Six organically grown fruit and vegetable samples were extracted using the EN QuEChERS method, and these extracts were spiked with 93 pesticides at the 10 and 100 ng/mL level. The spiked extracts were analyzed using the Agilent 7200A GC/Q-TOF operating in high resolution TOF mode with electron ionization. The data were analyzed using Agilent MassHunter Qualitative Analysis Software (B.07.00) with the new Agilent Exact Mass GC/Q-TOF Pesticides Personal Compound Database and Library. Two GC methods were tried: • A 20-minute run using a 5 m column coupled to a 15 m column through a Purged Ultimate Union • A 40.5-minute method in the same configuration but with two 15 m columns In each case, the first column was backflushed at the end of the run. At the 10 ng/mL spiking level, the 20-minute and 40.5-minute methods were able to identify 97.3 % and 97.1 % of the pesticides, respectively. At the 100 ng/mL level, the two methods found 99.6 % and 99.8 % of the pesticides, respectively. The Q-TOF was able to measure molecular ion masses with better than 2 ppm accuracy when the signal/noise ratio was >10.
Publication number: 5991-5633EN.pdf
Publication Date: April 10, 2015