Abstract: 1030 A. Introduction
An analytical laboratory’s role is to produce measurement- based data that is technically valid, legally defensible, and of known quality. All measurements contain error, which may be systematic (unvarying magnitude) or random (varying magnitude and equal probability of being positive or negative). A method’s analytical performance is defined by its unique combination of systematic and random errors.1–Quality assurance is a program designed to make the measurement process as reliable as possible. Quality control (QC) procedures are activities designed to identify and determine sources of error.