Standard Reference Material 2693 Bituminous Coal (Nominal Mass Fraction 0.5 % Sulfur) - This Standard Reference Material (SRM) is intended primarily for use in the evaluation of techniques employed in the determination of sulfur, mercury, chlorine, and ash content in coal and materials of a similar matrix. A unit of SRM 2693 consists of 50 g of bituminous coal ground to pass a 250 µm (60 mesh) sieve, homogenized, and packaged in an amber glass bottle and then sealed in an aluminized bag. This data is public in the Certificate of Analysis for this material.

Standard Reference Material 2719 Calcined Petroleum Coke - This Standard Reference Material (SRM) is intended primarily for use in the calibration of apparatus and the evaluation of techniques employed in the analysis of calcined petroleum coke and other materials with a similar matrix. SRM 2719 consists of 50 g of calcined petroleum coke ground to pass a 250 µm (60 mesh) sieve, homogenized, and bottled under an argon atmosphere. This data is public in the Certificate of Analysis for this material.

Standard Reference Material 2775 Sulfur in Foundry Coke - This Standard Reference Material (SRM) is intended primarily for use in the evaluation of test methods and for the calibration of instruments used to determine sulfur in foundry (metallurgical) coke. Each unit of SRM 2775 consists of 50 g of foundry coke that was ground to pass a 60 mesh (250 ?m) sieve, homogenized, and bottled under an argon atmosphere. This data is public in the Certificate of Analysis for this material.

Standard Reference Material 2776 Sulfur in Furnace Coke - This Standard Reference Material (SRM) is intended primarily for use in the evaluation of test methods and for the calibration of instruments used to determine sulfur in furnace (metallurgical) coke. Each unit of SRM 2776 consists of 50 g of furnace coke that was ground to pass a 250 ?m (60 mesh) sieve, homogenized, and bottled under an argon atmosphere. This data is public in the Certificate of Analysis for this material.

SRM 2973 Vitamin D Metabolites in Frozen Human Serum (High Level) - This Standard Reference Material (SRM) is intended for use as an accuracy control in the critical evaluation of methods for determining the amount-of-substance concentration of vitamin D metabolites in human serum. This SRM can also be used as a quality assurance tool for assigning values to in-house control materials for these constituents. This data is public in the Certificate of Analysis for this material.

SRM 671 Nickel Oxide, No. 1 - Standard Reference Material 671, Nickel Oxide No. 1 has been discontinued and is no longer being produced. The data is public in the Certificate of Analysis for this material.

Standard Reference Material 672 Nickel Oxide, No. 2 has been discontinued and is no longer being produced. The data is public in the Certificate of Analysis for this material.

Standard Reference Material 673 Nickel Oxide, No. 3 has been discontinued and is no longer being produced. The 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.