Interlaboratory studies kinds

Evaluation of results. A proper evaluation of results is one of the keys to the success of any kind of interlaboratory study. This should be based on clear instructions provided to participants, using, e.g. protocols accompanying test samples and... 

A detailed interlaboratory study of arsenic speciation in six different kinds of marine organisms was published (El Moll et al., 1996). Detection of arsenic species in the sample extracts was performed by means of LC-ICP-OES for AB and AC, and by HG-AAS for As111, Asv, MMA and DMA. Many precautions were taken to avoid contamination and losses of analytes, and to improve the accuracy of the results. Data for total As, extractable As, residual As and AB were reported. 

Standard methods of analysis, for example, those published by American Society for Testing and Materials or International Organization for Standardization (ISO), have the imprimatur of the organization and have been developed and validated for use in field laboratories. They have usually been subjected to a method performance study, a kind of interlaboratory study (q.v.), which establishes repeatability and reproducibility precision and possibly method bias. The published methods also indicate the range of concentrations for which the method can be used, and the detection limit. 

We have every reason to consider the estimation of measurement uncertainty in an analytical procedure followed by the judgement of compliance with a target uncertainty value as a kind of validation. This is in full agreement with ISO 17025 that points to several ways of validation, among them systematic assessment of the factors influencing the result and assessment of the uncertainty of the results... [31]. In line with this is also a statistical modelling approach to the validation process that has recently been developed and exemplified as applied to in-house [32] and interlaboratory [33] validation studies. 

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