Helium gas, which is widely used as a carrier gas for GCMS,  has become increasingly difficult to obtain in recent years, and there is an urgent need to consider alternatives. For Electron Ionization (EI) methods, it is necessary to increase injection to compensate for the severe sensitivity loss on moving from helium to nitrogen carrier gas. This then raises concerns over the likely need for increased maintenance frequency of GC inlets and columns. The APGCTM source developed by Waters is an atmospheric pressure ionization source for GC-MS providing soft ionization that enables highly sensitive and selective MRM analysis (Fig.1). The technique also allows the use of nitrogen carrier gas which has previously been shown to not significantly affect sensitivity compared to traditional helium use(1). The objective of this study was to conduct analysis of 391 pesticide components using nitrogen carrier gas and to evaluate the sensitivity and matrix effects.

• The API-GC-MS/MS method using the APGC source enables simultaneous analysis of 391 pesticides using nitrogen carrier gas
• High sensitivity detection of a peak equivalent to 1 ppb with 0.5 μL injection for all components
• Although the separation is inferior to that of helium, the required separation is achieved using the same column as for helium.
• Matrix effect: 70-120% recovery rate for more than 95% of components without the need for addition of any “analyte protectant” to samples
• Quantitative results of actual samples correlate well with the EI method In the future, it is expected that the high sensitivity of the APGC method can be used to simplify the pre-treatment process, for example, by eliminating the concentration process of the final solution.