Suggested QC Practices for On-line Analyzers

The USEPA regulates by establishing a contaminant, an MCL, and a method, or methods, that are required to use for compliance purposes. These methods are almost all laboratory methods and include sampling, sample preservation, holding times, and batch QC criteria. Even if an on-line analyzer uses the same measurement technique as a laboratory method, you cannot assume equivalence of an on-line test to a laboratory method because the on-line lacks some of the required QC. This poster suggests QC practices that could be applied to new on-line analyzer methods.