Development and validation of multiresidue analytical method in cotton and groundnut oil for 87 pesticides using low temperature and dispersive cleanup on gas chromatography and liquid chromatography-tandem mass spectrometry.

A method was developed and validated for the analysis of 87 pesticides in cotton and groundnut oil by GC with ECD and FPD detectors and LC-MS/MS. The extraction procedure based on QuEChERS followed by low-temperature freezing and dispersive cleanup steps was validated in two oil matrices for 87 pesticides of different classes. Linearity, expressed as coefficient of variation, was within the acceptable range. Of those tested, 77-83 and 77-89% pesticides showed recoveries within the acceptable range of 70-120% on LC-MS/MS in cottonseed oil and groundnut oil, respectively, at different spiking levels. In case of GC analysis, 63-65 and 53-82% pesticides showed recoveries within the acceptable range of 70-120% on GC in cottonseed oil and groundnut oil, respectively, at different spiking levels. The exceptions to these recoveries were the few organochlorines which consistently gave lower recoveries. Recovery factors can be employed while analysing these pesticides by this method as the results obtained were consistent in both oils. RSD was less than 20% for most of the pesticides. The calculated limit of quantitation (LOQ) for most of the pesticides satisfies the maximum residue level (MRL) requirements as per European Union (EU) guidelines and Food Safety and Standards Authority of India (FSSAI).