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.

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.

A comparison of the expanded uncertainty for certified values of iodine in food matrix CRMs. The CRMS were found by searching The European Virtual Institute for Speciation Analysis (EVISA) database using the terms "Iodine" and "Certified" in the Material category. The uncertainties are expanded uncertainties at approximately 95% confidence.

Standard Reference Material 131h Refined Cast Iron - This Standard Reference Material (SRM) is intended primarily for use in validation of chemical and instrumental methods of analysis. It can be used to validate value assignment of in-house reference materials and, if necessary, to calibrate carbon/sulfur analyzers. A unit of SRM 131h consists of a bottle containing 100 g of chips. This data is public in the Certificate of Analysis for this material.

SRM 1546a Meat Homogenate - This Standard Reference Material (SRM) is intended primarily for validation of methods for determining fatty acids, cholesterol, proximates, calories, elements, vitamins, and amino acids in canned meat products and similar materials. This SRM can also be used for quality assurance when assigning values to in-house reference materials. The meat homogenate is a mixture of pork and chicken products blended together in a commercial process. A unit of SRM 1546a consists of four cans, each containing approximately 85 g of material.

Standard Reference Material 1632d Trace Elements in Coal (Bituminous) - This Standard Reference Material (SRM) is intended primarily for use in the evaluation of techniques used in the analysis of coals and materials of a similar matrix. A unit of SRM 1632d consists of 50 g of bituminous coal that was ground to pass a 250 µm (60 mesh) sieve, homogenized, bottled under an argon atmosphere, and sealed in an aluminized bag. This data is public in the Certificate of Analysis for this material.

SRM 1632e Trace Elements in Coal (Bituminous) - This Standard Reference Material (SRM) is intended primarily for use in the evaluation of techniques used in the analysis of coals and materials of a similar matrix.

SRM 1633c Trace Elements in Coal Fly Ash - This Standard Reference Material (SRM) is intended for use in the evaluation of analytical methods for the determination of constituent elements in coal fly ash or materials of a similar matrix. SRM 1633c is a bituminous coal fly ash that was sieved through a nominal sieve opening of 74 µm (200 mesh) and then blended to assure homogeneity. A unit of SRM 1633c consists of 75 g of powdered material. This data is public in the Certificate of Analysis for this material.

SRM 1635a Trace Elements in Coal (Subbituminous) - This Standard Reference Material (SRM) is intended primarily for the evaluation of techniques used in the analysis of coals and materials of a similar matrix. A unit of SRM 1635a consists of 50 g of subbituminous coal that was ground to pass a 250 µm (60 mesh) sieve, homogenized, bottled under an argon atmosphere, and sealed in an aluminized bag. This data is public in the Certificate of Analysis for this material.

SRM 1849a Infant/Adult Nutritional Formula - This Standard Reference Material (SRM) is intended primarily for validation of methods for determining proximates, fatty acids, cholesterol, vitamins, elements, amino acids, and nucleotides in infant and adult nutritional formulas and similar materials. This SRM can also be used for quality assurance when assigning values to in-house reference materials. The SRM is a milk-based, hybrid infant/adult nutritional powder prepared by a manufacturer of infant formula and adult nutritional products.