Question

Four different methods are described for validating the results of a particular analysis. Indicate for each whether the method primarily checks the accuracy of the analysis or the precision of the analysis. Method 1: Five aliquots of the same sample are injected for a gas-chromatographic analysis by one person on the same day. a. precision.b. accuracy.Method 2: A known amount of analyte is added to an aliquot of the sample and analyzed with the sample. a. precision.b. accuracy. Method 3: Aliquots from a blood sample are sent to three separate laboratories for analysis using the same method. a. precision.b. accuracy. Method 4: Identical standards are analyzed by two different methods. a. accuracy.b. precision.

Answer 1

Answer:

Method 1 - precision

Method 2 - accuracy

Method 3 - precision

Method 4 - accuracy

Explanation:

The accuracy of a method refers to how close the experimental result is to the accepted value. Accuracy could be checked by carrying out the required test on the standard and not on the sample or by adding a known amount of analyte to the sample so that the results obtained can be carefully compared.

Precision on the other hand, refers to how close the results of a replicate analysis are to each other. In testing for precision, the analysis must be carried out several times, in order to check how close the results are to each other.