CRMs, Standard reference materials

ID-TIMS has frequently been used for certification of Standard Reference Materials by NIST (ex NBS) and IRMM (ex BCR), as in case of the Polymer Elemental Reference Material (PERM) project for the production of PE standards with certified concentrations of eight elements, namely Cd, Cr, Hg, Pb, As, S, Cl and Br [1], Also certification of the VDA-001 to -004 PE/Cd CRMs has taken advantage of both ID-TIMS [224,425] and... 

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). 

SRM stands for standard reference material. It is a standard chemical manufactured and certified by the National Institute of Standards and Technology (NIST) as being exactly as labeled. It is the ultimate standard. CRM stands for certified reference material. It is a standard chemical manufactured and certified by a vendor as being exactly as labeled. It is traceable to a SRM, meaning it has been compared to and certified with the use of an ultimate standard. 

In the above discussion, standard reference materials (SRMs) were mentioned often. A reference material (RM) is a material or substance suitable for use in calibrating equipment or standardizing solutions. A certified reference material (CRM) that a vendor indicates, via a certificate, is an RM. A standard reference material (SRM) is one that is distributed and certified by a certifying body, such as NIST. The SRM is the material to which all calibration and standardization materials should be traceable. A standard material becomes one when it is compared to or prepared from another. Ultimately, it all rests on the SRM — meaning all standard materials are traceable to an SRM (see Figure 5.10). 

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. 

For the largest field of application for LA-ICP-MS - geological research - many different geological and glass standard reference materials are available. Using standard reference materials in LA-ICP-MS, analytical results for trace analysis in homogeneous samples can be obtained with an accuracy better than 10%, and a precision of 2-5% is also possible.25 If no suitable CRM... 

To an increasing extent, the isotope dilution technique is being applied in the certification of standard reference materials, e.g., for Hg determination in a polyethylene certified reference material (CRM 680 and 681), or Cd and T1 determination in high purity Zn (CRM 325/2R), where ID-ICP-MS yields the most accurate data.45... 

A catalog of Standard Reference Materials is available from SRMINFO enh.nist.gov. European Reference Materials are available from http //www.erm-crm.org. See H. Emons, J. Marriott, and R. Matchatt,... 

This example is of a traceability [1] protocol [2] for the chemical measurement of an element by a primary method of measurement [3]. It can be used for the certification of a single-element reference material by a national reference laboratory. This protocol relates to a very pure strontium nitrate solution, stabilized by 10% (by volume) nitric acid1. This solution is to be certified for the amount of strontium substance n(Sr) per unit mass of aqueous solution m (sol). The general measurement method described is based in part on the experience of certifying a currently available certified reference material (CRM) [4], Standard Reference Material (SRM) 3153a [5],... 

The official European Community (EC) method for determination of the purity of milk fat is based on triglyceride composition as determined by GC on a packed column (EC, 1999). This is based on a formula for the composition of genuine milk fat of the type 100 = 14.197 C40 — 36.396 C42 + 32.364 C44 — e. The limit of detection varies with the adulterant fat, but is usually <5% foreign fat. A standard reference material (CRM 519) is available (Precht el al., 1998) which has been fully characterized and the triglyceride composition determined collaboratively. Other methods of analysis of the triglyceride data have been evaluated (Collomb et al., 1998a,b Lipp, 1996a,b Ulberth, 1995). 

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. 

Procedures for the analysis of some organochlorines in environmental samples (e.g., chlorinated dioxins - EPA Method 1613) [68] also require the use of surrogate standards (usually 13C-labeled) and certified or standard reference materials (CRMs or SRMs). At present there are no stable isotope labeled reference materials and no reference materials have yet been certified for PCA... 

Zambia, Thailand and USA (Florida) were analyzed by using the X-ray fluorescence method for elemental composition. These rock phosphates have also been evaluated for their agronomic effectiveness by means of radioisotope techniques (Zapata and Axmann, 1991). The samples were prepared as pellets and analyzed using the emission transmission method for trace elements (Markowicz and Haselberger, 1992). All samples were excited using an Mo tube with an Mo secondary target. For quality control of concentration data analysis of standard reference material CRM 032 (phosphate rock) produced by CEC, Brussels, has been used. Satisfactory agreement between certified and measured values was obtained. 

Certified reference material (CRM) A reference material, accompanied by a certificate, one or more whose property values are certified by a procedure that established its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence. For example, standard reference materials from the U.S. National Institute of Standards and Technology (http //www.nist.gov) are considered CRMs. 

I am pleased that you contacted me regarding this project. As you know, all certified reference materials (CRMs) sold in this country must be traceable to the Federal Institute of Standards and Technology (FIST). In other words, the solutions manufactured by The Solutions Makers must have been tested using standard reference materials (SRMs) formulated by FIST. I have read the procedure suggested by Professor Tee. The copper sulfate required is available as a SRM from FIST and I will forward the catalog information to you. 

SRM Standard Reference Material (trade mark for CRMs produced by NIST)... 

CRMs are also referred to as standard reference materials (SRMs) by some producers, e.g. the National Institute of Standards and Technology, USA. CRMs allow the user to link his results with those of internationally recognized standards. In addition, CRMs enable the user to verify his performance at any desired moment in terms of accuracy. CRMs can be ... 

Ideally the analyst would have a wide variety of samples, called certified reference materials (CRMs) or standard reference materials, with well-defined analyte concentrations. Practically, however, it is too expensive to produce the vast number of these materials that would be needed for all elements and samples. Instead, calibration is typically performed using aqueous standards, and the CRMs are employed as samples to verify accuracy. 

If available, run one or more certified standard reference materials (CRMs) to check the accuracy of the overall method (use eqn [7]). 

Certified (Standard) Reference Materials (CRM/ SRM) Real-world samples, as similar as possible to the unknown samples to be analyzed, for which the concentra-tion(s) of analyte(s) have been certified by expert laboratories using several independent analytical methods under strict international conditions (Section 2.2.1). Such materials are rare and expensive, and if available are used only occasionally to check on the performance of the method and/or to validate reference materials prepared in-house. 

Abbreviations AES, Auger emission spectrometry CRM, Certified reference material DL, Detection limit ED, Energy dispersive ESRF, European Synchrotron Radiation Facility EXAES, Extended X-ray absorption fine structure NEXAFS, Near edge X-ray absorption fine structure PCI, Phase contrast imaging RM, Reference material SR, Synchrotron radiation SRM, Standard reference material TXRF, Total reflection X-ray fluorescence XANES, X-ray absorption near edge structure XAS, X-ray absorption spectrometry XDM, X-ray diffraction microscopy XFCT, X-ray fluorescence computerized microtomography XPEEM, X-ray photoelectron microscopy XPS, X-ray photoelectron spectrometry XRD, X-ray diffraction XRF, X-ray fluorescence... 

Accurate elemental analysis at the microscopic/submicroscopic level is very important in fundamental scientific research and is of growing importance for the characterization at submicron/ nanoscale level in various areas of materials technology. All current micro- beam methods of analysis are relative, i.e., the signal measured requires either comparison to a reference material or validation through comparison with quantitatively reliable methods of analysis. Most so-called beam methods for microanalysis (e.g., electron probe microanalysis, micro-Auger spectroscopy, and secondary ion mass spectrometry) cannot yet be considered as accurate methods of analysis except when applied to compositionally or structurally quite simple samples. Their application to quantitative analysis must rely on the use of CRMs or standard reference materials (SRMs and RMs) for calibration, but, with very few exceptions, these materials are not available at present. 

The 238fj/235u jatio in standard reference materials for natural uranium has been meticulously scrutinized and revised by very precise measurements (Brennecka et al. 2010 Richter et al. 2010 Hiess et al. 2012). The NBS SRM 960 (NBL CRM 112a) served as the consensus value for of 137.88 but interlaboratory measurements with an accurate double-spike gave a slightly different average... 

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