Multi-residue analysis of pesticides in agricultural products by liquid chromatography time-of-flight mass spectrometry.

The applicability of liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) for determining pesticide residues in agricultural products was investigated. TOF-MS conditions for monitoring target ions, together with their fragment ions, were carefully optimized. The developed LC-TOF-MS method was evaluated for 154 pesticides in soybean and spinach by using matrix-matched standards. No significant matrix effect was observed for most of the tested pesticides at a concentration level of 0.01 mg/kg, where the limits of quantification were less than 0.01 mg/kg for 145 of the 154 pesticides (S/N>10). In addition, no significant interference was observed in the chromatograms of the blank extracts. These results indicate that LC-TOF-MS determination may become a powerful tool for multi-residue analysis of pesticides in agricultural products.