3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-06

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 –

June 2013

Laboratory Request Number: ISO13-07-06

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

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. ISO13-07-06

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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 ISO13-07-06

3M Decatur Groundwater Treatment Plant System; June 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 June 27, 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 ISO13-07-06. 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. ISO13-07-06

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)

ISO13-07-06-001 DAL-GW-ACI; Sample 1460 706 935 1580

ISO13-07-06-002 DAL-GW-ACI; Sample Dup 1500 710 948 1600

Average 1480 (1) 708 (1) 942 (1) 1590 (1)

%RPD Sample/Sample Dup 2.7 0.56 1.4 1.3

ISO13-07-06-004 DAL-GW-ACM2; Sample 1220 1030 2040 0.806

ISO13-07-06-005 DAL-GW-ACM2; Sample Dup 1200 1020 2000 0.738

Average 1210 (1) 1030 (1,2) 2020 (1) 0.772 (3)

%RPD Sample/Sample Dup 1.7 0.98 2.0 8.8

ISO13-07-06-007 DAL-GW-ACE; Sample 0.0568 108 0.0850 <0.0232

ISO13-07-06-008 DAL-GW-ACE; Sample Dup 0.0866 113 0.150 <0.0232

Average 0.0717 (3) 111 (1) 0.118 (3) <0.0232 (3)

%RPD Sample/Sample Dup 42 (4) 4.5 55 (4) NA

ISO13-07-06-010 DAL-GW-WW8R; Sample 2710 274 1300 4010

ISO13-07-06-011 DAL-GW-WW8R; Sample Dup 2800 289 1380 4210

Average 2760 (1) 282 (1) 1340 (1) 4110 (1)

%RPD Sample/Sample Dup 3.3 5.3 6.0 4.9

ISO13-07-06-013 DAL-GW-WW9R; Sample 2590 224 1140 4170

ISO13-07-06-014 DAL-GW-WW9R; Sample Dup 2660 225 1130 4130

Average 2630 (1) 225 (1) 1140 (1) 4150 (1)

%RPD Sample/Sample Dup 2.7 0.45 0.88 0.96

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 ±14%, PFBS ± 13%, PFHS ±13%, and PFOS ± 16%.

(2) Method uncertainty has been expanded to ±35% for PFBS based on the FMS recovery. See section 4 for more information.

(3) 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 ± 19%, PFHS ± 19%, and PFOS ± 21%.

(4) Sample/sample duplicate RPD did not meet acceptance criteria of ≤20%.

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. ISO13-07-06

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2.2 Sample Collection

Samples were collected on June 27, 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 June 28, 2013. 

2.3 Sample Preparation

All sample sets 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 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. ISO13-07-06

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Table 3. Instrument Parameters.

Instrument Name ETS Kirk

Analysis Dates

7/1/13 & 7/5/13 – external standard calibration

7/2/13 – internal calibration 

Analytical Method ETS-8-044.1

Liquid Chromatograph Agilent 1260

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

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

Injection Volume 2, 5, or 20 μL

Mass Spectrometer Applied Biosystems TripleQuad 5500

Ion Source Turbo Spray

Polarity Negative

Software 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 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 7/2/13.
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REPORT NO. ISO13-07-06

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3 Data Analysis

3.1 Calibration

Internal Standard Calibration Analysis on 7/2/13: 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 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 on 7/1/13 and 7/5/13: 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. 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.

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. ISO13-07-06

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Table 6. LOQ

Analyte Analysis Date Calibration LOQ, ng/mL 

PFOA 7/2/13 Internal standard 0.0240

PFBS 7/2/13 Internal standard 0.0250

PFHS 7/2/13 Internal standard 0.0250

PFOS 7/2/13 Internal standard 0.0232

PFOA 7/1/13 External standard 0.0192 (1)

PFBS 7/1/13, 7/5/13 External standard 0.0200 (1)

PFHS 7/1/13 External standard 0.0200 (1)

PFOS 7/1/13 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.

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 =
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REPORT NO. ISO13-07-06

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Table 7. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 7/1/13 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-130701-1 0.191 0.180 94.4 0.199 0.218 110

LCS-130701-2 0.191 0.176 92.1 0.199 0.203 102

LCS-130701-3 0.191 0.180 94.5 0.199 0.209 105

Average ± %RSD 93.7% ± 1.4% 106% ± 3.8%

LCS-130701-4 1.91 1.95 102 1.99 2.11 106

LCS-130701-5 1.91 1.93 101 1.99 2.12 107

LCS-130701-6 1.91 1.93 101 1.99 2.18 109

Average ± %RSD 101% ± 0.57% 107% ± 1.4%

LCS-130701-7 19.1 20.4 107

LCS-130701-8 19.1 19.3 101

LCS-130701-9 19.1 19.0 99.6

Average ± %RSD 103% ± 3.8%

ETS-8-044.1

External Standard 

Calibration

Analyzed 7/1/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130701-1 0.199 0.190 95.3 0.199 0.197 99.1

LCS-130701-2 0.199 0.188 94.3 0.199 0.190 95.3

LCS-130701-3 0.199 0.196 98.5 0.199 0.196 98.4

Average ± %RSD 96.0% ± 2.3% 97.6% ± 2.1%

LCS-130701-4 1.99 2.10 105 1.99 2.09 105

LCS-130701-5 1.99 2.08 105 1.99 2.10 105

LCS-130701-6 1.99 2.08 105 1.99 2.12 107

Average ± %RSD 105% ± 0.0% 106% ± 1.1%

LCS-130701-7 20.0 20.1 100 20.0 20.7 104

LCS-130701-8 20.0 19.1 95.4 20.0 19.7 98.4

LCS-130701-9 20.0 19.4 97.1 20.0 19.4 96.9

Average ± %RSD 97.5% ± 2.4% 99.8% ± 3.8%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 7/1/13 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-130701-1 0.185 0.192 104 0.190 0.187 98.6

LCS-130701-2 0.185 0.184 99.5 0.190 0.183 96.3

LCS-130701-3 0.185 0.183 99.1 0.190 0.183 96.5

Average ± %RSD 101% ± 2.7% 97.1% ± 1.3%

LCS-130701-4 1.85 1.95 106 1.90 1.91 100

LCS-130701-5 1.85 1.96 106 1.90 1.95 103

LCS-130701-6 1.85 1.97 106 1.90 1.95 102

Average ± %RSD 106% ± 0.0% 102% ± 1.5% 

LCS-130701-7 18.5 20.3 110

LCS-130701-8 18.5 20.0 108

LCS-130701-9 18.5 19.6 106

Average ± %RSD 108% ± 1.9%

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 7/2/13 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-130702-1 0.190 0.176 92.6 0.198 0.218 110

LCS-130702-2 0.190 0.177 93.4 0.198 0.232 117

LCS-130702-3 0.190 0.188 99.2 0.198 0.225 114

Average ± %RSD 95.1% ± 3.8% 114% ± 3.1%

LCS-130702-4 1.90 1.92 101 1.98 2.12 107

LCS-130702-5 1.90 1.97 104 1.98 2.15 108

LCS-130702-6 1.90 1.89 99.3 1.98 2.11 107

Average ± %RSD 101% ± 2.3% 107% ± 0.54%

LCS-130702-7 9.52 10.0 105

LCS-130702-8 9.52 9.13 95.9

LCS-130702-9 9.52 9.75 102

Average ± %RSD 101% ± 4.6%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 7/2/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130702-1 0.198 0.210 106 0.198 0.192 97.1

LCS-130702-2 0.198 0.209 105 0.198 0.197 99.4

LCS-130702-3 0.198 0.222 112 0.198 0.197 99.4

Average ± %RSD 108% ± 3.5% 98.6% ± 1.3%

LCS-130702-4 1.98 2.21 111 1.98 2.07 105

LCS-130702-5 1.98 2.17 110 1.98 1.99 101

LCS-130702-6 1.98 2.22 112 1.98 2.01 102

Average ± %RSD 111% ± 0.90% 103% ± 2.0%

LCS-130702-7 9.94 11.4 115 9.94 10.3 104

LCS-130702-8 9.94 10.2 103 9.94 9.25 93.1

LCS-130702-9 9.94 11.5 116 9.94 10.5 105

Average ± %RSD 111% ± 6.5% 101% ± 6.6%

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 7/2/13 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-130702-1 0.184 0.186 101 0.189 0.192 102

LCS-130702-2 0.184 0.173 94.1 0.189 0.185 97.9

LCS-130702-3 0.184 0.185 101 0.189 0.200 106

Average ± %RSD 98.7% ± 4.0% 102% ± 4.0%

LCS-130702-4 1.84 1.84 100 1.89 1.90 100

LCS-130702-5 1.84 1.86 101 1.89 1.99 105

LCS-130702-6 1.84 1.97 107 1.89 1.97 104

Average ± %RSD 103% ± 3.7% 103% ± 2.6% 

LCS-130702-7 9.21 9.63 105

LCS-130702-8 9.21 8.84 96.0

LCS-130702-9 9.21 9.59 104

Average ± %RSD 102% ± 4.9%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 7/5/13 PFBS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-130705-1 0.199 0.201 101

LCS-130705-2 0.199 0.200 101

LCS-130705-3 0.199 0.205 103

Average ± %RSD 102% ± 1.1%

LCS-130705-4 1.99 2.15 108

LCS-130705-5 1.99 2.27 114

LCS-130705-6 1.99 2.17 109

Average ± %RSD 110% ± 2.9%

LCS-130705-7 20.0 19.1 95.3

LCS-130705-8 20.0 19.9 99.7

LCS-130705-9 20.0 19.5 97.5

Average ± %RSD 97.5% ± 2.3%

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%.

Table 8. Analytical Method Uncertainty.

Analyte Calibration Method Standard Deviation Method Uncertainty

PFOA External Standard 6.94 ±14%

PFBS External Standard 6.50 ±13%

PFHS External Standard 6.68 ±13%

PFOS External Standard 8.07 ±16%

PFOA Internal Standard 9.56 ±19%

PFBS Internal Standard 9.13 ±18%

PFHS Internal Standard 9.41 ±19%

PFOS Internal Standard 10.7 ±21%
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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 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 or PFHS; however, the 

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

were prepared. The FMS sample recovery was 65.5% for PFBS. The method uncertainty has been 

expanded for PFBS to ±35% based on the FMS recovery %bias.

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.
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REPORT NO. ISO13-07-06

PAGE 13 OF 21

Table 10. DAL GW ACI 130627 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-001 DAL-GW-ACI-0-130627 1460 NA 706 NA

ISO13-07-06-002 DAL-GW-ACI-DB-130627 1500 NA 710 NA

ISO13-07-06-003 DAL-GW-ACI-FMS-130627 3070 79.5 2280 78.2

Average Concentration (ng/mL) ± %RPD 1480 ng/mL ± 2.7% 708 ng/mL ± 0.56%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-001 DAL-GW-ACI-0-130627 935 NA 1580 NA

ISO13-07-06-002 DAL-GW-ACI-DB-130627 948 NA 1600 NA

ISO13-07-06-003 DAL-GW-ACI-FMS-130627 2520 78.9 3380 89.9

Average Concentration (ng/mL) ± %RPD 942 ng/mL ± 1.4% 1590 ng/mL ± 1.3% 

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-06-001 DAL-GW-ACI-0-130627 99.1 95.9

ISO13-07-06-002 DAL-GW-ACI-DB-130627 101 95.5

ISO13-07-06-003 DAL-GW-ACI-FMS-130627 96.7 99.3

Average Concentration (ng/mL) ± %RSD 99.0% ± 2.3% 96.9% ± 2.1%

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.
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REPORT NO. ISO13-07-06

PAGE 14 OF 21

Table 11. DAL GW ACM2 130627

PFOA (1) PFBS (1)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-004 DAL-GW-ACM2-0-130627 1220 NA 1030 NA

ISO13-07-06-005 DAL-GW-ACM2-DB-130627 1200 NA 1020 NA

ISO13-07-06-006 DAL-GW-ACM2-FMS-130627 1970 76.0 1680 65.5 (2)

Average Concentration (ng/mL) ± %RPD 1210 ng/mL ± 1.7% 1030 ng/mL ± 0.98% (3)

PFHS (1) PFOS (5)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-004 DAL-GW-ACM2-0-130627 2040 NA 0.806 NA

ISO13-07-06-005 DAL-GW-ACM2-DB-130627 2000 NA 0.738 NA

ISO13-07-06-006 DAL-GW-ACM2-FMS-130627 NA (4) NA (4) NA (6) NA (6)

Average Concentration (ng/mL) ± %RPD 2020 ng/mL ± 2.0% 0.772 ng/mL ± 8.8%

13C4-PFOA (1) 13C4-PFOS (5)

3M LIMS ID Description %Recovery %Recovery

ISO13-07-06-004 DAL-GW-ACM2-0-130627 99.3 81.3

ISO13-07-06-005 DAL-GW-ACM2-DB-130627 96.8 75.8

ISO13-07-06-006 DAL-GW-ACM2-FMS-130627 96.1 NA (6)

Average Concentration (ng/mL) ± %RPD/RSD 97.4% ± 1.7% 78.6% ± 6.9%

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.

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

(3) Method uncertainty has been expanded to ±35% based on the FMS recovery %bias.

(4) Analyte concentration exceeded calibration range.

(5) Samples were analyzed by internal standard calibration.

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

REPORT NO. ISO13-07-06

PAGE 15 OF 21

Table 12. DAL GW ACE 130627

PFOA (1) PFBS (3)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-007 DAL-GW-ACE-0-130627 0.0568 NA 108 NA

ISO13-07-06-008 DAL-GW-ACE-DB-130627 0.0866 NA 113 NA

ISO13-07-06-009 DAL-GW-ACE-FMS-130627 8.52 84.5 NA (4) NA (4)

Average Concentration (ng/mL) ± %RPD 0.0717 ng/mL ± 42% (2) 111 ng/mL ± 4.5%

PFHS (1) PFOS (1)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-007 DAL-GW-ACE-0-130627 0.0850 NA <0.0232 NA

ISO13-07-06-008 DAL-GW-ACE-DB-130627 0.150 NA <0.0232 NA

ISO13-07-06-009 DAL-GW-ACE-FMS-130627 8.52 84.1 8.72 87.2

Average Concentration (ng/mL) ± %RPD 0.118 ng/mL ± 55% (2) <0.0232 ng/mL

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

3M LIMS ID Description %Recovery %Recovery

ISO13-07-06-007 DAL-GW-ACE-0-130627 90.1 78.0

ISO13-07-06-008 DAL-GW-ACE-DB-130627 82.4 81.4

ISO13-07-06-009 DAL-GW-ACE-FMS-130627 84.6 79.2

Average Concentration (ng/mL) ± %RSD 85.7% ± 4.6% 79.5% ± 2.1%

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration.

(2) Sample/sample duplicate RPD did not meet acceptance criteria of ≤20%.

(3) Samples were analyzed by external standard calibration.

(4) Sample was not analyzed by external standard calibration due to the inappropriate FMS spike level.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-06

PAGE 16 OF 21

Table 13. DAL GW WW8R 130627 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-010 DAL-GW-WW8R-0-130627 2710 NA 274 NA

ISO13-07-06-011 DAL-GW-WW8R-DB-130627 2800 NA 289 NA

ISO13-07-06-012 DAL-GW-WW8R-FMS-130627 6900 103 4070 94.2

Average Concentration (ng/mL) ± %RPD 2760 ng/mL ± 3.3% 282 ng/mL ± 5.3%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-010 DAL-GW-WW8R-0-130627 1300 NA 4010 NA

ISO13-07-06-011 DAL-GW-WW8R-DB-130627 1380 NA 4210 NA

ISO13-07-06-012 DAL-GW-WW8R-FMS-130627 5380 101 8370 107

Average Concentration (ng/mL) ± %RPD 1340 ng/mL ± 6.0% 4110 ng/mL ± 4.9%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-06-010 DAL-GW-WW8R-0-130627 95.0 95.6

ISO13-07-06-011 DAL-GW-WW8R-DB-130627 99.0 98.6

ISO13-07-06-012 DAL-GW-WW8R-FMS-130627 94.7 99.5

Average Concentration (ng/mL) ± %RSD 96.2% ± 2.5% 97.9% ± 2.1%

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. ISO13-07-06

PAGE 17 OF 21

Table 14. DAL GW WW9R 130627 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-013 DAL-GW-WW9R-0-130627 2590 NA 224 NA

ISO13-07-06-014 DAL-GW-WW9R-DB-130627 2660 NA 225 NA

ISO13-07-06-015 DAL-GW-WW9R-FMS-130627 6330 92.4 3970 93.2

Average Concentration (ng/mL) ± %RPD 2630 ng/mL ± 2.7% 225 ng/mL ± 0.45%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-013 DAL-GW-WW9R-0-130627 1140 NA 4170 NA

ISO13-07-06-014 DAL-GW-WW9R-DB-130627 1130 NA 4130 NA

ISO13-07-06-015 DAL-GW-WW9R-FMS-130627 5000 96.9 7240 77.6

Average Concentration (ng/mL) ± %RPD 1140 ng/mL ± 0.88% 4150 ng/mL ± 0.96%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-06-013 DAL-GW-WW9R-0-130627 99.6 95.4

ISO13-07-06-014 DAL-GW-WW9R-DB-130627 98.5 98.2

ISO13-07-06-015 DAL-GW-WW9R-FMS-130627 88.1 99.0

Average Concentration (ng/mL) ± %RSD 95.4% ± 6.7% 97.5% ± 1.9%

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. ISO13-07-06

PAGE 18 OF 21

Table 15. Trip Blank Results

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-016 DAL-GW-TRIP01-0 <0.0240 (1) NA <0.0250 (1) NA

ISO13-07-06-017 DAL-GW-TRIP01-LS 8.07 (1) 80.7 9.75 (1) 97.5

ISO13-07-06-018 DAL-GW-TRIP01-HS 3850 (2) 96.0 3730 (2) 92.8

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-06-016 DAL-GW-TRIP01-0 <0.0250 (1) NA <0.0232 (1) NA

ISO13-07-06-017 DAL-GW-TRIP01-LS 8.47 (1) 84.8 8.44 (1) 84.4

ISO13-07-06-018 DAL-GW-TRIP01-HS 3750 (2) 94.0 4050 (2) 102

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-06-016 DAL-GW-TRIP01-0 80.1 (1) 81.9 (1)

ISO13-07-06-017 DAL-GW-TRIP01-LS 76.8 (1) 78.5 (1)

ISO13-07-06-018 DAL-GW-TRIP01-HS 96.7 (2) 92.8 (2)

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration.

(2) 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. ISO13-07-06 

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 

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

Plant (GWTP) GAC System. 

8 Signatures 

Susan T. Wolf, 3M Pranbipal 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. 

Cd~&^^ HyQ-^—e^^^ 7-/ 7 - Q 

Quality Assu^nce Representative ^ Date^ 

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

Environmental Laboratory. 

PAGE 19 OF 21 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-06

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 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 6/27/13

PFOA 1180 1650 1410 2580 1910 2300 2220 1480 1860 1480

PFBS 792 1410 1830 723 588 830 1060 1360 1040 708

PFHS 1100 1460 1390 1380 895 1580 1090 777 940 942

PFOS 782 964 172 2810 1810 2940 2490 1670 2150 1590

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

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

PFOA 1250 0.387 0.102 <0.0240 0.124 0.0380 0.0422 0.0725 0.0717

PFBS 818 0.256 <0.0250 <0.0250 0.0360 <0.0250 0.392 24.8 111

PFHS 1240 0.552 0.117 <0.0250 0.178 0.0477 0.057 0.105 0.118

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

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

REPORT NO. ISO13-07-06

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 6/27/2013

PFOA 3630 4350 3250 3640 3190 2760 2760

PFBS 441 410 354 385 364 289 282

PFHS 1740 1930 1900 1760 1610 1330 1340

PFOS 4920 5710 4850 5120 4830 4180 4110

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 6/27/2013

PFOA 3360 2710 2850 3330 2650 2660 2630

PFBS 321 184 236 278 244 226 225

PFHS 1480 954 1400 1440 1200 1120 1140

PFOS 4080 3690 4100 4660 4340 4210 4150