This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of samarium. A unit of SRM 3147a consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of samarium. The solution contains nitric acid at a volume fraction of approximately 10 %, which is equivalent to a concentration (molarity) of approximately 1.6 mol/L. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of silicon. A unit of SRM 3150 consists of 50 mL of solution prepared gravimetrically to contain a known mass fraction of silicon in a high-density polyethylene bottle sealed in an aluminized bag. The solution is prepared gravimetrically from sodium metasilicate nonahydrate to contain a known mass fraction of silicon in water. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of silver. A unit of SRM 3151 consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of silver. The solution contains nitric acid at a mass fraction of approximately 14 %. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of tellurium. A unit of SRM 3156 consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of tellurium. The solution contains hydrochloric acid at a volume fraction of approximately 10 %, which is equivalent to an amount of substance concentration (molarity) of approximately 1.2 mol/L. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of thallium. A unit of SRM 3158 consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of thallium. The solution contains nitric acid at a volume fraction of approximately 10 %. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of vanadium. A unit of SRM 3165 consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of vanadium. The solution contains nitric acid at an amount of substance concentration (molarity) of approximately 1.6 mol/L. This data is public in the Certificate of Analysis for this material.

SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) - This Standard Reference Material (SRM) is intended for use in evaluating analytical methods for the determination of selected hydroxylated polycyclic aromatic hydrocarbons (hydroxylated PAHs) and phthalate, phenol, and volatile organic compound (VOC) metabolites in urine. All of the constituents for which certified and reference values are provided are naturally present in the urine. This data is public in the Certificate of Analysis for this material.

SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen) - This Standard Reference Material (SRM) is intended for use in evaluating analytical methods for the determination of selected hydroxylated polycyclic aromatic hydrocarbons (hydroxylated PAHs) and phthalate, phenol, and volatile organic compound (VOC) metabolites in urine. All of the constituents for which certified and reference values are provided are naturally present in the urine. This data is public in the Certificate of Analysis for this material.

Standard Reference Material 695 Trace Elements in Multi-Nutrient Fertilizer - This Standard Reference Material (SRM) is intended primarily for use in the evaluation of techniques employed in the analysis of multi-nutrient fertilizer materials and materials of a similar matrix. A unit of SRM 695 consists of approximately 70 g of jet-milled fertilizer. This data is public in the Certificate of Analysis for this material.

Standard Reference Material-1721: Southern Oceanic Air. Ambient Nominal Amount of Substance Fraction for Carbon Dioxide, Methane & Nitrous Oxide. This Standard Reference Material (SRM) is a primary gas mixture for which the amount-of-substance fraction, expressed as concentration, may be related to secondary working standards. This SRM is intended for the calibration of instruments used for ambient carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) determinations and for other applications. This data is public in the Certificate of Analysis for this material.