Protocol, method validation quantitative analysis

It is very likely that incomplete or missing records would prevent the verification of data integrity. Source records should be complete to facilitate an understanding of actual study conduct for critical phases of method development, method validation, and subject sample analysis. The records should confirm whether the testing was conducted in an appropriate manner, with well-designed and optimally controlled experiments. The documentation of actual laboratory events should demonstrate that the quantitative measures are suitable to achieve the objectives of the clinical or nonclinical protocol. The records should confirm that the reported results accurately reflect the actual concentration of the analyte in the biological matrix. It should be noted that the failure to adequately document critical details of study conduct has resulted in rejection of bioanalytical data for regulatory purposes. 

Whereas the components of (known) test mixtures can be attributed on the basis of APCI+/, spectra, it is quite doubtful that this is equally feasible for unknown (real-life) extracts. Data acquisition conditions of LC-APCI-MS need to be optimised for existing universal LC separation protocols. User-specific databases of reference spectra need to be generated, and knowledge about the fragmentation rules of APCI-MS needs to be developed for the identification of unknown additives in polymers. Method development requires validation by comparison with established analytical tools. Extension to a quantitative method appears feasible. Despite the current wide spread of LC-API-MS equipment, relatively few industrial users, such as ICI, Sumitomo, Ford, GE, Solvay and DSM, appear to be somehow committed to this technique for (routine) polymer/additive analysis. 

In Part 1 [1] we described a protocol for the evaluation of measurement uncertainty from validation studies such as precision, trueness and ruggedness testing. In this paper we illustrate the application of the protocol to a method developed for the determination of the dyes Cl solvent red 24 and Cl solvent yellow 124, and the chemical marker quinizarin (1,4-dihydroxyanthra-quinone) in road fuel. The analysis of road fuel samples suspected of containing rebated kerosene or rebated gas oil is required as the use of rebated fuels as road fuels or extenders to road fuels is illegal. To prevent illegal use of rebated fuels, HM Customs and Excise require them to be marked. This is achieved by adding solvent red 24, solvent yellow 124 and quinizarin to the fuel. A method for the quantitation of the markers was developed in this laboratory [2]. Over a period of time the method had been adapted to improve its performance and now required re-validation and an uncertainty estimate. This paper describes the experiments under-... 

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