The economics of residue analysis

Since the onset of residue analysis some 40 years ago, much attention has been paid to several analytical aspects [e.g., the fight to achieve lower limits of detection (LODs), the gain in specificity, and quality assurance]. In recent years, "omic approaches" have also been introduced to accomplish these purposes. However, when reviewing the literature, one "omic" of residue analysis is not represented: the economic. Residue analysis covers a broad working area, including banned (group A) substances and registered veterinary drugs (group B). Some 40 years ago, only thin-layer chromatography and gas chromatography with electron-capture detection were used for A substances, in combination with laborious sample clean-up and thus small sample throughput. The nominal or money price of such an analysis remained relatively stable from 1970 to 2010. However, the operational costs of analysis increased considerably over the years, in particular, personnel and equipment costs. But, higher operational costs were countered by much greater sample throughput, although this phenomenon remains limited. For B substances, the strategy of screening with microbiological inhibition tests at a very low price competes with sophisticated ultra-high-performance liquid chromatography with (high-resolution) mass spectrometry systems, where the number of analytes/run can theoretically reach 122,500. The question that we address in this contribution from an economics point of view is: "How do laboratories keep the balance between price of analysis, specificity, LOD, number of analytes, quantification and quality assurance?" (C) 2011 Elsevier Ltd. All rights reserved.