Essay On Method Validation

HOKLAS technical criteria of method validation:

Quantifying arsenic, cadmium, mercury & lead in food

Objective:

Develop a method validation for quantifying arsenic, cadmium, mercury & lead in food. The standard method is BS EN 15763:2009 and BS EN 13805:2002. The method validation steps follow ISO/IEC 17025:2005

The background information of method validation in ISO 17015:

Definition of the method validation

From ISO 1702 [1], Validation is the confirmation by examination and the provision of objective evidence that the particular requirements for a specific intended use are fulfilled. It can be classified as three main parts which are Specific intended use, Objective evidence and Confirmation. The meaning of specific intended use is that it is necessary to know why we should test the analyst. The common reasons are that the chemical is toxic to human, or it has the harmful effect to the animals or the environment. After identification of the reason for method validation, we need to have the method validation studies in different method validation parameters. For example, detection limits recovery and uncertainty. The final step is that using the method validation result to comparing with information obtained from customer’s requirements. The result also needs to meet the requirements from the standards.

Method validation is very important for the method application. It can determine the method performance characteristics and check if they meet the requirements for specific intended use. There are four advantages for method validation. The first one is that it can help the laboratory ensure the method can meet the accreditation requirement. For example, if the laboratory needs to have HOKAS certification, the method validation da...

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...he equation of R value

Figure 4: the example of R value

Stdconc (mg/l) Response Response found by cal. curve Residue

1 2.7 3 -0.3

2 5.7 5 0.7

4 9.2 9 0.2

6 12.4 13 -0.6

Figure 5: the example of Response Residual Plot

Figure 6: The definition of detection limit

Figure 7: The inter-laboratory study result of CRM-Tort-2

Figure 8:The IDL of each analyses in the standard method

Reference:

1. ISO/IEC 17025:2005 “Compliant Quality/Procedure Manual” cl. 5.4.5.1

2. ISO/IEC 17025:2005 “Compliant Quality/Procedure Manual” cl. 5.4.5.2 and Note1

3. http://mathbits.com/MathBits/TISection/Statistics2/correlation.htm

4. IOS 5725 “Accuracy (trueness and precision) of measurement methods and results” Part 2 to 5: 1994

5. ISO/ IEC Guide 43-1 “Proficiency testing by interlaboratory comparisons -- Part 1: Development and operation of proficiency testing schemes” 1997