Single Laboratory Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantitation of Microcystins in Marine and Estuarine Shellfish

Several reports have shown that the freshwater cyanobacterial toxins microcystins (MCs) can be transported along the freshwater to marine continuum and can be found in edible marine and estuarine shellfish. However, data for shellfish from commercial harvesting areas is limited. To further assess the concentrations found in these vectors and the risks that they pose to consumers, a validated analytical method is required. Herein, a liquid chromatography-tandem mass spectrometry-based method for the detection of eight MCs (MC-LA, -LF, -LR, -LW, -LY, -RR, -YR, and nodularin-R) was single laboratory validated in Eastern oysters (<i>Crassostrea virginica</i>), blue mussels (<i>Mytilus edulis</i>), hard clams (<i>Mercenaria mercenaria</i>), and softshell clams (<i>Mya arenaria</i>). Median recoveries for all four matrices ranged from 85.3 to 101.0% with RSDs between 3.5 and 14.3%. Overall, the method was found to be accurate, precise, and specific over an extended range of 10-500 μg/kg and determined to be fit for purpose for the screening of MCs in the shellfish matrices tested.