Chemistry 155 Introduction to Instrumental Analytical Chemistry

Chem 155 Unit 1 Page 44 of 313In general validation of an analysis is done usingsome kind of independent analysis of the sample.• For the purposes of this class, if the two methodsagree (t-test does not show a difference) then themethod is said to be validated.• If the two methods disagree (i.e. there isevidence of bias), then there is evidence forsystematic error like a matrix effect, aninterferant, or a mistake in the preparation ofstandards or samples.If an analysis is repeated as described below, whataspects of the analysis are validated (i.e. what musthave been ‘good’ for the answers to have come outthe same)?Validation ApproachCompletely independentmeasurements of thesame sample using adifferent instrument ortechnique.Use the same method,but measureindependently preparedstandards as samples.Aspect(s) validatedCalibration method,including matrix effects.Instrument, includingdistortion and drift.You! The analyst, did itrightYou! The analyst made nomistakes in theimplementation of theprocedure.Page 44 of 313