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Standards and reagents are available to researchers with certain assurances as to composition, purity and performance. The American Chemical Society (ACS) produces methods for analytical testing that employ standards, reagents and solvents. The American Society for Testing and Materials (ASTM) also produces methods for the manufacture, quality control and analysis of processes and products using standards, reagents and chemicals. The National Institute of Standards and Technology (NIST) is the producer of primary standards in the United States and produces certified reference materials (CRMs), including standard reference materials. Pharmaceutical-grade reagents are governed by bodies such as the United States Pharmacopeia (USP), which offers compendia based on the National Formulary (NF) and the Food Chemicals Codex (FCC). Together, these various bodies help ensure the quality and composition of chemical products used in research.
Please consult Table 1 for a detailed listing of commonly used purity-grade standards and organizations.
Table 1 – Examples of labeling for verified standards, chemicals and reagents
The use of validated standards offers significant cost and time savings for the laboratory and the extra assurance of industry compliance and synchronization with other laboratories running similar protocols. Many validated standards are also regulated by the U.S. EPA, which oversees the safety, handling, use and disposal of analytical, diagnostics, environmental and other fine chemical standards.
Commonly available standards and reagents include acids, bases, buffers, titrants, carbon standards, viscosity standards, compendial reagents, elemental analysis standards, chemicals used for specific instrument calibrations and chemicals for standardizing chromatographic and other analytical methods. Standards are also utilized in the clinical and in vitro settings, such as hematology and microbiology. Purified, validated, graded laboratory water is considered a reagent as well, and can either be produced using certified equipment or can be purchased.
The main considerations when purchasing a chemical, standard or reagent are:
- Intended use (e.g., chemical reaction, control, instrument calibration)
- Regulatory method or application required/followed
- Application (analytical chemistry, environmental, life sciences, petroleum, pharmaceutical, etc.)
- Instrument(s) used
- Projected length of use (will the product be available long-term?)
- Knowledge and availability of the proper storage environment
- Import and export procedures.
Figure 1 – A sampling of standards from Waters Corporation.Laboratory control and system performance standards for analytical techniques, such as different chromatographic methods, ensure optimal calibration of laboratory instruments for the designated test method. When using standards, it is important to never aliquot directly from a bottle. Instead, pour a small amount of standard into a temporary vessel and pipet directly from there.
Waters Corp.’s (Milford, Mass.) library of standards includes chemical, environmental, life and food sciences and instrument calibration and performance (see Figure 1). Instrument calibration standards from Waters and others are often method- and/or instrument-specific.
EMD Millipore (Billerica, Mass.) offers Certipur CRM analytical standards, as well as research biochemicals, pharmaceutical analytical standards and a comprehensive library of X-ray fluorescence (XRF) analysis standards.
High-performance reagents for the molecular biology laboratory are provided by Wako Chemicals USA (Richmond, Va.). An example from the Wako catalog is Bafilomycin A1, isolated from Streptomyces—a macrolide antibiotic designed to inhibit vacuolar-type H+-ATPases with a high degree of specificity.
Figure 2 – Analytical standards from SPEX CertiPrep.Conostan standards from SCP Science (Baied’Urfé, Quebec, Canada) are the industry’s only line of metallo-organic standards documented by NIST. Fungilab (Hauppauge, N.Y.) supplies ISO 17025/ISO Guide standards for ASTM D2162 (Standard Practice for Basic Calibration of Master Viscometers and Viscosity Oil Standards), which are traceable to national standards and are compatible with test equipment.
A full line of compendial EPA reagents and other analytical standards are available from Ricca Chemical Co. (Arlington, Texas).
SPEX CertiPrep (Metuchen, N.J.) offers a full line of organic and inorganic certified reference materials and calibration standards for analytical spectroscopy and chromatography (see Figure 2).
Emilia Raszkiewicz is managing editor, American Laboratory; [email protected]