Yeanwoong You (Thermo Fisher Scientific)

Yeanwoong You (Thermo Fisher Scientific)

Multi-residue pesticide analysis in food is increasingly challenged by the need for faster turnaround without compromising chromatographic quality or MS/MS robustness. Conventional GC-MS/MS methods are often operated in constant flow mode; however, temperature programming causes the actual linear velocity to drift, which can move the separation away from the chromatographic optimum during the run. In this work, we propose a constant linear velocity (CLV) strategy as a superior control mode for rapid multi-residue pesticide analysis. Using a 20 m × 0.18 mm I.D. × 0.18 μm 5MS capillary column and helium as the carrier gas, the method was designed to maintain a constant optimum linear velocity throughout the oven program from 50 to 310 °C. Theoretical evaluation based on carrier-gas dynamics and the Van Deemter relationship indicates that CLV preserves more stable chromatographic efficiency than constant flow operation, particularly during the higher-temperature portion of the run. This control approach is expected to improve peak uniformity, sustain separation efficiency, and reduce total analysis time relative to conventional constant flow methods. The proposed workflow therefore offers a practical and high-throughput GC-MS/MS platform for demanding food pesticide applications, with strong potential for routine laboratory implementation.

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