Validation and uncertainty analysis of a multiresidue method for 42 pesticides in made tea, tea infusion and spent leaves using ethyl acetate extraction and liquid chromatography-tandem mass spectrometry.
A rapid, specific and sensitive multiresidue method to determine 42 pesticides in made tea, tea infusion and spent leaves has been developed and validated for the routine analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was reproducible (Horwitz ratio (HorRat) <0.5 at 50 ng/g) and validated by the analysis of sample spiked at 50 and 100 ng/g in made tea, tea infusion and spent leaves. The samples were extracted with ethyl acetate+cyclohexane (9:1; v/v), and the extracts were cleaned up by dispersive solid phase extraction with primary secondary amine sorbent+graphitized carbon black+Florisil. The recoveries of all the pesticides were between 70% and 120% with a relative standard deviation of less than 15% and correlation coefficient for each pesticide was R(2) > or =0.99. The matrix effect on signal of respective compounds was measured by comparing matrix-matched calibration standards with those in solvent-only. The limits of quantitation (LOQ) met the requirements of the maximum residue limits (MRLs) for pesticides in tea as recommended by the European Union.
Kanrar
Bappaditya
B
Export Testing Laboratory, Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur 741252, West Bengal, India.
Mandal
Sudeb
S
Bhattacharyya
Anjan
A
D000085:Acetates; D002853:Chromatography, Liquid / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D012997:Solvents; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013662:Tea / Q000737:chemistry*; D035501:Uncertainty
D000085:Acetates; D010573:Pesticide Residues; D012997:Solvents; D013662:Tea; C007650:ethyl acetate