SRM 1950 Metabolites in Frozen Human Plasma - This Standard Reference Material (SRM) is intended primarily for validation of methods for determining metabolites such as fatty acids, electrolytes, vitamins, hormones, and amino acids in human plasma and similar materials. This SRM can also be used for comparison of measurement technologies used in metabolomic studies and for quality assurance when assigning values to in-house reference materials. This SRM is intended to represent "normal" human plasma.

This folder contains image data sets from 14 separate serial sectioning sessions. The entire data folder consists of 1379 8 bit tif images and is 47.3 GB in size. Serial sectioning was performed using FEI Helios 660 NanoLab focused ion beam scanning electron microscope (FIB SEM) and Auto Slice and View G3 software. The sample was a heavy metal stained and resin embedded Caenorhabditis elegans (C. elegans) that were exposed to 60 nm Au nanoparticles. Detailed descriptions of the worm preparation and resin block processing are described in Johnson, M.E. et al. (ACS Nano, 2016).

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.

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.

Standard Reference Material (SRM) 968 and its reissues are human serum based materials used as validation standards by clinical, epidemiological, and nutrition laboratories. Historically, about 300 units of this SRM have been sold annually. Based on this annual sales projection, as of November 1, 2015 there were about 16 months of inventory of the current issue: SRM 968e Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum.

SRM 3669 Arsenic Species in Frozen Human Urine (Elevated Levels) - This Standard Reference Material (SRM) is intended primarily for validating analytical methods and measurements for the determination of arsenic species in human urine. A unit of SRM 3669 consists of five pouches each containing a vial of arsenic species in frozen human urine at elevated levels. Each vial contains nominally 1.5 mL of urine. 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.

SRM 2193a Calcium Carbonate pH Standard [used as saturated Ca(OH)2 solution] - This Standard Reference Material (SRM) is intended for use in preparing solutions for calibrating electrodes for pH measuring systems at pH values above 11.0. This lot of calcium carbonate (CaCO3) was selected for its low level of alkali metal impurities. However, this SRM is certified ONLY as a pH standard, NOT as a pure substance. A unit of SRM 2193a consists of 30 g of CaCO3. 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 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.

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.