Prescribed method versus minimum performance characteristics approach

5 Prescribed method versus minimum performance characteristics approach 

In order to demonstrate comparability in contaminated land analysis, there is a view expressed that methods should be specified or prescribed, thus ensuring 

In addition, unless frequently updated, the specification or prescription of methodology hinders technological developments until newer methods or technologies can be incorporated and taken on board. Since legislative processes are extremely slow to progress, until this could happen, analysts would only be allowed to use out-dated methods based on old technologies. 

An alternative approach to the prescription of methodology is to allow analysts the freedom to use whatever method the analyst feels is suitable, provided the method is fully validated, satisfies minimum performance criteria and is shown to be fit for purpose. This approach leaves the analyst the choice of which method to use, dependent only upon the needs and requirements of the analysis pertaining to the circumstances of the analysis. At any time, using this approach, laboratory staff can adapt any method it is considered appropriate to do so to ensure that the method used is pertinent to the sample matrix being analysed and the determinand and concentration level of interest being determined. The responsibility for using the most appropriate method therefore resides with laboratory staff, in consultation with the consultant or contractor requiring the analysis. 

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