1、API PUBL*4579 74 0732270 0528468 T87 Interlaboratory Study of Three Methods for Analyzing Petroleum Hydrocarbons in Soils Diesel-Range Organics (DRO) Gasoline-Range Organics (GRO) Petroleum Hydrocarbons (PHC) HEALTH AND ENVIRONMENTAL SCIENCES API PUBLICATION NUMBER 4599 JUNE 1994 American Petroleum
2、Institute 1220 L Street. Northwest 11 Washington, D.C. 20005 API PUBL*4599 94 0732290 05284b9 913 Interlaboratory Study of Three Methods for Analyzing Petroleum Hydrocarbons in Soils Diesel-Range Organics (DRO) Gasoline-Range Organics (GRO) Petroleum Hydrocarbons (PHC) Health and Environmental Scien
3、ces Department API PUBLICATION NUMBER 4599 PREPARED UNDER CONTRACT BY: TISCH LE R/KOCU REK ENESCO-ROCKY MOUNTAIN ANALYTICAL LABORATORY MARCH 1994 American Petroleum Institute API PUBL+4599 94 0732290 0528470 b35 FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT
4、 TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. API IS NOT UNDERTAKING TO MEET THE DUTIES OF EMPLOYERS, MANUFAC- TURERS, OR SUPPLIERS To WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY RISKS AND PREC
5、AUTIONS, NOR UNDERTAKING THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED AS GRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY METHOD, APPARATUS, OR PRODUCT COV- ERED BY LETTERS PATENT. NEITHE
6、R SHOULD ANYTHING CONTAINED IN ITY FOR INFRINGEMENT OF LETTERS PATENT. THE PUBLICATION BE CONSTRUED AS INSURING ANYONE AGAINST LIABIL- Copyright O 1994 American Petroleum Institute ;i API PUBLJ4599 94 0732270 0528471 571 = ACKNOWLEDGMENTS THE FOLLOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS O
7、F TIME AND EXPERTISE DURING THIS STUDY AND IN THE PREPARATION OF THIS REPORT: API STAFF CONTACTS Roger Claff, Health and Environmental Sciences Department Bruce Bauman, Health and Environmental Sciences Department MEMBERS OF THE ENVIRONMENTAL MONITORING WORKGROUP Dominick DeAngelis, Mobil Oil Corpor
8、ation Hamy Gearhart, Conoco Inc. Lynn Lane, ARCO Products Company Frank McEiroy, Exxon Research and Engineering Company Lee Polite, Ammo Corporation Harold Rhodes, Texaco Research and Development Company Ileana Rhodes, Shell Development Company George Stanko, Shell Development Company Allen Verstuyf
9、t, Chevron Research and Technology company TischlerKocurek and Rocky Mountain Analytical Laboratory would also like to thank Jeff Lowry of Environmental Resource Associates for his assistance in preparing samples for this study. iii API PUBL*4599 94 = 0732290 0528472 408 ABSTRACT This report present
10、s the results of an interlaboratory study conducted by the American Petroleum Institute (API) to validate three methods for analyzing petroleum hydrocarbons in soil: diesel-range organics (DRO) for C, to C, hydrocarbons, gasoline-range organics (GRO) for C, to C, hydrocarbons, and petroleum hydrocar
11、bons (PHC) for C, to C, hydrocarbons. Secondary goals of the study were to estimate interlaboratory practical quantification levels (PQLs) for the three methods; and to demonstrate that the GRO method with optional photoionization detection (PID) could be used to analyze for benzene, toluene, ethylb
12、enzene, and total xylenes (BTEX) so that both BTEX and total hydrocarbons could be obtained from the same method and the same sample. Method performance was judged by accuracy, overall precision, and single analyst precision. Accuracy for DRO and PHC was 82434% while GRO accuracy was 70%. Overall pr
13、ecision, as relative standard deviation (RSD), averaged 27% for the three methods. Single analyst precision, as RSD, was about half of the overall precision (14%). Overall precision as RSD for BTEX analysis by GRO/PID were 27% for benzene, 19% for toluene, 44% for ethylbenzene, and 15% for total xyl
14、enes. Since accuracy and precision were found to be concentration-dependent, regression equations were developed to describe expected method performance at different concentrations. Practical quantification levels (PQLs) were estimated by two different methods. The range in PQLs was 12-20 mgkg for D
15、RO, 17-130 mg/kg for GRO, and 50-104 mg/kg for PHC. Acceptable method performance for the DRO, GRO, and PHC methods was demonstrated by this interlaboratory study. Performance in accuracy and precision was comparable to the results of other validation studies conducted by the U.S. Environmental Prot
16、ection Agency (EPA). TABLE OF CONTENTS Section Page EXECUTIVE SUMMARY e5-1 1 . INTRODUCTION 1-1 BACKGROUND 1-1 RATIONALE FOR METHOD VALIDATION . 1-2 VALIDATION STUDY GOALS AND OBJECTIVES . 1-2 STUDY DESIGN 2-1 SAMPLE PREPARATION . 2-1 PARTICIPATING LABORATORIES 2-2 DATA ANALYSIS . 2-4 Outliers . 2-4
17、 Accuracy and Precision . 2-5 Practical Quantification Levels (PQLs) False Positives and False Negatives 2-5 BTEX 2-6 3 . DISCUSSION 3-1 OUTLIERS 3-1 ACCURACY AND PRECISION . 3-2 Determination of Method Performance 3-2 Evaluation of Method Performance . 3-7 PRACTICAL QUANTIFICATION LEVELS (PQLs) 3-9
18、 FALSE POSITIVES AND FALSE NEGATIVES . 3-10 BTEX BY GRO/PID . 3-10 2 . 2-5 . 4- 1 4 . REFERENCES API PUBLm4599 94 I 0732290 0528474 280 = Table 2.1 . 2.2 . 3.1 . 3.2 . 3.3 . 3.4 . 3.5 . LIST OF TABLES Paqe Sample Concentrations 2-2 Participating Laboratories . 2-3 Regression Equations for Accuracy a
19、nd Precision . 3-3 Average Performance: Accuracy and Precision 3-7 Classes of Trace Analysis Methods . 3-8 Method PQLs . 3-9 Relative Standard Deviation for BTEX by GRO/PID . 3-10 LIST OF FIGURES Fiqure Page 3.1 . DRO Recovery and Precision 3-4 3.2 . GRO Recovery and Precision . 3-5 PHC Recovery and
20、 Precision 3-6 3.3 . API PUBL*4599 94 0332290 0528475 117 = LIST OF APPENDICES A. METHOD PROTOCOLS Diesel Range Organics Gasoline Range Organics Pet roleum Hydrocarbons B. VERIFICATION OF PREPARED CONCENTRATIONS C. DATA AND CALCULATIONS Summary of Laboratory Results Youden Laboratory Ranking Test Gr
21、ubbs Outlier Test Recovery and Interlaboratory (Overall) Precision Intralaboratory (Single Analyst) Precision F-tests on EPA Regression Equations API PUBLM4599 94 0732290 052847b 053 EXECUTIVE SUMMARY This report presents the results of an interlaboratory study conducted by the American Petroleum In
22、stitute (API) for the purpose of validating three methods for the analysis of petroleum hydrocarbons in soil. These methods overcome many of the limitations of currently available methods and if validated, could be considered for use as consensus methods for petroleum hydrocarbons in soils. The thre
23、e methods which were the subject of this interlaboratory study are: Diesel-Range Organics (DRO) for C, to C, hydrocarbons Gasoline-Range Organics (GRO) for c6 to C, hydrocarbons Petroleum Hydrocarbons (PHC) for c6 to C, hydrocarbons The GRO and DRO methods were developed by API, and the PHC method w
24、as developed by Shell Development Company. A secondary goal of the study was to estimate interlaboratory practical quantification levels (PQLs) for each method. A third goal was to demonstrate that the GRO method with optional photoionization detection (PID) could be used to analyze for benzene, tol
25、uene, ethylbenzene, and total xylenes (BTEX) so that both BTEX and total hydrocarbons could be obtained from the same method and the same sample. Results and conclusions from this study are: Acceptable method performance for the DRO, GRO, and PHC methods has been demonstrated by this interlaboratory
26、 study. Performance in accuracy and precision is comparable to the results of other validation studies conducted by the U.S. Environmental Protection Agency (EPA). Method performance was judged by accuracy, overall precision, and single analyst precision. With the exception of GRO accuracy, the perf
27、ormance among the three methods was essentially the same. Accuracy for DRO and ES- 1 API PUBL*4599 94 m 0732290 0528477 TT m PHC was 82-84% while GRO accuracy was 70%. Overall precision, as relative standard deviation (RSD), averaged 27% for the three methods. Single analyst precision, as RSD, was a
28、bout half of the overall precision (1 4%). Since accuracy and precision were found to be concentration-dependent, regression equations were developed for all three methods to describe expected method performance at different concentrations. A reliable regression equation could not be developed for P
29、HC single analyst precision, however, so the average precision .was used to describe method performance for this parameter. The PHC single analyst precision regression could be improved with data from future studies. - Precision as measured by average relative standard deviation (RSD) for benzene, t
30、oluene, ethylbenzene, and xylene isomers (BTEX) analyses by GRO/PID were 27% for benzene, 19% for toluene, 44% for ethylbenzene, and 15% for total xylenes. Some laboratories did not strictly follow method protocols. Alternative standards, detectors, and integration techniques were used by some labor
31、atories. Recurrence of such deviations from method protocols can be minimized by emphasizing the requirements already specified in the methods and pointing out problems that result if they are not followed. Practical Quantification Levels (PQLs) were estimated by two different methods. The range in
32、PQLs was 12-20 mg/kg for DRO, 17-130 mg/kg for GRO, and 50-104 mg/kg for PHC. False positive rates were 22% for GRO and 20% for PHC. The false positive rate for DRO was not calculated because all laboratories reported measurable DRO concentrations in DRO blank samples. The blank samples were either
33、inadvertently spiked with diesel fuel or were low-level DRO samples mislabeled as blanks. False negatives were reported for low-concentration samples only. The false negative rate for DRO and GRO was 22% at concentrations of about 5 mg/kg; the PHC false negative rate was 3% at concentrations of 50 t
34、o 100 mg/kg. The average rejection rate for outliers was 25%, slightly higher than for similar interlaboratory studies conducted by EPA. ES-2 API PUBL*4599 94 0732290 0528478 926 = Section 1. INTRODUCTION BACKGROUND Since 1987, the American Petroleum Institute (API) has funded efforts to establish r
35、eliable analytical laboratory methods for the measurement of a wide range of petroleum hydrocarbons in soil. Currently available methods, although many are approved by the U.S. Environmental Protection Agency (EPA) and are in wide use by laboratories, are generally limited to certain analytes and/or
36、 are lacking in rigorous method performance data. For example, many total petroleum hydrocarbon (TPH) tests use Freon-I 13, which is not effective in extracting heavy distillates. TPH tests also have low recoveries for volatile hydrocarbon components of gasoline. Results from analyte-specific method
37、s, such as EPAs SW-846 methods and 600 series, are difficult to correlate to particular petroleum products. As a consequence, API sought to develop improved methods for gasoline-range and diesel-range organics in soil. API conducted a literature search and symposium to identify an analytical procedu
38、re for gasoline-range organics, originally defined as hydrocarbons in the C,-C, range, at environmental (ppb or ppm) concentrations. The selected method was to rely on existing technology and consider regulatory guidelines. The method selected was a capillary column gas chromatography/flame ionizati
39、on detector (GC/FID) technique, with sample introduction by extraction in methanol followed by purge-and-trap. A single laboratory validation study was conducted, as well as an evaluation of sampling techniques. The initial draft of the GRO method, the results of the single laboratory validation stu
40、dy, and the evaluation of sampling techniques are presented in Enseco (1 991). The interlaboratory study presented in this report is a continuation of the GRO research reported in Enseco (1991). Since that study, two additional methods - a diesel-range organics (DRO) method to measure C10-C28 hydroc
41、arbons, and a 1-1 API PUBLr9599 94 = 0732290 0528479 862 petroleum hydrocarbons (PHC) method to measure C,-C, hydrocarbons - have been drafted and are also addressed by this interlaboratory validation study. The GRO and DRO methods were developed by API, and the PHC method was developed by Shell Dev
42、elopment Company. RATIONALE FOR METHOD VALIDATION According to EPA (1988), validation consists of the selection of a cost-effective method capable of producing measurements of the type and quality desired for a particular application; and the verification that the selected method is technically soun
43、d and has been reduced to practice for practical purposes. General validation consists of testing, evaluating, and characterizing the method to the extent necessary to demonstrate that the method achieves a specified performance. General validation includes (EPA, 1988): Formal performance testing Pe
44、er review and comment Development of acceptance criteria Specification of QNQC requirements This report documents the results of multiple laboratory performance testing of the GRO/DRO/PHC methods on prepared soil samples, the modification of method protocols in response to subsequent peer review and
45、 comment, and the development of method acceptance criteria based on performance data. The resulting revised method protocols, including QNQC requirements, are provided in Appendix A. VALIDATION STUDY GOALS AND OBJECTIVES The primary goal of this study was to validate the GRO, DRO, and PHC methods w
46、ith acceptable accuracy and precision. If validated, the methods could be considered for use as consensus methods for petroleum hydrocarbons in soils. A secondary goal of the study was to estimate interlaboratory practical quantification levels (PQLs). A third goal was to demonstrate that the GRO me
47、thod with optional photoionization detection 1-2 API PUBL*4577 74 0732270 0528480 584 W (PID) could be used to analyze for benzene, toluene, ethylbenzene, and total xylenes (BTEX) so that the analytical results for both BTEX and total volatile hydrocarbons could be obtained from the same method and
48、the same sample. Detailed descriptions of these methods and the single laboratory validation results have been described previously (Walters et al., 1992; Parr et al., 1991; Enseco, 1991; Rhodes et al., 1991a,b). All three methods are based on determination by gas chromatography-flame ionization det
49、ection (GC/FID) and are derived from EPA SW- 846 Methods 8000, 8015, and 8100, and The American Society of Testing and Materials (ASTM) Method D 3328-78. All three methods have extensive quality control requirements, including quality control (QC) check sample analyses, surrogate spikes, blank analyses, and calibration. Matrix spikes, duplicates, field blanks, and other related QC samples are recommended as necessary to meet specific project objectives. The primary goal of each method is to determine the total concentration of chromatographable material that responds to an FID w
