GC Determination of Residual Amount of Fenpropathrin in Vegetable with MWCNT′s-Solid Phase Extraction

Sample of vegetable was extracted with acetonitrile, and the supernatant was taken and evaporated to near dryness. The residue was dissolved with n-hexane, and purified by passing through a column packed with 100 mg/6 mL of multiwall carbon nanotubes (MWCNT′s). The column was eluted with n-hexane. The eluate obtained was evaporated to near dryness and made up to 5.00 mL with n-hexane. The solution was used for GC analysis using either ZB-2 or DB-5MS chromatographic column for separation and ECD for detection. Linearity range of fenpropathrin was kept between 0.075-1.25 mg·L-1, with detection limits (3S/N) of 1.07 μg·kg-1 (with DB-5MS column) and 0.769 mg·kg-1 (with ZB-2 column). Tests for recovery and precision were tested by addition of 0.075, 0.25, 1.00 mg·kg-1 of standard solution, and analyzed by the proposed method, values of recovery obtained were in the range of 83.9%-103% and values of RSD′s (n=6) in the range of 0.60% -3.2%.