Method development, matrix effect, and risk assessment of 49 multiclass pesticides in kiwifruit using liquid chromatography coupled to tandem mass spectrometry

In the present study, a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method with a minimal matrix effect (ME) was developed and validated for simultaneous determination of a diverse range of pesticides (49) in kiwifruit. Samples extracted by the quick, easy, cheap, effective, rugged, and safe (QuEChERS) citrate-buffered method were analyzed either without purification or following purification (with primary secondary amine (PSA) or PSA + graphitized carbon black (GCB)). With the addition of a clean-up step, the suppression of the ME decreased, with a higher number of pesticides determined by the application of PSA + GCB. The method exhibited good linearity with coefficients of determination (R-2) >= 0.9972 and satisfactory recoveries (70-120%) with a relative standard deviations (RSDs) < 10%. The limits of quantification (LOQ) were lower than the maximum residue limits (MRLs) set by the Korean Ministry of Food and Drug Safety (MFDS) and the CODEX Alimentarius. The developed method was applied to the real samples and the results indicated that the quantitated levels of all pesticides, except for pyraclostrobin and carbendazim, are lower than the MRLs set by the regulatory authorities. The percentage of the acceptable daily intake was < 20%, suggesting that there is no risk associated with the intake of residual pesticides through kiwifruit.