Simultaneous analysis of pesticide residues by GC-MS/MS method using Nitrogen carrier gas
Introduction
In the field of mass spectrometry, helium has primarily been used as the carrier gas for gas chromatography. However, due to the ongoing global supply chain disruptions, reduced production caused by issues at supply plants, and political and economic factors, there has been a long-term shortage of helium, leading to continuous price increases. To continue performing mass spectrometry, it is becoming essential to select alternative carrier gases to helium. Nitrogen or hydrogen are generally considered as alternative carrier gases, but it is desirable to understand the characteristics of each gas type for proper operation. In the case of Nitrogen carrier gas, it is cost-effective, safe, and inert, making it an excellent choice as a carrier gas. However, to maintain separation efficiency, it is necessary to set the average linear velocity to a much lower value, resulting in longer measurement times. Additionally, detection sensitivity generally decreases by about an order of magnitude, making it difficult to detect low-concentration samples that were detectable with helium carrier gas. Switching to an alternative carrier gas requires a review of the previously used measurement conditions. For the simultaneous analysis of pesticide residues, nitrogen was chosen as it is considered safer and easier to use compared to hydrogen. Various measurement conditions were optimized for this purpose. This report introduces an example of analysis using Nitrogen carrier gas for the simultaneous analysis of pesticide residues in food by GC-MS/MS method.