Reenie M. Parris

Comparison of methods for the gas-chromatographic determination of PCB congeners and chlorinated pesticides in marine reference materials

SummaryThree gas-chromatographic (GC) columns with different selectivity (DB-5, DB-1701, and C-18) and two different GC detectors (electron-capture and mass-spectrometric) were used to analyze three Standard Reference Materials (SRMs), which are available from the National Institute of Standards and Technology (NIST), and two Certified Reference Materials (CRMs), which are available from the Community Bureau of Reference (BCR), for polychlorinated biphenyl (PCB) congeners and chlorinated pesticides. The materials analyzed were: SRM 1588, Organics in Cod Liver Oil; SRM 1941, Organics in Marine Sediment; SRM 1974, Organics in Mussel Tissue (Mytilus edulis); CRM 349, Chlorobiphenyls in Cod Liver Oil; and CRM 350, Chlorobiphenyls in Mackerel Oil. Results from these different methods are compared, and concentrations for additional PCB congeners and chlorinated pesticides in these reference materials, which have not been measured previously, are reported.

Preparation and analysis of a marine sediment reference material for the determination of trace organic constituents

SummaryA river sediment Standard Reference Material (SRM) has been prepared and analyzed for determination of the concentrations of trace organic constituents. SRM 1939, “Polychlorinated Biphenyls (PCBs) in River Sediment A”, has been certified for the concentrations of three PCB congeners using the results obtained from capillary column gas chromatography with electron capture detection (GC-ECD) and from multidimensional (dual column) capillary gas chromatography with mass spectrometric detection (MCGC-MSD). For SRM certification, two independent analytical procedures are usually required. If only one analytical technique is used or if the procedures are not independent, then the concentrations are reported as “noncertified or informational” values rather than “certified” values. Noncertified values for 14 additional PCB congeners and five chlorinated pesticides, determined by GC-ECD, are also reported as well as noncertified concentrations for five polycyclic aromatic hydrocarbons (PAHs), determined using gas chromatography with mass spectrometric detection (GC-MSD). SRM 1939 complements SRM 1941, “Organics in Marine Sediment”, since both materials have 12 PCB congeners, five PAHs and five chlorinated pesticides in common. However, the concentrations differ by an order of magnitude for PAHs, and from one to over two orders of magnitude for the PCB congeners and chlorinated pesticides.

Polychlorinated Biphenyl (PCB) Congeners and Chlorinated Pesticides in a Cod Liver Oil Reference Material

Abstract A cod liver oil reference material, Standard Reference Material (SRM) 1588, which was issued by the National Institute of Standards and Technology (NIST) in 1989, has certified concentrations for five polychlorinated biphenyl (PCB) congeners and ten chlorinated pesticides. Recently, this SRM has been extensively characterized by additional analyses at NIST and by analyses at the Canadian Wildlife Service (CWS) where the SRM was used as a control sample during routine analyses of wildlife tissue specimens. In this paper the results from NIST and CWS are compared and the concentrations for over 40 PCB congeners and 20 chlorinated hydrocarbons are reported.

Liquid chromatography—gas chromatography procedure to determine the concentration of dibenzothiophene in a crude oil matrix

Abstract The concentration of dibenzothiopene in SRM 1582, Wilmington crude oil, was determined using a technique which combines liquid chromatography and gas chromatography. In particular, liquid chromatography was utilized for initial sample clean-up and separation of the thiophenes. A dual-flame photometric detector specific for sulfur-containing compounds was used as the detector for gas chromatography. In order to further minimize possible sources of error due to the natural hydrocarbon matrix of the oil, a standard addition method was also utilized.

Standard Reference Materials for the Determination of Polycyclic Aromatic Hydrocarbons in Environmental Samples -- Current Activities

SummaryRecent activities at the National Institute of Standards and Technology (NIST) related to the development of standard reference materials (SRMs) for the determination of polycyclic aromatic hydrocarbons (PAHs) are described. These activities include: (1) the development of four new calibration solution SRMs, a marine sediment SRM, and a frozen mussel tissue SRM; (2) noncertified measurements of PAHs for two additional sediment SRMs; and (3) the establishment of reference Ames bioassay mutagenicity values on three existing SRMs. Activities in progress include the recertification of the existing air particulate and diesel particulate SRMs and the preparation of a new diesel particulate extract SRM.

NIST standard reference materials (SRMs) for polychlorinated biphenyl (PCB) determinations and their applicability to toxaphene measurements

Abstract In the past five years the National Institute of Standards and Technology (NIST) has developed several Standard Reference Materials (SRMs) to assist in the validation of measurements of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in environmental samples. The following natural matrix SRMs have been issued: SRM 1588, Organics in Cod Liver Oil; SRM 1939, PCB Congeners in River Sediment; SRM 1941, Organics in Marine Sediment; SRM 1974, Organics in Mussel Tissue (Mytilus edulis); and SRM 1945, Whale Blubber. All of these SRMs have been analyzed for selected PCB congeners and chlorinated pesticides, and three of these materials (SRMs 1939, 1941, and 1974) have also been analyzed for polycyclic aromatic hydrocarbons (PAHs). In 1982, SRM 1649, Urban Dust/Organics, was issued with certified concentrations for selected PAHs. Recently, SRM 1649 has been analyzed for selected PCB congeners and chlorinated pesticides. Toxaphene measurements have not been made at NIST for these SRMs; however, these SRMs represent the environmental matrices that are typically analyzed for toxaphene. Recommended values for toxaphene concentrations could be established on any of these materials through interlaboratory comparison exercises involving laboratories experienced in making toxaphene measurements. In this paper we describe these SRMs and discuss their suitability as potential reference materials for toxaphene measurements.

Analysis of nitrogen heterocycles in shale oil by a dual capillary column heart cutting technique

Abstract The analysis of nitrogen heterocycles in a shale oil matrix is described. A dual column gas chromatograph is used for the analysis after a simple sample preparation scheme is used. Details of the apparatus, especially the inter-column pneumatic microswitch, are given. Quantitation by the standard addition method using internal volume corrections is described. Future direction for further development of this technique is briefly discussed.

CCQM-K27-Subsequent: Key Comparison (subsequent) for the Determination of Ethanol in Aqueous Matrix

Ethanol is important both forensically (“drunk driving” or driving while under the influence, “DWI”, regulations) and commercially (alcoholic beverages). Blood-and breath-alcohol testing can be imposed on individuals operating private vehicles such as cars, boats, or snowmobiles, or operators of commercial vehicles like trucks, planes, and ships. The various levels of blood alcohol that determine whether these operators are considered legally impaired vary depending on the circumstances, and locality Accurate calibration and validation of instrumentation is critical in areas of forensic testing where quantitative analysis directly affects the outcome of criminal prosecutions, as is the case with the determination of ethanol in blood and breath. Additionally, the accurate assessment of the alcoholic content of beverages is a commercially important commodity. In 2002, the CCQM conducted a Key Comparison (CCQM-K27) for the determination of ethanol in aqueous matrix with nine participants. A report on this project has been approved by the CCQM and can be found at the BIPM website [1]. CCQM-K27 was comprised of three samples, one at low mass fraction of ethanol in water (nominal concentration of 0.8 mg/g), one at high level (nominal concentration of 120 mg/g), and one wine matrix (nominal concentration of 81 mg/g). Overall agreement among eight participants using gas chromatography with flame ionization detection (GC-FID), titrimetry, isotope dilution gas chromatography/mass spectrometry (GC-IDMS), and gas chromatography-combustion-isotope ratio mass spectrometry (ID-GC-C-IRMS) was good. The ninth participant used a headspace GC-FID method that had not been validated in an earlier pilot study (CCQM-P35).

CCQM-K12: The determination of creatinine in serum

A Key Comparison on the determination of creatinine in human serum organized by the Consultative Committee on Amount of Substance (CCQM) was carried out in 2001. To address the measurement traceability needs of the clinical chemistry community, the CCQM is undertaking Key Comparisons to document the capabilities of national metrology institutes (NMIs) that provide measurement services in this area. This Key Comparison, along with two others recently completed, CCQM-K6 and CCQM-K11, determination of total cholesterol and glucose, respectively, in serum, will provide a basis for evaluating the capabilities of NMIs for the determination of well-defined, organic substances of similar molecular weights and concentrations in human serum. Participants in CCQM-K12 included: National Institute of Standards and Technology (NIST) [USA], Coordinating Laboratory; Institute for Reference Materials and Measurements (IRMM) [EU]; Korea Research Institute of Standards and Science (KRISS) [S Korea]; Laboratory of the Government Chemist, (LGC) [UK]; and Physikalisch-Technische Bundesanstalt (PTB) [Germany]. Two frozen human serum materials were analyzed by each of the participants using either ID-GC/MS-based methods (three laboratories) or ID-LC/MS-based methods (two laboratories). Agreement of results among the participants was excellent, in accordance with the agreement found in a pilot study (CCQM-P9) for creatinine in serum. The resulting Key Comparison Reference Values had expanded uncertainties of less than 1% for both materials. In conclusion, five NMIs have demonstrated their ability to make reference measurements of creatinine in serum using isotope dilution-based methods that, when executed properly, provide measurements that are precise, accurate and SI traceable. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the Mutual Recognition Arrangement (MRA).

CCQM-K11: The determination of glucose in serum

A Key Comparison on the determination of glucose in human serum organized by the Consultative Committee on Amount of Substance (CCQM) was carried out in 2001. To address the measurement traceability needs of the clinical chemistry community, the CCQM is undertaking Key Comparisons to document the capabilities of national metrology institutes (NMIs) that provide measurement services in this area. This Key Comparison, along with two others recently completed, CCQM-K6 and CCQM-K12, determination of total cholesterol and creatinine, respectively, in serum, will provide a basis for evaluating the capabilities of NMIs for the determination of well-defined, organic substances of similar molecular weights and concentrations in human serum. Participants in CCQM-K11 included: National Institute of Standards and Technology (NIST) [USA], Coordinating Laboratory; Korea Research Institute of Standards and Science (KRISS) [S Korea]; and Physikalisch-Technische Bundesanstalt (PTB) [Germany]. A frozen human serum material was analysed by each of the participants using ID-GC/MS-based methods. Agreement of results among the participants was good, with a relative range of <1%, yielding a Key Comparison Reference Value of 0.7762 ? 0.0088 mg/g. These results were in accordance with the good agreement found for two serum materials in a pilot study (CCQM-P8) involving the same participants. In conclusion, three NMIs have demonstrated their ability to make reference measurements of glucose in serum using isotope dilution-based methods that, when executed properly, provide measurements that are precise, accurate and SI traceable. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the Mutual Recognition Arrangement (MRA).