Determination of Multiclass Harmful Residues in Shellfish Using LC-MS

A multi-residue procedure with liquid chromatography-tandem mass spectrometry analysis was developed to simultaneously detect the presence of 4 diarrheic shellfish poisoning toxins, 14 sulfonamides, chloramphenicol and thiamphenicol in shellfish tissues. Samples were first purified by a modified rapid procedure and separated on a ZOBRAX Eclipse Plus C18 column and quantified using electron spray ionization-mass spectrometry-mass spectrometry. The results showed that the limits of quantification (LOQ) of SPX1, OA-C, GYM, and PTX-2 were 1.0, 2, 0.5 and 2 μg/kg, respectively. The LOQ for the antibiotics was below acceptable limits established by most countries. Compared to the external standard method, this matrix matched the calibration method effectively, overcame the matrix effects and gave better quantitative results. Recoveries of spiked compounds ranged between 67.6% and 109.8%, with relative standard deviations below 15% for most target analytes. Only sulfathiazole had a %RSD of 18.6% at the lowest spiked concentration. The proposed method was accurate, rapid and reliable.https://doi.org/10.21423/jrs-v05n01p009 (DOI assigned 4/17/2019)