Food Testing & Agriculture
A multiple reaction monitoring (MRM) method was developed and evaluated on an Agilent 7000C Triple Quadrupole GC/MS for the analysis of 162 multiclass pesticides in tobacco. This system was equipped with a Multimode Inlet, and injections of 1 µL were made in the splitless mode. The midcolumn backflushing technique was applied for time-effective elimination of less volatile matrix components from the GC column. This reduced the cycle time and prevented contamination of the MS ion source. A modified QuEChERS sample preparation technique was used. Numerous tobacco samples were analyzed for method validation. Key performance parameters investigated were linearity, recovery, %RSD, limit of detection (LOD), and limit of quantitation (LOQ). Assuming the water content in all tobacco samples was zero, this study showed excellent recoveries (70 to 120%) for 95% of all test pesticides at 0.05 and 0.5 mg/kg (pesticide:tobacco, w:w), and LOQs of 0.01 mg/kg or lower for most pesticides. We obtained excellent linearity from 0.01 to 2 mg/kg (pesticide:tobacco, w:w), and repeatability over seven injections at concentration levels near LOQ, and at 0.1 mg/kg in a tobacco matrix.
Publication number: 5991-5763EN.pdf
Publication Date: April 29, 2015