Reference materials suppliers

Useful Web sites NIST standard reference materials, http //ts.nist.gov/ts/htdocs/230/ 232/232.htm reference materials suppliers www.starna.com,www.agilent.com, www.varianinc.com. 

Record all operating details and conditions, including yields, product or compound names, lot numbers of standards and reference materials, suppliers, and anyexpiration dates. 

Database functions for chemicals, reference materials, suppliers, specifications, personal, and bibliographies. 

Associated with factor costs are linkages with material suppliers, subcontractors and support services (e.g. temporary staffing agencies, travel agents, reference libraries, and office maintenance services). The availability and cost of these factors need to be considered. 

Some of the intended categories of use of radioisotopic reference material have been reviewed recently by Fajgelj et al. (1999). They include assignment of property values, establishing the traceability of a measurement result, determining the uncertainty of a measurement result, calibration of an apparatus, assessment of a measurement method, use for recovery studies and use for quality control purposes. It should be noted however that, in general, natural matrix reference materials are not recommended for calibration purposes. This should preferably be done with pure chemical forms of the element labelled with the isotope of interest. Calibrated isotopic sources of this kind are available from a number of commercial suppliers and are not the subject of this review. 

Another major supplier of stable isotope reference materials is the Institute for Reference Materials and Measurements (IRMM) in Geel, Belgium. These materials... 

There are no special problems with the reconstitution or handling of these kinds of materials for electrolytes. The concentration of electrolytes is high, and no contamination problems are to be expected. Many commercial suppliers deliver reference materials for electrolytes in serum and urine. 

Tab. 6.6 Examples of biological, food, agricultural and related RMs for chemical composition available from, principally, government agency suppliers (Ihnat 1988,1992,1998a International Atomic Energy Agency 1998 Institute for Reference Materials and Measurements 1999 National Oceanic and Atmospheric Administration 1995 Trahey 1998) ...

Tab. 8.1 Major producers and suppliers of reference materials for inorganic and organic chemical composition quality control. The table lists in alphabetical order the popular names, or abbreviations, which may not be the full official title...

The revised database holds over 23 000 analyte values for 660 measurands and 1670 reference materials produced by 56 different producers, from 22 countries. The database is restricted to natural matrix materials (i.e. made from naturally occurring materials, excluding calibration standards manufactured from pure chemicals). Information has been extracted from the relevant certificates of analysis, information sheets, and other reports provided by the reference material producers. As a general rule, the authors have only included in the compilation reference materials for which a certificate of analysis or similar documentation is on file. Information included in the survey is on values for measurands determined in reference materials, producers, suppliers, the cost of the materials, the unit size supplied, and the recommended minimum weight of material for analysis, if available. The new searchable database has been designed to help analysts to select reference materials for quality assurance purposes that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest and their samples to be analyzed see Table 8.3. 

The Promochem Group was the first international specialist supplier of certified reference materials (CRMs) and pharmaceutical reference substances used in environmental, medical and trace element analysis. Their experience provides a viewpoint that echoes, reinforces and expands on many of the trends discussed above (Jenks 1997). From the middle of the 1980 s, sales of CRM by Promochem increased between 10 % and 20 % annually, depending on the market sector and application. Since then National and International Metrology Institutes, such as the now privatized U.K. Laboratory of the Government Chemist (LGC), the European and U.S. Pharmacopoeias, the E.U. IRMM and others have recognized that efficient distribution of RMs, backed by available technical support, is as important as production and certification. Thus, they have moved to spread their influence outside their national origins. The Web and e-commerce will continue to grow as major facilitators of better information dissemination and supply of CRMs. 

In most cases, mass spectra on single compounds were obtained with reference materials provided by commercial suppliers. This is the case for fatty acids, diacids and TAGs (Ribechini et al., 2008a). Nevertheless when the molecules of interest are not commercialy available it may be useful to synthesise and purify them in the laboratory as shown for the esters of beeswax (Gamier et al., 2002). 

Note (4) is very important as it highlights the fact that the reference material used for the method validation cannot be used again when the method is in routine use for calibration purposes. The same type of material can be used, but it needs to come from a different supplier. The same material cannot be used for calibration purposes and then as a quality control material. 

Some reference material producers/suppliers use different names to describe their materials. For example, a Standard Reference Material (SRM) is a certified reference material issued by the National Institute of Standards and Technology (NIST), while European Reference Materials (ERMs) are CRMs produced under a joint collaboration between three European reference materials producers, i.e. BAM (Federal Institute for Materials Research and Testing, Germany), IRMM (European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Belgium) and LGC (UK). 

Reactive Interactions. Likewise, your material supplier may not be much help for reactive interactions on your compatibility chart. For these combinations, the first thing you need to know is how much heat or gas can be generated. In some cases, this can be as simple as using the heat of mixing published in a technical reference book. In others, it may involve use of special equipment to accurately measure the amount of heat and pressure generated during a complex chemical reaction. 

At the same time, decisions must be made regarding the producers of these materials. For new reference material needs, identified within agencies such as NIST or NRC-Canada, this entails a decision as to whether to produce the material in-house or to sub-contract the work elsewhere. For externally recognized needs, both a supplier (e.g., either one of the recog-... 

To examine an entire process from beginning to end (raw material suppliers to stability of the final product) as a unit operation. With this frame of reference, the important factors in ihe entire process and their effect on each other can be determined. The use of initial screening experiments on each of the individual steps would identify the important factors to include in the overall design. This is the only practical way to determine how the process is going to react at the high and low set points for each of the important factors in the process while the other important factors are at either their high or low set points. 

As far as the use of the certified reference material is concerned, in an ideal situation the supplier or producer should give advice on the appropriate use to the user. In addition it is essential to obtain information relevant to storage temperature, influence of moisture and influence of contamination. The possibility of dividing the certified reference material into different portions after opening in order to maintain its original properties should always be considered. 

Standard reference materials are available from several suppliers in the UK, a selection of agricultural substances is available from the Laboratory of the Government Chemist, and in the US from the National Institute of Standards and Technology (NIST), where the Standard Reference Materials programme is described at ... 

This reference discusses new uses for UV and EB irradiation, the response of polymers to irradiation, and tests related to dosimetry and radiometry, as well as safety and hygiene. It is also fortified with new problems and worked solutions, in addition to useful figures and tables, and appendices with supplementary information on equipment manufacturers, raw materials suppliers, and principles of green chemistry and sustainability. 

Standard reference material (SRM) for wavelength accuracy, stray light, resolution check, and photometric accuracy can be purchased from NIST. Certified reference materials (CRMs) which are traceable to NIST and recertification services can be purchased from instrument manufacturers and commercial vendors [12]. The cost of neutral-density filters and prefabricated standard solutions in sealed cuvettes can be substantial. When purchasing performance verification standards from a secondary supplier other than a national standard organizations such as NIST in the United States and National Physical Laboratory (NPL) in the United Kingdom, make sure that the traceability of the standards are available in the certificates. The traceability establishes the relationship of individual results to the national standard through an unbroken chain of comparisons. 

Residue-testing laboratories might also need to review their sample preparation processes and consider modifying or eliminating tissue homogenization prior to residue extraction. Suppliers of proficiency-testing services should also question whether certain drugs are appropriate to include in such studies. For example, liver spiked with sulfaquinoxaline, sulfadiazine, or sulfamerazine is not suitable for preparation of spiked interlaboratory check samples or reference materials. 

The principal services include provision of high level calibration services (Fig. 3) and/or standards to suppliers offering secondary services or standards, preparation of standards and reference materials, and limited services direct to field... 

Suppliers. BCR, Institute for Reference Materials and Measurements (IRMM), Belgium NIST, National Institute of Standards and Technology, United States NRCC, National Research Council of Canada. Classifications CRM, Certified Reference Material DORM, Dogfish Muscle Reference Materials for Trace Metals LUTS, Nondefatted Lobster Hepatopancreas Reference Material for Trace Metals SRM, Standard Reference Material TORT, Lobster Hepatopancreas Marine Reference Material for Trace Metals. 

The information and data presented in this book are not intended to be used as a substitute for more up-to-date and accurate information on the specific plastics and processes. Such specific details can be obtained from in-house sources, testing laboratories, computer databases, material suppliers, data/information sources, consultants, and various institutions. References in this book represent examples for additional sources of plastics and processes. 

Information about CRMs is available from a number of sources. Many suppliers provide a database on their website. The recognized producers of CRMs in Europe are IRMM, LGC, and BAM. Information about CRMs produced by them, called European Reference Materials (ERMs). can be found on the ERM website (www. erm-crm.org). The ERMs are divided into six different categories (groups) ... 

In addition to Dow s own technology base 1n RIM, Injection molding and compression molding, the data 1n this study was developed from literature references and from consultation with authorities 1n the automotive Industry, material suppliers and equipment manufacturers. 

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