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.

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.

SRM 2950a Respirable Alpha Quartz on Filter Media (Nominal Mass of Alpha Quartz: 5 µg to 500 µg) - This Standard Reference Material (SRM) is intended primarily for the calibration of X-ray diffraction (XRD) spectrometers for the determination of respirable alpha quartz using National Institute for Occupational Safety and Health (NIOSH) Method 7500, or the equivalent. This data is public in the Certificate of Analysis for this material.

Liquid-chromatography-mass spectrometry (LC-MS) raw data sets from various instruments delivered in their native instrument format. 31 files in all. 7.5 GB data.

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 potassium (K) and chloride (Cl-) determinations employed in clinical analysis, including those using ion-selective electrodes, and for routine critical evaluation of the daily working standards used in these procedures. This lot of potassium chloride (KCl) was prepared to ensure a material of high purity and homogeneity and has been assayed after heating at 110 degrees C to 120 degrees C.

Sulfonephthalein pH indicator dyes have historically been noted for impurities originating from the synthesis process which lead to batch to batch differences in pH measurements. Uncertainties up to 0.1 pH units have been attributed to impurities in these reagents.