Matrix (chemical analysis)

In chemical analysis, matrix refers to the components of a sample other than the analyte[1] of interest.

[2] For example, the ionic strength of the solution can have an effect on the activity coefficients of the analytes.

[3] In this technique, the response of the sample is measured and recorded, for example, using an electrode selective for the analyte.

Then, a small volume of standard solution is added and the response is measured again.

Matrix enhancement and suppression is frequently observed in modern analytical routines, such as GC, HPLC, and ICP.