Multi-residue pesticide analysis is challenging due to the low limits of detection required in a diverse range of food commodities. As there are currently in excess of 1000 pesticides in use, laboratories are under increasing pressure to broaden the range of pesticides determined in ever shorter turnaround times. Therefore, the analytical methods they employ need to be sensitive and robust in a wide variety of sample matrices.
Typically, this analysis is carried out using a dedicated GC-MS/MS system using an EI source. As shown by Portolēs et al, this source causes extensive fragmentation of some analytes leading to low sensitivity of the molecular ion.
APGC is a “soft” ionization technique which results in an increased abundance of the parent ion and therefore enhancing sensitivity and specificity. An additional advantage is that the APGC source is interchangeable with the ESI source enabling a single MS platform to be used for the analysis of both LC and GC amenable pesticides.
In this application note, we demonstrate that the Waters Xevo TQ-S equipped with an APGC source provides a sensitive and repeatable solution for the analysis of pesticides in QuEChERS extracts of strawberry, pear, and spinach.