3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 1 OF 21

Final Report

Analysis of PFOA, PFBS, PFHS, and PFOS in Aqueous Samples from 

3M Decatur, Alabama: Groundwater Treatment Plant GAC System – 

May 2013

Laboratory Request Number: ISO13-07-05

Method Requirement: 3M Method ETS-8-044.1 

Report Date – Date of Last Signature

Testing Laboratory

3M EHS Operations

3M Environmental Laboratory

Building 260-5N-17

Maplewood, MN 55144-1000

Requester 

Gary Hohenstein

3M Building 224-5W-03

Saint Paul, MN 55144-1000

Phone: (651) 737-3570

The testing reported herein meet the requirements of ANSI/ISO/IEC 17025:2005 “General 

Requirements for the Competence of Testing and Calibration Laboratories”, in 

accordance with the A2LA Testing Certificate # 2052.01. Additionally, the laboratory’s 

quality system has been audited and was determined to be in conformance with the EPA 

GLPs (40 CFR 792) by an independent A2LA assessment.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 2 OF 21

3M Environmental Laboratory

3M Environmental Laboratory Technical Director: William K. Reagen, Ph.D. 

3M Principal Analytical Investigator: Susan Wolf

Report Author: Kevin Eich

Analytical Report ISO13-07-05

3M Decatur Groundwater Treatment Plant System; May 2013 Sampling 

Report Date: Date of Last Signature

1 Introduction/Summary 

The 3M Environmental Laboratory analyzed water samples from the groundwater treatment plant GAC 

system at the 3M Decatur, AL facility. Water samples were collected by Weston Solutions personnel 

on May 31, 2013. Samples were returned to the 3M Environmental Laboratory for analysis of 

Perfluorooctanoate (PFOA), Perfluorobutane sulfonate (PFBS), Perfluorohexane sulfonate (PFHS),

Perfluorooctane sulfonate (PFOS), and the surrogate recovery standards 13C4-PFOA and 13C4-PFOS 

under laboratory project number ISO13-07-05. Analysis of the samples was completed as specified 

under 3M Environmental Laboratory General Project Outline (GPO) number GPO11-1006.

The 3M Environmental Laboratory provided sample containers for five sampling locations; ACI, ACM2, 

ACE, WW8R, and WW9R. The sample set consisted of a field sample, field sample duplicate and a 

field matrix spike. Each empty container was marked with a “fill to here” line that corresponded to a 

final volume of 200 mL. Containers reserved for field matrix spikes were fortified with an appropriate 

matrix spike solution containing all analytes prior to being sent to the field for sample collection. 

Sample bottles for sampling locations ACM2 and ACE, along with the Trip Blank sample and low spike, 

were fortified with internal standards and surrogates prior to being sent to the field for sample collection. 

Samples were prepared and analyzed by method ETS-8-044.1 “Method of Analysis for the 

Determination of Perfluorinated Compounds in Water by LC/MS/MS; Direct Injection Analysis”. Select 

internal standards were used to aid in the data quality objectives. 

Table 1 summarizes the sample results using the analytical method identified above. All results for 

quality control samples prepared and analyzed with the samples will be reported and discussed 

elsewhere in this report.

The testing reported herein meet the requirements of ANSI/ISO/IEC 17025:2005 “General 

Requirements for the Competence of Testing and Calibration Laboratories”, in 

accordance with the A2LA Testing Certificate # 2052.01. Additionally, the laboratory’s 

quality system has been audited and was determined to be in conformance with the EPA 

GLPs (40 CFR 792) by an independent A2LA assessment.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 3 OF 21

Table 1. Sample Results Summary

3M LIMS ID Sample Description

PFOA 

Concentration 

(ng/mL)

PFBS 

Concentration 

(ng/mL)

PFHS 

Concentration 

(ng/mL)

PFOS 

Concentration 

(ng/mL)

ISO13-07-05-001 DAL-GW-ACI; Sample 1840 1010 924 2090

ISO13-07-05-002 DAL-GW-ACI; Sample Dup 1880 1070 956 2200

Average 1860 (1) 1040 (1) 940 (1) 2150 (1)

%RPD Sample/Sample Dup 2.2 5.8 3.4 5.1

ISO13-07-05-004 DAL-GW-ACM2; Sample 868 1240 1660 0.571

ISO13-07-05-005 DAL-GW-ACM2; Sample Dup 885 1230 1630 0.598

Average 877 (1) 1240 (1) 1650 (1) 0.585 (2)

%RPD Sample/Sample Dup 1.9 0.81 1.8 4.6

ISO13-07-05-007 DAL-GW-ACE; Sample 0.0706 24.9 0.108 <0.0232

ISO13-07-05-008 DAL-GW-ACE; Sample Dup 0.0744 24.7 0.102 <0.0232

Average 0.0725 (2) 24.8 (2) 0.105 (2) <0.0232 (2)

%RPD Sample/Sample Dup 5.2 0.81 5.7 NA

ISO13-07-05-010 DAL-GW-WW8R; Sample 2750 287 1320 4130

ISO13-07-05-011 DAL-GW-WW8R; Sample Dup 2770 291 1340 4220

Average 2760 (1) 289 (1) 1330 (1) 4180 (1)

%RPD Sample/Sample Dup 0.72 1.4 1.5 2.2

ISO13-07-05-013 DAL-GW-WW9R; Sample 2680 231 1130 4210

ISO13-07-05-014 DAL-GW-WW9R; Sample Dup 2640 221 1110 4200

Average 2660 (1) 226 (1) 1120 (1) 4210 (1)

%RPD Sample/Sample Dup 1.5 4.4 1.8 0.24

NA = Not Applicable

(1) Reported results were prepared and analyzed by ETS-8-044.1 using external standard calibration. The analytical method 

uncertainties associated with the reported results are as follows: PFOA ±16%, PFBS ± 17%, PFHS ±15%, and PFOS ± 27%.

(2) Reported results were prepared and analyzed by ETS-8-044.1 using internal standard calibration. The analytical method 

uncertainties associated with the reported results are as follows: PFOA ± 13%, PFBS ± 16%, PFHS ± 19%, and PFOS ± 

10%.

2 Methods - Analytical and Preparatory

2.1 Methods

Analysis was completed using 3M Environmental Laboratory Method ETS-8-044.1 “Method of Analysis 

for the Determination of Perfluorinated Compounds in Water by LC/MS/MS; Direct Injection Analysis”. 

Table 2 Target Analytes.

Target Analytes Acronym

Reference Material 

Structure

Perfluorooctanoic Acid (C8 Acid) PFOA Linear + Branched

Perfluorobutanesulfonate (C4 Sulfonate ) PFBS Linear

Perfluorohexanesulfonate (C6 Sulfonate) PFHS Linear

Perfluorooctanesulfonate (C8 Sulfonate) PFOS Linear + Branched
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 4 OF 21

2.2 Sample Collection

Samples were collected on May 31, 2013 in NalgeneTM (high-density polyethylene) bottles prepared at

the 3M Environmental Laboratory. Prior to sample collection, bottles designated for field matrix spikes 

were spiked in the laboratory with a known volume of an appropriate matrix spiking solution containing 

PFOA, PFBS, PFHS, and PFOS. Sample bottles for sampling locations ACM2 and ACE, along with 

the Trip Blank sample and Trip Blank low spike, were fortified with a mixture of mass-labeled internal 

standards at a nominal concentration of 1 ng/mL and a mixture of surrogate recovery standards at a 

nominal concentration of 0.1 ng/mL. Collected sample bottles were received by the laboratory at 

ambient conditions on June 6, 2013. 

2.3 Sample Preparation

Sample sets ACI, ACM2, WW8R, WW9R, and the Trip Blank high spike were diluted 1:100 and 

analyzed for all analytes. The 1:100 dilutions were prepared by removing a 0.1 mL aliquot of the well 

mixed sample and adding 9.8 mL of methanol and 0.1 mL of a surrogate spiking solution. Prepared 

samples were analyzed by external standard calibration. 

The ACE and ACM2 sample sets and the Trip Blank sample and Trip Blank low spike were prepared 

and analyzed for all analytes by transferring an aliquot of the well mixed sample into an autovial. 

Prepared samples were analyzed by internal standard calibration. 

During the preparation of the laboratory control samples for internal standard calibration, an aliquot of a 

separate internal standard spiking solution was added to the laboratory control samples (nominal 

concentration of 1 ng/mL). The sample bottles for ACE, ACM2, and Trip Blank were spiked with an 

internal standard mix at a nominal concentration of 1 ng/mL prior to being sent to the field for sample 

collection. The laboratory control samples were analyzed in the same manner as the samples. 

2.4 Analysis

All samples and quality control samples were analyzed for four target analytes using high performance 

liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). Pertinent instrument parameters, 

the liquid chromatography gradient program, and the specific mass transitions analyzed are described 

in the tables below.

Due to the nature of the sample, the wide range of concentrations found in the sample, and the 

environmental occurrence of multiple isomers of the laboratory’s analytes of interest, the software used 

for processing the analytical results is not able to consistently integrate the analytical peak, manual 

integration of the analytical peak is necessary. All manual integrations are performed following the 

procedures outlined in method ETS-12-010. The consistency of the laboratory’s integration is ensured 

through the training of laboratory personnel, the peer review process required for all manual 

integrations, the review of manual integrations by the QAU, and where necessary the review of manual 

integrations by laboratory management.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 5 OF 21

Table 3. Instrument Parameters.

Instrument Name ETS Kirk ETS Buster

Analysis Dates 6/17/13 – external standard calibration 

6/19/13 – external standard calibration

6/21/13 – internal standard calibration

Analytical Method ETS-8-044.1 ETS-8-044.1

Liquid Chromatograph Agilent 1260 Agilent 1100

Guard column Betasil C18 (4.6 mm X 100 mm), 5 μ Betasil C18 (4.6 mm X 100 mm), 5 μ

Analytical column Betasil C18 (4.6 mm X 100 mm), 5 μ Betasil C18 (4.6 mm X 100 mm), 5 μ

Injection Volume 2, 5, or 20 μL 2, 5, 20, or 25 μL

Mass Spectrometer Applied Biosystems TripleQuad 5500 Applied Biosystems API 4000

Ion Source Turbo Spray Turbo Spray

Polarity Negative Negative

Software Analyst 1.6.1 Analyst 1.6.1

Table 4. Liquid Chromatography Gradient Program.

Step 

Number

Total Time 

(min)

Flow Rate 

(μL/min)

Percent A

(2 mM ammonium acetate)

Percent B

(Methanol)

0 0.00 750 90.0 10.0

1 0.50 750 90.0 10.0

2 4.00 750 70.0 30.0

3 6.00 750 70.0 30.0

4 11.0 750 20.0 80.0

5 13.0 750 20.0 80.0

6 13.5 750 10.0 90.0

7 16.0 750 10.0 90.0

8 16.5 750 90.0 10.0

9 19.0 750 90.0 10.0

Table 5. Mass Transitions 

Analyte

Mass Transition

Q1/Q3

Internal Standard (1) Mass Transition

Q1/Q3

PFOA

413/369

[

13 413/219 C8]PFOA 421/376

413/169

PFBS

299/80

[

18O2]PFBS 303/84

299/99

PFHS

399/99

[

13C3]PFHS 402/99

399/80

PFOS

499/99

[

13 499/80 C8]PFOS 507/80

499/130

[

13C4]PFOA surrogate 417/372 [13C8]PFOA 421/376

[

13C4]PFOS surrogate 503/80 [13C8]PFOS 507/80

Dwell time was 20 (ETS Kirk) or 50 (ETS Buster) msec for each transition. The individual transitions were summed to produce 

a “total ion chromatogram” (TIC), which was used for quantitation. 

(1) Internal standards were used for the analysis on 6/21/13.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 6 OF 21

3 Data Analysis

3.1 Calibration

Internal Standard Calibration Analysis: Samples were analyzed against a matrix-matched stable 

isotope internal standard calibration curve. Calibration standards were prepared by spiking known 

amounts of stock solutions into 100 mL of laboratory prepared reagent water. The calibration standards 

contained an internal standard mix at a nominal concentration of 1 ng/mL. A total of thirteen calibration 

standards ranging from 0.025 ng/mL to 25 ng/mL (nominal) were analyzed with the prepared samples. 

Of these thirteen calibration standards, eleven contained the surrogates at concentrations ranging from 

0.025 ng/mL to 10 ng/mL nominal. A quadratic, 1/x weighted, calibration curve of the ratio of the 

standard peak area counts over the internal standard peak area counts was used to fit the data for 

each analyte. The data were not forced through zero during the fitting process. Calculating the 

standard concentrations using the peak area ratios and the resultant calibration curve confirmed 

accuracy of each curve point. The reference standards of PFOA and PFOS used to prepare the 

calibration standards consisted of both linear and branched isomers. Each curve point was quantitated 

using the overall calibration curve and reviewed for accuracy. Method calibration accuracy 

requirements of 100±25% (100±30% for the lowest curve point) were met for all analytes. The 

correlation coefficient (r) was greater than 0.995 for all analytes.

External Standard Calibration Analysis: Samples were analyzed against an external standard 

calibration curve. Calibration standards were prepared by spiking known amounts of the stock solution 

containing the target analytes into 90:10 methanol: Milli-Q laboratory water. A total of ten spiked 

standards ranging from 0.02 ng/mL to 25 ng/mL (nominal) were analyzed. The ten standards also

contained the surrogates at concentrations ranging from 0.02 ng/mL to 25 ng/mL nominal. A quadratic, 

1/x weighted, calibration curve of the standard peak area counts was used to fit the data for each 

analyte. The data were not forced through zero during the fitting process. Calculating the standard 

concentrations using the peak area counts and the resultant calibration curve confirmed accuracy of 

each curve point. Each curve point was quantitated using the overall calibration curve and reviewed for 

accuracy. Method calibration accuracy requirements of 100±25% (100±30% for the lowest curve point) 

were met for all analytes. The correlation coefficient (r) was greater than 0.995 for all analytes. 

3.2 System Suitability

A calibration standard was analyzed four times at the beginning of the analytical sequence to 

demonstrate overall system suitability. The acceptance criteria for system suitability samples is less 

than or equal to 5% relative standard deviation (RSD) for peak area/ratio and retention time criteria of 

less than or equal to 2% RSD. These criteria were met for all analytes. 

3.3 Limit of Quantitation (LOQ)

The LOQ as defined in method ETS-8-044.1 is the lowest non-zero calibration standard in the curve 

that meets linearity and accuracy requirements and for which the area counts are at least twice those of 

the appropriate blanks. The LOQs associated with the sample analysis are listed in Table 6. 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 7 OF 21

Table 6. LOQ

Analyte Analysis Date Calibration LOQ, ng/mL 

PFOA 6/21/13 Internal standard 0.0240

PFBS 6/21/13 Internal standard 0.0250

PFHS 6/21/13 Internal standard 0.0250

PFOS 6/21/13 Internal standard 0.0232

PFOA 6/17/13 External standard 0.0192 (1)

PFBS 6/17/13 External standard 0.0200 (1)

PFHS 6/17/13 External standard 0.0200 (1)

PFOS 6/19/13 External standard 0.0185 (1)

(1) The dilution factor was not applied to the LOQ.

3.4 Continuing Calibration 

During the course of the analytical sequence, several continuing calibration verification samples 

(CCVs) were analyzed to confirm that the instrument response and the initial calibration curve were still 

in control. The method acceptance criteria of 100% ± 25% was met for all analytes. 

3.5 Blanks

Two types of blanks were prepared and analyzed with the samples: method blanks/solvent blanks and 

field/trip blanks. Each blank result was reviewed and used to evaluate method performance to 

determine the LOQ for each analyte.

3.6 Lab Control Spikes (LCSs) 

Low, mid, and high lab control spikes were prepared for the target analytes and analyzed in triplicate, 

while only low and high lab control spikes were prepared for the surrogates. LCSs were prepared by 

spiking known amounts of the analytes into either 10 mL of laboratory-prepared matrix matched water 

or 1 mL of Milli-Q water to produce the desired concentration. When applicable, the LCSs were then 

diluted with methanol in the same manner as the samples. Method ETS-8-044.1 states that the 

average recovery of LCSs at each spiking level be within 80%-120% with a RSD ≤20%. All LCS 

samples met method accuracy criteria with the following exceptions:

• 6/19/13 analysis: The acceptance criteria for accuracy were met with the exception of the high 

set of LCS for PFOS (127%). 

• 6/21/13 analysis: The acceptance criteria for precision were met with the exception of the low 

set of LCS for PFHS (27%). 

A method deviation for LCS not meeting method acceptance criteria is filed with the raw data.

All LCSs were used in the determination of the analytical method uncertainty in section 3.7. 

The following calculations were used to generate data in Table 7. 

* 100%

Spike Concentration

Calculated Concentration LCSPercent Recovery =

* 100%

average LCS recovery

standard deviation LCS replicates LCS% RSD =
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 8 OF 21

Table 7. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 6/17/13 PFOA (Linear + Branched) PFOA surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130617-1 0.191 0.179 93.5 0.199 0.220 110

LCS-130617-2 0.191 0.189 98.8 0.199 0.221 111

LCS-130617-3 0.191 0.192 101 0.199 0.218 110

Average ± %RSD 97.8% ± 3.9% 110% ± 0.52%

LCS-130617-4 1.91 2.01 105 1.99 2.21 111

LCS-130617-5 1.91 1.98 104 1.99 2.21 111

LCS-130617-6 1.91 2.02 106 1.99 2.25 113

Average ± %RSD 105% ± 0.95% 112% ± 1.0%

LCS-130617-7 19.1 21.8 114

LCS-130617-8 19.1 20.8 109

LCS-130617-9 19.1 22.0 115

Average ± %RSD 113% ± 2.9%

ETS-8-044.1

External Standard 

Calibration

Analyzed 6/17/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130617-1 0.199 0.202 101 0.199 0.187 94.2

LCS-130617-2 0.199 0.201 101 0.199 0.197 98.8

LCS-130617-3 0.199 0.207 104 0.199 0.197 99.2

Average ± %RSD 102% ± 1.7% 97.4% ± 2.9%

LCS-130617-4 1.99 2.11 106 1.99 2.08 105

LCS-130617-5 1.99 2.10 105 1.99 2.06 104

LCS-130617-6 1.99 2.18 109 1.99 2.16 108

Average ± %RSD 107% ± 2.0% 106% ± 2.0%

LCS-130617-7 20.0 23.1 115 20.0 23.2 116

LCS-130617-8 20.0 21.8 109 20.0 21.5 107

LCS-130617-9 20.0 23.8 119 20.0 24.2 121

Average ± %RSD 114% ± 4.4% 115% ± 6.2%
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 9 OF 21

Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 6/19/13 PFOS (Linear + Branched) PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130617-1 0.185 0.180 97.3 0.190 0.190 99.9

LCS-130617-2 0.185 0.186 101 0.190 0.184 96.7

LCS-130617-3 0.185 0.183 98.7 0.190 0.196 103

Average ± %RSD 99.0% ± 1.9% 99.9% ± 3.2%

LCS-130617-4 1.85 1.94 105 1.90 1.93 102

LCS-130617-5 1.85 1.92 104 1.90 1.90 99.9

LCS-130617-6 1.85 1.99 108 1.90 1.97 104

Average ± %RSD 106% ± 2.0% 102% ± 2.0% 

LCS-130617-7 18.5 24.0 130

LCS-130617-8 18.5 22.6 122

LCS-130617-9 18.5 23.9 129

Average ± %RSD 127% ± 3.4% (1)

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 6/21/13 PFOA (Linear + Branched) PFOS (Linear + Branched)

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130621-1 0.190 0.163 85.8 0.184 0.169 91.6

LCS-130621-2 0.190 0.158 83.0 0.184 0.161 87.4

LCS-130621-3 0.190 0.171 89.9 0.184 0.166 90.0

Average ± %RSD 86.2% ± 4.0% 89.7% ± 2.4%

LCS-130621-4 1.90 2.00 105 1.84 1.84 100

LCS-130621-5 1.90 1.76 92.5 1.84 1.73 94.0

LCS-130621-6 1.90 1.80 94.9 1.84 1.79 97.2

Average ± %RSD 97.5% ± 6.8% 97.1% ± 3.1%

LCS-130621-7 9.52 8.23 86.4 9.21 8.25 89.6

LCS-130621-8 9.52 9.28 97.5 9.21 8.65 93.9

LCS-130621-9 9.52 9.13 95.9 9.21 8.84 96.0

Average ± %RSD 93.3% ± 6.4% 93.2% ± 3.5%

(1) LCS average or RSD did not meet method acceptance criteria.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 10 OF 21

Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 6/21/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130621-1 0.198 0.187 94.5 0.198 0.177 89.5

LCS-130621-2 0.198 0.185 93.2 0.198 0.276 139

LCS-130621-3 0.198 0.186 93.9 0.198 0.176 88.6

Average ± %RSD 93.9% ± 0.69% 106% ± 27% (1)

LCS-130621-4 1.98 1.96 99.0 1.98 1.96 98.9

LCS-130621-5 1.98 1.98 99.8 1.98 1.78 89.8

LCS-130621-6 1.98 1.91 96.6 1.98 1.88 95.0

Average ± %RSD 98.5% ± 1.7% 94.6% ± 4.8%

LCS-130621-7 9.94 8.87 89.3 9.94 8.13 81.7

LCS-130621-8 9.94 9.67 97.3 9.94 9.48 95.3

LCS-130621-9 9.94 9.48 95.4 9.94 9.30 93.6

Average ± %RSD 94.0% ± 4.4% 90.2% ± 8.2%

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 6/21/13 PFOA surrogate PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130621-1 0.198 0.197 99.6 0.189 0.180 95.2

LCS-130621-2 0.198 0.188 94.9 0.189 0.186 98.6

LCS-130621-3 0.198 0.202 102 0.189 0.186 98.7

Average ± %RSD 98.8% ± 3.7% 97.5% ± 2.0%

LCS-130621-4 1.98 2.18 110 1.89 1.96 103

LCS-130621-5 1.98 2.01 101 1.89 1.87 98.8

LCS-130621-6 1.98 2.03 102 1.89 1.89 100

Average ± %RSD 104% ± 4.7% 101% ± 2.2%

(1) LCS average or RSD did not meet method acceptance criteria.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 11 OF 21

3.7 Analytical Method Uncertainty

Analytical uncertainty is based on historical QC data that is control charted and used to evaluate 

method accuracy and precision. The method uncertainty is calculated following ETS-12-012.2. The 

standard deviation is calculated for the set of accuracy results (in %) obtained for the QC samples. The 

expanded uncertainty is calculated by multiplying the standard deviation by a factor of 2, which 

corresponds to a confidence level of 95%.

 

• The analytical method uncertainty as calculated by ETS-12-012.2 for PFOS by external

standard calibration was ± 19%. The recovery of the high set of LCS analyzed on 6/19/13 was 

127% for PFOS by external standard calibration for the samples analyzed on this date. The 

analytical uncertainty was expanded to ±27% for all samples quantitated using external 

standard for PFOS. 

Table 8. Analytical Method Uncertainty.

Analyte Calibration Method Standard Deviation (%) Method Uncertainty

PFOA External Standard 8.18 ±16%

PFBS External Standard 8.60 ±17%

PFHS External Standard 7.33 ±15%

PFOS External Standard NA ±27%

PFOA Internal Standard 6.58 ±13%

PFBS Internal Standard 7.76 ±16%

PFHS Internal Standard 9.55 ±19%

PFOS Internal Standard 5.19 ±10%

NA= Not Applicable

3.8 Field Matrix Spikes (FMS)

A field matrix spike was collected at each sampling point to verify that the analytical method is 

applicable to the collected matrix. Field matrix spikes are generated by adding a measured volume of 

field sample to a container spiked by the laboratory with the target analytes prior to shipping sample 

containers for sample collection. Field matrix spike recoveries within method acceptance criteria of 

100±30% confirm that “unknown” components in the sample matrix do not significantly interfere with 

the extraction and analysis of the analytes of interest. The standards used for the preparation of the 

field matrix spiking solutions contained reference materials comprised of both linear and branched 

isomers for PFOA and PFOS. Field matrix spikes are presented in section 4 of this report. 

In addition, field matrix spikes for this project consisted of stable isotope surrogate recovery standard 

spikes of [

13C4]-PFOA and [13C4]-PFOS, which were added at a nominal concentration of 0.1 ng/mL to 

sample bottles associated with sampling locations ACM2 and ACE, and the Trip Blank sample and Trip 

Blank low spike, prior to sample collection. The [13C4]-labeled PFOA was selected to represent PFOA. 

The [

13C4]-labeled PFOS was selected to represent PFBS, PFHS, and PFOS. Surrogate spike 

recoveries within method acceptance criteria of 100±30% confirm that “unknown” components in the 

sample matrix do not significantly interfere with the preparation and analysis of the analytes of interest.

*100%

Spike Concentraton

(Sample Concentration of FMS Average Concentration:FieldSample & FieldSample Dup.) FMS Recovery − =
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 12 OF 21

Table 9. Field Matrix Spike Concentrations 

Final Concentration (ng/mL)

Location Description PFOA PFBS PFHS PFOS

ACI Field Matrix Spike 2000 2010 2000 1990

ACM2 Field Matrix Spike 1000 1000 998 994

ACE Field Matrix Spike 10.0 10.0 9.99 10.0

WW8R, WW9R Field Matrix Spike 4010 4020 3990 3980

Trip Blank

Low Field Matrix Spike 10.0 10.0 9.99 10.0

High Field Matrix Spike 4010 4020 3990 3980

4 Data Summary and Discussion

The tables below summarize the sample results and field matrix spike recoveries for the five locations 

as well as the Trip Blank. Each table provides the average concentration and the relative percent 

difference (%RPD) of the sample and sample duplicate. Results and average values are rounded to 

three significant figures. Percent relative difference (%RPD) values are rounded to two significant 

figures. Because of rounding, values may vary slightly from those listed in the raw data. Field matrix 

spikes meeting the method acceptance criteria of ±30%, demonstrate that the method is appropriate for 

the given matrix. 

All field matrix spike samples and surrogate recovery standards met method acceptance criteria except 

where noted below.

DAL-GW-ACM2; the FMS sample (1000 ng/mL) was not appropriate for PFOS; however, the 

surrogate recovery standard 13C4-PFOS, met method acceptance criteria. No additional QC samples 

were prepared.

DAL GW ACE; the FMS sample (10 ng/mL) was not appropriate for PFBS; however, the surrogate 

recovery standard 13C4-PFOS, met method acceptance criteria. No additional QC samples were 

prepared.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 13 OF 21

Table 10. DAL GW ACI 130531 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-001 DAL-GW-ACI-0-130531 1840 NA 1010 NA

ISO13-07-05-002 DAL-GW-ACI-DB-130531 1880 NA 1070 NA

ISO13-07-05-003 DAL-GW-ACI-FMS-130531 3820 98.0 2950 95.0

Average Concentration (ng/mL) ± %RPD 1860 ng/mL ± 2.2% 1040 ng/mL ± 5.8%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-001 DAL-GW-ACI-0-130531 924 NA 2090 NA

ISO13-07-05-002 DAL-GW-ACI-DB-130531 956 NA 2200 NA

ISO13-07-05-003 DAL-GW-ACI-FMS-130531 2910 98.5 4350 111

Average Concentration (ng/mL) ± %RPD 940 ng/mL ± 3.4% 2150 ng/mL ± 5.1% 

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-05-001 DAL-GW-ACI-0-130531 100 94.4

ISO13-07-05-002 DAL-GW-ACI-DB-130531 100 96.1

ISO13-07-05-003 DAL-GW-ACI-FMS-130531 96.6 91.9

Average Concentration (ng/mL) ± %RSD 98.9% ± 2.0% 94.1% ± 2.2%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 14 OF 21

Table 11. DAL GW ACM2 130531

PFOA (1) PFBS (1)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-004 DAL-GW-ACM2-0-130531 868 NA 1240 NA

ISO13-07-05-005 DAL-GW-ACM2-DB-130531 885 NA 1230 NA

ISO13-07-05-006 DAL-GW-ACM2-FMS-130531 1800 92.4 2130 89.5

Average Concentration (ng/mL) ± %RPD 877 ng/mL ± 1.9% 1240 ng/mL ± 0.81%

PFHS (1) PFOS (2)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-004 DAL-GW-ACM2-0-130531 1660 NA 0.571 NA

ISO13-07-05-005 DAL-GW-ACM2-DB-130531 1630 NA 0.598 NA

ISO13-07-05-006 DAL-GW-ACM2-FMS-130531 2440 79.7 NA (3) NA (3)

Average Concentration (ng/mL) ± %RPD 1650 ng/mL ± 1.8% 0.585 ng/mL ± 4.6%

13C4-PFOA (1) 13C4-PFOS (2)

3M LIMS ID Description %Recovery %Recovery

ISO13-07-05-004 DAL-GW-ACM2-0-130531 101 117

ISO13-07-05-005 DAL-GW-ACM2-DB-130531 103 118

ISO13-07-05-006 DAL-GW-ACM2-FMS-130531 94.9 NA (3)

Average Concentration (ng/mL) ± %RPD/RSD 99.7% ± 4.3% 98.1% ± 10%

NA = Not Applicable

The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were added to the samples during sample preparation.

(1) Samples were analyzed by external standard calibration. 

(2) Samples were analyzed by internal standard calibration. 

(3) Sample was not analyzed using internal calibration due to the high FMS concentration. 

 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 15 OF 21

Table 12. DAL GW ACE 130531 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-007 DAL-GW-ACE-0-130531 0.0706 NA 24.9 NA

ISO13-07-05-008 DAL-GW-ACE-DB-130531 0.0744 NA 24.7 NA

ISO13-07-05-009 DAL-GW-ACE-FMS-130531 8.13 80.6 NA (2) NC

Average Concentration (ng/mL) ± %RPD 0.0725 ng/mL ± 5.2% 24.8 ng/mL ± 0.81%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-007 DAL-GW-ACE-0-130531 0.108 NA <0.0232 NA

ISO13-07-05-008 DAL-GW-ACE-DB-130531 0.102 NA <0.0232 NA

ISO13-07-05-009 DAL-GW-ACE-FMS-130531 8.81 87.1 9.76 97.6

Average Concentration (ng/mL) ± %RPD 0.105 ng/mL ± 5.7% <0.0232 ng/mL

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-05-007 DAL-GW-ACE-0-130531 105 123

ISO13-07-05-008 DAL-GW-ACE-DB-130531 111 110

ISO13-07-05-009 DAL-GW-ACE-FMS-130531 112 115

Average Concentration (ng/mL) ± %RSD 110% ± 3.5% 116% ± 5.9%

NA = Not Applicable

NC = Not Calculated; Spike level was less than 0.5x the endogenous sample concentration.

(1) Samples were analyzed by internal standard calibration. 

(2) The sample concentration exceeded to the calibration range of 25 ng/mL.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 16 OF 21

Table 13. DAL GW WW8R 130531 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-010 DAL-GW-WW8R-0-130531 2750 NA 287 NA

ISO13-07-05-011 DAL-GW-WW8R-DB-130531 2770 NA 291 NA

ISO13-07-05-012 DAL-GW-WW8R-FMS-130531 6320 88.8 3910 90.1

Average Concentration (ng/mL) ± %RPD 2760 ng/mL ± 0.72% 289 ng/mL ± 1.4%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-010 DAL-GW-WW8R-0-130531 1320 NA 4130 NA

ISO13-07-05-011 DAL-GW-WW8R-DB-130531 1340 NA 4220 NA

ISO13-07-05-012 DAL-GW-WW8R-FMS-130531 5110 94.7 7550 84.8

Average Concentration (ng/mL) ± %RPD 1330 ng/mL ± 1.5% 4180 ng/mL ± 2.2%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-05-010 DAL-GW-WW8R-0-130531 96.0 95.2

ISO13-07-05-011 DAL-GW-WW8R-DB-130531 94.5 96.0

ISO13-07-05-012 DAL-GW-WW8R-FMS-130531 99.1 93.5

Average Concentration (ng/mL) ± %RSD 96.5% ± 2.4% 94.9% ± 1.3%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation. 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 17 OF 21

Table 14. DAL GW WW9R 130531 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-013 DAL-GW-WW9R-0-130531 2680 NA 231 NA

ISO13-07-05-014 DAL-GW-WW9R-DB-130531 2640 NA 221 NA

ISO13-07-05-015 DAL-GW-WW9R-FMS-130531 6620 98.8 4030 94.6

Average Concentration (ng/mL) ± %RPD 2660 ng/mL ± 1.5% 226 ng/mL ± 4.4%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-013 DAL-GW-WW9R-0-130531 1130 NA 4210 NA

ISO13-07-05-014 DAL-GW-WW9R-DB-130531 1110 NA 4200 NA

ISO13-07-05-015 DAL-GW-WW9R-FMS-130531 4910 95.0 8530 109

Average Concentration (ng/mL) ± %RPD 1120 ng/mL ± 1.8% 4210 ng/mL ± 0.24%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-05-013 DAL-GW-WW9R-0-130531 100 93.8

ISO13-07-05-014 DAL-GW-WW9R-DB-130531 95.4 92.6

ISO13-07-05-015 DAL-GW-WW9R-FMS-130531 92.5 99.3

Average Concentration (ng/mL) ± %RSD 96.0% ± 4.0% 95.2% ± 3.7%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation. 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 18 OF 21

Table 15. Trip Blank Results

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-016 DAL-GW-TRIP01-0 <0.0240 (1) NA <0.0250 (1) NA

ISO13-07-05-017 DAL-GW-TRIP01-LS 7.99 (1) 79.9 9.88 (1) 98.8

ISO13-07-05-018 DAL-GW-TRIP01-HS 4250 (2) 106 3870 (2) 96.3

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-05-016 DAL-GW-TRIP01-0 <0.0250 (1) NA <0.0232 (1) NA

ISO13-07-05-017 DAL-GW-TRIP01-LS 8.89 (1) 89.0 9.11 (1) 91.1

ISO13-07-05-018 DAL-GW-TRIP01-HS 4080 (2) 102 4190 (2) 105

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-05-016 DAL-GW-TRIP01-0 128 (1) 111 (1)

ISO13-07-05-017 DAL-GW-TRIP01-LS 111 (1) 112 (1)

ISO13-07-05-018 DAL-GW-TRIP01-HS 105 (2) 92.5 (2)

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration.

(2) Samples were analyzed by external standard calibration. 
 &RQFOXVLRQ

0(19,5210(17$//$%25$25<

5(325712 ,62

/DERUDWRU\FRQWUROVSLNHVZHUHXVHGWRGHWHUPLQHWKHDQDO\WLFDOPHWKRGDFFXUDF\DQGSUHFLVLRQIRUDOO

DQDO\WHV 7KHDFFXUDF\DQGSUHFLVLRQZHUHWKHQXVHGWRHVWLPDWHWKHPHWKRGXQFHUWDLQW\IRUWKH

UHVXOWV )LHOGPDWUL[VSLNHUHFRYHULHVGHPRQVWUDWHGWKDWWKHDQDO\WLFDOPHWKRGZDVDSSURSULDWHIRUWKH

JLYHQVDPSOHPDWUL[ $QDO\VLVZDVFRPSOHWHGXVLQJ0(QYLURQPHQWDO/DERUDWRU\0HWKRG(76

 0HWKRGRI$QDO\VLVIRUWKH'HWHUPLQDWLRQRI3HUIOXRULQDWHG&RPSRXQGVLQ:DWHUE\/&0606

'LUHFW,QMHFWLRQ$QDO\VLV $QDO\WLFDOUHVXOWVDUHUHSRUWHGLQ7DEOHDQG RIWKLVUHSRUW

 'DWDI 6DPSOH5HWHQWLRQ

$OOUHPDLQLQJVDPSOHDQGDVVRFLDWHGSURMHFWGDWDKDUGFRS\DQGHOHFWURQLFZLOOEHDUFKLYHGDFFRUGLQJ

WR0(QYLURQPHQWDO/DERUDWRU\VWDQGDUGRSHUDWLQJSURFHGXUHV

 $WWDFKPHQWV

$WWDFKPHQWA: $QDO\WH7UHQG'DWDIRUVHOHFWVDPSOLQJSRLQWVDWWKH'HFDWXU*URXQG:DWHU7UHDWPHQW

3ODQW*:73*$*6\VWHP

 6LJQDWXUHV

LSDO$QDO\WLFDO,QYHVWLJDWRU

:LOOLDP. 5HDJHQ3K' 0(QYLURQPHQWDO/DERUDWRU\7HFKQLFDO'LUHFWRU 'DWH

7KH0(QYLURQPHQWDO/DERUDWRU\
V4XDOLW\$VVXUDQFH8QLWKDVDXGLWHGWKHGDWDDQGUHSRUWIRUWKLV

SURMHFW

'DWH

This test report shall not be reproduced except in full, without written approval of the 3M 

Environmental Laboratory. 

3$*(2)
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 20 OF 21

Attachment A: Analyte Trend Data for select sampling points at the Decatur Ground Water Treatment 

Plant (GWTP) GAC System 

ACI (Activated Carbon Influent) - Sample Results in ng/mL

ACI 6/17/11 2/8/12 6/29/12 8/28/12 12/14/12 1/17/13 2/13/13 3/27/13 4/29/13 5/31/13

PFOA 1410 1180 1650 1410 2580 1910 2300 2220 1480 1860

PFBS 1110 792 1410 1830 723 588 830 1060 1360 1040

PFHS 983 1100 1460 1390 1380 895 1580 1090 777 940

PFOS 691 782 964 172 2810 1810 2940 2490 1670 2150

ACE (Activated Carbon Effluent) - Sample Results in ng/mL

ACE 6/17/11 2/8/12 8/28/12 12/14/12 1/17/13 2/13/13 3/27/13 4/29/13 5/31/13

PFOA 2.57 1250 0.387 0.102 <0.0240 0.124 0.0380 0.0422 0.0725

PFBS 11.9 818 0.256 <0.0250 <0.0250 0.0360 <0.0250 0.392 24.8

PFHS 2.50 1240 0.552 0.117 <0.0250 0.178 0.0477 0.0570 0.105

PFOS 2.07 741 0.103 0.0376 <0.0232 0.0329 <0.0232 <0.0232 <0.0232

The ACE location was not sampled on 6/29/12.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-05

PAGE 21 OF 21

Attachment A: Analyte Trend Data for select sampling points at the Decatur Ground Water Treatment 

Plant (GWTP) GAC System 

WW8R - Sample Results in ng/mL

WW8R 12/13/2012 1/17/2013 2/13/2013 3/27/2013 4/29/2013 5/31/2013

PFOA 3630 4350 3250 3640 3190 2760

PFBS 441 410 354 385 364 289

PFHS 1740 1930 1900 1760 1610 1330

PFOS 4920 5710 4850 5120 4830 4180

WW9R - Sample Results in ng/mL

WW9R 12/13/2012 1/17/2013 2/13/2013 3/27/2013 4/29/2013 5/31/2013

PFOA 3360 2710 2850 3330 2650 2660

PFBS 321 184 236 278 244 226

PFHS 1480 954 1400 1440 1200 1120

PFOS 4080 3690 4100 4660 4340 4210