ABSTRACT

Quality assurance and quality control programs mandate that every laboratory follow a set of well-de ned guidelines so as to achieve analytical results with a high degree of accuracy. e term quality assurance refers to a set of principles that are de ned, documented, and strictly observed such that the accuracy of the results of analysis may be stated with a high level of con dence and is legally defensible. e quality assurance plan includes documentation of sampling events, receipt of samples in the laboratory, and relinquishment of samples to respective individuals who perform the analysis. All these events are recorded on chain-of-custody forms with dates and times, as well as the names and signatures of the individuals who are responsible for performing the tasks. e plan, in a broader sense of the term, also includes quality control.