Quality assurance is the overarching term used to describe the activities employed to ensure the proper performance of a system. These activities can be classified into three categories: quality control, quality assessment, and internal corrective measures. Typically, these activities work cyclically: quality control is performed before and during the analysis, while quality assessment occurs during and after the investigation. Internal corrective measures are implemented based on the findings from post-analysis quality assessment or before the start of a new analysis.

The quality assurance process begins with drafting clear and concise use objectives for the analysis and concludes with specifications for the expected results. This exhaustive process includes sampling, blank tests, calibration checks, quality control checks, accuracy, precision, detection limit, selectivity, sensitivity, robustness, and the rate of false results. Finally, the quality assurance process entails reviewing whether the results meet the specifications and use objectives of the analysis.