Quality control samples are key tools used to monitor and evaluate the quality stability of analytical testing processes. By regularly inserting samples with known characteristics into the analysis process, the accuracy, precision, and reliability of experimental results are verified. The quality control sample is a 'process supervisor'. It is usually made of a complex matrix similar to real samples (such as biological samples), with a known amount of analyte added to monitor the stability of daily testing. For example, when conducting drug analysis, it is sufficient to use it to ensure that the instruments and methods are within the error range of the results. It generally does not require a value traceability certificate, but if it is a fixed value, it must ensure accurate assignment.
Standard samples are substances or materials with sufficient uniformity, stability, and accurate measurement values, used for calibrating instruments, verifying detection methods, and evaluating the accuracy of measurement results. The standard sample is a 'result calibrator'. Its matrix is simpler (such as pure water), and its core function is to calibrate instruments, validate methods, or serve as blind samples for third-party capability verification, ensuring accurate and comparable measurement results. Standard products must provide complete traceability documents.
Simply put, quality control samples focus on "controlling the process", while standard samples focus on "accurate results". Some standard samples can also be used as quality control samples, but not vice versa.
Quality control samples and standard samples are important tools used in laboratories to ensure measurement accuracy, and they have the following commonalities:
All are physical reference materials: they are physical or chemical substances with specific properties, used for calibrating instruments, verifying methods, or monitoring processes.
Both require uniformity and stability: their characteristic values are uniform and stable within a specific time and space range, which is the basis for ensuring the reliability of measurement results.
Both are used for quality control: they jointly serve the quality management system of the laboratory, ensuring the accuracy and reliability of testing data.