In Chapter 14 we discussed the process of developing a standard method, including optimizing the experimental procedure, verifying that the method produces acceptable precision and accuracy in the hands of a signal analyst, and validating the method for general use by the broader analytical community. Knowing that a method meets suitable standards is important if we are to have confidence in our results. Even so, using a standard method does not guarantee that the result of an analysis is acceptable. In this chapter we introduce the quality assurance procedures used in industry and government labs for monitoring routine chemical analyses.
- 15.1: The Analytical Perspective—Revisited
- The focus of this chapter is on the two principal components of a quality assurance program: quality control and quality assessment. In addition, considerable attention is given to the use of control charts for routinely monitoring the quality of analytical data.
- 15.2: Quality Control
- Quality control encompasses all activities that bring an analysis into statistical control. The most important facet of quality control is a set of written directives describing the relevant laboratory-specific, technique-specific, sample-specific, method-specific, and protocol-specific operations. Good laboratory practices (GLPs) describe the general laboratory operations that we must follow in any analysis.
- 15.3: Quality Assessment
- The written directives of a quality control program are a necessary, but not a sufficient, condition for obtaining and maintaining a state of statistical control. Although quality control directives explain how we are to conduct an analysis, they do not indicate whether the system is under statistical control. This is the role of quality assessment, the second component of a quality assurance program.
- 15.4: Evaluating Quality Assurance Data
- Now we turn our attention to how we incorporate this quality assessment data into a complete quality assurance program. There are two general approaches to developing a quality assurance program: a prescriptive approach, in which we prescribe an exact method of quality assessment, and a performance-based approach in which we can use any form of quality assessment, provided that we can demonstrate an acceptable level of statistical control.
- 15.E: Quality Assurance (Exercises)
- These are homework exercises to accompany "Chapter 15: Quality Assurance" from Harvey's "Analytical Chemistry 2.0" Textmap.
Thumbnail: Examples of property control charts that show a sequence of results.