Introduction -- Standards are materials containing a known concentration of an analyte. They provide a reference to determine unknown concentrations or to calibrate analytical instruments. The accuracy of an analytical measurement is how close a result comes to the true value. Determining the accuracy of a measurement usually requires calibration of the analytical method with a known standard. This is often done with standards of several concentrations to make a calibration or working curve.

Standard reference materials are costly and always in limited supply. Care in handling these material is required so they are not contaminated, diluted, or wasted.

Primary Standards -- A primary standard is a reagent that is extremely pure, stable, has no waters of hydration, and has a high molecular weight.

Secondary Standards -- A secondary standard is a standard that is prepared in the laboratory for a specific analysis. It is usually standardized against a primary standard.

NIST Standard Reference Materials -- The National Institute of Standards and Technology (NIST) provide a wide variety of standard reference materials for validating and calibrating analytical methods. Some examples of for chemical composition elements in iron, steels, and other metal alloys
sulfur in fossil fuels, polychlorinated biphenyls (PCBs) in oils, elements in foods and beverages (e.g. milk powder, wheat flour)

Standard reference materials ensures accurate and reliable analysis and is required for the validation of new techniques and procedures. Certified reference materials are traceable materials produced by a commercial supplier with a well-defined traceability to NIST. Traceability is established via criteria and protocols defined by NIST that are tailored to meet the needs of the metrological community to be served. The NTRM concept was established to allow NIST to respond to the increasing needs for high quality reference materials. Reference material are required by other agencies and programs such as the American Society for Testing Materials (ASTM), the International Organization for Standardization (ISO), the American Association for Clinical Chemistry, the International Union of Pure and Applied Chemistry AACC, and the European Economic Community.

Standards in the Chemistry and Biochemistry Department

NMR Materials

Metals, Alloys, and Inorganic Materials from NITS

Std weights, GC Standards (2) Alkanes and ROH's

Return to Instrumentation or Teaching Instruments