Advanced Topic 944 of 1102 Analytical, Lab & Spectroscopy
Quality Control
Procedures such as blanks and standards ensure analytical reliability.
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In-depth explanation of Quality Control
Quality control ensures that analytical results are reliable through a set of checks run alongside the samples. These include method blanks to detect contamination, replicate analyses to estimate precision, calibration verification standards to check instrument response, and spiked samples to check accuracy through recovery. Certified reference materials with known composition are analysed to test accuracy directly, and control charts track results over time to reveal drift. Method validation establishes that a procedure is accurate, precise, linear, selective and robust over its working range. Acceptance criteria are set in advance so that out-of-control results trigger investigation.
Going deeper: Quality Control
Key ideas: Run a blank, a calibration check every 10 samples, a duplicate, a matrix spike and a reference material in each batch. Spike recovery = (found in spiked minus found in unspiked)/amount added x 100. Control charts mark the mean and plus or minus 2 s (warning) and 3 s (action) limits, and a run of seven points on one side of the mean flags bias. Document corrective actions.
Common mistakes and connections: Students believe a good calibration alone guarantees good results, but matrix effects and drift still occur. Spiking after sample preparation hides losses, so spike before extraction. Reusing the same data for calibration and validation overstates performance. Related to accuracy and precision, standard deviation, calibration and sampling.
Visualization of Quality Control
A control chart tracks a check standard run after run; results scatter inside the control limits when the method is in control, and drift or outliers trigger investigation. The interactive lesson shows this as a live animation or chart.
Worked example and use case
A spike recovery between 90 and 110 percent indicates that the method is accurate in that matrix.
Frequently asked questions about Quality Control
What is Quality Control?
Procedures such as blanks and standards ensure analytical reliability.
Is Quality Control a beginner, intermediate or advanced topic?
Quality Control is a advanced topic in Analytical, Lab & Spectroscopy. It builds on beginner and intermediate topics, so review those first if needed.
What should I learn before Quality Control?
Study these earlier topics in Analytical, Lab & Spectroscopy first: Standard Deviation, Detection Limit, Sampling.
What comes after Quality Control?
The next topics in Analytical, Lab & Spectroscopy are Electrophoresis and Centrifugation.
Can I practise Quality Control with quizzes?
Yes. The interactive lesson includes a self-check question on Quality Control, and the Analytical, Lab & Spectroscopy quiz draws on every topic in this area.
Where Quality Control fits in Analytical, Lab & Spectroscopy
Quality Control is topic 68 of 99 in Analytical, Lab & Spectroscopy.