TABLE OF CONTENTS Analysis is the measurement of the amount of substance x present in the sample using an analytical method; everything else in the sample is the matrix. Some general names that one can give to x and the process of analysis are:
Analyte
Matrix
Measurand
Test
When an analysis is performed the amount of a chemical component present in a sample is identified and measured. The chemical entity being investigated (qualitatively or quantitatively) is called the analyte. There may be components, other than x, present in the sample. All the other components are called the matrix. The process of analysing the sample to determine the amount of the analyte in the matrix is called a test.
Consider the analysis of paint for lead content. The lead is the analyte; the paint is the matrix; and the process of analysing the paint sample for lead is the test.
Frequently, the amount of analyte present in a sample is determined indirectly, e.g. by measuring something that is proportional to the amount of analyte. Therefore, a more accurate way to describe what has been measured in an analytical method (test) is the term measurand. Measurand is defined as a "particular quantity subject to measurement". [5]
An analysis of paint for lead content is based on the absorption or emission of radiation by lead atoms. The lead atoms are the measurand.
[5]International Standards Organization, International...
