QA/QC In-Depth Focus 2018

• Expanding the detection and quantification of contaminants in food samples
  Monitoring contaminants in seafood samples is crucial, but developments in regulations and marine feed mean the situation is constantly changing. Tania Portolés explains her work at the Research Institute for Pesticides and Water (IUPA), Spain, in ensuring food security in such samples.
• Lot-to-lot variation: A neglected issue in method validation of LC-MS-based assays
  Food analysis, particularly the determination of contaminants and residues, is often based on LC-MS methods in combination with external solvent-based or matrix-matched calibration. The performance of such methods is typically evaluated by in-house validation from replicate analysis of a single lot of a matrix. However, different lots of a matrix might have different extraction recovery factors (RE) or signal suppression/enhancement (SSE) effects, resulting in lot-to-lot variation. Therefore, failing to consider this variation might lead to an underestimation of the uncertainty of the measurement result. Here, David Stadler and Rudolf Krska from the University of Natural Resources and Life Sciences, Vienna, discuss the impact of the lot-to-lot variation on the accuracy of a multi-mycotoxin assay.