3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-01

PAGE 1 OF 20

Final Report

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

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

January 2013

Laboratory Request Number: ISO13-07-01

Method Requirement: 3M Method ETS-8-044.1

Report Date – Date of Last Signature

Testing Laboratory

3M EHS&S 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

Testing Cert #2052.01

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. Testing that complies with this International Standard 

also meets principles of ISO 9001:2000. 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-01

PAGE 2 OF 20

3M Environmental Laboratory

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

3M Principal Analytical Investigator: Susan Wolf

Report Author: Chelsie Grochow

Analytical Report ISO13-07-01

3M Decatur Groundwater Treatment Plant System; January 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 January 17, 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-PFOAand 13C4-PFOS 

under laboratory project number ISO13-07-01.

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.

Testing Cert #2052.01

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. Testing that complies with this 

International Standard also meets principles of ISO 9001:2000. 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-01

PAGE 3 OF 20

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)

ISO13-07-01-001 DAL-GW-ACI; Sample 1920 600 901 1830

ISO13-07-01-002 DAL-GW-ACI; Sample Dup 1890 575 888 1780

Average 1910 (1) 588 (1) 895 (1) 1810 (1)

%RPD Sample/Sample Dup 1.6 4.3 1.5 2.8

ISO13-07-01-004 DAL-GW-ACM2; Sample <0.0240 1290 <0.0250 <0.0232

ISO13-07-01-005 DAL-GW-ACM2; Sample Dup <0.0240 1250 <0.0250 <0.0232

Average <0.0240 (2) 1270 (1) <0.0250 (2,3) <0.0232 (2)

%RPD Sample/Sample Dup NA 3.1 NA NA

ISO13-07-01-007 DAL-GW-ACE; Sample <0.0240 <0.0250 <0.0250 <0.0232

ISO13-07-01-008 DAL-GW-ACE; Sample Dup <0.0240 <0.0250 <0.0250 <0.0232

Average <0.0240 (2) <0.0250 (2) <0.0250 (2) <0.0232 (2)

%RPD Sample/Sample Dup NA NA 3.4 NA

ISO13-07-01-010 DAL-GW-WW8R; Sample 4410 414 1950 5840

ISO13-07-01-011 DAL-GW-WW8R; Sample Dup 4290 405 1900 5580

Average 4350 (1) 410 (1) 1930 (1) 5710 (1)

%RPD Sample/Sample Dup 2.8 2.2 2.6 4.6

ISO13-07-01-013 DAL-GW-WW9R; Sample 2670 182 936 3620

ISO13-07-01-014 DAL-GW-WW9R; Sample Dup 2740 186 972 3760

Average 2710 (1) 184 (1) 954 (1) 3690 (1)

%RPD Sample/Sample Dup 2.6 2.2 3.8 3.8

NA = Not Applicable

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

associated with the reported results are as follows: PFOA ±19%, PFBS ±16%, PFHS ±17%, and PFOS ±17%.

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

associated with the reported results are as follows: PFOA ±21%, PFBS ±23%, PFHS ±21%, and PFOS ±19%.

(3) The method uncertainty has been expanded for PFHS to ±31%. See section 4 of the report for additional information.

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. ISO13-07-01

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2.2 Sample Collection

Samples were collected on January 17, 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 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 January 22, 2013. 

2.3 Sample Preparation

Sample sets ACI, ACM2, WW8R, WW9R, and the Trip Blank field matrix spikes 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 sample set and the Trip Blank sample were prepared and analyzed for all analytes by 

removing a 0.4 mL aliquot of the well mixed sample and diluting it with 0.4 mL of methanol (dilution 

factor of 2). The ACM2 sample set and the Trip Blank low spike sample were re-analyzed using a 1:2

dilution. Prepared samples were analyzed by internal standard calibration.

During the preparation of the laboratory control samples, 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 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 then diluted with 

methanol in the same manner as the ACE and Trip Blank 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. ISO13-07-01

PAGE 5 OF 20

Table 3. Instrument Parameters.

Instrument Name ETS Kirk ETS Kirk

Analysis Dates 1/24/13 – external calibration 1/30/13 – internal calibration

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

Liquid Chromatograph Agilent 1260 Agilent 1260

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 20 μL 40 μL

Mass Spectrometer Applied Biosystems API 5500 Applied Biosystems API 5500

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 402/80

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 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 1/30/13.
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REPORT NO. ISO13-07-01

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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 50 mL of 50:50 methanol:laboratory reagent water. The calibration 

standards contained an internal standard mix at a nominal concentration of 0.5 ng/mL. A total of twelve

calibration standards ranging from 0.0125 ng/mL to 25 ng/mL (nominal) were analyzed with the 

prepared samples. Of these twelve calibration standards, ten contained the surrogates at 

concentrations ranging from 0.0125 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 twelve spiked 

standards ranging from 0.02 ng/mL to 100 ng/mL (nominal) were analyzed. Of these twelve calibration 

standards, ten 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 except for PFOA and PFOA 

surrogate analyzed using external calibration which had area counts RSDs of 6.3% and 6.2%, 

respectively. A method deviation is included with the raw data.

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 the table below.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-01

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Table 6. LOQ

Analyte Calibration LOQ, ng/mL

PFOA Internal standard 0.0240 (1)

PFBS Internal standard 0.0250 (1)

PFHS Internal standard 0.0250 (1)

PFOS Internal standard 0.0232 (1)

PFOA External standard 24.0 (2)

PFBS External standard 2.00 (2)

PFHS External standard 2.00 (2)

PFOS External standard 23.2 (2)

(1) The dilution factor of 2 was applied to the LOQ.

(2) The dilution factor of 100 was 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. 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 exception:

1/30/13 Analysis (internal standard calibration): The high set of LCS samples for PFOA had an 

average recovery of 78.9% and PFHS had an average recovery of 79.2%. 

A method deviation is included with the raw data. All LCSs were used in the determination of the 

analytical method uncertainty in section 3.9. 

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 =
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REPORT NO. ISO13-07-01

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Table 7. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 1/24/13 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-130124-1 0.479 0.46 96.0 0.464 0.45 96.5

LCS-130124-2 0.479 0.46 96.0 0.464 0.44 95.3

LCS-130124-3 0.479 0.46 96.2 0.464 0.443 95.5

Average ± %RSD 96.1% ± 0.12% 95.8% ± 0.67%

LCS-130124-4 4.79 5.67 118 4.64 5.32 115

LCS-130124-5 4.79 5.60 117 4.64 5.29 114

LCS-130124-6 4.79 5.62 117 4.64 5.37 116

Average ± %RSD 117% ± 0.49% 115% ± 0.87%

LCS-130124-7 19.1 20.5 107 18.5 20.4 110

LCS-130124-8 19.1 19.9 104 18.5 19.7 106

LCS-130124-9 19.1 19.5 102 18.5 19.3 104

Average ± %RSD 104% ± 2.4% 107% ± 2.9% 

ETS-8-044.1

External Standard 

Calibration

Analyzed 1/24/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130124-1 0.500 0.531 106 0.500 0.545 109

LCS-130124-2 0.500 0.544 109 0.500 0.524 105

LCS-130124-3 0.500 0.531 106 0.500 0.528 106

Average ± %RSD 107% ± 1.6% 107% ± 2.0%

LCS-130124-4 5.00 5.50 110 5.00 5.30 106

LCS-130124-5 5.00 5.44 109 5.00 5.25 105

LCS-130124-6 5.00 5.66 113 5.00 5.38 108

Average ± %RSD 111% ± 1.9% 106% ± 1.4%

LCS-130124-7 20.0 21.4 107 20.0 19.6 97.9

LCS-130124-8 20.0 20.2 101 20.0 18.6 93.2

LCS-130124-9 20.0 19.7 98.6 20.0 18.2 91.2

Average ± %RSD 102% ± 4.2% 94.1% ± 3.7%

(1) LCSs did not meet acceptance criteria of 100 ± 20%.
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 1/24/13 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-130124-1 0.499 0.502 101 0.478 0.468 97.8

LCS-130124-2 0.499 0.498 99.8 0.478 0.468 97.9

LCS-130124-3 0.499 0.500 100 0.478 0.455 95.2

Average ± %RSD 100% ± 0.64% 97.0% ± 1.6%

LCS-130124-4 4.99 4.83 96.8 4.78 4.62 96.7

LCS-130124-5 4.99 4.80 96.2 4.78 4.61 96.4

LCS-130124-6 4.99 4.91 98.3 4.78 4.68 97.8

Average ± %RSD 97.1% ± 1.1% 97.0% ± 0.76% 

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 1/30/13 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-130130-1 0.190 0.162 85.1 0.184 0.157 85.5

LCS-130130-2 0.190 0.161 84.6 0.184 0.156 84.9

LCS-130130-3 0.190 0.167 87.7 0.184 0.157 85.4

Average ± %RSD 85.8% ± 1.9% 85.3% ± 0.38%

LCS-130130-4 1.90 1.57 82.8 1.84 1.52 82.8

LCS-130130-5 1.90 1.60 84.5 1.84 1.55 84.0

LCS-130130-6 1.90 1.54 81.1 1.84 1.55 84.0

Average ± %RSD 82.8% ± 2.1% 83.6% ± 0.83%

LCS-130130-7 19.0 15.7 82.6 18.4 15.5 84.1

LCS-130130-8 19.0 13.9 73.1 18.4 13.6 74.1

LCS-130130-9 19.0 15.4 81.1 18.4 15.4 83.6

Average ± %RSD 78.9% ± 6.5% (1) 80.6% ± 7.0%

(1) LCSs did not meet acceptance criteria of 100 ± 20%.
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 1/30/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130130-1 0.198 0.173 87.3 0.198 0.170 86.1

LCS-130130-2 0.198 0.165 83.4 0.198 0.164 82.7

LCS-130130-3 0.198 0.170 86.0 0.198 0.172 86.7

Average ± %RSD 85.6% ± 2.3% 85.2% ± 2.5%

LCS-130130-4 1.98 1.62 81.9 1.98 1.64 82.7

LCS-130130-5 1.98 1.67 84.5 1.98 1.61 81.2

LCS-130130-6 1.98 1.65 83.3 1.98 1.64 82.9

Average ± %RSD 83.2% ± 1.6% 82.3% ± 1.1%

LCS-130130-7 19.9 16.8 84.4 19.9 16.6 83.5

LCS-130130-8 19.9 14.8 74.4 19.9 14.5 72.9

LCS-130130-9 19.9 16.3 81.7 19.9 16.1 81.1

Average ± %RSD 80.2% ± 6.5% 79.2% ± 7.0% (1)

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 1/30/13 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-130130-7 0.198 0.186 93.9 0.189 0.173 91.7

LCS-130130-8 0.198 0.187 94.3 0.189 0.173 91.3

LCS-130130-9 0.198 0.185 93.3 0.189 0.168 89.0

Average ± %RSD 93.8% ± 0.54% 90.7% ± 1.6%

LCS-130130-4 1.98 1.78 90.0 1.89 1.69 89.6

LCS-130130-5 1.98 1.82 91.7 1.89 1.71 90.2

LCS-130130-6 1.98 1.75 88.2 1.89 1.72 91.2

Average ± %RSD 90.0% ± 1.9% 90.3% ± 0.89%

(1) LCSs did not meet acceptance criteria of 100 ± 20%.
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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 method uncertainty was determined to be ±19% for 

PFOA and ±20% for PFHS using internal standard calibration, but based on the percent bias of the 

high level LCSs, the method uncertainty has been expanded for PFOA and PFHS.

 

Table 8. Analytical Method Uncertainty.

Analyte Calibration Method Standard Deviation Method Uncertainty

PFOA External Standard 9.36 ±19%

PFBS External Standard 7.88 ±16%

PFHS External Standard 8.28 ±17%

PFOS External Standard 8.60 ±17%

PFOA Internal Standard NA ±21%

PFBS Internal Standard 11.4 ±23%

PFHS Internal Standard NA ±21%

PFOS Internal Standard 9.66 ±19%

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. 

*100%

Spike Concentraton

(Sample Concentration of FMS Average Concentration:FieldSample & FieldSample Dup.) FMS Recovery − =

Table 9. Field Matrix Spike Concentrations 

Final Concentration (ng/mL)

Location Description PFOA PFBS PFHS PFOS

ACI Field Matrix Spike 2020 1990 1970 2000

ACM2, ACE Field Matrix Spike 10.1 9.96 9.86 10.0

WW8R, WW9R Field Matrix Spike 4040 3980 3940 4000

Trip Blank

Low Field Matrix Spike 10.1 9.96 9.86 10.0

High Field Matrix Spike 4040 3980 3940 4000
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4 Data Summary and Discussion

The tables below summarize the sample results and field matrix spike recoveries for the three 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. 

DAL-GW-ACM2; the FMS sample (10 ng/mL) was not appropriate for PFBS; however, the FMS 

sample for PFOA, PFOS, and the surrogate recovery standards 13C4-PFOA and 13C4-PFOS, met 

method acceptance criteria. No additional QC samples were prepared. The FMS did not meet 

acceptance criteria for PFHS with a recovery of 69.1%. Since this is the only appropriate spike level, 

the sample method uncertainty will be expanded to ±31% for PFHS.
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Table 10. DAL GW ACI 130117 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-001 DAL-GW-ACI-0-130117 1920 NA 600 NA

ISO13-07-01-002 DAL-GW-ACI-DB-130117 1890 NA 575 NA

ISO13-07-01-003 DAL-GW-ACI-FMS-130117 4060 107 2660 104

Average Concentration (ng/mL) ± %RPD 1910 ng/mL ± 1.6% 588 ng/mL ± 4.3%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-001 DAL-GW-ACI-0-130117 901 NA 1830 NA

ISO13-07-01-002 DAL-GW-ACI-DB-130117 888 NA 1780 NA

ISO13-07-01-003 DAL-GW-ACI-FMS-130117 3020 108 4140 117

Average Concentration (ng/mL) ± %RPD 895 ng/mL ± 1.5% 1810 ng/mL ± 2.8% 

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-01-001 DAL-GW-ACI-0-130117 88.6 95.9

ISO13-07-01-002 DAL-GW-ACI-DB-130117 88.1 93.8

ISO13-07-01-003 DAL-GW-ACI-FMS-130117 84.4 87.9

Average Concentration (ng/mL) ± %RSD 87.0% ± 2.6% 92.5% ± 4.5%

NA = Not Applicable

(1) Samples were diluted 1:100 with methanol and analyzed by external standard calibration on 1/24/13. The surrogate recovery 

standards 13C4-PFOA and 13C4-PFOS were added to the samples during sample preparation.
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Table 11. DAL GW ACM2 130117

PFOA (1) PFBS (2)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-004 DAL-GW-ACM2-0-130117 <0.0240 NA 1290 NA

ISO13-07-01-005 DAL-GW-ACM2-DB-130117 <0.0240 NA 1250 NA

ISO13-07-01-006 DAL-GW-ACM2-FMS-130117 7.66 75.8 1250 NC

Average Concentration (ng/mL) ± %RPD <0.0240 ng/mL 1270 ng/mL ± 3.1%

PFHS (1) PFOS (1)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-004 DAL-GW-ACM2-0-130117 <0.0250 NA <0.0232 NA

ISO13-07-01-005 DAL-GW-ACM2-DB-130117 <0.0250 NA <0.0232 NA

ISO13-07-01-006 DAL-GW-ACM2-FMS-130117 6.81 69.1 (3) 7.06 70.6

Average Concentration (ng/mL) ± %RPD <0.0250 ng/mL (4) <0.0232 ng/mL

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

3M LIMS ID Description %Recovery %Recovery

ISO13-07-01-004 DAL-GW-ACM2-0-130117 93.0 91.1

ISO13-07-01-005 DAL-GW-ACM2-DB-130117 87.8 86.7

ISO13-07-01-006 DAL-GW-ACM2-FMS-130117 86.2 86.6

Average Concentration (ng/mL) ± %RSD 89.0% ± 4.0% 88.1% ± 2.9%

NA = Not Applicable

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

(1) Samples were diluted 1:2 with methanol and analyzed by internal standard calibration on 1/30/13.

(2) Samples were diluted 1:100 with methanol and analyzed by external standard calibration on 1/24/13.

(3) FMS did not meet acceptance criteria of 100 ± 30%.

(4) Method uncertainty has been expanded to ± 31% for PFHS.
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Table 12. DAL GW ACE 130117 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-007 DAL-GW-ACE-0-130117 <0.0240 NA <0.0250 NA

ISO13-07-01-008 DAL-GW-ACE-DB-130117 <0.0240 NA <0.0250 NA

ISO13-07-01-009 DAL-GW-ACE-FMS-130117 7.60 75.2 7.33 73.6

Average Concentration (ng/mL) ± %RPD <0.0240 ng/mL <0.0250 ng/mL

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-007 DAL-GW-ACE-0-130117 <0.0250 NA <0.0232 NA

ISO13-07-01-008 DAL-GW-ACE-DB-130117 <0.0250 NA <0.0232 NA

ISO13-07-01-009 DAL-GW-ACE-FMS-130117 7.15 72.5 7.38 73.8

Average Concentration (ng/mL) ± %RPD <0.0250 ng/mL <0.0232 ng/mL

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-01-007 DAL-GW-ACE-0-130117 82.9 78.1

ISO13-07-01-008 DAL-GW-ACE-DB-130117 84.4 85.7

ISO13-07-01-009 DAL-GW-ACE-FMS-130117 87.2 87.3

Average Concentration (ng/mL) ± %RSD 84.8% ± 2.6% 83.7% ± 5.9%

NA = Not Applicable

(1) Samples were diluted 1:2 with methanol and analyzed by internal standard calibration on 1/30/13.
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Table 13. DAL GW WW8R 130117 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-010 DAL-GW-WW8R-0-130117 4410 NA 414 NA

ISO13-07-01-011 DAL-GW-WW8R-DB-130117 4290 NA 405 NA

ISO13-07-01-012 DAL-GW-WW8R-FMS-130117 9070 117 4460 102

Average Concentration (ng/mL) ± %RPD 4350 ng/mL ± 2.8% 410 ng/mL ± 2.2%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-010 DAL-GW-WW8R-0-130117 1950 NA 5840 NA

ISO13-07-01-011 DAL-GW-WW8R-DB-130117 1900 NA 5580 NA

ISO13-07-01-012 DAL-GW-WW8R-FMS-130117 5620 (2) 93.8 9390 (2) 92.0

Average Concentration (ng/mL) ± %RPD 1930 ng/mL ± 2.6% 5710 ng/mL ± 4.6%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-01-010 DAL-GW-WW8R-0-130117 81.5 86.3

ISO13-07-01-011 DAL-GW-WW8R-DB-130117 81.2 83.8

ISO13-07-01-012 DAL-GW-WW8R-FMS-130117 72.2 86.9 (2)

Average Concentration (ng/mL) ± %RSD 78.3% ± 6.7% 85.7% ± 1.9%

NA = Not Applicable

(1) Samples were diluted 1:100 with methanol and analyzed by external standard calibration on 1/24/13. The surrogate recovery 

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

(2) Samples re-analyzed using a 1:400 dilution.
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Table 14. DAL GW WW9R 130117 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-013 DAL-GW-WW9R-0-130117 2670 NA 182 NA

ISO13-07-01-014 DAL-GW-WW9R-DB-130117 2740 NA 186 NA

ISO13-07-01-015 DAL-GW-WW9R-FMS-130117 6720 99.4 3980 95.4

Average Concentration (ng/mL) ± %RPD 2710 ng/mL ± 2.6% 184 ng/mL ± 2.2%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-013 DAL-GW-WW9R-0-130117 936 NA 3620 NA

ISO13-07-01-014 DAL-GW-WW9R-DB-130117 972 NA 3760 NA

ISO13-07-01-015 DAL-GW-WW9R-FMS-130117 4520 (2) 90.5 7310 (2) 90.5

Average Concentration (ng/mL) ± %RPD 954 ng/mL ± 3.8% 3690 ng/mL ± 3.8%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-01-013 DAL-GW-WW9R-0-130117 85.2 89.7

ISO13-07-01-014 DAL-GW-WW9R-DB-130117 89.4 92.8

ISO13-07-01-015 DAL-GW-WW9R-FMS-130117 75.7 86.6 (2)

Average Concentration (ng/mL) ± %RSD 83.4% ± 8.4% 89.7% ± 3.4%

NA = Not Applicable

(1) Samples were diluted 1:100 with methanol and analyzed by external standard calibration on 1/24/13. The surrogate recovery 

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

(2) Samples re-analyzed using a 1:400 dilution.
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Table 15. Trip Blank Results

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-016 DAL-GW-TRIP-0- <0.0240 (1) NA <0.0250 (1) NA

ISO13-07-01-017 DAL-GW-TRIP-LS 7.60 (1) 75.2 7.36 (1) 73.9

ISO13-07-01-018 DAL-GW-TRIP-HS 4300 (2) 106 4020 (2) 101

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-01-016 DAL-GW-TRIP-0- <0.0250 (1) NA <0.0232 (1) NA

ISO13-07-01-017 DAL-GW-TRIP-LS 7.44 (1) 75.5 7.37 (1) 73.7

ISO13-07-01-018 DAL-GW-TRIP-HS 3830 (2,3) 97.2 4430 (2) 111

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-01-016 DAL-GW-TRIP-0- 85.6 (1) 82.9 (1)

ISO13-07-01-017 DAL-GW-TRIP-LS 88.4 (1) 85.0 (1)

ISO13-07-01-018 DAL-GW-TRIP-HS 84.7 (2) 85.8 (2)

NA = Not Applicable

(1) Samples were diluted 1:2 with methanol and analyzed by internal standard calibration on 1/30/13.

(2) Sample was diluted 1:100 with methanol and analyzed by external standard calibration on 1/24/13.

(3) Sample re-analyzed using a 1:400 dilution.
3M ENVIRONMENTAL LABORATORY 

REPORT NO. ISO13-07-01 

5 Conclusion 

Laboratory control spikes were used to determine the analytical method accuracy and precision for all 

analytes. The accuracy and precision were then used to estimate the method uncertainty for the 

results. Field matrix spike recoveries demonstrated that the analytical method was appropriate for the 

given sample matrix. 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". Analytical results are reported in Table 1 and 10-15 of this report. 

6 Data / Sample Retention 

All remaining sample and associated project data (hardcopy and electronic) will be archived according 

to 3M Environmental Laboratory standard operating procedures. 

7 Attachments 

Appendix A: Trend Data for Activated Carbon influent (ACI) 

Appendix B: Trend Data for Activated Carbon Effluent (ACE) 

8 Signatures 

Mil A3 

Susan T. Wolf, 3M Principal Analytical Investigator Date 

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

The 3M Environmental Laboratory's Quality Assurance Unit has audited the data and report for this 

project. 

Quality Assurance Representative/ / Date 

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

Environmental Laboratory. 

PAGE 19 OF 20 
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REPORT NO. ISO13-07-01

PAGE 20 OF 20

Appendix 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 6/17/2011 2/8/2012 6/29/2012 8/28/2012 12/14/2012 1/17/2013

PFOA 1410 1180 1650 1410 2580 1910

PFBS 1110 792 1410 1830 723 588

PFHS 983 1100 1460 1390 1380 895

PFOS 691 782 964 172 2810 1810

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

ACE 6/17/2011 2/8/2012 8/28/2012 12/14/2012 1/17/2013

PFOA 2.57 1250 0.387 0.102 <0.0240

PFBS 11.9 818 0.256 <0.0250 <0.0250

PFHS 2.50 1240 0.552 0.117 <0.0250

PFOS 2.07 741 0.103 0.0376 <0.0232

The ACE location was not sampled on 6/29/12.