Rapid estimation of chlorpyrifos in feed samples using Gas Chromatograph- Micro Electron Capture Detector (GC-µECD)

Abstract

In this research paper, we have standardized a rapid method for estimation of chlorpyrifos residues in feed samples using Gas Chromatograph- Micro Electron Capture Detector(GC-µECD). The extraction method used for this study was QuEChERS viz. quick, easy, cheap, effective, rugged and safe. Validation was done by performing the following parameters; Linearity, Limit of detection (LOD), Limit of quantification (LOQ), Matrix effect and Recovery percentage. A regression equation with regression coefficient (r2) of 0.9913 was obtained indicating excellent linearity. LOD and LOQ of the method were obtained as 0.1 mg/L and 0.4 mg/L respectively. Recovery percentage of the spiked concentration 0.1 ppm was obtained as 85.7% and for 0.5 ppm it was 77.7%. We have analyzed in different feedstuffs (representing green fodder, dry fodder and concentrates) collected from six different districts (Guntur and East Godavari (Andhra Pradesh), Warangal (Telangana state) and Dakshina Kannada, Raichur and Gulbarga (Karnataka state)). From a total of 565 samples collected, 37 samples were positive for chlorpyrifos indicating a positivity rate of 6.55%. Among the positive samples except one oil meal sample, all the samples are under maximum permissible limits (MPL) suggested by codex alimentarius for animal feeds.