This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of tungsten. A unit of SRM 3163 consists of 50 mL of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of tungsten in a high-density polyethylene bottle sealed in an aluminized bag.

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.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of ytterbium. A unit of SRM 3166a consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of ytterbium. The solution contains nitric acid at a volume fraction of approximately 10 %, equivalent to 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.

SRM 635a Portland Cement (Blended with Slag) - This Standard Reference Material (SRM) is intended primarily for use in validation of chemical and instrumental methods of analysis of cements and materials of similar matrix for elemental contents. It can be used to validate value assignment of in-house reference materials. This data is public in the Certificate of Analysis for this material.

SRM 690 Iron Ore (Canada) is for use in checking chemical methods of analysis and in calibration with instrumental methods of analysis. This data is public in the Certificate of Analysis for this material.

SRM 691 Iron Oxide, Reduced is intended primarily for use in evaluating chemical methods and in calibrations associated with optical emission and x-ray spectrometric methods of analysis. This data is public in the Certificate of Analysis for this material.

SRM 692 iron Ore (Labrador) is intended primarily for use in checking chemical methods of analysis and in calibration with instrumental methods of analysis. This data is public in the Certificate of Analysis for this material.

SRM 693 Iron Ore (Nimba) - Standard Reference Material 693 Iron Ore (Nimba) is material in the form of powder (<0.1 mm) for use in checking chemical methods of analysis and in calibration with instrumental methods of analysis. This data is public in the Certificate of Analysis for this material.