Quality Assurance involves making sure that the entirety of operations are done within well-defined limits of acceptability to produce quality results. This includes the employment of standard operating procedures, training, reliable and well-maintained equipment, traceability, and annual review of Quality Control Results. On the other hand, Quality Control is a component of Quality Assurance that focuses on evaluating practices to identify problems that may be degrading the quality of results. This includes the provision of standard reference materials, spike samples, and certification programs.

https://anlab.ucdavis.edu/Pages/qa-qc#:~:text=The%20QA%2FQC%20Program%20has,measure%20non%2Dconforming%20method%20performance.