This Standard Reference Material (SRM) is intended as a primary calibration standard for the quantitative determination of fluoride using anion ion chromatography (IC) or other methods. A unit of SRM 3183 consists of 50 mL of solution in a high density polyethylene bottle sealed in an aluminized bag. The solution is prepared gravimetrically to contain a known mass fraction of fluoride dissolved in filtered (0.22 µm) water having a minimum resistivity of 18 megaohm centimeters. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended as a primary calibration standard for the quantitative determination of bromide using anion ion chromatography (IC) or other methods. A unit of SRM 3184 consists of five 10 mL sealed borosilicate glass ampoules of solution prepared gravimetrically to contain a known mass fraction of bromide dissolved in filtered (0.22 µm) water having a minimum resistivity of 18 megaohm centimeters. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended as a primary standard for the quantitative determination of nitrate using anion ion chromatography (IC) or other methods. A unit of SRM 3185 consists of five 10 mL sealed borosilicate glass ampoules of solution. The solution is prepared gravimetrically to contain a known mass fraction of nitrate dissolved in filtered (0.22 µm) water having a minimum resistivity of 18 megaohm centimeters. 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 phosphate using anion ion chromatography (IC) or other methods. A unit of SRM 3186 consists of five 10 mL sealed borosilicate glass ampoules of solution prepared gravimetrically to contain a known mass fraction of phosphate dissolved in filtered (0.22 ?m) water having a minimum resistivity of 18 megaohm centimeters. This data is public in the Certificate of Analysis for this material.

Standard Reference Material SRM 915c Calcium Carbonate - This Standard Reference Material (SRM) is intended for use as an analytical standard of known purity. It is intended primarily for use in the calibration and standardization of procedures for calcium (Ca) determinations employed in clinical analysis and for routine critical evaluation of the daily working standards used in these procedures. This data is public in the Certificate of Analysis for this material.

SRM 194a Ammonium Dihydrogen Phosphate - This Standard Reference Material (SRM) is a highly purified and homogeneous lot of crystalline ammonium dihydrogen phosphate (NH4H2PO4). It is intended primarily for use as a working standard in the calibration and standardization of procedures employed in the fertilizer industry for the determination of ammoniacal nitrogen and phosphorus. A unit of SRM 194a consists of one bottle containing 90 g of crystalline ammonium dihydrogen phosphate. This data is public in the Certificate of Analysis for this material.

Standard Reference Material 200b Potassium Dihydrogen Phosphate (KH2PO4) - This Standard Reference Material (SRM) is a highly purified and homogeneous lot of crystalline potassium dihydrogen phosphate (KH2PO4). It is intended primarily for use as a working standard in the calibration and standardization of procedures employed in the fertilizer industry for the determination of potassium and phosphorus. A unit of SRM 200b consists of one bottle containing 90 g of crystalline potassium dihydrogen phosphate. This data is public in the Certificate of Analysis for this material.

SRM 3239 Isoflavones Calibration Solution - This Standard Reference Material (SRM) is intended primarily for use in calibration of instruments and techniques used for the determination of isoflavones. SRM 3239 consists of two solutions containing isoflavones at levels that reflect the mass fraction ratios found in soy products. This data is public in the Certificate of Analysis for this material.

This Standard Reference Material (SRM) is intended for use as an analytical standard of known potassium (K) and chloride (Cl-) content. This lot of potassium chloride (KCl) was prepared to ensure a material of high purity and homogeneity and has been assayed after drying at 500 °C. A unit of SRM 999c consists of a single glass bottle containing 30 g of the material. This data is public in the Certificate of Analysis for this material.

SRM 972a Vitamin D Metabolites in Frozen Human Serum - 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.