ABSTRACT
Black tea samples (390) collected from local markets situated in different locations of India were monitored for the residues of 386 pesticides using QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) based extraction and analysis by gas and liquid chromatography tandem mass spectrometry (GC-MS/MS and LC-MS/MS). Residues of seventeen pesticides were detected, of which propargite, cypermethrin, and novaluron showed the highest % positive detections. A comparison of the concentrations of the detected pesticide residues with the available national and international maximum residue limits (MRLs) showed that seven samples exceeded the Indian MRLs while no sample was found to exceed the CODEX MRLs. The risk due to the detected pesticide levels evaluated in terms of hazard quotient (HQ) and hazard index (HI) was found to be very low (<1), suggesting that the pesticide residues in the tea were safe for consumption by Indian adults and children.
Subject(s)
Camellia sinensis , Pesticide Residues , Pesticides , Child , Humans , Pesticides/analysis , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods , Chromatography, Liquid/methods , Tea/chemistry , Food Contamination/analysis , Risk AssessmentABSTRACT
Although a lot of work has been conducted in the pesticide residues analysis in food matrices but the quality determination (with respect to major contaminants such as pesticide residues) in medicinal plant matrices has a long way to go. Hence a study was conducted to determine pesticide residues in four medicinal herbs, which are highly traded commodities in international market. Samples were extracted and cleaned up by modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach and analyzed by gas chromatograph-mass spectrometer (GC-MS). The method was subjected to thorough validation procedure in-terms of accuracy, precision, limits of quantification (LOQ), matrix effect, linearity and uncertainty analysis. The mean recoveries for most of the pesticides were in the range of 70-120% with RSD <20% and measurement uncertainties were less than 20% for all the compounds at spiking level of 0.5 mg kg-1 in all the matrices. The limits of quantification (LOQ) ranged from 0.01 to 0.069 mg kg-1. The proposed method was successfully applied to determine pesticide residues in 52 commercial market samples obtained from different locations in India.
ABSTRACT
A simple multi-residue method based on modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach was established for the determination of 17 organochlorine (OC), 15 organophosphorous (OP) and 7 synthetic pyrethroid (SP) pesticides in an economically important medicinal plant of India, Senna (Cassia angustifolia), by gas chromatography coupled to electron capture and flame thermionic detectors (GC/ECD/FTD) and confirmation of residues was done on gas chromatograph coupled with mass spectrometry (GC-MS). The developed method was validated by testing the following parameters: linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effect, accuracy-precision and measurement uncertainty; the validation study clearly demonstrated the suitability of the method for its intended application. All pesticides showed good linearity in the range 0.01-1.0 µg mL(-1) for OCs and OPs and 0.05-2.5 µg mL(-1) for SPs with correlation coefficients higher than 0.98. The method gave good recoveries for most of the pesticides (70-120%) with intra-day and inter-day precision < 20% in most of the cases. The limits of detection varied from 0.003 to 0.03 mg kg(-1), and the LOQs were determined as 0.01-0.049 mg kg(-1). The expanded uncertainties were <30%, which was distinctively less than a maximum default value of ±50%. The proposed method was successfully applied to determine pesticide residues in 12 commercial market samples obtained from different locations in India.