NISTIR 7869

Interlaboratory Comparison Study to 

Support the Deepwater Horizon Natural 

Resource Damage Assessment: Description 

and Results for QA11Blood01- PAHs, PAH 

Metabolites, and DOSS in Solution and Blood

John R. Kucklick 

Michele M. Schantz 

http://dx.doi.org/10.6028/NIST.IR.7869 
NISTIR 7869 

Interlaboratory Comparison Study to 

Support the Deepwater Horizon Natural 

Resource Damage Assessment: Description 

and Results for QA11Blood01- PAHs, PAH 

Metabolites, and DOSS in Solution and Blood

John R. Kucklick 

Michele M. Schantz 

Analytical Chemistry Division 

Material Measurement Laboratory 

National Institute of Standards and Technology 

Gaithersburg, MD 20899 and Charleston, SC 29412 

http://dx.doi.org/10.6028/NIST.IR.7869 

July 2011 

U.S. Department of Commerce 

Rebecca Blank, Acting Secretary 

National Institute of Standards and Technology 

Patrick D. Gallagher, Under Secretary of Commerce for Standards and Technology and Director 
   

                         

                                 

                            

                     

                         

                      

                         

                     

                 

                           

                   

                           

                            

                     

  

                     

                       

                                 

                                  

                       

                  

                           

                              

                         

                            

                

                         

                    

                                 

                

                                    

                           

                         

                                

                 

                             

                           

                         

ABSTRACT

To support natural resource damage assessment (NRDA) in response to the Deepwater Horizon

(DWH) oil spill in the Gulf of Mexico, a large number of samples were collected from protected

species including marine mammals and sea turtles. Analysis of these samples will continue for

the foreseeable future. To support NRDA sample analyses, NOAA will require analytical

laboratories in addition to the commercial laboratories that are currently listed as providing

support to NRDA. To compare the data among these laboratories, interlaboratory comparison

studies have been initiated, and the results from the fourth exercise, QA11Blood01, are

reported here. In this exercise, selected polycyclic aromatic hydrocarbons (PAHs), alkylated

PAHs, hydroxylated PAH metabolites and dioctyl sodium sulfosuccinate (DOSS) were

determined in the exercise material, which consisted of a whole blood and plasma collected

from American alligators (Alligator mississippiensis) amended with the test compounds. A

solution containing known amounts of the test compounds was also distributed to help gauge

analyses conducted on a matrix‐free sample. The results from this fourth exercise are reported

along with a summary of the analytical methods used.

INTRODUCTION

The National Institute of Standards and Technology (NIST) has conducted three interlaboratory

comparison exercises to support the natural resource damage assessment (NRDA) in response

to the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico with marine sediment [1], crude

oil [2], and mussel tissue [3] as the matrices of interest. The exercises were initiated to provide

information on the comparability of data from different laboratories for PAHs (polycyclic

aromatic hydrocarbons), alkylated PAHs, and petroleum biomarkers (hopanes and steranes). A

large number of coastal sediment and tissue samples (e.g., oysters) have been collected outside

of the spill zone to define baseline environmental conditions prior to being exposed to oil. For

the foreseeable future, subsequent analysis of oiled sediments and oil‐exposed oysters will be

required as well. To support these efforts, additional analytical laboratories are being used to

provide greater capacity for the NRDA evaluation.

The present exercise was designed to evaluate measurements of wildlife blood for selected

PAHs, alkylated PAHs, hydroxylated PAH metabolites, and dioctyl sodium sulfosuccinate (DOSS).

Blood was a matrix of interest for NRDA as this tissue was commonly collected from wildlife for

assessment of hydrocarbon exposure. The study was performance‐based; hence, laboratories

were free to use the methods of their choosing. It is important to note that this exercise was

not designed nor intended to reflect method performance for past results reported by the

laboratories but rather to provide the laboratories the opportunity to assess methods of

interest. The analytes chosen for this study were those commonly found in oil and/or used for

source apportionment studies, or are metabolites of aromatic hydrocarbon exposure.

The data received from six laboratories for the exercise are summarized in this report along

with summaries of the analytical methods used by each laboratory. For this exercise,

laboratory performance was based on p‐scores that help gauge laboratory precision. Due to
                           

                         

     

                              

                           

                           

                             

                         

                           

                                 

                           

                     

                               

                                 

                            

   

                        

                 

     

the small number of laboratories participating, z‐scores, which are indicative of agreement to a

consensus value, were not calculated. Among laboratory agreement is thus shown graphically.

SOURCE OF MATERIAL

There were four materials sent out to participants (Table 1): (1) a mixture of the PAH‐related

compounds in isooctane, (2) DOSS in methanol, (3) the target compounds added to pooled

alligator plasma, and (4) the target compounds added to pooled alligator whole blood. The

compounds used to prepare the samples above were purchased in either neat form or solution

from Accustandard (New Haven, CT), Chiron (Trondheim, Norway) or Sigma (St. Louis, MO).

Individual stock solutions of compounds were used to prepare a mixed spiking solution in

ethanol that was added to the blood materials, a mixed PAH solution in isooctane, and a DOSS

solution in methanol. Alligator plasma and whole blood were pooled from wild alligators,

which were sampled during capture‐release health assessments, and captive alligators. The

blood (approximately 275 g of plasma or whole blood) was added to a 500 mL Erlenmeyer flask,

spiked with approximately 0.8 g of the mixed analyte spiking solution, and stirred for 4 hours in

the dark before aliquotting into 4.5 mL cryovials. Cryovials were then immediately frozen at ‐80 o

C.

Table 1: Summary of samples and target compounds added to the QA11blood01 materials.

Blood material values are pg/g while solution is ng/g.

Material

Compound QA11Plasma QA11WholeBlood QA11Solution#1‐PAH QA11Solution#2‐DOSS

Fluorene 5007 5029 16.6

Phenanthrene 2925 2938 9.06

Pyrene 1992 2001 6.17

Benzo[a]pyrene 1745 1752 5.34

2 methylnaphthalene 21387 21480 68.8

2,6‐dimethyl naphthalene 8516 8553 26.5

1,7‐dimethylphenanthrene 543 546 1.71

9‐methylphenanthrene 1982 1990 6.11

3‐methylphenanathrene 4785 4806 14.8

1‐naphthol 1644 1651 5.04

2,3‐dihydroxynaphthalene 7220 7252 22.1

2‐methyl‐1‐naphthol 337 338 1.13

2‐hyrdoxyfluorene 5320 5343 16.5

1‐hydroxypyrene 846 850 2.67

Dioctylsodium succinate (DOSS) 29965 30095 110
                         

                              

                       

                   

                       

                   

                               

                 

         

                        

                 

                     

                         

                         

                         

                               

  

                       

                             

                              

                           

                                   

                           

                              

                             

                           

                           

                             

                              

                                

     

SAMPLE DISTRIBUTION

Four cryovials of QA11Plasma or QA11WholeBlood each containing 4 mL of frozen material

were sent to seven laboratories the week of October 10, 2011. Each laboratory was requested

to analyze three samples of each blood material and three measurements of QA11Solution#1‐

PAH and QA11Solution#2‐DOSS with their laboratory's and/or program's current analytical

protocols being used for the determination of the concentrations (mass/mass) of the parent

PAH compounds, alkylated PAH compounds, hydroxylated PAH compounds and DOSS.

The instructions including the list of target analytes sent to participants are given in Appendix A.

EVALUATION OF EXERCISE RESULTS

Establishment of the Assigned Values

Laboratory data submission: Each participating laboratory was asked to submit data from three

replicate determinations of the “unknown” material QA11Plasma and QA11WholeBlood and

was requested to report results of concurrent analyses of QA11Solution#1‐PAH and

QA11Solution#2‐DOSS. The solution materials were used because NIST does not have a

reference material for PAHs in blood, and the solutions provided information on laboratory

measurements made on a matrix‐free sample. Laboratories were requested to report these

results to at least three significant figures and to provide brief descriptions of their cleanup and

analytical procedures.

Determination of laboratory analyte means: For each laboratory, the laboratory analyte mean

of the three sample results (S1, S2, and S3) was calculated for each analyte. Non‐numerical

data were treated as follows: A mean "<value" was used when three "<values" were reported;

NA (not analyzed/determined) was used for three reported NAs; and, if the reported results

were of mixed type, e.g., S1 and S2 were numerical values and S3 was reported as “<value”, the

two similar "types" were used to either determine the mean or to set a non‐numerical

descriptor.

Determination of assigned values: In prior exercises, the inclusion of a laboratory’s data in the

consensus value was based on their performance on the reference material. If values were

within 30% of the assigned value for the reference material, their measurements on the

unknown were included in the calculation of the consensus value for the unknown. This

approach was not possible in the present exercise as there was no reference material included

in the exercises. Consequently, the consensus values for this exercise are simply the median of

all values submitted by all laboratories. No values were excluded due to the small number of

laboratories submitting data.
                           

                               

                             

             

                         

                           

                            

                            

                                  

                        

                                 

               

                   

                           

                         

                          

                   

                             

                           

        

     

         

                           

                         

                                

                               

                           

                       

                                      

                                   

 

REPORTED RESULTS

Laboratories were assigned numerical identification codes in order of receipt of their data with

the exception of the two NIST data sets, which are designated Laboratory 1 and 2. The

laboratory mean replicate data are shown in Tables 2, 3 and 4 for QA11Solution#1‐PAH and

QA11Solution#2‐DOSS, QA11Plasma, and QA11Wholeblood, respectively. Included in the

tables are the by‐compound mean and standard deviation for the three measurements made

on each matrix by each laboratory and the exercise assigned median values plus standard

deviation. The gravimetric concentration that was based on the original weighing of the target

compounds to make the exercise materials is also provided. Summaries of the methods used

by each laboratory are in Appendix B. A second set of plasma and whole blood samples was

distributed to laboratory 5 in February 2012 for an additional DOSS determination. Laboratory

5 therefore has two sets of DOSS values, those from the initial determination in 2011 and from

the second set of samples analyzed in 2012.

Performance Scores

The exercise coordinators recognize that different environmental monitoring programs have

different data quality objectives and needs. The acceptability of the results submitted by a

particular laboratory will be decided by the individual program(s) for which the laboratory

provides data. Typically, each program will use these exercise results in conjunction with the

laboratory's performance in the analysis of certified reference materials and/or control

materials, and of other quality assurance samples. These exercise results are exhibited in a

number of ways in this report to facilitate their use by most environmental monitoring

programs in their acceptability assessments.

Precision Assessment (p‐score)

p‐score = σlab / σtarget

For the calculation of p‐scores [4‐5] for this program, the σ values used are coefficients of

variation (CV calculated as relative standard deviations) with the current target σ (CV) for the

three replicates being 15 %. The value of 15 % was chosen for use interlaboratory comparison

exercises of this type run by NIST. P‐scores are only available for analytes where three

measurements were made by the laboratory. Tables 2 through 4 summarize the relative

standard deviations (RSDs) calculated from the three concentrations reported by the laboratory

for each analyte quantified. Table 5 gives the p‐scores (15 %). A p‐score of 1 indicates that the

laboratory’s CV was 15 %, and a p‐score of 2 indicates that the laboratory’s CV was 30 %.
   

                       

                             

                                

                     

                          

                               

                   

                             

                         

                       

                            

                              

                              

                               

                         

                            

                         

                           

                                 

                        

                   

                                

                       

                                     

               

                         

                            

                               

                               

                                      

                              

                               

               

                               

                                

                             

                        

                         

                    

RESULTS and DISCUSSION

NOAA’s NRDA office requested that NIST coordinate an interlaboratory comparison exercise for

PAHs, PAH metabolites, and DOSS in blood as this tissue had been collected from several

wildlife species following the spill. With the help of NOAA and NRDA, NIST requested that five

laboratories outside of NIST participate in an interlaboratory comparison exercise using blood‐

based samples. Of these five laboratories, four submitted data sets with two additional data

sets submitted by NIST. Laboratory 5 submitted two data sets for DOSS (see above). The

listing of participating laboratories is given in Appendix C.

Tables 2 through 4 summarize the laboratory means and exercise assigned values for the PAHs,

alkylated PAHs, hydroxylated PAHs and DOSS in the solution, plasma, and whole blood

materials, respectively. The consensus values for the materials were simply the median

concentrations of the submitted results. Given the small number of values reported, no data

were excluded from the derivation of the consensus value. The gravimetric values are given in

the tables for guidance. For most compounds, the gravimetric value was within the range of

data reported back by the laboratories especially for the solution material. This was also true

for the blood materials with the exception of the methylnaphthalenes that had higher

gravimetric values than the reported values. The most likely explanation for this discrepancy is

that the methylnaphthalenes that were added to the blood were partially lost through

evaporation at some point in the preparation of the blood materials. There were few reported

values for the hydroxylated PAHs so it is difficult to gauge the accuracy of the gravimetric values

relative to these compounds. Prior experience with hydroxylated compounds has shown that

concentrations can change in solution either through degradation, conjugation, or possibly

sorption to container walls. DOSS was measured by three laboratories (Labs 3, 5, and 6). The

median of measured values for DOSS agreed very well with the gravimetric concentration

(Tables 2‐4). The CV for the three labs was higher for DOSS in the blood materials (ca. 40 %)

than for the solution (ca. 5 %).

As expected, the agreement among laboratories for the compounds in the matrix‐free solution

was better than that observed in the blood materials. The coefficients of variation (standard

deviation/median) were 17 %, 53 %, and 70 % for the solution, plasma, and whole blood,

respectively. Excluding the high fluorene and pyrene values reported by Lab 6 reduced the CVs

to 33 % for plasma and 48 % for whole blood. This indicates that reported values in plasma are

less variable among laboratories than those made on whole blood. This result is reasonable as

the plasma is largely free of cellular material relative to whole blood and therefore should be

less subject to matrix effects during analysis.

The precision or “p” scores, which are a measure of within laboratory repeatability, are given in

Table 5. Again, a p‐score of ≤1 indicates that a laboratory’s reported values are within 15 % of

their mean reported value. P‐scores were only calculated on the blood materials and were

generally <0.5 for most analytes in most laboratories. 1,7‐dimethylphenanthrene had a higher

p‐score than other compounds probably due to the low concentration of this compound

relative to other compounds in the samples (Tables 2‐4).
                         

                          

                           

                             

                             

                             

                                      

                             

                              

                                     

                         

                       

                                

                               

                             

                        

                             

                        

                             

                                  

                           

                             

                                   

                          

                             

                           

                     

                         

                       

                           

       

                         

               

                           

                       

The methods used to analyze the samples varied among laboratories (Appendix B Tables B1‐

B7). Extraction methods for the PAHs included microwave extraction (Lab 1), liquid:liquid

extraction (Labs 2, 4, and 5), and QuECHERS (Quick Easy Cheap Effective Rugged Safe,

essentially liquid:liquid extraction with acetonitrile following the addition of salts; Labs 3 and 6).

DOSS was extracted by QuECHERS (Labs 3 and 6) or by liquid:liquid extraction using acetonitrile

(Lab 5). Cleanup of samples prior to PAH analysis included size exclusion followed by solid

phase extraction (Labs 1, 3, and 4) and no cleanup (labs 2, 5, and 6). Prior experience in our

laboratory has shown cleanup of blood extracts is required for the analysis of persistent organic

pollutants by GC/MS [4], hence it was surprising that several laboratories opted for no cleanup.

Labs did not clean up extracts prior to DOSS analysis. For the analysis of the parent PAHs, five

laboratories used GC/MS with 5% methylpolysiloxane‐phase column (Labs 2 through 5) or a

50% methylpolysiloxane‐phase column (Lab 1). Lab 6 used UPLC/FLR/MS/MS with a C18

column. For alkylated PAHs, all labs used GC/MS with columns noted in Table B5; although, Lab

6 used GC/MS/MS. All labs used LC/MS/MS for the analysis of DOSS. Hydroxylated PAHs were

determined by Labs 1 and 2 using GC/MS following derivatization with MSTFA and Lab 6

performed the analysis by UPLC/FLR/MS/MS. Additional details are given in Appendix B.

In conclusion, results demonstrated that it is possible to measure a suite of parent and

alkylated PAHs in blood with reasonable agreement among laboratories. The three laboratories

that measured the oil dispersant compound, DOSS, were also able to provide a consensus value

that was very close to the nominal concentration of DOSS in the samples (Tables 3 and 4). PAH

metabolites were a challenge for laboratories with very few results being submitted by the

group. While there are several methods for PAH metabolites in urine published in the

literature, this is not the case for PAHs in blood which may explain the low number of values

submitted by laboratories. Based on preliminary work done by NIST, hydroxylated PAHs also

might not achieve stable concentrations when spiked in blood. Further studies are needed to

determine the feasibility of providing a reference material for hydroxylated PAHs in blood and

to provide reliable methods for hydroxylated PAH analysis in blood samples.

Acknowledgments

The time and effort of the analysts and management of the participating laboratories are

gratefully acknowledged. We also gratefully acknowledge the laboratory of Dr. Louis Guillette,

specifically Dr. Thomas Rainwater and Dr. Satomi Kohno, for supplying us with the alligator

plasma and whole blood.

Disclaimer

Certain commercial equipment, instruments, or materials are identified in this report to specify

adequately the experimental procedure. Such identification does not imply recommendation

or endorsement by the National Institute of Standards and Technology, nor does it imply that

the materials or equipment identified are the best available for the purpose.
                   

                 

                   

                   

                 

                   

                   

                 

                   

             

                     

                 

                             

                 

                   

References

1. Schantz, M.M. and Kucklick, J.R., Interlaboratory Analytical Comparisons Study to

Support Deepwater Horizon Natural Resource Damage Assessment: Description and

Results for Marine Sediment QA10SED01, NISTIR 7792, Gaithersburg, MD (2011).

2. Schantz, M.M. and Kucklick, J.R., Interlaboratory Analytical Comparisons Study to

Support Deepwater Horizon Natural Resource Damage Assessment: Description and

Results for Crude Oil QA10OIL01, NISTIR 7793, Gaithersburg, MD (2011).

3. Schantz, M.M. and Kucklick, J.R., Interlaboratory Analytical Comparisons Study to

Support Deepwater Horizon Natural Resource Damage Assessment: Description and

Results for Mussel Tissue QA10TIS01, NISTIR 7819, Gaithersburg, MD (2011).

4. ISO/IEC 17043: 2010 Conformity Assessment‐General Requirements for Proficiency

Testing

5. IUPAC “The International Harmonized Protocol for the Proficiency Testing of (Chemical)

Analytical Laboratories,” Pure & Appl. Chem., 65 (9), 2123‐2144 (1993).

6. Keller JM, Swarthout RF, Carlson BK, Yordy J, Guichard A, Schantz MM, Kucklick JR. 2009.

Comparison of five extraction methods for measuring PCBs, PBDEs, organochlorine

pesticides, and lipid content in serum. Anal Bioanal Chem 393(2): 747‐760.
Table 2: Tabular results from the analysis of QA11Solution#1‐PAH and QA11Solution#2‐DOSS. All values are ng

refers to concentration expected based on the mass of compound added to the solution.

Laboratory

Compound mean

1

RSD (%) mean

2

RSD (%) mean

3

RSD (%)

4

mean RSD (%) mean

5

RSD (%) mean

6

RSD (%) m

fluorene 15.9 2.0 16.7 7.4 14.4 NA 11.1 3.4 12.2 3.7 9.07 7.9 

phenanthrene 9.75 0.7 9.27 5.0 7.07 NA 8.08 1.7 7.35 3.8 <LOD NA 

pyrene 6.15 3.1 5.09 6.5 5.43 NA 5.24 12 5.05 5.1 7.61 5.6 

benzo[a]pyrene1‐methylnaphthalene

4.75

<LOD

3.7

NA

6.86

NA

9.0

<LOD

4.51<1.6

NA

<LOD

4.13<1.5

9.9

NA

4.00

NA

0.8

NA

7.30

NA

10

NA

2‐methylnaphthalene 58.7 0.8 65.2 6.6 78.2 NA 62.9 2.4 50.5 2.6 55.1 4.6 

2,6‐dimethylnaphthalene 23.2 1.8 19.9 9.9 24.3 NA 22.6 8.6 20.6 6.7 24.4 2.8 1,7‐dimethylphenanthrene 2.26 7.0 1.79 10 1.37 NA 2.07 13 NA NA NA NA 

9‐methylphenanthrene 7.44 1.6 6.16 12 5.42 NA 5.26 2.2 4.81 2.6 5.52 1.5 

3‐methylphenanthrene 15.2 1.8 16.4 8.2 12.4 NA 11.6 7.4 12.1 5.6 14.9 10.6 

1‐naphthol <LOD NA 6.86 9.0 NA NA NA NA NA NA 5.14 4.4 2,3‐dihydroxynaphthalene <LOD NA <1 NA NA NA NA NA NA NA <LOD NA 

2‐methyl‐1‐naphthol <LOD NA <1 NA NA NA NA NA NA NA <LOD NA 

2‐hydroxyfluorene 7.80 2.3 NA NA NA NA NA NA NA NA 12.7 1.6 

1‐hydroxypyrene 2.06 0.3 other NA NA NA NA NA NA NA <LOD NA DOSS (ion) NA NA NA NA 116 1.0 NA NA 110 7.7 121 1.3 
Table 3: Tabular results from the analysis of QA11Plasma. All values are pg/g. Gravimetric refers to concentrat

on the mass of compound added to the blood.

Laboratory 

Compound mean 

1 

RSD (%) 

2 

mean 

RSD 

(%) 

3 

mean 

RSD 

(%) 

4 

mean RSD (%) mean 

5a 

RSD (%) 

5b 

mean RSD (%) mean 

6 

RSD (%) m

fluorene 4897 NA 4333 5.3 4290 3.6 4310 5.0 3480 2.6 10646 12.2 

phenanthrene 3285 NA 6693 3.0 3120 0.6 2733 1.5 2200 4.5 <LOD NA 

pyrene 2406 NA 1900 4.6 2420 0.7 1890 3.2 1623 2.8 11078 7.9 

benzo[a]pyrene 1-methylnaphthalene 

NA 

<LOD 

NA NA 

1620 

NA 

3.8 

NA 

1807 

422 

1.7 6.6 

1353 <300 

1.7 NA

1180 

 NA

0.8 

 NA 

<LOD 

NA 

NA NA 

2-methylnaphthalene 30838 NA 9140 3.7 14100 18.4 17700 3.4 14167 1.1 11671 11.5 

2,6-dimethylnaphthalene 14335 NA 4690 4.2 5090 12.1 6523 3.2 5773 1.8 3002 18.7 

1,7-dimethylphenanthrene <LOD NA 608 13.2 646 2.3 508 16.2 NA NA <LOD NA 

9-methylphenanthrene 1864 NA 2313 10.7 2350 1.1 1820 4.7 1657 10.7 944 NA 

3-methylphenanthrene 4451 NA 4897 3.7 5130 1.2 4273 3.5 3947 2.8 7442 27.0 

1-naphthol NA NA 1963 5.4 NA NA NA NA NA NA <LOD NA 

2,3-dihydroxynaphthalene NA NA NA NA NA NA NA NA NA NA 26227 NA 

2-methyl-1-naphthol NA NA NA NA NA NA NA NA NA NA <LOD NA 

2-hydroxyfluorene NA NA NA NA NA NA NA NA NA NA 3444 15.3 

1-hydroxypyrene NA NA other NA NA NA NA NA NA NA <LOD NA 

DOSS (ion) NA NA NA NA 29300 1.2 NA NA 49300 19.2 30300 NA 33041 14.0 
Table 4: Tabular results from the analysis of QA11WholeBlood. All values are pg/g. Gravimetric refers to conce

based on the mass of compound added to the blood.

Laboratory 

Compound mean 

1 

RSD (%) mean 

2 

RSD (%) mean 

3 

RSD (%) mean 

4 

RSD (%) mean 

5a 

RSD (%) 

5b 

mean RSD (%) mean 

6 

RSD (%) media

fluorene 5178 5.6 4217 7.9 3030 4.0 1237 4.1 2333 1.6 12051 19.1 3623 

phenanthrene 3228 5.1 7723 3.5 3040 1.4 2517 13.2 2013 5.2 <LOD NA 3040 

pyrene 2285 7.4 1747 3.2 2367 2.2 1840 5.2 1447 6.9 11859 11.4 2063 

benzo[a]pyrene 1-methylnaphthalene 

NA 

<LOD 

NA NA

1627 

NA

10.5 

NA 

1123 

356 

12.7 

4.2 

678 

<300 

10.3 

NA 

555 

NA 

17.1 

NA 

<LOD 

NA 

NA 

NA 

901 

2-methylnaphthalene 22377 2.6 9730 3.9 8390 12.8 15767 11 8720 74.1 5853 54.9 9225 

2,6-dimethylnaphthalene 10286 3.9 4620 8.4 4017 7.9 5860 14 5150 2.5 2167 21.3 4885 

1,7-dimethylphenanthrene <LOD NA 858 6.6 632 1.4 402 6.5 NA NA NA NA 632 9-methylphenanthrene 1697 2.1 2473 5.9 2330 0.9 1663 7.2 1623 10.5 450 NA 1680 

3-methylphenanthrene 4228 2.2 5613 1.0 5123 0.6 3990 11.8 3360 6.0 4985 8.7 4607 

1-naphthol NA NA 2100 5.7 NA NA NA NA NA NA 10789 NA 

2,3-dihydroxynaphthalene NA NA NA NA NA NA NA NA NA NA <LOD NA 

2-methyl-1-naphthol NA NA NA NA NA NA NA NA NA NA <LOD NA 

2-hydroxyfluorene NA NA NA NA NA NA NA NA NA NA <LOD NA 

1-hydroxypyrene NA NA other NA NA NA NA NA NA NA <LOD NA 

DOSS (ion) NA NA NA NA 27567 3.7 NA NA 55367 3.7 27200 NA 28236 3.6 27901 
Table 5: p scores based on a relative standard deviation of 15% for the blood materials.

Lab 1 Lab 2 Lab 3 Lab 4 Lab 5a 

plasma whole blood plasma whole blood plasma whole blood plasma whole blood plasma whole bl

fluorene NA 0.37 0.35 0.53 0.24 0.27 0.33 0.27 0.17 0.11 

phenanthrene NA 0.34 0.20 0.23 0.04 0.10 0.10 0.88 0.30 0.35 

pyrene NA 0.49 0.31 0.21 0.05 0.14 0.21 0.35 0.19 0.46 

benzo[a]pyrene NA NA 0.25 0.70 0.11 0.85 0.11 0.69 0.06 1.14 1‐methylnaphthalene NA NA NA NA 0.44 0.28 NA NA NA NA 

2‐methylnaphthalene NA 0.58 0.25 0.26 1.23 0.85 0.23 0.72 0.07 4.94 

2,6‐dimethylnaphthalene NA 0.62 0.28 0.56 0.81 0.53 0.22 0.95 0.12 0.17 

1,7‐dimethylphenanthrene NA NA 0.88 0.44 0.16 0.10 1.08 0.43 NA NA 

9‐methylphenanthrene NA 0.14 0.72 0.39 0.08 0.06 0.31 0.48 0.72 0.70 

3‐methylphenanthrene NA 0.14 0.25 0.07 0.08 0.04 0.23 0.79 0.19 0.40 

1‐naphthol NA NA 0.36 0.38 NA NA NA NA NA NA 

2,3‐dihydroxynaphthalene NA NA NA NA NA NA NA NA NA NA 

2‐methyl‐1‐naphthol NA NA NA NA NA NA NA NA NA NA 

2‐hydroxyfluorene NA NA NA NA NA NA NA NA NA NA 

1‐hydroxypyrene NA NA NA NA NA NA NA NA NA NA 

DOSS (ion) NA NA NA NA 0.08 0.25 NA NA 1.28 0.24 
                         

  

Figures 1a and 1b: QA11Solution#1‐PAH. Consensus is the median of all values.

0

2

4

6

8

10

12

14

16

18

fluorene phenanthrene pyrene benzo[a]pyrene

ng/g

Fig. 1a: Solution

1

2

3

4

5

6

Consensus

Gravimetric
 

   

0

10

20

30

40

50

60

70

80

90

ng/g

Fig. 1b: Solution

123456

Consensus

Gravimetric
                               

  

Figures 2a and 2b: Graphical results from QA11Plasma. Consensus is the median of all values.

0

2000

4000

6000

8000

10000

12000

fluorene phenanthrene pyrene benzo[a]pyrene

pg/g

Fig 2a: QA11Plasma

1

2

3

4

5

6

Consensus

Gravimetric
   

0

5000

10000

15000

20000

25000

pg/g

Fig. 2b: QA11Plasma

1

2

3

4

5

6

Consensus

Gravimetric
                             

   

Figures 3a and 3b: Graphical results from QA11WholeBlood. Consensus is the median of all

values.

0

2000

4000

6000

8000

10000

12000

14000

fluorene phenanthrene pyrene benzo[a]pyrene

pg/g

Fig 3a: QA11WholeBlood

1

2

3

4

5

6

Consensus

Gravimetric
   

0

5000

10000

15000

20000

25000

pg/g

Fig 3b: QA11WholeBlood

1

2

3

4

5

6

Consensus

Gravimetric
          

 

Appendix A: Instructions for the Exercise
                   

   

               

   

                               

                           

                        

                           

                           

                                   

           

                          

                         

  

   

                                    

                                

                           

     

                         

                   

                               

                             

        

                                 

                             

                               

                       

                 

                             

                                 

                                   

   

Interlaboratory Analytical Comparison Study to Support Deepwater Horizon Natural Resource

Damage Assessment

Intercomparison Exercise: Blood QA1101 Description of Materials and

Instructions

Intercomparison Exercise Materials:

There are three materials to be used for the exercise. The plasma and whole blood

(QA11Plasma and QA11WholeBlood) samples are 4.5 mL aliquots of plasma and whole blood in

collected non‐lethally from American alligators. Both materials have been amended with the

parent PAHs, alkylated PAHs and PAH metabolites listed in Table 1 and dioctyl sodium

sulfosuccinate (DOSS). Concentrations range from <1 ng/mL up to approximately 20 ng/mL.

Four vials per material are supplied; three are to be analyzed for the exercise and an extra vial

is supplied as a backup.

Two additional solutions are also supplied. The first solution contains parent, alkylated PAHs

and PAH metabolites in isooctane (QA11Solution#1‐PAH) and the second solution is DOSS in

methanol (QA11Solution#2‐DOSS).

Storage of Materials:

The blood materials should be stored at a minimum of ‐20 oC in the dark. Blood can be stored

in a ‐80 oC freezer as well (preferred). The two solutions (QA11Solutions #1 and #2) should be

stored between of ‐4 o

C and ‐20 oC in the dark until use.

Instructions for Use:

You are to analyze all materials using your laboratory's and/or program's analytical protocols,

for the concentrations (mass/mass) of the parent PAH compounds, alkylated PAH compounds,

PAH metabolites and DOSS. A target list of compounds are presented in Table 1; however,

participants do not need to quantify all of these compounds and can add additional compounds

when reporting the data.

The amount of blood used for each analysis should correspond to the amount of blood that you

would typically analyze as prescribed in your protocols. Prior to opening the blood cryovials

you should vortex the vial to mix the contents. Samples for analysis should be withdrawn

immediately after opening the cryovial and should be processed without delay. Unused

material can be stored frozen in the cryovials.

The PAH and DOSS solutions (QA11Solutions #1 and #2) should be analyzed as is without

cleanup. The mass of each vial (solution, cap and vial) was taken just prior to shipment. Weight

each vial prior to use and use the supplied tare mass (vial plus cap) to adjust for solvent

evaporation.
                       

                      

                           

                           

                             

                             

                     

                        

     

                               

                         

                       

                              

                           

                               

                                   

                               

                           

         

                            

                         

                           

                                  

     

     

               

                     

                   

                          

                         

                          

                             

                          

                               

                                   

                                   

   

You should analyze three samples of QA11Plasma and QA11WholeBlood and make three

measurements each of the QA11Solution#1‐PAH and QA11Solution#2‐DOSS. If time allows, we

are asking that you analyze the blood materials in separate batches; i.e., separate extractions,

cleanup, and calibration curves. This will allow a more realistic assessment of laboratory

precision over a longer term than the assessment obtained when a laboratory places all three

samples in the same batch and the resulting extracts are analyzed using the same calibration

curve, etc. Likewise, if time allows, make three separate measurements of QA11Solution#1‐

PAH and QA11Solutions#2‐DOSS using a separate calibration curve for each measurement.

Reporting of Results:

Please report one result, as if three figures were significant, for each of the analytes quantified

in each of the three replicates of the QA11WholeBlood and QA11Plasma and the determination

of compounds in QA11Solution#1‐PAH and QA11Solution#2‐DOSS. Report results in units of

pg/g. Report the date of measurement of each sample in the requested m/d/y format.

If you know that a target or non‐target compound is interfering (coeluting) with the

determination of a target analyte, please identify this issue by qualifying the data and note the

data qualifier used at the bottom of your table of results. Please note that any changes you

make to the column or row headings within the tables will not be seen by the coordinators

because only the table entries and comments at the bottom of the tables are automatically

transferred to the exercise database.

We prefer that concentration values be reported for each analyte determined. If the measured

concentration is below your typical reporting concentration for an analyte in a particular

matrix, you can report the number and list the appropriate detection limit, quantification limit,

etc. at the bottom of the data table. However, if you need to report non‐numerical data please

use the following conventions:

NA "Not analyzed", "not determined"

<"value" "Less than specified concentration", e.g., <8 pg/g

Other "Other"; add note of explanation at end of data table, e.g., interference

DL "Below detection limit" may be used, however, <"value" is preferable

Do not use negative numbers or parentheses to indicate "less than detection limits".

The attached file is an EXCEL file, QA11Blood01.xls. If you have any software/hardware

conversion problems, please contact John Kucklick. The data file templates also include places

for you to list the surrogate/internal standards and type of calibration curve used, and to

provide a brief description of the analyses. Please do not add spaces before entering numbers

in the table cells and enter them as "numbers" not as "labels". Please do not insert any

columns or rows within the table in the data file. If you wish to include additional data and/or

other information or comments, you may add it to the bottom of the data table in the attached

file.
                           

               

                           

   

     

       

  

                           

             

  

   

       

       

 

Submit your results by November 28, 2011 as an attached file via e‐mail to:

John.kucklick@nist.gov

Further Information:

If you need further information, please contact John at the following address or phone

numbers:

John Kucklick

NIST/Hollings Marine Laboratory

331 Fort Johnson Road

Charleston, SC 29412

Phone:843‐725‐4816

Table 1: List of Analytes of Interest in the Interlaboratory Analytical Comparison Study to

Support Deepwater Horizon Natural Resource Damage Assessment

Parent PAHs:

Benzo[a]pyrene

Fluorene

Pyrene

Phenanthrene

Alkylated PAHs:

2,6‐dimethylnaphthalene

2‐methylnaphthalene

1,7‐dimethylphenanthrene

9‐methylphenanthrene

3‐methyl phenanthrene

PAH Metabolites:

2,3‐dihydroxynaphthalene

1‐naphthol

2‐hyrdoxyfluorene

2‐methyl‐1‐naphthol

1‐hydroxypyrene

Oil Dispersant Indicator Compound:

dioctyl sodium sulfosuccinate (DOSS)
Appendix B:  Summary      of Methods Used
Table B1: Methods used for solutions.

PAHs

Calibrati

curve #

Lab # Instrument Phase Dimensions Mode of injection points 

1 GC/MS Rxi‐17sil 60 m x 0.25 mm x 0.25 μm PTV 6 

2 GC/MS HP5‐MS 30 m x 0.25 mm x 0.25 μm splitless 4 

3 Agilent 7890/Agilent 5975 MSD DB‐5 60 m x 0.25 mm x 0.25 μm on‐column 7 

4 GC/MS Restek Rtx‐5 30 m x 0.25 mm x 0.25 μm split/splitless 5 

5 GC/MS 5% Diphenyl, 95% Dimethy polysiloxane 30 m x 0.25 mm x 0.25 μm split/splitless 10 

6 Waters Acquity UPLC/FLR/MS/MS Waters CSH C18 0.1 m x 2.1 mm x 1.7 μm NA 6 

Alkylated PAHs

Calibrati

curve #

Lab # Instrument Phase Dimensions Mode of injection points 

1 GC/MS Rxi‐17sil 60 m x 0.25 mm x 0.25 μm PTV 6 

2 GC/MS HP5‐MS 30 m x 0.25 mm x 0.25 μm splitless 4 

3 Agilent 7890/Agilent 5975 MSD DB‐5 60 m x 0.25 mm x 0.25 μm on‐column 7 

4 GC/MS Restek Rtx‐5 30 m x 0.25 mm x 0.25 μm split/splitless 5 

5 GC/MS 5% Diphenyl, 95% Dimethy polysiloxane 30 m x 0.25 mm x 0.25 μm split/splitless 10 

6 Waters Quattro Micro GC/MS/MS Restek 5% diphenyl/ 95% dimethyl polysiloxane 31 m x 0.25 mm x 0.25 μm splitless 5 

Hydroxylated PAHs

Calibrati

curve #

Lab # Instrument Phase Dimensions Mode of injection points 

1 GC/MS Rxi‐17sil 60 m x 0.25 mm x 0.25 μm PTV 6 

2 GC/MS HP5‐MS 30 m x 0.25 mm x 0.25 μm splitless 4 

6 Waters Acquity UPLC/FLR/MS/MS Waters CSH C18 0.1 m x 2.1 mm x 1.7 μm NA 6 

DOSS

Calibrati

curve #

Lab # Instrument Phase Dimensions Mode of injection points 

3 Waters AcquityUPLC/AB Sciex QTrap 5500 C 18 0.05 m x 2.1 mm x 1.8 μm (particle size) on‐column 6 

5 HPLC/MS/MS C8 150 mm x 3 mm x 3 μm (particle size) NA 7 

6 Waters Acquity UPLC/MS/MS Waters BEH Shielded RP18 0.05 m x 2.1 mm x 1.7 μm (particle size) NA 6 
Table B2: Internal standards used for each compound for the analysis of solutions

Lab

Compoundfluorenephenanthrenepyrenebenzo[a]pyrene

1

naphthalene‐d8naphthalene‐d8

pyrene‐d10

benzo[a]pyrene‐d12

2

phenanthrene‐d10phenanthrene‐d10

fluoranthene‐d10

benzo[a]pyrene‐d12

3

acenaphthene‐d10acenaphthene‐d10

benzo[a]pyrene‐d12benzo[a]pyrene‐d12

4

phenanthrene‐d10

phenanthrene‐d10

fluoranthene‐d10

benzo[a]pyrene‐d12

5

Acenaphthene‐d10

phenanthrene‐d10

chrysene‐d12

perylene‐d12

1‐methylnaphthalene2‐methylnaphthalene2,6‐dimethylnaphthalene

1,7‐dimethylphenanthrene

9‐methylphenanthrene3‐methylphenanthrene

naphthalene‐d8naphthalene‐d8naphthalene‐d8

phenanthrene‐d10phenanthrene‐d10phenanthrene‐d10

naphthalene‐d8naphthalene‐d8

phenanthrene‐d10phenanthrene‐d10phenanthrene‐d10

naphthalene‐d8naphthalene‐d8

acenaphthene‐d10acenaphthene‐d10

acenaphthene‐d10*

acenaphthene‐d10

2‐methylnaphthalene‐d10

2‐methylnaphthalene‐d10

2,6‐dimethylnaphthalene‐d12

fluoranthene‐d10

phenanthrene‐d10phenanthrene‐d10

NA

naphthalene‐d8naphthalene‐d8

NA

phenanthrene‐d10phenanthrene‐d10

1‐naphthol

2,3‐dihydroxynaphthalene

2‐methyl‐1‐naphthol

2‐hydroxyfluorene1‐hydroxypyrene

13C pentachlorophenol13C pentachlorophenol13C pentachlorophenol

13C 6‐hydroxy chrysene13C 6‐hydroxy chrysene

naphthol‐d7naphthol‐d7naphthol‐d7naphthol‐d7naphthol‐d7

DOSS DOSS-d34 

*the response factor for

1‐methylphenanthrene

was used to quantify 9‐

methyl phenanthrene

DOSS‐d34 
Table B3: Methods used for the analysis of QA11Plasma and QA11WholeBlood

Lab # Reported 

g extracted 

QA11Plasama 

g extracted 

QA11WhloeBlood 

Extraction Method Extraction Solvent Extraction Time 

1 12/1/2011 4 4 

Focused Microwave Extraction 

5 mL sample + 5 mL formic acid + 6 mL 20% dichloromethane:hexane (V:V), repeat once 

250 W, 10 min 

ramp, 3 min hold, 90 oC, max 

pressure was 1.72 MPa with stirring and PowerMax on 

2 12/5/2011 4 4 Liquid:liquid 

Hexane:MTBE (1:1) 1st time followed by hexane:toluene (1:1) twice 

overnight in refrigerator for 1st solvent; then 10 to 15 min for other 2 solvent mixes 

3 11/28/2011 2 2 

PAHs - ASE; DOSS -QuEChERs 

PAHs - methylene chloride; DOSS - acetonitrile 

PAHs - 24 min @ 2000 psi and 100 deg C; DOSS - n/a 

4 12/12/2011 4 4 

liquid-liquid extraction Hexane 30 minutes. 

5 11/28/2011 

1 for PAH 0.1 

for DOSS 

1 for PAH 0.1 for 

DOSS Solvent partition 

Acetonitrile for DOSS, Hexane for PAH 1 min 

6 12/12/2011 0.5 and 1.0 0.5 and 1.0 QuEChERS/LLE Acetonitrile/Hexane 40 min 
Table B4: Methods used for the analysis of QA11Plasma and QA11WholeBlood

Method used for qu

Lab# Sample extract cleanup method PAH Alkyl PAH Hydroxylated 

1 Size exclusion chromatography (PlGel 300 mm x 7.5 mm) followed by alumina SPE

2 none

3 PAHs ‐ silica/alumina columns and HPLC‐SEC; DOSS ‐ none4 Chromatographic clean‐up using Biobead, 5% Silica and 2% Alumina columns

5 None

6 N/A

IS IS NA IS IS ISIS IS IS IS

IS IS 

IS IS IS 
Table B5: Methods used for the analysis of QA11Plasma and QA11WholeBlood

Lab Mode of Calibration cu

# Instrument Phase Dimensions injection points 1 GC/MS Rxi-17sil 60 m x 0.25 mm x 0.25 μm PTV 6 

2 GC/MS HP5-MS 30 m x 0.25 mm x 0.25 μm splitless 4 

3 Agilent 7890/Agilent 5975 MSD DB-5 60 m x 0.25 mm x 0.25 μm on-colμmn 7 

4 GC/MS Restek Rtx-5 30 m x 0.25 mm x 0.25 μm split/splitless 5 

5 GC/MS 5% Diphenyl, 95% Dimethy polysiloxane 30 m x 0.25 mm x 0.25 μm split/splitless 10 

6 Waters Acquity UPLC/FLR/MS/MS Waters CSH C18 0.1 m x 2.1 mm x 1.7 μm NA 6 

Lab 

Alkylated PAHs 

Mode of Calibration cu

# Instrument Phase Dimensions injection points 1 GC/MS Rxi-17sil 60 m x 0.25 mm x 0.25 μm PTV 6 

2 GC/MS HP5-MS 30 m x 0.25 mm x 0.25 μm splitless 4 

3 Agilent 7890/Agilent 5975 MSD DB-5 60 m x 0.25 mm x 0.25 μm on-column 7 

4 GC/MS Restek Rtx-5 30 m x 0.25 mm x 0.25 μm split/splitless 5 

5 GC/MS 5% Diphenyl, 95% Dimethy polysiloxane 30 m x 0.25 mm x 0.25 μm split/splitless 10 

6 Waters Quattro Micro GC/MS/MS 

Restek 5% diphenyl/ 95% dimethyl polysiloxane 31 m x 0.25 mm x 0.25 μm splitless 5 

Lab 

Hydroxylated PAHs 

Mode of Calibration cu

# Instrument Phase Dimensions injection points 

2 GC/MS HP5-MS 30 m x 0.25 mm x 0.25 μm splitless 4 

6 Waters Acquity UPLC/FLR/MS/MS Waters CSH C18 0.1 m x 2.1 mm x 1.7 μm NA 6 

DOSS 

Lab Mode of Calibration cu

# Instrument Phase Dimensions injection points 

3 5 6 

Waters AcquityUPLC/AB Sciex QTrap 5500HPLC/MS/MSWaters Acquity UPLC/MS/MS 

 C 18 

C8 

Waters BEH Shielded RP18 

0.05 m x 2.1 mm x 1.8 μm (particle size) 150 mm x 3 mm x 3 μm (particle size)0.05 m x 2.1 mm x 1.7 μm (particle size)

on column 

 NA  NA 

6 7 6 
Table B6: Methods used for the analysis of QA11Plasma and QA11WholeBlood

PAHs

Lab # IS/surrogate added prior to extraction Used? Added prior to analysis 

1 napthalane‐d8; pyrene‐d10; benzo[a]pyrene‐d12; phenanthrene‐d10 Yes

2 naphthalene‐d8; phenanthrene‐d10; fluoranthene‐d10; B[a]P‐d12 Yes

3 naphthalene‐d8, acenaphthene‐d10, Benzo[a]pyrene‐d12 Yes phenanthrene‐d10; prior to cle

phenanthrene‐d10; fluoranthene‐d10, benzo(a)pyrene‐d12, 2‐methylnaphthalene‐d10 and acenaphthene‐d10, pyrene‐d10 

4 2,6‐Dimethylnaphthalene‐d12 Yes benzo(e)pyrene‐d12

naphthalene‐d8, acenaphthene

5 fluorene‐d10, fluoranthene‐d10, terphenyl‐d14 yes phenanthrene‐d10, chrysene‐d

6 naphthalene‐d8 Yes chrysene‐d12 

Alkylated PAHs

Lab # IS/surrogate added prior to extraction Used? Added prior to analysis 

1 napthalane‐d8; pyrene‐d10; benzo[a]pyrene‐d12; phenanthrene‐d10 Yes

2 naphthalene‐d8; phenanthrene‐d10; fluoranthene‐d10; B[a]P‐d12 Yes

3 naphthalene‐d8, acenaphthene‐d10, benzo[a]pyrene‐d12 Yes phenanthrene‐d10; prior to cle

phenanthrene‐d10; fluoranthene‐d10, benzo[a]pyrene‐d12, 2‐methylnaphthalene‐d10 and d10‐acenaphthene, d10‐pyrene 

4 2,6‐dimethylnaphthalene‐d12 Yes benzo(e)pyrene

naphthalene‐d8, acenaphthene

5 fluorene‐d10, fluoranthene‐d10, terphenyl‐d14 yes phenanthrene‐d10, chrysene‐d

6 naphthalene‐d8 Yes chrysene‐d12 

Hydroxylated PAHs

Lab # IS/surrogate added prior to extraction Used? Added prior to analysis 

2 naphthol‐d7 Yes

6 naphthalene‐d8 chrysene‐d12

DOSS

Lab # IS/surrogate added prior to extraction Used? Added prior to analysis 

3 DOSS‐d34 Yes Sodium dodecyl sulfate‐d25 

5 DOSS‐d34 Yes DOSS‐C13 

6 Sodium dodecyl sulfate‐d1 (SDS‐d1) Yes Sodium dodecyl sulfate‐d25 (SD

*used to calculate surrogate recovery
Table B7: Internal standards used for each compound for the analysis of QA11Plasma and QA11WholeBlood

Lab 

1 2 3 4 5 

PAHs 

fluorene naphthalene-d8 phenanthrene-d10 acenaphthene-d10 phenanthrene-d10* Acenaphthene-d10 

phenanthrene naphthalene-d8 phenanthrene-d10 acenaphthene-d10 phenanthrene-d10* phenanthrene-d10 

pyrene pyrene-d10 fluoranthene-d10 benzo[a]pyrene-d12 fluoranthene-d10* chrysene-d12 

benzo[a]pyrene benzo[a]pyrene-d12 benzo[a]pyrene-d12 benzo[a]pyrene-d12 benzo[a]pyrene-d12* perylene-d12 

1-methylnaphthalene 2-methylnaphthalene 

naphthalene-d8 naphthalene-d8 naphthalene-d8 

Alkylated PAHs 

naphthalene‐d8naphthalene‐d8

2-methylnaphthalene-d10**2-methylnaphthalene-d10**

 NA  naphthalene-d8 

2,6-dimethylnaphthalene naphthalene-d8 naphthalene-d8 acenaphthene-d10 2,6-dimethylnaphthalene-d12** naphthalene-d8 1,7-dimethylphenanthrene phenanthrene-d10 phenanthrene-d10 acenaphthene-d10 fluoranthene-d10* NA 9-methylphenanthrene phenanthrene-d10 phenanthrene-d10 acenaphthene-d10 phenanthrene-d10* phenanthrene-d10 

3-methylphenanthrene phenanthrene-d10 phenanthrene-d10 acenaphthene-d10 phenanthrene-d10* phenanthrene-d10 

PAH Metabolites 

1-naphthol naphthol-d7 

2,3-dihydroxynaphthalene naphthol-d7 

2-methyl-1-naphthol naphthol-d7 

2-hydroxyfluorene naphthol-d7 

1-hydroxypyrene naphthol-d7 

DOSS 

DOSS DOSS-d34 DOSS-d34 

notes: 

acceptable range 60 % to 

130 % 

*the response factor for

1‐methylphenanthrene

was used to quantify 9‐

methyl phenanthrene

*acceptable range 30 % to 

130 % 

**acceptable range 20 % to 

130 % 

acceptable range 70 % 

to 130 % 
Appendix C: Participating Laboratories
             

             

                 

                 

                

   

                    

Participating Laboratories

Axys Analytical Services Ltd., Sidney, BC Canada

Columbia Analytical Services Inc., Kelso, WA USA

National Institute of Standards and Technology, Charleston, SC USA

National Institute of Standards and Technology, Gaithersburg, MD USA

National Oceanic and Atmospheric Administration, Northwest Fisheries Science Center, Seattle,

WA USA

University of Connecticut, Center for Environmental Sciences and Engineering, Storrs, CT USA