Organics in Mussel Tissue (Mytilus edulis) - This Standard Reference Material (SRM) is a frozen mussel tissue homogenate intended for use in evaluating analytical methods for the determination of selected polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polybrominated diphenyl ether (PBDE) congeners in marine bivalve mollusk tissue and similar matrices. All of the constituents for which certified and reference values are provided in SRM 1974c were naturally present in the tissue material before processing. A unit of SRM 1974c consists of five jars each containing approximately 10 g (wet basis) of frozen tissue homogenate. This data is public in the Certificate of Analysis for this material.

SRM 1941b Organics in Marine Sediment - This Standard Reference Material (SRM) is marine sediment collected at the mouth of the Baltimore (MD) Harbor. SRM 1941b is intended for use in evaluating analytical methods for the determination of selected polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB) congeners, and chlorinated pesticides in marine sediment and similar matrices. Information values are also provided for total organic carbon (TOC), total carbon, hydrogen, and nitrogen. All of the constituents for which certified, reference, and information values are provided in SRM 1941b were naturally present in the sediment before processing. A unit of SRM 1941b consists of a bottle containing 50 g of radiation-sterilized, freeze-dried sediment. This data is public in the Certificate of Analysis for this material.

SRM 1941b Organics in Marine Sediment - This Standard Reference Material (SRM) is marine sediment collected at the mouth of the Baltimore (MD) Harbor. SRM 1941b is intended for use in evaluating analytical methods for the determination of selected polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB) congeners, and chlorinated pesticides in marine sediment and similar matrices. Information values are also provided for total organic carbon (TOC), total carbon, hydrogen, and nitrogen. All of the constituents for which certified, reference, and information values are provided in SRM 1941b were naturally present in the sediment before processing. A unit of SRM 1941b consists of a bottle containing 50 g of radiation-sterilized, freeze-dried sediment. This data is public in the Certificate of Analysis for this material.

SRM 1947 Lake Michigan Fish Tissue - This Standard Reference Material (SRM) is a frozen fish tissue homogenate that was prepared from fish collected from Lake Michigan, and is intended primarily for use in evaluating analytical methods for the determination of selected trace elements, methylmercury, total mercury, polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, polybrominated diphenyl ether (PBDE) congeners, perfluoroalkyl acids (PFAAs), proximates, ?-hexabromocyclododecane (?-HBCD), caloric content, and fatty acids in fish tissue and similar matrices. All of the constituents for which certified, reference, and information mass fraction values are provided are naturally present in the fish tissue homogenate. A unit of SRM 1947 consists of five bottles, each containing approximately 8 g (wet basis) of frozen tissue homogenate. This data is public in the Certificate of Analysis for this material.

SRM 1946 Lake Superior Fish Tissue - This Standard Reference Material (SRM) is a frozen fish tissue homogenate that was prepared from lake trout (Salvelinus namaycush namaycush) collected near the Apostle Islands in Lake Superior (U.S./Canada), and is intended primarily for use in evaluating analytical methods for the determination of polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, polybrominated diphenyl ether (PBDE) congeners, perfluorooctanesulfonic acid (PFOS), fatty acids (including omega-3 fatty acids), extractable fat, methylmercury, total mercury, proximates , ?-hexabromocyclododecane (?-HBCD), and selected trace elements in fish tissue and similar matrices. All of the constituents for which certified, reference, and information mass fraction values are provided are naturally present in the fish tissue homogenate. A unit of SRM 1946 consists of five bottles, each containing approximately 7 g to 9 g (wet basis) of frozen tissue homogenate. This data is public in the Certificate of Analysis for this material.

SRM 1953 Organic Contaminants in Non-Fortified Human Milk - This Standard Reference Material (SRM) is intended for use in evaluating analytical methods for the determination of selected polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, polybrominated diphenyl ether (PBDE) congeners, and elements in human milk and similar matrices. Reference concentration values are provided for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), as well as some inorganic constituents. An information concentration value is provided for the PCB mixture Aroclor 1260. All of the constituents for which certified, reference, and information concentration values are provided in SRM 1953 are naturally present in the milk. A unit of SRM 1953 consists of five bottles of approximately 5 mL of frozen non-fortified human milk. This data is public in the Certificate of Analysis for this material.

SRM 1957 Organic Contaminants in Non-Fortified Human Serum (Freeze-Dried) - This Standard Reference Material (SRM) is intended for use in evaluating analytical methods for the determination of selected polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polybrominated diphenyl ether (PBDE) congeners in human serum and similar matrices. Reference values are provided for selected polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), perflourinated compounds (PFCs), and serum lipid. Information values are provided for selected hydroxylated compounds. All of the constituents for which values are provided in SRM 1957 are naturally present in the freeze-dried human serum. A unit of SRM 1957 consists of five 30 mL vials each containing freeze-dried non-fortified human serum. Before use, the serum in each vial must be reconstituted with 10.7 mL of distilled or HPLC-grade water. This data is public in the Certificate of Analysis for this material.

Real-time PCR results of a round robin evaluation of 5 assays that target dreissenid mussel DNA. Water samples collected from waters with and without dreissenid mussels were analyzed using these five assays in four USGS laboratories. Samples from waters without dreissenid mussels were spiked with known amounts of dreissend DNA.

Real-time PCR results of a round robin evaluation of 5 assays that target dreissenid mussel DNA. Water samples collected from waters with and without dreissenid mussels were analyzed using these five assays in four USGS laboratories. Samples from waters without dreissenid mussels were spiked with known amounts of dreissend DNA.

SRM 1958 Organic Contaminants in Fortified Human Serum (Freeze-Dried) - This Standard Reference Material (SRM) is intended for use in evaluating analytical methods for the determination of selected polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polybrominated diphenyl ether (PBDE) congeners in human serum and similar matrices. Reference values are provided for selected polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho PCB congeners, perfluorinated compounds (PFCs), and serum lipid. Information values are provided for selected toxaphene congeners and hydroxylated compounds. A unit of SRM 1958 consists of five vials, each containing freeze-dried fortified human serum. Before use, the serum in each bottle must be reconstituted with 10.7 mL of distilled or HPLC-grade water. This data is public in the Certificate of Analysis for this material.