New and Upcoming SRMs and RMs
Great Lakes Sediment Organics and Trace Elements (SRM 1936): The primary driver for this SRM is to provide traceability to NIST for sediment measurements made by other agencies and other agency contract laboratories. Traceability will help with validating data produced by these laboratories. Additional drivers include the unusual types of contaminants present in the Great Lakes (especially chlorinated flame retardants) and that NIST does not have a freshwater sediment certified for organic contaminants. In essence it will be a current, fresh water sediment material characterized for legacy and emerging organic contaminants. (TPL Jessica Reiner)
Frozen Prenatal Serum (SRM 1949): Hormones are critical components in the regulation of a large variety of biological processes. During pregnancy, major changes in the content of proteins, hormones, and vitamins take place to support the needs of the fetus resulting in different serum matrix qualities compared to non-pregnant individuals. Often the assays developed for healthy non-pregnant individuals are affected by these changes in serum constituents during pregnancy, potentially causing inaccuracies in diagnostics. Therefore, NIST has begun production on a material with serum pools from women during each of the three trimesters of pregnancy as well as a non-pregnant female serum. The intention is to certify this material for important nutritional biomarkers and hormones, including thyroid hormones, which would greatly improve diagnostic accuracy for health during pregnancy. (TPL Stephen Long and Ashley Boggs-Russell)
Boron Isotopes in Marine Carbonate (RM 8301): This material will be used to underpin boron isotope (δ 11 B) measurements in coral, foraminifera, or other marine carbonate that are used as proxies for ocean pH in contemporary or paleooceanographic studies. No carbonate RMs currently exist that have been formally value-assigned for δ 11 B by a national metrology institute and can be shipped internationally because of international restrictions on the import of endangered species. RM 8301 Boron Isotopes in Marine Carbonate is a solution matrix that was prepared by dissolved high purity calcium carbonate in nitric acid, and adding boron isotope spikes and the appropriate ratios of NIST 3100 series single element SRMs to artificially synthesize the composition typically found in corals and foraminifera. Each unit will contain ampoules of RM 8301-Coral and RM 8301-Foram, which vary in boron isotope signatures and the abundance of various major and minor trace element constituents. This synthetic carbonate RM will also have values assigned for the suite of trace elements found in marine carbonate skeletons that are commonly used in paleo-oceanography or biomonitoring pollution studies. (TPL Russell Day; Co-PI Joseph Stewart)
Mercury Isotopes in UM-Almaden Mono-Elemental Secondary Standard (RM 8610): A promising new field has emerged using mercury isotopes for pollution source apportionment or as tracers of mercury biogeochemical cycling in the environment. With the growth of this community there has been an increasing demand for appropriate isotopic standards to help address the analytical challenges associated with measuring mercury isotopes. A cinnabar ore was sourced from the mercury mines of Almaden, Spain by Dr. Joel Blum from the University of Michigan, and informally distributed for years as the community's only secondary standard. This material was transferred to NIST, and we have created a formal reference material to allow broader and more systematic distribution. The value assignment was associated with an interlaboratory exercise, NIST Mercury Isotope Standards Development Inter-Laboratory Exercise, involving 5 mercury isotope expert labs from the U.S., Canada, and France. (TPL Russell Day).
Updates to Existing Materials
Lake Michigan Fish Tissue (SRM 1947): The measurement of mercury isotopes in biological matrices is becoming more common in the research community. But there are few biological reference materials available for analysts to evaluate their analytical methods and establish commutability of measurements among laboratories. Fish tissue is perhaps the most commonly measured biological matrix for mercury, so SRM 1947 has been recently updated to include mercury isotope values. This makes it the first fish tissue reference material mercury isotope value assignment and distribution by an NMI. (TPL Russell Day)
Trace Elements in Soil Containing Lead from Paint (SRM 2586): This material has been updated to include reference values for rare earth elements (REEs) and perfluorooctane sulfonate (PFOS). This is the first soil material to have values for REEs and PFOS, which is environmentally important to have a standard when monitoring for contamination. (TPL Colleen Bryan)