title: Multiresidue determination and uncertainty analysis of 87 pesticides in mango by liquid chromatography-tandem mass spectrometry.
abstract: A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method was optimized and validated for the multiresidue analysis of 87 pesticides in mango at the ≤ 10 ng g(-1) level. The method involves extraction of 10 g of homogenized mango samples (+10 mL of water + 1 g of sodium acetate + 10 g of sodium sulfate) with 10 mL of ethyl acetate; cleanup by dispersive solid-phase extraction with a combination of primary secondary amine (PSA, 50 mg), graphitized carbon black (GCB, 25 mg), and anhydrous sodium sulfate (150 mg); and final estimation by LC-MS/MS with multiple reaction monitoring. Direct analysis (no clean up) resulted in significant suppression in ionization of the majority of the test compounds over the electrospray ionization probe. However, clean up with the above combination of PSA + GCB reduced the matrix-induced signal suppressions significantly, and the signals in the cleaned extracts were nearly equivalent to the corresponding solvent standards. Substitution of PSA with florisil also gave equivalent clean up effects. The method was quite rugged as evident from a low Horwitz ratio (mostly <0.5) and low measurement uncertainties at 10 ng g(-1). The limit of quantification was <10 ng g(-1) for all of the pesticides with recoveries within 70-120% for most pesticides even at 2.5 ng g(-1). The method offers a significantly effective, sensitive, cheaper, and safer alternative to the existing methods of multiresidue analysis.
authors.affiliation: National Research Centre for Grapes, PO Manjri Farm, Pune 412 307, India. kbgrape@yahoo.com
authors.forename: Kaushik
authors.initials: K
authors.lastname: Banerjee
authors.forename: Dasharath P
authors.initials: DP
authors.lastname: Oulkar
authors.forename: Shubhangi B
authors.initials: SB
authors.lastname: Patil
authors.forename: Manjusha R
authors.initials: MR
authors.lastname: Jadhav
authors.forename: Soma
authors.initials: S
authors.lastname: Dasgupta
authors.forename: Sangram H
authors.initials: SH
authors.lastname: Patil
authors.forename: Sunita
authors.initials: S
authors.lastname: Bal
authors.forename: Pandurang G
authors.initials: PG
authors.lastname: Adsule
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods*; D003365:Costs and Cost Analysis; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D031022:Mangifera / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000191:economics / Q000379:methods*; D035501:Uncertainty
chemical_list: D010573:Pesticide Residues