QqQ and Q-TOF liquid chromatography mass spectrometry direct aqueous analysis of herbicides and their metabolites in water

Triple quadrupole mass spectrometry (QqQ) is the most popular and widely used technique used to analyze pesticide residues in food and environmental compartments. However, recent advances in quadrupole-time-of-flight mass spectrometry (Q-TOF) may lead to this approach becoming a useful tool for analysis of pesticide residues. In this work, results of QqQ and Q-TOF were compared to determine their accuracy, when determining the concentration of herbicides and their metabolites in water. Double distilled and river water were therefore spiked with 18 analytes, differing in physical–chemical properties, and then directly analyzed either by QqQ and Q-TOF mass spectrometry. Results of Q-TOF were comparable to QqQ. The latter, operating in tandem mass spectrometry, was superior in terms of compound coverage, LOQ and precision for most analytes. However, results between the two analysis methods were comparable for LOD, linearity range (4 orders of magnitude) and accuracy. Validation parameters in pure and surface water showed contrasting results. Overall, the results of this study suggest that Q-TOF may represent a valid alternative to triple quadrupole, although the specific mass spectrometer under use still plays a major role.