No Compromise GC-MS - Atmospheric Pressure GC (APGC)
Pesticide residues are often high on the list of consumer concerns and consequently analytical laboratories are tasked with screening samples for as many pesticides as possible in a single analysis. Most countries have clearly defined regulations governing pesticide residue levels, for example Maximum Residue Limits (MRLs) for pesticide residues in food commodities. To ensure compliance analytical techniques that are sensitive, accurate, and robust are required. Multi-residue analysis can prove challenging due to the low limits of detection required to achieve MRL compliance for a diverse range of pesticides in a wide range of food commodities. With more than 1000 pesticides known to be in use, laboratories are under increasing pressure to increase the scope of the analytical methods for routine monitoring purposes.
Various technologies are used to meet this challenge, the most common being Liquid Chromatography (LC) and Gas Chromatography (GC) coupled to tandem quadrupole mass spectrometry. Implementation of these techniques allows the laboratory to cover a range of compounds with varying chemistries as required by legislation. In GC/MS/MS the traditional ionization mode used is Electron Impact (EI). This is a relatively “hard” ionization method and results in a high degree of analyte fragmentation, which compromises the selectivity and sensitivity of the MS/MS measurement. Atmospheric Pressure Gas Chromatography (APGC) is a “soft” ionization technique resulting in less fragmentation and subsequently increasing the sensitivity and selectivity of MS/MS methods.