOP standard operating procedures
 g microgram UHP ultra high purity USEPA United States Environmental Protection Agency

# SECTION 

# ONE Introduction

1

- 1 

## SECTION 1 INTRODUCTION

The USEPA has an interest in obtaining air emissions data for hydrogen cyanide from gold mining operations. Hydrogen cyanide is used in gold extraction process and may be emitted at low levels from several area sources or gold mining unit pro cesses, including:

 heap leach pads,

 mill process tanks,

 leach solution conveyance channels and

 tails ponds.

Area sources will be measured by using the USEPA surface emissions isolation flux chamber technologies with appropriate sample collection and analytical methodologies. The results will be reported as pounds emitted of HCN per hour for the gold mine area sources. Preliminary annual emissions of HCN will also be estimated based on projected operations and/or historical operating data if the nec essary data is available.

This Quality Assurance Project Plan (QAPP) provides the field sampling and analytical protocols needed to conduct the requested „comprehensive flux chamber testing programs‟ at three gold mining sites: Newmont Gold Quarry, Kinross Round Mountain, and Barrick Cortez. The QAPP describes the technical approach for the comprehensive study, assessment method including method validation components, quality assurance program components, and data reduction and emission estimation procedur es that will be used to generate air emissions of hydrogen cyanide from gold mining unit processes at these three gold mines, and hydrogen cyanide site air emissions from the same mines. Each mine will have subsequent site specific protocol document prepa red that will provide specific process information and sample locations for that site.

Dr. C. E. Schmidt and Mr. Tom Card will provide technical services to Nevada Gold Mines for the purpose of measuring hydrogen cyanide emissions from area sources at mini ng sites and estimating hydrogen cyanide emissions from these area sources and these three mines.

# SECTION 

# TWO Project Description

2

- 1 

## SECTION 2 PROJECT DESCRIPTION

The technical approach to the project includes conducting area source testin g at total of three gold mine sites, including Newmont Gold Quarry, Kinross Round Mountain, and Barrick Cortez. Testing will focus on three types of area sources that may have sub

- sources within each type, including:

1) 

### tall, open process tanks that are located in process areas with poor access,

2) large heap leach pads with surface material of different age under leach (wet and dry areas), and

3) tailings ponds with large aqueous areas and beach (sediment pads) with wet and dry surfaces, open leach cha nnels with pregnant and barren cyanide solution, and process ponds.

This document focuses on area sources, and includes a detailed assessment approach following USEPA protocols for assessment of unique area sources using the USEPA flux chamber technology . The product of this assessment is a matrix table of flux data that, when used along with the surface area of the area sources tested or unit processes, results in a listing of air emissions of hydrogen cyanide from each source tested, and, by summation, the site hydrogen cyanide emissions from all area sources.

Only general information is provided in the QAPP; specific frequency of testing for the comprehensive study will be provided in the test site specific protocol. However, based on experience wor king at mine sites and assessing hydrogen cyanide emissions from these types of sources, general information that is illustrative of the magnitude and distribution of samples per area source is provided in Table 2

- 1.

# SECTION 

# TWO Project Description

2

- 2 Table 2

- 1 Summary of the General Scope of Work Projections

Field measurements will be made using the USEPA flux chamber with sample collection and analysis of samples taken from the flux chamber using NIOSH Method 6010 or NIOSH Method 7904 as indicated in Table 2

- 2. Copies of Methods 6010 and 7904 are provided in Appendix B and Appendix C, respectively. 

### SOURCE SCOPE COMMENT

Process Tanks Two locations each on tank of interest; Minimum of first and last tank in a series of tanks. Minimum tank type and number, aerated and non

- aerated locations

Tailings Pond

- Liquid Surface Two to four tests per zone of pond; number of tests TBD using spatial screening data of pond water (pH, cyanide levels) Access limited to pier, boat or barge stations

Tailings Pond

- Beach Two to four tests per zone of beach, such as w et and dry sediment layer; multiple beach areas recommended per solid component of pond source Range of dry and wet beach locations available by foot

Active Leach Pad Two to four locations per zone on wet and dry surfaces.

Inactive Leach Pad Two to four locations on surface.

Replicate Samples Minimum of 5% per batch, one per day

Media Blank Samples Minimum of 5% per batch, one per day

Snow covered process units Weather permitting, the effects of snow cover will be tested Snow cover is expected to impede mass transfer.

# SECTION 

# TWO Project Description

2

- 3 Table 2

- 2 Summary of Analytical Species and Proposed Methods.

Target Species Analytical Method Sample Media Analytical Instrument Laboratory/Manufacturer

Hydrogen Cyanide (gas phase) NIOSH 6010 Soda lime solid sorbent tube Spectroscopy ALS Laboratory Group 960 W. LeVoy Drive Salt Lake City, UT 84123 801.266.7700

Hydrogen Cyanide (gas phase) NIOSH 7904 (modified) 0.25 N NaOH

solution Spectroscopy ALS Laboratory Group 960 W. LeVoy Drive Salt Lake City, UT 84123 801.266.7700



### 2.1 Area Source Emissions Assessment

For this study, assessment of hydrogen cyanide emissions will be performed using the USEPA recommended surface emission isolation flux chamber (flux chamber) and appropriate sample collection/analytical technologies. A schematic diagram of the USEPA emiss ion flux chamber is provided below.

The emission flux chamber is a dynamic environmental chamber designed for operation on land surfaces, but is applicable to sludge and liquid surfaces as well. The chamber qualifies as a mixed tank reactor or a „contin uously stirred tank reactor‟ (CSTR) and has been designed to assess flux without a significant bias, even for diffusion

- limited sources. The chamber is pressure vented and operated at 5.0 liters per minute (lpm) sweep air flow rate and sample gas is withd rawn from the chamber at equilibrium (5 residence times or 30 minutes; chamber volume is 30 liters and the flow rate of sweep air gas is 5.0 lpm). Because the emission chamber equipment is identical to the USEPA/Environmental Monitoring Systems Laboratory (EMSL) design, and because the protocol for use is followed to exact specifications, the data generated by this technology can be used to quantify area source emission fluxes to within the specifications of accuracy, precision, and repeatability of the pu blished method. All data collected for this effort will be directly comparable to previously collected flux data by this technology, and will be within the method quality assurance/quality control specifications.

Samples are collected from the USEPA flu x chamber at equilibrium using appropriate and valid sample collection and analytical methodology. The analytical methods, combined with the field quality control testing (minimum amount of field system blank tests and replicate sample tests) will be adeq uate to demonstrate compliance with method performance.

# SECTION 

# TWO Project Description

2

- 4 A mine site can consist of a composite of various sources of hydrogen cyanide emissions from area sources, which are dependent on many variables, including: operational considerations, size of the area source, spatial variability, diurnal factors, and seasonal factors. The various area sources can be described as unique „unit processes‟, which when combined in a facility assessment, can be used to estimate hydrogen cyanide emissions from the facili ty. Several studies have been conducted using the USEPA emission flux chamber at identical or similar sites, and the technology is applicable to this assessment effort. The strengths of the flux chamber technology for this application are:

1. The air emissi ons from a given unit process measured using flux chambers are unaffected by upwind sources;

2. The sensitivity (3.3  g/m 3 or a flux of about 0.13  g/m 2 , min - 1 ) for Method 7904 using a sensitivity of 0.1  g/sample and a 30 liter sample volume provides for a low level flux assessment;

3. Other flux chamber studies (Round Mountain) have been conducted for hydrogen cyanide emissions from other mines, and all data collected from these studies will be directly comparable to the data collected in this study;

4. All data collected will be of known accuracy and precision;

5. The technology is a direct measurement approach and no modeling is required to obtain emission factor information since data are reported in engineering units, for example, mass per time/surface area.

6. Th e USEPA technology, using the USEPA/EMSL User‟s Guide (available on ceschmidt.com website) and specified equipment, is a verified approach producing data that can be used to

# SECTION 

# TWO Project Description

2

- 5 estimate emissions from a process by knowing the surface area and measured flux o f the test

source.
This approach provides specific flux data from a given test location. Thus, the exact areas tested must be carefully selected so that they represent the unit process fugitive emissions, and air emissions from the gold mine site. Theref

ore, proper planning is needed prior to testing including: identifying all project variables that may affect surface emissions; identifying all significant and unique area sources which includes discerning significant emission sources from non

- significant emission sources (note

- significance is determined by a combination of flux potential and surface area); properly allocating project resources between planning/preparation efforts, field testing, and reporting. These details will be provided in the site

- s pecific SOPs.

Although not specified in this conceptual approach, additional screening level data will be collected to assist in field sample collection. Colorimetric tubes for hydrogen cyanide will be used as needed in conjunction with flux chamber testin g in order to „fine tune‟ sorbent sample collection.



### 2.1.1 Measurement of Surface Flux

Emissions from various surfaces at the gold mine sites will be evaluated using the flux chamber. One or more samples will be made at the locations identified in Table 2

- 1, or other area source identified from discussions with site operators or from site inspections. Testing may also be conducted on non

- operating sources or reclaim areas at a lower frequency of data collection in order to rule out potential sources as descri bed in the site

- specific SOPs.



### 2.1.2 Calculation of Flux Data

The flux of compounds will be calculated using data on the concentration of compounds from the flux chamber sample (μg/m 3 ), the sweep air added to the chamber (lpm), and the surface area of the chamber (0.13 m 2 ). The flux chamber provides a direct measure of the flux of compounds (μg/m 2 ,min - 1 ) from a given surface at a given point in time.



### 2.1.3 Calculation of Emission Rate Data

The emission rate (μg/min) of compounds from the selected unit process w ill be calculated using the flux data (μg/m 2 ,min - 1 ) and the surface area tested (m 2 ). The emission rate of compounds from the mining sites can be estimated by summing the hydrogen cyanide flux from each unique area of the unit processes and multiplying th e representative flux by the total area for the source to provide the total estimated unit process emissions. Site emissions are obtained by summing all unit process emissions. Data evaluation and correction as needed for large area sources or other fact ors that affect site emissions are described in Section 8.

# SECTION 

# THREE Project Organization and Responsibility

3

- 1 

## SECTION 3 PROJECT ORGANIZATION AND RESPONSIBILITY

The organization for the program includes the team of Dr. C. E. Schmidt, and Mr. Tom Car d, ALS Laboratory Group will provide laboratory services. Tom Card is responsible for the collection of facility and process operations data as well as assisting in flux chamber testing, and C. E. Schmidt is responsible for conducting flux chamber measur ements. Tom Card is responsible for calculating unit process emissions and site emissions of hydrogen cyanide.

The field sampling and analytical activities are the responsibility of Dr. C. E. Schmidt. Dr. Schmidt will: arrange for the field sampling, c oordinate with mine site operators, coordinate with the subcontract laboratory for analytical services, conduct the field sampling, ship samples for analysis, receive and review laboratory data, and report (Technical Memorandum) the results of the field sa mpling.

# SECTION 

# FOUR Quality Assurance Objectives

4

- 1 

## SECTION 4 QUALITY ASSURANCE OB J ECTIVES

The purpose of a QA/QC program is to produce data of known quality that satisfy the project objectives set forth in this document. The QA/QC program shall:

 Provide a mechanism for ongoing control and evaluation of measurement data quality.

 Provide an estimate of data quality in terms of accuracy, precision, completeness, representativeness, and comparability for use in data interpretation.

The QA objectives for accuracy and precision are presented by sample matrix for all sampling and analytical pa rameters in Tables 4

- 1 and 4

- 2. These values are estimates of the degree of uncertainty that is considered acceptable in order for the data to fulfill the needs of the program area source testing. The QA/QC program focuses on controlling and quantifying measurement error within these limits, and provides a basis for understanding the uncertainty associated with these data. In the first step of data validation, measurement data are compared to the QA objectives to determine whether gross performance probl ems occurred.

The basis for assessing precision, accuracy, completeness, representativeness, and comparability is discussed in the following subsections. Specific calculations for data quality measurements are presented in Section 13.

Data Quality Objectives (DQOs) are qualitative and quantitative statements, which specify the quality of the data to satisfy the end uses of the data to be collected. As such, different data uses may require different levels of data quality. There are five analytical levels, which address various data uses, and the methods required to achieve the desired level of quality. These levels are:

 Screening (DQO Level 1): This provides the lowest data quality but the most rapid results. It is often used for health and safe ty monitoring at the site, preliminary comparison to local regulations or criteria, initial site characterization to locate areas for subsequent and more accurate analyses, and for engineering screening of alternatives. These types of data include those g enerated on

- site through the use of real

- time monitoring equipment at the site like the OVA.

 Field Analyses (DQO Level 2): This provides rapid results and better quality than in Level 1. This level may include mobile lab generated data depending on the l evel of quality control exercised.

 Engineering (DQO Level 3): This provides an intermediate level of data quality and is used for site characterization. Engineering analyses may include mobile lab generated data and some analytical lab methods (e.g., lab oratory data with quick turnaround used for screening but without full quality control documentation).

 Conformational (DQO Level 4): This provides the highest level of data quality and is used for purposes of risk assessment, evaluation of remedial alte rnatives and primary responsible party determination. These analyses require full Contract Laboratory Program (CLP) analytical and data validation procedures in accordance with USEPA recognized protocol.

# SECTION 

# FOUR Quality Assurance Objectives

4

- 2  Non

- Standard (DQO Level 5): This refers to analyse s by non

- standard protocols, for example, when exacting detection limits or analysis of an unusual chemical compound is required. These analyses often require method development or adaptation. The level of quality control is usually similar to DQO Level 4 data.

The data collected for this testing effort include Level 2 screening data using colorometric detection tubes for hydrogen cyanide and Level 4 detailed offsite analysis for hydrogen cyanide. The laboratory will perform under DQO Level 4 analysis; however, it will not be asked to prepare or submit a CLP type data package. These back

- up data will be archived and available upon request.



### 4.1 Precision

Precision measures the reproducibility of repetitive measurements. It is strictly defined as the degree of mutual agreement among independent measurements as the result of repeated application of the same process under similar conditions. Analytical precision is a measurement of the variability associated with duplicate (two) or replicate (more than two) an alyses of the same sample in the laboratory. Total precision is a measurement of the variability associated with the entire sampling and analysis process. It is determined by analysis of duplicate or replicate field samples, and incorporates the variabil ity caused by matrix variability, field sampling procedures, and analytical variability. The results of total and analytical precision must be interpreted by taking into consideration all possible sources of variability. Duplicate samples will be analyze d to assess field and laboratory precision, and the results will be reported as the relative percent difference (RPD) between duplicate measurements. In all cases, field precision objectives for RPD will be less than 50 percent. Analytical precision obje ctives are presented for each method and matrix in Table 4

- 2.



### 4.2 Accuracy

Accuracy is a statistical measurement of correctness, and includes components of random error (variability due to imprecision) and systematic error (bias). As such, it reflects the to tal error associated with a measurement. A measurement is accurate when the value reported does not differ from the true value, or known concentration, of the spike or standard. Analytical accuracy is typically measured by determining the percent recover y of known target analytes that are spiked at known concentrations into a field sample (a matrix spike) or reagent water (a method spike) before extraction at known concentrations. The stated accuracy limits apply to spiking levels at five times the metho d detection limits or higher. The individual methods provide equations for acceptance criteria at lower spiking levels.

Surrogate compound recovery is also reported and is used to assess method performance for each sample analyzed for volatile compounds

. Sampling accuracy is assessed by evaluating results for field and trip blanks.

Both accuracy and precision are calculated for specific sampling or analytical batches, and the associated sample results must be interpreted considering these specific measu res. Application of calculated precision and accuracy to measurement sample results will be discussed in Section 13. An additional consideration in applying accuracy and precision is the concentration level of the samples; a procedure

# SECTION 

# FOUR Quality Assurance Objectives

4

- 3 capable of producin g the same value within 50 percent would be considered precise for low

- level (near the detection limit) analyses of minor constituents, but would be unacceptable, and possibly useless, for major constituents at high concentrations.



### 4.3 Completeness

Completenes s, also referred to as percent data capture, is defined as the percentage of valid data reported compared to the total number of samples collected for analysis. Valid data are determined during the data assessment process and satisfy the QA objectives. C ompleteness is determined after precision and accuracy are calculated. The objective for completeness for all measurement parameters and all sample matrices is 90 percent.



### 4.4 Representativeness

Objectives for representativeness will be defined for each sampli ng and analysis task and will be a function of the investigative objectives. Representativeness will be achieved through use of the standard sampling and analytical procedures described in this QAPP and the frequency of testing as described in Section 5.



### 4.5 Comparability

Comparability is the confidence with which one data set can be compared to another. The objectives for this QA/QC program are to produce data with the greatest degree of comparability possible. The number of matrices sampled and the range o f field conditions encountered must be considered in ultimately determining comparability. Comparability will be achieved by using the same (standard) methods for sampling and analysis, reporting data in standard units, and using standard and comprehensiv e reporting formats. Analysis of reference samples may also be used to provide additional information that can be used to assess comparability of analytical data produced within the program.

Table 4

- 1 Sample Matrix and Parameters

Parameter Method Instrume nt or Laboratory DQO Level
Hydrogen Cyanide Colorometric Tube Detection Colorometric Tube Detection 2 Hydrogen Cyanide

NIOSH 6010/7904 ALS Laboratory Group 960 W. LeVoy Drive Salt Lake City, UT 84123 801.266.7700 4

# SECTION 

# FOUR Quality Assurance Objectives

4

- 4 Table 4

- 2 Accuracy, Precision and Sensitivity of Analysis

Parameter Method Accuracy Precision Sensitivity

Hydrogen Cyanide Colorimetric ±50% ±50% 5 ppmv (n=1) 0.5 ppmv (n=10) Hydrogen Cyanide NIOSH 6010 + 15% ±30% 0.1  g/sample Hydrogen Cyanide NIOSH 7904 + 20% ±30% 0.1  g/sample

# SECTION 

# FIVE Sampling Procedures

5

- 1 

## SECTION 5 SAMPLING PROCEDURES

This section contains detailed descriptions of the sample collection protocols to be used for field sampling. All field personnel will be familiar with the pr ocedures they will be using and will have a copy of the QAPP available for reference.

Section 5.1 describes three distinct types of air sampling:

 5.1.1 Real

- Time Detection of Flux Chamber Gas Air Using Colorometeric Tube Detection

 5.1.2 Surface Emission Isolation Flux Chamber Sampling

 5.1.5 Sampling for Hydrogen Cyanide in the Flux Chamber Using Sorbent Technologies



### 5.1 Air Sampling

5.1.1 Real

- Time Portable Detection of Flux Chamber Gas Using Colorometric Tube Detection

Colorometric tube detection may be used in sc reening the flux chamber gas concentration in order to assist in quantitative gas sample collection (Section 5.1.4). For the flux chamber screening using this approach, a sample is drawn into the color tube using a hand plunger with a sample draw of eithe r 50 ml or 100 ml. The detection is noted by color change on the tube scale. More gas sample can be drawn in for improved sensitivity. These screening data will be recorded in the field documentation but will not be used for quantitative analysis.



### 5.1.2 Surfa ce Emission Isolation Flux Chamber Sampling

Isolation emission flux chamber sampling is a direct measurement of emission rates of air contaminants from area sources. Flux chambers can be used for measuring source emissions from:

 Liquid surface, quiescent or agitated;

 Solid land surfaces;

 Open ports in processes; and

 Cracks or vents in a process.

Flux measurements will be conducted on solid and liquid surfaces on mining sources. All flux chamber measurements will be conducted as per the USEPA guidance docu ment, “Measurement of Gaseous Emission Rates from Land Surfaces Using an Emission Isolation Flux Chamber”, February 1986. All liquid and solid surface testing will be conducted by placing the chamber directly on the liquid or solid surfaces. The method i s briefly described below.

The enclosure device, referred to as the flux chamber, is used to sample gaseous emissions from a defined surface area. Clean, dry sweep air is added to the chamber at a fixed, controlled rate. The chamber temperature and volum etric flow rate of air through the chamber is recorded and the concentration of the species of interest is measured at the exit of the chamber. The emission rate is calculated as:

# SECTION 

# FIVE Sampling Procedures

5

- 2 (C i ) (Q) ER i = A where: ER i = Emission rate of species i (μg/m 2

- mi n) C i = Measured concentration of species i (μg/l) Q = Air flow rate (l/min) A = Exposed Surface Area (m 2 )

The response time of the flux chamber is characterized by the residence time. The chamber residence time (t) is a function of chamber volume (V) and air flow rate (Q). The quotient of volume and flow rate (V/Q = t) is the theoretical residence time. Four to five residence times are normally needed to establish steady

- state conditions in the chamber at which time representative sampling can occur. T his will require 24 to 30 minutes per sampling point.

The chamber is an acrylic topped, pressure vented, stainless steel cylinder designed to penetrate the sampling surface. The chamber has a 0.13 m 2 exposed surface area and a volume of approximately 0.03

m 3 . One 1⁄4 inch port will be used to withdraw sample gas. Sealing on hard surfaces such as heap leach can be accomplished by piling solid media of the area around the base sufficient to prevent ambient air entrainment.

Dry, hydrocarbon

- free sweep air (zero grade air) will be provided from compressed gas cylinders. The sweep air will pass through a calibrated rotameter with a needle

- valve flow control. Inlet and outlet lines are made of Teflon and all fittings in contact with the gas will be Teflon or stainless steel. The outlet line will include a sampling manifold for monitoring and/or collection of the gaseous specie of interest. This manifold will consist of ports for gas

- canister sampling and gas

- syringe collection. A thermocouple and readout w ill be used (when possible) to measure the surface and air temperatures at the sample point.

The flux chamber will be wiped clean and dried before each use and then placed over the sampling area. The sweep air is added to a flow rate of 5.0 liters per min ute and the time noted when the chamber is placed on the test surface. Air temperatures inside and outside the chamber are also taken and recorded. Once steady state is reached (about 30 minutes), gas samples are collected. Samples will be collected usi ng either solid or liquid sorbent media and calibrated sampling pumps. Note that the method recommends a sweep air flow rate of 5.0 lpm.

Data will be recorded on the data form shown in Figure 5

- 1. The following data collection steps will be taken:

Locate equipment at the sampling location;

 Document location of measurement, date, time, and operator;

 Initiate sampling by starting sweep air, checking the flow rate, placing the chamber on the testing location, and sealing the bottom of the chamber;

 Document t he gas flow rate (5.0 lpm) and the initial and final temperatures of ambient air, of air inside the chamber, and of the bulk soil/waste;

# SECTION 

# FIVE Sampling Procedures

5

- 3  Document any other data such as source characteristics, relevant process data if any, meteorological conditions, etc., for possible correlations with emission rate measurements or method verification;

 Monitor the chamber operation and record field data every residence time;

 Collect gas samples at steady state indicated by the number of chamber residence times (e.g., 5 resi dence times or 30 minutes); and

 Fill out appropriate chain

- of

- custody forms and master sample log entries for sample collected.

The sample matrix given in Table 2

- 1 includes general flux chamber testing descriptions and typical quality control testing effo rts (minimum blank tests 5%, replicate tests 5%). However, specific sampling activities will be provided in the site

- specific SOPs.



### 5.1.3 Sampling for Hydrogen Cyanide from the Flux Chamber

Samples will be collected as grab samples from the flux chamber by colo rometric tube for screening
purposes . Integrated sample collection is required for the collection of quantitative hydrogen cyanide assessment. The collection media required for the integrated sample collection is either solid sorbent or liquid reagen t in an impinger. Prior to sample collection, all sampling media will be cleaned/prepared according to the specific analytical methods selected.



### 5.1.3.1 Grab Sampling
Grab samples will be collected by colorometric tube detection from the chamber contents or exhaust gas line.

To collect grab samples from the flux chamber:

 Attach sampling line from the flux chamber to the colorometric detector tube using 1⁄4” Teflon tubin g and silicone connector;

 Record sample time on data sheet and withdraw plunger collecting the sample; and

 After sample collection is completed, read the tube indicator results and disconnect from the chamber.



### 5.1.3.2 Integrated Sampling
Integrated samples (solid sorbent or liquid impinger) will be collected on either solid or liquid sampling media. The sorbent media will be used to collect exhaust gas samples after chamber equilibrium. Gas will be metered by using a calibrated personal (battery powered) samplin g pump. The pump will be calibrated immediately before and after use with the sampling media in

- line (note

- „dummy‟ sample media that will not be analyzed) flow controller on the canister. Prior to sample collection, each sorbent will be prepared in the laboratory.

To collect sorbent samples from the flux chamber:

# SECTION 

# FIVE Sampling Procedures

5

- 4  Attach sampling line from the flux chamber to the sorbent media using a clean, 1⁄4

- inch Teflon or stainless steel tube with 1⁄4

- inch Swagelok fittings;

 Record start time on data sheet and turn on the calibrated sampling pump;

 The integrated sample will be collected at the method specific flow rate over a period of time that will allow for the collection of an adequate volume of gas to attain minimum detection limits;

 After sample collection is comp leted, the pump is shut off and the sample line is disconnected from the chamber;

 The sample collection is recorded on the chain

- of

- custody sheet;

 Prior to transporting to the laboratory, all media are sealed and preserved as per the sample collection protocol; and

 Complete appropriate chain

- of

- custody forms, master sample log entries, labels for samples collected, and ship media.

# SECTION 

# FIVE Sampling Procedures

5

- 5 Figure 5

- 1 Surface Flux Measurement Data Form

# SECTION 

# FIVE Sampling Procedures

5

- 6 

### 5.1.4 Sampling for Hydrogen Cyanide in the Flux Chamber Using Sorbent Tech nologies

There are no agency

- approved methods for ambient

- level air sampling and analysis for hydrogen cyanide. Therefore, existing occupational (NIOSH) methods will be modified and adapted for use in this program.

There are two approaches to sample coll ection: a solid sorbent, or a liquid sorbent (impingers, or bubbler). The decision to use either one depends on the objectives of the sampling. The solid sorbent is an easier method to use, as it does not require the use of liquid impingers, while the liq uid impinger method allows a higher sampling flow rate and has a lower potential for clogging, thus providing the possibility of lower detection limits and greater reliability. While the liquid impinger method may provide lower detection limits and greater reliability, it uses a corrosive impinger solution which requires a high level of care in terms of safety and is readily subject to contamination and loss of the sample. Therefore, these considerations need to be taken into account. The method of choice is source and area source specific, and will be identified in the site

- specific SOPs.



### 5.1.4.1 NIOSH Methods for Hydrogen Cyanide
Due to the origin of these methods, they are oriented towards occupational settings and therefore are designed for a much higher detec tion and quantification range

— in ppmv vs. the ppbv levels needed in ambient level air sampling. However, these methods can be extended, usually by sampling at a higher flow rate or for a longer period of time to increase the total sampled volume, or by inc reasing the sensitivity of the analysis method. These modifications will be described below.



### 5.1.4.1.1 NIOSH 7904 (modified)

— Impinger Sampling/ Visible Absorption Spectroscopy

This method has been modified using a liquid impinger of 0.25 N NaOH to collect the gaseo us hydrogen cyanide. A sample is collected at 0.5 to 1 liter per minute (lpm). The resulting solution is analyzed spectrophotometrically. The detection limit for this method is estimated to be 0.1  g cyanide.



### 5.1.4.1.2 NIOSH 6010

— Sorbent Sampling/Visible Absorptio n Spectroscopy

This method uses a soda lime (hydrated calcium, sodium, and potassium hydroxides) sorbent tube with 600 mg in the front section and 200 mg in the back for breakthrough. Sampling is specified at 0.05 to 0. 2 lpm for up to 90 liters. If the s ample conditions require it, the total air volume will be increased up to 900 liters. The analysis is performed by color development after water extraction with an oxidizing reagent followed by a complexing agent. The resulting solution is analyzed spect rophotometrically at 580 nm. The detection limit cited by the method is 0.1  g/sample.



### 5.1.5 Meteorological Monitoring

The m ining sites maintain permanent site meteorological monitoring stations, and local (near the air monitoring) meteorological monitoring may be conducted at the point of testing with a portable station.

Parameters monitored will be:

 Wind speed

 Wind direction

# SECTION 

# FIVE Sampling Procedures

5

- 7  Temperature

 Relative humidity

 Barometric pressure The portable monitoring station, if used, will be mounted on 3 meter towers.



### 5.2 Liquid Sampling/Field Analysis

Each flux chamber sample taken from a free liquid surface will have the following liquid phase parameters samples and analyzed:

 Solution temperature.

 Solution pH (by field pH meter).

 Free cyanide (field test kit).

 pH/WAD and free cyanide (mine process lab)



### 5.2.1 Temperature

Solution temperature wil l be by electronic thermocouple. Temperature will be taken in situ

.


### 5.2.2 pH

Solution pH will be by portable field instrument backed up by colorimetric strips. The field instrument will be calibrated with pH 7 and pH 10 buffer solution prior to each sampling d ay.



### 5.2.3 Field Liquid Cyanide Concentration (free cyanide)

Field liquid phase cyanide concentration will be determined by using a Chemetrics field test kit. Two different test kits will be used. One for low range (colorimetric) for concentrations up to 1 mg/l and high range (titrimetric) with a range of 5 to 50 mg/l. For intermediate concentrations, the sample will be diluted with distilled water.

The Colorimetric Method. The kit employs the Isonicotinic/Barbituric Acid Method. To perform a test,
two accesso ry solutions are added to the sample to convert cyanide to cyanogen chloride. The analyst then snaps off the tip of the reagent ampoule below the surface of the sample. The sample is automatically aspirated into the ampoule where the resulting cyanogen c hloride reacts with the isonicotinic and barbituric acids to form a blue color. Test results are expressed in parts per million (mg/l) cyanide. Total testing time is about 20 minutes. This chemistry provides two advantages over the more commonly used pyr idine methods: (1) The shelf

- life of the reagent is extended, and (2) The analyst is not exposed to the noxious and hazardous fumes from the pyridine reagent.

The Titrimetric Method. CHEMetrics employs silver nitrate as the titrant and dimethylaminobenzal rhodamine as the indicator. A color change from orange to yellow signals the end of the titration. Results are expressed as ppm (mg/L) CN

# SECTION 

# FIVE Sampling Procedures

5

- 8 

### 5.2.4 Laboratory Liquid Cyanide Concentration

A sample will be taken for analysis by the site process laboratory using their standard analytical technique. This technique will be reported in the site specific protocol. Values will be reported for both free and WAD cyanide.

# SECTION 

# SIX Sample Custody

6

- 1 

## SECTION 6 SAMPLE CUSTODY

Sample possession during all testing efforts must be traceable from the time of collection until the results are verified and reported. Sample custody procedures provide a mechanism for documentation of all information related to sample collection and handling to achieve t his objective.

Dr. Schmidt will be responsible for seeing that the field team adheres to proper custody and documentation procedures for all sampling operations. Preformatted field data and Chain

- of

- Custody forms will be used as the primary documentation mechanism to ensure that information pertaining to each sample is properly recorded. In addition, a master sample logbook will be maintained for all samples collected. Examples of these data documentation forms are presented in this section. Copies of t he Chain

- of

- Custody forms and the field logs will be retained in the project file.



### 6.1 Documentation Procedures

6.1.1 Field Records

Field personnel will be required to keep accurate written records of their daily activities in a bound logbook. All entries will be legible, written in waterproof ink, and contain accurate and inclusive documentation of an individual's field activities, i ncluding field data and observations, any problems encountered, and actions taken to solve the problem. The type of data recorded in the field logbook includes field measurements, ambient conditions, and any other information pertinent to sample collectio n. Entry errors or changes will be crossed out with a single line, dated, and initialed by the person making the correction. Entries made by individuals other than the person to whom the logbook was assigned will be dated and signed by the individual mak ing the entry. Field logbooks will be available for review.



### 6.1.2 Sample Labels

Each sample collected will receive a sample label that identifies the sample by a unique sample identification number. These labels are affixed to the sample container prior to sa mple collection.



### 6.1.3 Sample Master Logbook

A sample master log will be maintained for all samples collected. Each sample will be assigned a unique identification number; a full description of the sample, its origin, and disposition will be included in the l og entry.



### 6.2 Chain

- of

- Custody Procedures

After the samples are collected and documented in the master logbook, a Chain

- of

- Custody form will be completed and will accompany the samples to the laboratory. Figure 6

- 1 presents a Chain

- of

- Custody form used for samples. Team members collecting the samples are responsible for the care and custody of the samples until they are transferred or dispatched to the appropriate laboratory. When transferring samples, the individuals relinquishing and receiving the sample s will sign, date, and note the time on the record.

# SECTION 

# SIX Sample Custody

6

- 2 This record documents sample possession from collection to the laboratory sample control center.

When the samples are received by the laboratory, the sample control officer will verify the Chain

- of

Cust ody form against the samples received. If any discrepancies are observed, they will be recorded on the Chain

- of

- Custody form and Dr. Schmidt will be notified to correct the problem.



### 6.2.1 Shipment

All sample shipments will be accompanied by the Chain

- of

- Custody record, which identifies the contents of each crate. The person relinquishing the samples to the laboratory will request the signature of a laboratory representative to acknowledge receipt of the samples. Sample collection and shipment will be coordinat ed to ensure that the receiving laboratory has staff available to process the samples according to method specifications.

All shipping containers will be secured for safe transportation to the laboratory. The method of shipment, courier name(s), and other pertinent information is entered in the “Remarks” section when the samples are to be shipped (i.e., Federal Express, Express Mail, etc.) instead of hand

- delivered.



### 6.3 Sample Handling Procedures

The objective of sample handling procedures is to ensure that sa mples arrive at the laboratory intact, at the proper temperature, and free of external contamination. Sorbent and canister samples will be shipped
to the laboratory by field sampling personnel.

Sample packaging requirements for hazardous material s requiring interstate transport are defined in the Code of Federal Regulations 40 (CFR) 49, Chapter 1, Part 171. These requirements outline in detail the proper classification and transportation procedures for hazardous materials that will be used in the transporting of samples.



### 6.4 Sample Preservation

Once the samples have been collected, the methods specify preservation, storage requirements and holding time limitations. Table 6

- 1 summarizes the preservation requirements for the type of samples collected d uring this program.

Table 6

- 1 Parameters for Sample Preservation

Media/Parameter Preservation and Storage Requirements Maximum Holding Time (Days)

NIOSH 6010 Solid Sorbent Tubes Tube sealed, vials sealed, 4 o C 14 Days NIOSH 7904 Impinger Solution Glass vial, vials sealed, 4 o C 5 Days

# SECTION 

# SEVEN Calibration P rocedures and Frequency

7

- 1 

## SECTION 7 CALIBRATION PROCEDUR ES AND FREQUENCY

Information is presented in this section pertaining to the laboratory calibration of sampling equipment. Included are descriptions of each procedure or references to applicable standard operating procedures (SOPs), the frequency of calibrations, and the calibration standards to be used.



### 7.1 Laboratory Instrument Calibration

Laboratory instruments are calibrated according to manufacturer's specifications and are in compliance with the analytical method requirements. Detailed calibration procedures and recommended frequencies are included along with the analytical SOPs, which can be found in the appendix to this volume. A brief description of the analytical methodologies, and their associated calibration procedures, is included in Section 9.



### 7.2 Sampling Equipment Calibration Procedures

An important function in maintaining data quality is the check

- out and calibration of all sampling equipment. Using referenced procedures, the equipment will be calibrated prior to field sampling. These results will be properly documented and retained. If a referenced calibration technique for a particular piece of apparatus is not available, then state

- of

- the

- art techniques are used. A discussion of the procedures used to calibrate equipment is presented below. Calibration frequency of the field sampling equipment is presented in Table 7

- 1. No other field calibration is required other than the personal sampl ing pumps.

Table 7

- 1

Calibration Frequency of Field Sampling Equipment

Sampling Equipment Calibration Before Sampling Frequency

Daily After Sampling
pH Meter; Buffer Standards X X X Personal Sampling Pumps X X X

Note that the personal sampling pumps are calibrated using a primary gas standard (DC Lite calibrator) immediately before and after each sample collection. The average of the calibration run data is used as the flow rate for the sample collection interval.

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 1 

## SECTION 8 DATA REDUCTION, VALI DATION AND REPORTING

The data reduction, validation, and reporting procedures described in this section will ensure that complete documentation is maintained throughout the progr am, that transcription and data reduction errors are minimized, that the quality of the data is reviewed and documented, and that the reported results are properly qualified and in a conventional format.



### 8.1 Data Reduction

The reduction of raw data generated at the laboratory bench is the responsibility of the analyst producing it. The data interpretation that is required to calculate sample concentrations follows the methodology described in the specific analytical SOP. After all analyses have been complet ed, a preliminary laboratory report is generated for review by the laboratory supervisors who verify that the analyses were properly performed and interpreted. After the final review by the laboratory supervisor, the raw data is transferred to sample cont rol and presented for review by the QA coordinator. Raw data, together with all supporting documentation, are stored permanently in confidential files by sample control.

The QA coordinator reviews the data for adherence to the QC method limits. In additi on, the data are reviewed for the presence of outliers. An outlier is an unusually large (or small) value in a set of observations. There are many possible reasons for outliers, among which are:

 Faulty instruments or component parts.

 Inaccurate reading of a record, dialing error, etc.

 Errors in transcribing data.

 Calculation errors.

Sometimes analysts or operators can identify outliers by noting the above types of occurrences when they record observations. In these instances, the errors are corrected, or if correction is not possible the suspect observations may be removed from the data before calculations are performed. If no such information exists, the Dixon Criteria are used to test suspected outliers at the 5 percent significance level if there ar e three or more points in the data set containing the outlier. Outliers identified by this method may be removed from the data before further processing (see W.J. Dixon, “Processing Data for Outliers,” Biometrics , 1953, Vol. 9, No. 1, pp. 74

- 89).



### 8.2 Data Tra nsfer and Verification

A laboratory database is used to store and transfer analytical data from the laboratory. Sample control staff are responsible for entering into the system and verifying sample and result information and generating hard copies of the analytical results.



### 8.3 Data Validation

Dr. Schmidt will review field documentation and all measurement data for acceptable sample collection and analysis procedures, adherence to prescribed QA procedures, and agreement with the acceptance

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 2 criteria described in Section 4. Initially, the reviewer will determine whether hold times were met and that all required analytical QC checks were reported with the data. Then, all QC sample results will be reviewed to evaluate the sampling and analytic al performance. Reagent blank results will be evaluated to identify any systematic contamination; spike and duplicate results will be compared to the QA objectives presented in Section 4, and the results will be used to calculate precision and accuracy fo r the data set. This process will identify any analytical methods and compounds for which the QA objectives are not satisfied, and corresponding sample data will be qualified with a “flag” indicating the problem. Samples collected on the same day, analyz ed in the same run or batch, or individual samples may be flagged, depending on the type of problem that has been identified. Reanalysis or resampling may be recommended at this time if data are determined to be unacceptable for the intended application.

The qualifier codes, or “flags,” will be stored with the data and printed with the data when reported or transferred for any purpose. The specific statistical procedures and qualifier codes used in the validation process are described in detail in Secti on 13. After data are received from the laboratory, entered, checked, and qualified, they are a permanent part of the database and cannot be deleted or altered.



### 8.4 Analytical Data Reporting

Data reporting for this project will consist of QA reporting, invest igative data reporting, and QC data reporting.

General reporting practices for measurement data will include:

 Heading information identifying the sample batch and the analytical method.

 Unique sample identification number or code.

 Consistent units of measu re.

 Consistent number of significant figures.

 No blank or dashed places reported; all spaces will contain a designation (i.e., not analyzed, not sampled, etc.).

 Explanation of outlier values or the cause for deviation from historical data.

 Comparison with regulatory threshold values if applicable.

 Quality assurance flags.

 Quantification of accuracy and precision for analytical data.



### 8.4.1 Investigative Data Reporting

Measurement data generated during the course of an investigation will be reported in tabular form from the computerized database. The formats of the reports will vary, depending on the objectives of the investigation. In general, data will be presented according to sampling location, analytical method, parameter, and/or matrix. All data will be rep orted with the qualifiers discussed above, and units will be specified.

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 3 

### 8.4.2 General Reporting Procedures

The procedures employed to ensure report quality involve the following:

 All calculations and measurements will be verified by recalculation by the person initially providing data. The calculations and measurements are then checked by another individual who signs and dates the calculation sheets. Any calculations and measurements that differ from the initial totals are resolved by both individuals. Once the calculations and measurements are included in an internal working copy of a document, the figures are rechecked during peer review. If there are many such calculations within a report, a certain percentage (10 to 50 percent) are checked again during p eer review.

 Numerical values presented in reports and comparisons of numbers appearing in text, tables, and appendixes will be addressed in the manner discussed above.



### 8.4.3 QC Data Reporting

Quality control results will be reported by sample matrix and method in tabular form. How these QC results influence the measurement data will be delineated. For example, matrix spike interference will influence specific samples, while laboratory blank contamination will influence all samples extracted or analyzed on a sp ecific day or during a specific analytical run. Two levels of tables may be constructed for each type of QC check. The first level table will contain all QC data, and will present one line per parameter or analysis. First level table formats will be use d in presenting duplicate samples and analyses, matrix and method spikes, and system blank results. First level QC data tables will be generated for all investigations.

Specially developed table formats will be used occasionally as an aid to interpretatio n of the investigative data. The particular format will depend on how the QC results are expected to influence the investigative data. This type of table might be used to identify corresponding investigative results (samples analyzed on corresponding dat es), which may be inaccurate. Specialty tables will be generated automatically or manually, depending on the volume of data to be processed and the complexity of the calculations.



### 8.5 Emissions Estimate

8.5.1 Background

Fate modeling is an approach to quantify emis sions from liquid and solid surfaces using the physical mass transfer characteristics of the system combined with the chemical properties of the specific compounds of interest. The general fate modeling equation is (EPA

- 453/R

- 94

- 080A)

where r

v = the system emission rate (g/s), K t is the overall mass transfer coefficient (m/s), C x is the surface liquid phase concentration of constituent x (g/m 3 ) and A is the system surface area (m 2 ).

K t is a function of the individual liquid phase and gas phase mass transfer coefficients. These coefficients are essentially a measure of the thickness of the laminar diffusion layer on the liquid side and gas side of

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 4 the interface. However, since this thi ckness cannot usually be measured directly, these coefficients are estimated by indirect means. Since they are estimated values, they will also contain the other system uncertainties, such as surface perturbations, area deviations, liquid phase chemistry non

- equilibria, and gas phase concentrations inhibiting mass transfer.

The overall mass transfer, K t is calculated from the liquid and gas phase mass transfer coefficients by

where k l is the liquid phase mass transfer coefficient (m /s), H is the gas/liquid partition coefficient (Henry‟s Law Coefficient, g/m 3 gas per g/m 3 liquid), and k g is the gas phase mass transfer coefficient. Except for cases of extreme turbulence (packed towers, etc.) the liquid phase mass transfer is not limit ing when the gas/liquid partition coefficient is less than 0.01. This value is around 0.005 for cyanide. These types of compounds are called „gas phase limited‟ compounds. Therefore, for these compounds

The concentration term, C x , is the net positive driving force. Therefore

where C

lx is the liquid phase concentration of constituent x , C gx is the gas phase concentration of constituent x , and H x is the partition coefficient of constituent x . For small systems, C gx , the gas phase concentration of the constituent, is assumed to be zero (the infinite dilution assumption). However, for large systems (heap pads, ponds, etc.), C gx can be significant, due to the accumulation of the constituent i n the gas phase. In essence, as a constituent volatilizes across a large surface, the downwind concentration becomes larger and larger. This increasing gas phase concentration causes a significant retardation of further volatilization. This effect mus t be taken into account when measurements from a flux chamber (a small system) are used as the basis for estimating the emissions from a heap pad or pond (a large system) or emissions may be significantly over estimated. This is normally accounted for in the estimation of k

g by including the F a factor described below.



### 8.5.2 Corrections to be Applied to Flux Chamber Data to Calculate Complete Process Emissions

k g is a function of gas phase turbulence (wind conditions). Wind not only controls the thickness of th e laminar layer, it also increases overall effective surface area by the creation of surface perturbations (waves). As mentioned above, the presence of significant gas phase concentrations can also be accounted for by k

g .

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 5 Normally k

g is measured in a surf

ace isolation flux chamber. The flux chamber has an idealized gas phase environment representing relatively calm conditions (surface wind speed less than a 10 meter height equivalent of 3 m/s) and a relatively small surface area (0.13 m 2 ).

In order to account for and more accurately rep resent the actual environmental conditions at the site, the value from the flux chamber must be adjusted for wind speed and process size using the following adjustment factors.

and

where U

10 is the wind speed (m/s) a 10 meters above the process surface and A is the system surface area (m 2 ).

Both of these factors are based on work done by MacKay and Matasugu ( Evaporation Rates of Liquid Hydrocarbon Spills On Land and Water, The Canadian Jour nal of Chemical Engineering, Vol. 51, August 1973). Their gas phase mass transfer coefficient equation is reported in EPA

- 453/R

- 94

- 080A and is used as the impoundment gas phase mass transfer correlation in WATER9. The wind factor ( F w ) results in an upwar d emissions adjustment for winds above 3 m/s while the area factor ( F a ) results in a downward emissions adjustment for large areas. In order to obtain an accurate estimate of emissions, both factors must be taken into account.

The F a factor is based on th e known fact that evaporation from large bodies of water is always less than from the small pans that generally quantify evaporation. This reduction in evaporation rate is due to the higher humidity on the downwind side of the impoundment that suppresses the evaporation rate.

Evaporation is a surrogate for all gas phase mass transfer because evaporation is limited by only gas phase resistance. As reported in MacKay and Matsugu (1973) the standard value used to account for this difference is 0.7; that is t he evaporation from large bodies is normally around 70% of that from pans. Large bodies also retain heat better than pans and this tends to counteract some of the area effects. So from a true mass transfer (and not thermodynamic effect) the 70% value is very conservative. For the testing that is proposed in this plan for large surfaces, 70% would be too high a value. This is because that value, as reported by MacKay and Matsugu, also accounts for the effect of heat retention by larger bodies compared to the much smaller surfaces that are the subject of direct measurement in the underlying test that took place in those cases. The higher heat retention of larger bodies will result in a higher

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 6 evaporative or thermodynamic transfer of a substance into the g as phase. This is a mechanism that is separate and apart from a true chemical mass transfer mechanism. This effect will not be present in the case of the flux testing since the flux measurements will be conducted on the source itself, thereby accounting for the heat retention of the source being measured. In summary, an evaporation pan has two primary differences than a reservoir:

1. The pan has a lower humidity over it (gas phase accumulation) accelerating evaporation (volatilization).

2. The pan has a lower thermal mass, resulting in cooling from the water vaporization, decreasing evaporation (volatilization).

Since the issue in question is cyanide and not water evaporation, Item 2, the thermal mass, does not come into play. Therefore, the pan rate has no m itigating factors, resulting in a cyanide volatilization rate of much less than the standard 70% value used for water reservoirs.

MacKay and Matsugu conducted experiments to quantify how the size of the actual source/s ystem will affect mass transfer rates when scaling up from a smaller area such as a flux chamber, focusing on mass transfer (apart from the thermodynamic mechanism) and developed the mathematical relationship described in the equation above. Their values also agreed with other investigators (listed in the above citation). Their empirical relationship for the gas phase mass transfer coefficient has been standardized by the USEPA in the WATER9 fate model. Their original work is p roved as an attachment to this document . T his factor will correct the flux chamber measured emissions from the large (wet) processes at gold mines to reflect actual conditions at the site, and is expected to result in calculated process emissions
t hat are 35% to 55% less than the flux chamber measured emissions

. To provide an example of how this is intrinsically integrated into the WATER9 fate model, the emissions hav e been calculated from a small section (flux chamber sized) of a large pond (1,000 meters in diameter) using WATER9 algorithms. Since WATER9 cannot accommodate ionizing compounds, like cyanide, methanol is used as an example compound. Assume that the pond has a liquid phase methanol concentration of 5 mg/l and a Henry‟s Law value of 0.000148 mg/l per mg/l. At a wind speed of 3 m/s, using these values, WATER9 would calculate the emissions under the flux chamber of 3.56 x 10 - 8 g/s

. Using this flux chamber value, and multiplying by the pond area, the entire pond emissions would be 0.215 g/s. However, if we just directly put the area (785,000 m 2 ) of the pond in WATER9, the resulting emissions would be 0.091 g/s. Therefore, the val ue measured by the flux chamber (0.215 g/s) overestimated the emissions by over a factor of two, and subsequently must be corrected to produce the actual emissions value of 0.091 g/s.



### 8.5.3 Emissions from Wet Surfaces

For wet (including covered irrigated) sur faces the flux chamber data will be used to calculate emissions (g/s) based on the above described approach. A gas phase mass transfer coefficient ( k g ) will be calculated for each process type (mill tanks, ponds, leach solution channels, leach pads, etc.) by the following equation:

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 7 Where:

k g = gas phase mass transfer coefficient (m/s)

r v = hydrogen cyanide emissions from surface (g/s) as calculated from the flux chamber concentration data.

α o = predicted non

- ionized cyanide fraction

pK a = ionization coefficient [H+] = hydrogen ion concentration (moles/liter)

C l = total liquid phase cyanide (non

- complexed) (g/m 3 ). This will be free not weak acid dissociable (WAD) cyanide.

H = Henry‟s Law Coefficient (g/m 3 per g/m 3 ),

A = Process surface area (m 2 ), for this case the flux chamber area of 0.13 m 2

. 

### 8.5.3.1 Ionization Coefficient
The ionization and gas

- liquid partition (Henry‟s Law) values will be the temperature dependent values as reported by Yoo et al. Korean J. of Chem. Eng., 3(1) (1986) 67

- 72.

The ionization coefficient is calculated by

ln(K) = A + Bt + C ln(t) + D/t

where

K = the ionization coefficient (g

- mole/Kg)

t = is the temperature ( o K) (273 < t < 423)

A =

- 12.1960, B =

- 0.031482, C = 3.7658, D = - 6340.7



### 8.5.3.2 Gas/Liquid Partition Coefficient
The gas

- liquid partition (Henry‟s Law) coefficient is calculated by

ln(H) = A + Bt + C ln(t) + D/t

where

# SECTION 

# EIGHT Data Reduction, Validation and Reporting

8

- 8 H = the gas

- liquid partition coefficient (Kg

- atm/mole)

t = the temperature ( o K) (273 < t < 373)
A = 9.5850, B =

- 0.03147, C = 3.1704, D =

- 6302.0

The partition coefficient, H can be put in the non

- dimensional form by

H m g / l

m g / l = H K g
− a t m

m o l e 1
, 000 g / K g

1
, 000 m g g ∗ 1
, 000 l

m 3 ∗ R T

where

R = gas constant (8.2057*10 - 5 m 3

- atm/(gmole

o K)

T = temperature ( o K)



### 8.5.3.3 Emissions Calculation
The emissions (g/s) from wet surfaces will be calculated by the formula (with the parameters previously defined)

where the process parameters of pH, temperature, cyanide concentration, unit process area, and wind speed during the tests will be used to calculate emissions (g/s) for each individual process. Annual emissions will also be calculated based on projected (or historical) annual average pH, temperature, cyanide concentration, unit pr ocess area, and wind speed. Because the study will define new zones within each process unit, it is not likely that historical data on these parameters for each individual zone will be available. Thus, preliminary annual HCN emissions may have to be base d on the calculated short

- term emissions (g/s) described in the section and the annual operating schedule (e.g., 8,760 hours per year). Additionally, an effort will be made to account mass transfer impedance that results from annual snow

over.



### 8.5.4 Emissions f rom Dry Surfaces

There is no equivalent method for calculating emissions from dry (non

- irrigated) surfaces (e.g., inactive leach pads). Past measurements have shown that these emissions are a very small part of the site emissions. They will be estimated by taking representative flux chamber measurements of dry surfaces and then multiplying those measured emission rates by the representative surface areas. Those emissions will be assumed to be constant over the annual emission estimation period.

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# EIGHT Data Reduction, Validation and Reporting

8

- 9 

### 8.5.5 Total Sit e Emissions from Area Sources

Total site emissions from area sources will be calculated by summing the area source emissions described above

.


### 8.6 Process Data Needs

In order to complete an annual emission estimate, the following data is needed (on an annual basis) for each process unit zone. For pH, the hydrogen ion concentration should be averaged, not the pH value.

1. Process solution pH, cyanide (free and WAD) concentration, and temperature. 2. Area under leach for each process solution system. 3. Fraction of leac h surface that is wet (including covered irrigated surfaces). 4. Pond area, beach area, tank area. 5. Atmospheric data (wind speed, temperature). 6. Process elevation above sea level.

# SECTION 

# NINE Analytical Procedures and Calibration

9

- 1 

## SECTION 9 ANALYTICAL PROCEDURE S AND CALIBRATION

This section contains brief descriptions of calibration procedures and analytical methodology for the analysis of air samples that will be collected during the testing. Reproductions of the methods used during this program are included as an appendix to this volume. Each method is briefly described in the following sections.



### 9.1 Method Detection Limits

The method detection limit (MDL) is defined as the minimum concentration of a substance that can be

me asured and reported with 99 percent confidence that the analyte concentration is greater than zero. Laboratories perform MDL studies on an annual or quarterly basis (depending on the method) to demonstrate that they can meet or exceed the method

- recommend ed MDLs. The USEPA procedure used for establishing MDLs is described in Appendix B of Part 136 Definition and Procedure for the Determination of the Method Detection Limit

- Revision 1.1, 40 CFR 136, 1984. This procedure consists of analyzing seven aliquo ts of a standard spiked at three

- to

- five times the expected MDL, which is taken through all the sample processing steps of the analytical method. The MDL is defined as three times the standard deviation of the mean value for the seven analyses. In the fe w cases where the individual laboratory has experimentally determined MDLs higher than recommended method detection limits, the method

- recommended MDL is shown in parentheses in the appropriate table or text.



### 9.2 Laboratory Standards and Reagents

Laboratory st andards and reagents are obtained from the following suppliers:

For organic analysis, analytical standards are obtained from either USEPA sources, SUPELCO, Radian laboratory in Austin, and MSD Isotopes. Spectral grade and reagent grade solvents and reagen ts are obtained from chemical suppliers such as Aldrich, Sigma, Burdick and Jackson, EM Science, and Baxter.

All standards and laboratory reagents, with the exception of common laboratory solvents, are dated upon receipt. The preparation and use of all st andards are recorded in bound laboratory notebooks that document standard traceability to USEPA or NIST standards. Additional information recorded includes date of preparation, concentration, name of the preparer, and expiration date, if applicable.



### 9.3 Metho ds of Sorbent Analysis for Hydrogen Cyanide

The following subsections describe the analytical procedure to be used for the determination of hydrogen cyanide in the flux chamber.



### 9.3.1 NIOSH Method 7904 (modified)

The method has been to modified using a liqui d impinger of 0.25 N NaOH to collect the gaseous hydrogen cyanide. Sample is collected at 0.5 to 1 liter per minute (lpm). The resulting solution is analyzed with a visible absorption apectroscopy. The detection limit for this method is estimated to be 0 .1  g cyanide. Calibration is performed using standard solutions of NaCN in 0.25 N NaOH.

# SECTION 

# NINE Analytical Procedures and Calibration

9

- 2 

### 9.3.2 NIOSH Method 6010

This method uses a soda lime (hydrated calcium, sodium, and potassium hydroxides) sorbent tube with 600 mg in the front section and 200 mg in the back for breakthrough. Sampling is specified at 0.05 to 2 lpm for up to 90 liters. The analysis is performed by color development after water extraction with an oxidizing reagent followed by a complexing agent. The resulting solution is analyzed spectrophotometrically using a visible absorption spectrometer operated at 580 nm. Calibration is performed using st andard solutions of KCN in 0.1 N NaOH. The detection limit cited by the method is 0.1  g/sample.

# SECTION 

# TEN Internal Quality Control

10

- 1 

## SECTION 10 INTERNAL QUALITY CON TROL

Internal QC consists of collecting and/or analyzing a series of duplicate, replicate, blank, and matrix spike samples to ensure that the analytical results are within QC limits specified for the program. Laboratory QC samples are documented at the bench and reported with the analytical results. The QC sample results are used to quantify precision and accuracy, and identify any problems or limitations in the associated sample results. Field QC samples will be documented in field logbooks and submitted “blind” to the laboratory. These components of the sampling program will help produce data of known quality throughout the sampling and analysis component of the program.



### 10.1 Analytical Laboratory Quality Control Samples

Laboratory QC is necessary to control the analytical process, to assess the accuracy and precision of analytical results, and to identify assignable causes for atypical analytical results. The QC checks in the laboratory protocol are specific to the analytical method and generally include the use of one or more of the following QC samples.



### 10.1.1 Calibration Standards

Initial calibration is performed as required for each analytical method, usually using a range of calibration standards with the low standard near the detection limit for the compound. These standards are used to determine the linear dynamic range for the initial instrument calibration. Both Method 6010 and 7904 mandate daily calibration using six standards over the working range of the samples.



### 10.1.2 Quality Control Check Samples

Quality control check samples are standard samples containing the analytes of interest at a specified concentration, usually in the mid

- calibration range. These samples are prepared independent of the calibration standard, and are used to d emonstrate that the instrument is operating within acceptable accuracy and precision limits. Quality control check samples will be conducted as needed during sample analysis, but are not required by these methods for hydrogen cyanide

.


### 10.1.3 Reagent Blanks

A reagent blank is a sample composed of all the reagents (in the same quantities) used in preparing a real sample for analysis. It is carried through the same sample preparation procedure as a real sample. Reagent blanks are used to ensure that interfer ences from the analytical system, reagents, and glassware are under control. The required frequency for analyzing reagent blanks is specified in the analytical SOP for each method, and generally consists of one per day for each method/instrument and/or on e per extraction batch.



### 10.1.4 Method Spike/Method Spike Duplicates

A method spike is a sample of target analytes at known concentrations that is spiked into a field sample before sample preparation and analysis. Two aliquots of the sample may be spiked and use d for the

# SECTION 

# TEN Internal Quality Control

10

- 2 duplicate analysis. The results of the analysis of the duplicate spiked samples are used to measure the percent recovery of each spiked compound and to compare the recovery between samples, which provides an estimate of the accuracy and precisio n of the method. Method spike and duplicate spike samples are not required for these methods.



### 10.1.5 Laboratory Duplicates (Duplicate Analysis)

Laboratory duplicates are repeated but independent determinations of the same sample by the same analyst, at essentially the same time and under the same conditions. The sample is split in the laboratory and each fraction is carried through all stages of sample preparation and analysis. Duplicate analyses measure the precision of each analytical method. Labora tory duplicate analyses are performed for 10 percent of samples analyzed, or at least one per day.

Table 10

- 1 summarizes the specific internal QC checks performed as required for the analytical methods. This table also includes information relating to th e initial calibration and ongoing calibration checks.



### 10.2 Field Quality Control Samples

10.2.1 Field Duplicate Samples

A field duplicate sample is a second sample collected at the same location with the original sample. Duplicate sample results are used to assess precision, including variability associated with both the laboratory analysis and the sample collection process. Duplicate samples will be collected simultaneously or in immediate succession using identical recovery techniques, and treated in an identical manner during storage, transportation, and analysis.

Recovery and analysis of 5 percent or at least one duplicate sample per day for each method will be performed. The sample containers will be assigned a control number such that they cannot be identifie d (blind duplicate) as duplicate samples by laboratory personnel performing the analysis.



### 10.2.2 Field Blank

Field blanks are samples of purified air/sampling reagents that are collected and processed in the field using the same sampling and handling procedures as other samples. Field blanks are used to assess the potential introduction of contaminants to the samples during sample collection in the flux chamber and analysis in the laboratory. The frequency requirements for preparing field blanks will be 5 perce nt of the samples collected over the course of the sampling program with at least one field blank per day.

# SECTION 

# TEN Internal Quality Control

10

- 3 Table 10

- 1 Summary of Internal Quality Control

ANALYTICAL METHOD PARAMETER PROCEDURE QC CHECK FREQUENCY ACCEPTANCE

CRITERIA CORRECTIVE ACTION

NIOSH 6010 HCN Method Blank Prior To Sample Analysis Daily <0.1  g 1. Repeat 2. Clean System and Leak

- Check Linearity Check (Multi

- Point Calibration) Daily RSD <30% 1. Repeat Calibration 2. Repeat Linearity Check

Single Point Response Factor Check As needed + 30% RPD 1. Repeat RF Check 2. Repeat Calibration

Duplicate Analysis 10%, Minimum 1 Per Batch + 30% RPD 1. Repeat Analysis

NIOSH 7904 HCN Method Blank Prior To Sample Analysis Daily <0.1  g 1. Repeat 2. Clean System and Leak

- Check Linearity Check (Multi

- Point Calibration) Daily RSD <30% 1. Repeat Calibration 2. Repeat Linearity Check

Single Point Response Factor Check As needed + 30% RPD 1. Repeat RF Check 2. Repeat Calibration

Duplicate Analysis 10%, Minimum 1 Per Batch + 30% RPD 1. Repeat Analysis

# SECTION 

# ELEVEN Performance and Systems Audits

11

- 1 

## SECTION 11 PERFORMANCE AND SYST EMS AUDITS

Systems audits, performance audits, and data quality audits are independent assessments of sample collection and analysis procedures. Audit results are used to evaluate the ability of the system to produce data that fulfill the objectives established for the program, satisfy the quality control criteria, and iden tify any areas requiring corrective action. A systems audit is a qualitative review of the overall sampling or measurement system, while a performance and data quality audit is a quantitative assessment of a measurement system.



### 11.1 Technical Systems Audit

A t echnical systems audit is an on

- site, qualitative review of the sampling or analytical system. Sampling systems will be inspected at the beginning of the sampling task by Dr. Schmidt. Due to the limited activity and adherence to standard protocols, no fo rmal systems auditing will be performed.

The internal laboratory systems reviews routinely include:

 Calibration procedures and documentation;

 Completeness of data forms, notebooks, and other reporting requirements;

 Data review and validation procedures ;

 Data storage, filing, and record

- keeping procedures;

 Sample custody procedures;

 Quality control procedures, control limits, and documentation;

 Operating conditions of facilities and equipment;

 Documentation of maintenance activities; and

 Systems a nd operations overview.

The field systems review will include:

 Calibration procedures and documentation for field meters and other measurement devices.

 Complete documentation of field logbooks and sampling data sheets.

 Organization and minimization of p otential contamination sources while in the field.

 Proper sample collection, storage, and transportation procedures.

 Compliance with the established Chain

- of

- Custody procedures for sample documentation and transfer to the laboratory.



### 11.2 Performance Audits an d Data Quality Audits

Performance audits and data quality audits quantitatively assess the data produced by a measurement system. A performance audit involves submitting accepted reference standards for analysis for each

# SECTION 

# ELEVEN Performance and Systems Audits

11

- 2 analytical method and/or analytical instrument. The standards for each matrix are selected to reflect the range of concentrations expected for the sampling program. The performance audit answers questions about whether the measurement system is within control limits and whether the data produced meet the analytical quality assurance specifications. The data quality audit evaluates data quality indicators, and identifies limitations that may be encountered in data applications.

Due to the modest size of this program and the use o f standard protocols, no performance auditing is scheduled for this effort.

# SECTION 

# TWELVE Preventative Maintenance

12

- 1 

## SECTION 12 PREVENTATIVE MAINTEN ANCE

12.1 Field Equipment/Instruments

The field equipment for this project includes flux chamber technology equipment, personal sampling pumps, calibration equipment, and meteorological monitoring equipment. Specific preventative maintenance procedures to be followed for field equipment are t hose recommended by the manufacturer.

Critical spare parts and disposable or expendable items will be kept on

- site to minimize instrument down time.



### 12.2 Laboratory Instruments

As part of their QA/QC Program, a routine preventative maintenance program will be conducted by the selected laboratory to minimize the occurrence of instrument failure and other system malfunctions. Designated laboratory personnel will be responsible for performing routine scheduled maintenance, and coordinate with the vendor for th e repair of all instruments. All laboratory instruments are maintained in accordance with manufacturer's specifications and the requirements of the specific method employed. This maintenance will be carried out on a regular, scheduled basis, and will be documented in the laboratory instrument service logbook for each instrument. Emergency repair or scheduled manufacture's maintenance is provided under a repair and maintenance contract with factory representatives. Routine preventative maintenance schedu les will be provided with the selected laboratories SOPs.

## Specific Routine Procedures Used to Access Data



# SECTION 

# THIRTEEN Precision, Accuracy, and Completeness

13

- 1 

## SECTION 13 SPECIFIC ROUTINE PRO CEDURES USED TO ACCE SS

DATA PRECISION, ACCU RACY, AND COMPLETENE SS

The assessment of measurement data is required to ensure that the QA objectives for the project are met, and that quantitative measures of data quality are provided. A distinction must be made between routine quality control and data assessment that is conducted as a part of laboratory operations, and th e project

related data assessment process conducted after the data have been reported. It must be assumed that the planning and monitoring that have gone into the sampling and analysis process have served to control the process as much as possible to prod uce data of sufficient quality for project needs. After the data have been reported, it is necessary to identify any part of the process that could not be controlled, and to what extent that may affect the quality of the reported data.

The routine QC proc edures conducted in the laboratory are established in the analytical SOPs. The laboratory is responsible for following those procedures and operating the analytical systems within statistical control limits. These procedures include proper instrument mai ntenance, calibration checks, and internal QC sample analyses at the required frequencies (i.e., reagent blanks, matrix spike/matrix spike duplicates [MS/MSD], laboratory duplicates). One of the additional ongoing data assessment processes is to maintain control charts for representative QC sample analyses in order to monitor system performance. This provides verification that the system is in statistical control and indicates when performance problems occur, so the problems can be corrected as soon as po ssible. When reporting the sample data, the laboratory is required to provide the results of associated QC sample analyses.

Problems occur in spite of all precautions taken in planning and execution of the sampling and analysis task. In these cases, th e data assessment conducted by Dr. Schmidt after the data have been reported must identify the problem, determine which data are affected, and state how these data may be limited for use in the intended applications.

The discussion of data assessment prese nted in this section pertains to the project

- related assessment of data that have been reported after laboratory analyses have been completed. Data assessment procedures established for the testing include:

 Evaluation of blank results to identify systemat ic contamination.

 Statistical calculations for accuracy and precision using the appropriate QC sample results.

 Estimation of completeness in terms of the percent of valid data.

 Recommendations for corrective actions such as reanalysis or resampling if da ta are critically affected.

 Assignment of data qualifier flags to the data as necessary to reflect limitations identified by the
process.
Some basic statistical calculations used in the data assessment process are presented along with a discussion of spec ific applications to environmental sample results.

## Specific Routine Procedures Used to Access Data



# SECTION 

# THIRTEEN Precision, Accuracy, and Completeness

13

- 2 

### 13.1 Blank Data Assessment

Reagent blank results indicate whether any of the contaminants reported in sample results may be attributed to laboratory sources and, therefore, would not likely present in the sam pled medium. The most common laboratory contaminants are methylene chloride, phthalates, acetone, and toluene. These are recognized as being ubiquitous in the laboratory environment and controlling them to within acceptable low levels is part of standard laboratory procedure.

If contamination from these compounds is reported in blank samples, the samples associated with the blank, either the same analytical or extraction batch, may be qualified using a data qualifier (B) to indicate that some or all of th ese compounds may be from laboratory sources. If the concentrations reported in the samples are similar to the blank concentrations, it is likely that all of the contamination was introduced; this assessment is then made in the report for the sampling tas k.



### 13.2 Accuracy

As previously defined, accuracy is associated with correctness and is a comparison between a measured value and a known, or „true‟, value. Accuracy is calculated from method spike (spikes of the pure matrix) or matrix spike results.

Spike resu lts are reported by the laboratory as percent recovery and are compared to the accuracy objectives stated in Section 4. Results that do not satisfy the objectives are assigned a data qualifier flag (A) to indicate uncertainty associated with inaccuracy.

M ethod spikes are spikes of a reference material into a sample matrix (e.g., canister or cryotrap) in the lab. If recovery is outside the established limits, samples from the same batch may be qualified. If any results appear atypical and could be related , those results may also be qualified. The flagged data will be discussed in the report for the sampling task, and specific limitations such as poor or enhanced recovery for specific compounds will be stated.

The percent recovery of matrix spike samples w ill be calculated using Equation 13

- 1.

A

- B %R = ─────────── X 100 Equ. 13

- 1

C

Where:

A = The analyte concentration determined experimentally from the spiked sample;

B = The background level determined by a separate analysis of the unspiked sample and;

C = The amount of the spike added.

## Specific Routine Procedures Used to Access Data



# SECTION 

# THIRTEEN Precision, Accuracy, and Completeness

13

- 3 

### 13.3 Precision

Precision is a measure of variability between duplicate or replicate analyses and is calculated for field and laboratory replicates. By definition, field precision incorporates laboratory precision. Precision is calculated as the RPD between duplicate analyses or MS or MSD as appropriate. The calculated RPDs are compared to the objectives stated in Section 4. Results that do not satisfy the objectives are assigned a data qualifier flag i ndicating uncertainty associated with imprecision (P).

An average RPD may be calculated and reported as a measure of overall analytical precision for compounds with multiple measurements. The specific samples collected or analyzed in duplicate are flagged if they do not satisfy the QA objectives. In addition, associated samples may be flagged to indicate variability due to poor precision. For poor field duplicate precision, samples collected by the same sampling team, from the same equipment, or on the s ame day may be affected; close evaluation of those results should indicate the most likely source of variability and the corresponding samples will be qualified as warranted. For poor laboratory precision, samples processed and analyzed in the same batch will be more closely evaluated, and any anomalous results will be qualified.

Dr. Schmidt is responsible for ensuring that these codes are assigned to the data as required by the established QC criteria, and that they are reported and understood by project staff using the data for specific applications. He is also responsible for initiating corrective actions for analytical problems identified during the QC data assessment process. These corrective actions range from verifying that the method was in statis tical control during the analytical runs, to reanalysis of the sample, to resampling.

The relative percent difference (%RPD) will be calculated for each pair of duplicate analysis using the Equation 13

- 2.

S

- D %RPD = ────────── X 100 Equ. 13

- 2

(S + D)/2

Where: S = First sample value (original or MS value)

D = Second sample value (duplicate or MSD value)



### 13.4 Completeness

Completeness is determined after the QC data have been evaluated and the results applied to the measurement data. In addition to results identified as being outside of the QC limits established for the method, the occurrence of matrix effects, and lost samples, samples that could not be analyzed for any other reason are included in the assessment of completeness. The percentage of valid results is reported as completeness.

## Specific Routine Procedures Used to Access Data



# SECTION 

# THIRTEEN Precision, Accuracy, and Completeness

13

- 4 Data completeness will be calculated using Equation 13

- 3.

Valid Data Obtained Completeness = ─────────────── X 100 Equ. 13

- 3

Total Data Planned



### 13.5 Corrective Action

Review of sampling logs and/or analytical results may indicate problems that invalidate the results or critically influence their use. In these cases, corrective action may be required to ensure that valid data are provided. Corrective actions include: r ecalibration and reanalysis if the analytical system is shown to be out of statistical control; reanalysis if systematic contamination has occurred; resampling if sampling procedures or sample handling have been improper or caused contamination. The sever ity of the problem and the importance of affected samples will dictate when one of these actions will be required.

General recommendations in any case are to follow good laboratory practice and good management practice for all aspects of the sampling and analysis program. These include development and strict adherence to SOPs for all areas, and the establishment of clear responsibilities and lines of communication within the sampling and analytical staff, as well as between project and laboratory staff.

# SECTION 

# FOURTEEN Corrective Action

14

- 1 

## SECTION 14 CORRECTIVE ACTION

During the course of the testing program, it is the responsibility of the Dr. Schmidt to see t hat all measurement procedures are followed as specified and that measurement data meet the prescribed acceptance criteria. In the event a problem arises, it is imperative that prompt action be taken to correct it



### 14.1 Reporting Malfunctions

Problems that requ ire corrective action will be documented by Dr. Schmidt as presented in the field log book. He will initiate the corrective action request in the event that QC results exceed acceptability limits or upon identification of some other problem or potential p roblem. Corrective action may also be initiated by the laboratory coordinator or Mr. Card based upon QC data or audit results. Depending upon the severity of the problem, corrective actions range from use of data qualifier flags, to reanalysis of the

sam ple or samples affected, to resampling and reanalysis.

# SECTION 

# FIFTEEN Quality Assurance Reports to Management

15

- 1 

## SECTION 15 QUALITY ASSURANCE RE PORTS TO MANAGEMENT

Effective management of a field sampling and analytical effort requires timely assessment and review of field activities. This will require effective interaction between the field team members, the laboratory, and the client.

Dr. Schmidt will be responsible for informing team members on the status of their respective tasks and resul ts of the QC activities. This will ensure that quick and effective solutions can be implemented should any data quality problems arise. The use of frequent, oral reporting provides an effective mechanism for ensuring ongoing evaluation of measurement eff orts. These discussions will include the following:

 Summary of activities and general program status.

 Summary of calibration and QC data.

 Summary of unscheduled maintenance activities.

 Summary of corrective action activities.

 Status of any unresolved prob lems.

 Assessment and summary of data completeness.

 Summary of any significant QA/QC problems, corrective action, and recommended and/or implemented solutions not included above.

# SECTION 

# SIXTEEN Health and Safety

16

- 1 

## SECTION 16 HEALTH AND SAFETY

All project personnel working at mining sites for more that five days per year are required to have a current mine safety training certificate issued by the US Department of Labor, Mine Safety and Heath Administration, OMB Number 1219

- 0070. In addition, site

- specific Hazard Training will be required for each facility. It is also likely that assistance while working on the mining sites will include an escort.

Inspection of certificates and hazard training will be the first order of business at each mine site. All site personnel are required to comply with mine safety regulations. Compliance with traffic laws is critical, and there will be no access to restri cted zones allowed.

# A

TTACHMENT 1 F lux Chambe r Users Guide

# A

TTACHMENT 2 N I O SH 6010

### HYDROGEN CYANIDE 6010



### HCN MW: 27.03 CAS: 74-90-8 RTECS: MW6825000

METHOD: 6010, Issue 2 EVALUATION: FULL Issue 1: 15 May 1989 Issue 2: 15 August 1994

OSHA : 10 ppm (skin) NIOSH: STEL 4.7 ppm ACGIH: C 10 ppm (skin)

(1 ppm = 1.105 mg/m 3 @ NTP) PROPERTIES: gas; BP 26 °C; vapor density 0.93 (air = 1.00); d(liq) 0.69 g/mL @ 20 °C; VP 82.7 kPa (620 mm Hg) @ 20 °C; explosive range 5 to 40% v/v in air

SYNONYMS: hydrocyanic acid, prussic acid, formonitrile

SAMPLING

SAMPLER: SOLID SORBENT TUBE

(soda lime, 600 mg/200 mg)

FLOW RATE: 0.05 to 0.2 L/min

VOL-MIN: 2 L @ 5 ppm -MAX: 90 L

SHIPMENT: routine

SAMPLE STABILITY: at least 2 weeks @ 25 °C [1]

BLANKS: 2 to 10 field blanks per set MEASUREMENT

TECHNIQUE: SPECTROPHOTOMETRY,

VISIBLE ABSORPTION

ANALYTE: cyanide ion complex

DESORPTION: 10 mL deionized water; stand 60 min

COLOR DEVELOPMENT: N-chlorosuccinimide/ succinimide oxidizing agent and barbituric acid/pyridine coupling agent; absorption @ 580 nm in 1-cm cuvette

CALIBRATION: standard solutions of KCN in 0.1 N NaOH

RANGE: 10 to 300 μg CN - per sample [1]

ESTIMATED LOD: 1 μg CN - per sample [1]

PRECISION ( S r ): 0.041 @ 10 to 50 mg per sample [1] ACCURACY

RANGE STUDIED: 2 to 15 mg/m 3 [1] (3-L samples)

BIAS: Not significant

OVERALL PRECISION ( S ˆ rT ): 0.076 [1]

ACCURACY: ± 15.0%

APPLICABILITY: The working range is 0.3 to 235 ppm (3 to 260 mg/m 3 ) for a 3-L air sample. This method is applicable to STEL measurements. Particulate cyanides are trapped by the initial glass fiber membrane disk. This method is more sensitive a nd subject to fewer interferences than NIOSH Method 7904, which uses ion specific electrode analysis. The method was used t o determine HCN in firefighting environments [2].

INTERFERENCES: A high concentration of hydrogen sulfide gives a negative interference.

OTHER METHODS: This is based on the method of Lambert, et al. [3]. NIOSH Method 7904 uses an ion specific electrode for measurement. The method has been adapted for use with a Technicon Autoanalyzer [4].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 2 of 5

SAMPLING: REAGENTS:

1. Potassium cyanide*, reagent grade. 2. Succinimide, reagent grade. 3. N-Chlorosuccinimide, reagent grade. 4. Barbituric acid, reagent grade. 5. Pyridine, spectrophotometric quality. 6. Phenolphthalein, 1% (w/v) in ethanol or methanol, reagent grade. 7. Hydrochloric acid, concentrated, reagent grade. 8. Sodium hydroxide (NaOH), reagent grade.* 9. Sodium lime (CaO + 5-20% NaOH), reagent grade (Aldrich #26,643-4 or equivalent). Crush and sieve to 10/35 mesh. Store in capped container.* 10. Water deionized-distilled. 11. Sodium hydroxide solution, 0.1 N .* 12. Calibration stock solution. 1 mg /mL CN -

. Dissolve 0.125 g KCN in 0.1 N NaOH in a 50- mL volumetric flask. Dilute to mark with 0.1 N NaOH. Standardize by titration with standard AgNO 3 solution (see APPENDIX). 13. Hydrochloric acid solution, 0.15 N

. 14. N-Chlorosuccinimide/succinimide oxidizing reagent. Dissolve 10.0 g succinimide in about 200 mL distilled water. Add 1.00 g Nchlorosuccinimide. Stir to dissolve. Adjust volume to 1 liter with distilled water. Stable 6 months when refrigerated. 15. Barbituric acid/Pyridine reagent. Add about 30 mL distilled water to 6.0 g barbituric acid in a 100-mL Erlenmeyer flask. Slowly add 30 mL pyridine with stirring. Adjust the volume to 100 mL with water. Stable 2 months when refrigerated. EQUIPMENT:

1. Sampler, glass tube, 9 cm long, 7-mm OD, 5-mm ID, with plastic caps, containing two sections (front = 600 mg; back = 200 mg) granular soda lime 10/35 mesh, separated and contained with silanized glass wool plugs, with a 5-mm diameter glass fiber filter disk placed before the plug on inlet side. Tubes are commerically available. (SKC, Inc. 226-28 or equivalent.) 2. Spectrophotometer, visible, 580 nm, with cuvettes, 1-cm light path. 3. Personal sampling pump, 0.05 to 0.2 L/min, with flexible connecting tubing. 4. Pipets, volumetric 0.1-, 0.5-, 1.0-, 2.0-, 10.0-mL. 5. Vials, glass or plastic, 15-mL with PTFE-lined caps. 6. Flasks, volumetric, 25-, 50-, 100-, 1000-mL, with stoppers. 7. Pipets, transfer, disposable. 8. Syringes, 10-μL, readable to 0.1 μL. 9. Flask, Erlenmeyer, 100-mL. 10. Syringes, 10-mL, polyethylene with luer tip. 11. Filter cassette, with membrane filter, 13-mm diameter, 0.45-μm pore size, with luer fitting.

* See SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS: HCN gas and cyanide particulates are highly toxic and may be fatal if swallowed, inhaled, or absorbed through the skin [5]. Soda lime and NaOH are very caustic [5]. Use gloves and a fume hood for handling these chemicals. 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Break ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. 3. Sample at an accurately known flow rate between 0.05 and 0.2 L/min for a total sample size of 0.6 to 90 L. 4. Cap tube. Pack securely for shipment.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 3 of 5

SAMPLE PREPARATION:

5. Score each sampler with a file. Break sampler at score line. 6. Transfer front and back sorbent sections to separate vials. Discard glass wool plugs separating and retaining sorbent sections. NOTE: An estimate of particulate cyanide may be obtained by analyzing the initial glass fiber filter disk as follows; however, no evaluation data are available for particulate cyanides determined in this manner. (i) Transfer the glass wool plug at the tube inlet and the glass fiber filter disk immediately behind it to a third vial. (ii) Add 10.0 mL 0.1 N NaOH to each vial. (iii) Proceed with step 8. 7. Add 10.0 mL deionized-distilled water to each vial containing a sorbent section. Cap each vial. 8. Allow to stand 60 minutes, with occasional agitation. Transfer to a 10-mL plastic syringe fitted with an in-line 0.45-μm filter. Collect the filtrate in a clean vial.

CALIBRATION AND QUALITY CONTROL:

9. Calibrate daily with at least six working standards over the range 1 to 300 μg CN - per sample.

a. Prepare a working standard solution, 1.00 μg /mL.CN - , by diluting 100 μL of calibration stock solution to 100 mL with 0.1 N NaOH. b. Pipet 0.5-, 1.00-, 1.50-, 2.00- and 2.50-mL of the working standard solution into 25-mL volumetric flasks to make 0.50-, 1.00-, 1.50-, 2.00- and 2.50- μg CN - standards.

c. Analyze together with field samples and blanks (steps 12 through 19). d. Prepare calibration graph (absorbance vs. μg CN - ). 10. Determine desorption efficiency (DE) at least once for each lot of soda lime used for sampling. Prepare at least three tubes at each of five levels plus three media blanks.

a. Remove and discard back sorbent section of a blank sampler. b. Inject a known amount of calibration stock solution directly onto the soda lime with a microliter syringe.

c. Cap, and allow to stand overnight. d. Desorb (steps 5 through 8) and analyze together with working standards and blanks (steps 12 through 19).

e. Prepare a graph of DE vs. μg CN - recovered. 11. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and DE graph are in control.

MEASUREMENT:

12. Set spectrophotometer according to manufacturer's recommendations and to conditions on p. 6010-1. 13. Pipet a sample aliquot estimated to contain 0.5 to 2.5 μg CN - into a 25-mL volumetric flask. Alternately, to cover an unknown sample concentration range, pipet 0.5-, 1.00-, and 3.00-mL aliquots into separate 25-mL vol. flasks for each field sample. Larger or smaller aliquots may be taken, based on prior knowledge of expected analyte level. 14. Pipet 0.5 mL 0.1 N NaOH into a 25-mL volumetric flask for reagent blank. 15. Add one drop phenolphthalein solution to each standard or sample. NOTE: Add a little deionized-distilled water to increase volume for easier mixing. All solutions should be alkaline (pink) at this point. 16. Starting with the reagent blank, add dropwise 0.15 N HCl, with mixing, until pink color just disappears. CAUTION: HCN may be produced. Work in hood. Immediately add 1.0 mL N-chlorosuccinimide/succinimide oxidizing reagent. Mix and let stand.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 4 of 5

NOTE 1: To avoid possible loss of HCN, add the oxidizing agent before proceeding to the

next sample. NOTE 2: Do not prepare more samples than can be analyzed within the 30-minute maximum

time for color development. 17. After at least 5 min. standing (but not longer than 15 min), starting with the reagent blank, add 1.0-mL barbituric acid-pyridine coupling reagent. Mix. 18. Adjust sample volume to 25 mL with deionized-distilled water and allow to stand at least 12 min (but not longer than 30 min) for color development. 19. Read absorbance at 580 nm in a 1-cm light path cuvette on a spectrophotometer. If sample absorbance is outside the range of the calibration standards, take an aliquot, re-analyze (steps 12 through 19), and apply the appropriate aliquot factor in calculations.

CALCULATIONS:

20. Calculate the mass, μg, of CN - in aliquot analyzed. Apply the appropriate aliquot factor to calculate the mass, μg, of CN - in the original 10-mL solution. 21. Determine the mass, μg CN - (corrected for DE), found in the sample front (W f ) and back (W b ) sorbent sections and in the average media blank front (B f ) and back (B b ) sorbent sections. If W b > W f /10, report breakthrough and possible sample loss. 22. Calculate concentration, C, of HCN in the air volume sampled, V(L).

where 1.039 = conversion factor, CN - to HCN

EVALUATION OF METHOD:

The method was evaluated by sampling the test atmospheres of HCN generated from a compressed mixture of HCN in nitrogen [1]. The range of HCN concentration was equivalent to 2 to 15 mg/m 3 for a 3-L air sample. Twenty-two samples collected at 0.2 L/min for 15 minutes indicated overall precision S ˆ rT of 0.076 with nearly 100% recovery. Breakthrough occurred after 40 minutes of sampling at the flow rate of 0.2 L/min at an HCN concentration of 148 mg/m 3 . Sample tubes spiked with solutions of KCN and analyzed after storage, indicated that the samples of cyanide ions were stable on the tube for at least 2 weeks. Analysis of 22 tubes which were spiked with KCN standard solutions in the range 10 to 50 μg indicated a recovery of nearly 100% with a pooled precision of 0.041. Desorption efficiency may be poor below 10 μg CN - [6].

REFERENCES:

[1] Williamson, George. "Method Development Protocol and Backup Data Report on Hydrogen Cyanide" Internal NIOSH/MRSB Report, Unpubl. NIOSH (1988). [2] Williamson, George. "Analysis of Air Samples on Project 166 (Firesmoke) on HCN; Sequence NIOSH/MRSB-6366A, Unpubl. NIOSH, (1988). [3] Lambert, J. L., Ramasamy, J., and J. V. Paukstelis, "Stable Reagents for the Colorimetric Determination of Cyanide by Modified Konig Reactions," Analyt. Chem.

, 47 , 916-918 (1975). [4] DataChem Laboratories, NIOSH Sequence #6837-K (unpublished, March 21, 1990). [5] NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of Health and Human Services. Publ. (NIOSH) 81-123 (1981), available as stock #PB 83-154609 form NTIS, Springfield, VA 22161. [6] DataChem Laboratories, User Check, NIOSH Sequence #6837-J (unpublished, March 19, 1990).

METHOD WRITTEN BY: George Williamson, NIOSH/DPSE.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 5 of 5

APPENDIX: STANDARDIZATION OF CALIBRATION STOCK SOLUTION

Titrate an aliquot of the cyanide standard stock solution (Reagent 12) with standard silver nitrate (AgNO 3 ) solution. The end point is the first formation of a white precipitate, Ag[Ag(CN) 2 ]. Calculate the cyanide concentration with the following equation:

M c = 52.04 V a (M a /V c )

Where M c

= cyanide concentration (mg/mL) V a = volume (mL) of standard silver nitrate solution M a = concentration (moles/L) of standard silver nitrate solution V c = volume (mL) of calibration stock solution titrated

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

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TTACHMENT 3 N I OS H 7904

### CYANIDES, aerosol and gas 7904

HCN and salts MW: 27.03 (HCN); CAS: 74-90-8 (HCN); RTECS: MW6825000 (HCN); 65.11 (KCN) 151-50-8 (KCN) TS8750000 (KCN)

METHOD: 7904, Issue 2 EVALUATION: FULL Issue 1: 15 February 1984 Issue 2: 15 August 1994

OSHA : 11 mg/m 3 ; skin (HCN)

5 mg/m 3 ; skin (cyanides, as CN - ) NIOSH: C 5 mg/m 3 /10 min (as CN - ) ACGIH: C 11 mg/m 3 ; skin (HCN);

5 mg/m 3 ; skin (cyanides, as CN) PROPERTIES: HCN: gas, BP 26 °C; VP 620 mm Hg 20 °C; vapor density 0.94 (air = 1); KCN: solid, d 1.52 g/mL, MP 634 °C

SYNONYMS: HCN: hydrocyanic acid, prussic acid, formonitrile, cyanides.

SAMPLING

SAMPLER: FILTER + BUBBLER (0.8-μm PVC membrane + 15 mL 0.1 N KOH) [1]

FLOW RATE: 0.5 to 1 L/min

VOL-MIN: 10 L @ 0.5 mg/m 3 (as CN - ) -MAX: 180 L @ 11 mg/m 3 (as CN - )

SHIPMENT: routine

SAMPLE STABILITY: analyze within 5 days; particulate on filter may liberate HCN gas [2]

BLANKS: 2 to 10 field blanks per set MEASUREMENT

TECHNIQUE: ION-SPECIFIC ELECTRODE

ANALYTE: cyanide ion (CN - )

EXTRACT FILTER: 25 mL 0.1 N KOH; 30 min

RINSE BUBBLER: 2 mL 0.1 N KOH; dilute to 25 mL with 0.1 N KOH

MEASURE: mV reading of cyanide ion electrode

vs. reference electrode

CALIBRATION: solutions of KCN in 0.1 N KOH

RANGE: 0.05 to 2 mg CN ESTIMATED LOD: 2.5 μg CN - [2]

PRECISION ( S r ): 0.043 (HCN) [3]; 0.038 (KCN) [2] ACCURACY

RANGE STUDIED: 5 to 21 mg/m 3 (HCN) [3]; 2.6 to 10 mg/m 3 (KCN) [2]

BIAS: - 7.6% OVERALL PRECISION ( S ˆ rT ): 0.062 (HCN) [3];

0.103 (KCN) [2]

ACCURACY: ± 20.0%

APPLICABILITY: The working range (as CN - ) is 0.5 to 15 mg/m 3 for a 90-L air sample or 5 to 20 mg/m 3 for a 10-L air sample.

INTERFERENCES: Sulfide, chloride, iodide, bromide, cadmium, zinc, silver, nickel, cuprous iron and mercury interfere. In humid atmospheres, some particulate cyanide collected on the filter will liberate hydrogen cyanide which will be trapped in th e bubbler [2]. The method cannot distinguish between HCN formed in this manner and HCN originally present in air.

OTHER METHODS: This method combines and replaces Methods S288 [4], S250 [5], and P&CAM 116 [6]. Method 6010 (Hydrogen Cyanide) uses a soda lime tube as sampler, with colorimetric measurement.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94CYANIDES, aerosol and gas: METHOD 7904, Issue 2, dated 15 August 1994 - Page 2 of 4

REAGENTS:

1. Deionized water. 2. Potassium cyanide.* 3. Calibration stock solution, 1000 μg/mL CN -

. Dissolve 0.250 g KCN in 0.1 N KOH to make 100 mL solution. Stable for at least 1 week in polyethylene bottle. 4. Potassium hydroxide (KOH), 0.1 N . Dissolve 5.6 g KOH in deionized water; dilute to 1000 mL. 5. Lead acetate paper. 6. Cadmium carbonate (if sulfide present). 7. Hydrogen peroxide, 30% (if sulfide present). 8. Sodium sulfite, 1 M (if sulfide present).

* See SPECIAL PRECAUTIONS. EQUIPMENT:

1. Sampler: polyvinyl chloride membrane filter, 37-mm diameter, 0.8-μm pore size in 2-piece filter cassette holder, followed by a glass midget bubbler containing 15 mL 0.1 N KOH. 2. Personal sampling pump, 0.5 to 1 L/min, with splashover protection and flexible connecting tubing. 3. Vials, polyethylene, with screw caps, 20-mL, and plastic tape for sealing. 4. Cyanide ion electrode, (Orion 94-06 or equivalent). 5. Reference electrode. 6. pH meter, readable to 0.1 mV. 7. Magnetic stirrer and stirring bars. 8. Jars, ointment, 60-mL, squat-form with aluminum-lined screw caps. 9. Pipets, 0.05- to 2 and 25-mL, with pipet bulb. 10. Volumetric flasks, 25-mL. 11. Beakers, 50-mL. 12. Analytical balance, readable to 0.1 mg.

SPECIAL PRECAUTIONS: Hydrogen cyanide gas and the cyanide particulates may be fatal if swallowed, inhaled or absorbed through the skin. Work in a hood.

Amyl nitrite is the antidote for cyanide poisoning [7].

SAMPLING:

1. Calibrate each personal sampling pump with a representative sampler in line. 2. Sample at 0.5 to 1 L/min for a total sample size of 10 to 180 L. NOTE: Maintain bubblers in a vertical position during sampling. Do not allow the solution level to fall below 10 mL. 3. Remove the bubbler stem and tap it gently against the inside wall of the bubbler. Rinse the bubbler stem with 1 to 2 mL of unused 0.1 N KOH. Add the rinse to the bubbler. 4. Quantitatively transfer the contents of the bubbler to a 20-mL vial. Close cap tightly and wrap with plastic tape to avoid sample loss during transit. Label each vial.

SAMPLE PREPARATION:

5. Transfer the filter from the cassette filter holder to a 60-mL ointment jar. 6. Pipet 25.0 mL 0.1 N KOH into the jar. Cap and allow to stand for at least 30 min with occasional shaking to complete extraction. Analyze within 2 h after extraction. 7. Empty the contents of the vial into a 25-mL volumetric flask using 0.1 N KOH to rinse the vial. Add rinse to the volumetric flask. Dilute to the mark with 0.1 N KOH. NOTE: Sulfide ion irreversibly poisons the cyanide ion specific electrode and must be removed if present. Check

for the presence of sulfide ion by touching a drop of sample to a piece of lead acetate paper; the paper will discolor in the presence of sulfide ion. If this test is positive, remove sulfide by one of the following methods:

a. Add 1 mL 1 M H 2 O 2 and 1 mL 1 M Na 2 SO 3 to sample solutions prior to diluting to volume.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94CYANIDES, aerosol and gas: METHOD 7904, Issue 2, dated 15 August 1994 - Page 3 of 4

b. Add a small amount (spatula tip) of powdered cadmium carbonate to the sample. Swirl to disperse the solid and recheck the liquid with lead acetate paper. If sulfide ion has not been removed completely, add more cadmium carbonate. Avoid a large excess of cadmium carbonate and long contact time with the solution. When a drop of liquid no longer discolors a strip of lead acetate paper, filter the sample through a small plug of glass wool in a Pasteur pipette and proceed with the analysis.

CALIBRATION AND QUALITY CONTROL:

8. Prepare at least six working standards fresh daily to cover the range 50 to 2000 μg CN - per sample by diluting aliquots of 1000 μg/mL calibration stock solution with 0.1 N KOH (e.g., 0.05 to 2.0 mL calibration stock solution diluted to 25 mL). 9. Analyze the working standards according to steps 11 and 12 together with the samples and blanks. 10. Prepare a calibration graph on semilog paper by plotting cyanide ion concentration on the logarithmic axis and mV on the linear axis.

MEASUREMENT:

11. Transfer the solution to be measured to a 50-mL beaker. Immerse the cyanide ion electrode and reference electrode in the sample and start the magnetic stirrer. 12. With the magnetic stirrer on, allow the potential reading to stabilize. Record the mV reading. NOTE 1: Potential readings are a function of temperature. Measure samples and working standards at the same temperature (± 2 °C). NOTE 2: The cyanide electrode will malfunction if chloride, iodide and bromide ions, which form insoluble silver salts, are present in sufficient quantity. Several metal ions are also known to complex with cyanide such as cadmium, zinc, silver, nickel, cuprous iron and mercury. Consult the electrode instruction manual for the procedure to use when such ions are present.

CALCULATIONS:

13. Read the mass, μg, of cyanide ion present in the sample filter (W f ), sample bubbler (W b ), average media blank filter (B f ) and media blank bubblers (B b ) from the calibration graph. 14. Calculate the concentration (mg/m 3 ) of particulate cyanide, C p , and hydrogen cyanide, C HCN , in the air volume sampled, V (L):

where 1.04 is the stoichiometric conversion factor from CN - to HCN. NOTE: Particulate cyanides will be collected on the filter. In humid atmospheres, however, it has been observed that during the collection of particulate cyanide, HCN is gradually liberated [2]; therefore, particulate cyanide interference is not completely removed.

EVALUATION OF METHOD:

HCN : Method S288 was issued on September 2, 1977 [4]. Test atmospheres of HCN were generated by calibrated flow from a compressed mixture of HCN in nitrogen [3,8]. The range of HCN concentrations in air was 5 to 21 mg/m 3 for 12-L air samples. Eighteen HCN samples collected at 0.2 L/min for 60 min indicated overall precision of 6.2%, with a 96.7% recovery. An eight-day storage

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94CYANIDES, aerosol and gas: METHOD 7904, Issue 2, dated 15 August 1994 - Page 4 of 4

stability study involving six samples at the OSHA standard concentration level indicated a 92.4% average recovery for the one-day old samples and a 92.6% for eight-day old samples. A collection efficiency study at twice the OSHA standard level, which included backup bubblers, indicated that an average of 99.8% of HCN was collected in the first bubbler. The HCN air generated concentrations were independently confirmed by a titration method [3].

KCN : Method S250 was issued on January 30, 1976 [5]. A set of six weighed KCN samples in the range of 1.8 to 2.5 mg KCN per filter indicated a 97% recovery and a 3.8% measurement precision [2]. Spiking with aqueous or basic solutions of KCN proved unsuccessful (low recovery) because of the cyanide instability in the presence of water and CO 2 . Test atmospheres of KCN were generated by atomization of an aqueous solution (162 g/L) of KCN into a dry airstream. Eighteen KCN samples collected in 0.1 N NaOH at 1.5 L/min for 60 min indicated overall precision, S ˆ rT , of 0.103. Collection was accomplished with cellulose ester membrane filters followed with backup bubblers. The collection efficiency at twice the OSHA level was 100.0% on the filters. Cyanide salts are known to decompose in moist air with liberation of HCN. This instability was determined with two sets of six samples at the one and two times the OSHA level. Each of the samples which were twice the OSHA level were connected with two backup bubblers. Both sets indicated a loss of 16.5%.

REFERENCES:

[1] Perkins, J.B., D.G. Tharr, J. Palassis, D.B. Fannin, and P.M. Eller, Case Studies: Reduction of Blank Values in the Determination of Particulate Cyanides. Appl

. Occup

. Environ

. Hyg

. 5 :836-837 (1990). [2] Documentation of the NIOSH Validation Tests, S250, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977). [3] Backup Data Report for Hydrogen Cyanide, S288, available as "Ten NIOSH Analytical Methods, Set 5," Order No. BP 287-499 from NTIS, Springfield, VA 22161. [4] NIOSH Manual of Analytical Methods, 2nd. ed., V. 4, S288, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 78-175 (1978). [5] Ibid, V. 3, S250, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-C (1977). [6] Ibid, V. 1, P&CAM 116, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-A (1977). [7] Criteria for a Recommended Standard...Occupational Exposure to Hydrogen Cyanide and Cyanide Salts, 5-9, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-108 (1976). [8] NIOSH Research Report-Development and Validation of Methods for Sampling and Analysis of Workplace Toxic Substances, U.S. Department of Health and Human Services, Publ. (NIOSH) 80-133 (1980).

METHOD REVISED BY:

J. Palassis, NIOSH/DTMD; S250 and S288 originally validated under NIOSH Contracts CDC-99-74-45 and 210-76-0123, respectively.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

# A

TTACHMENT 4 M ackay and Matsugu (1 973)

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