title: Residue decline and risk assessment of fluopyram + tebuconazole (400SC) in/on onion (Allium cepa).
abstract: A method was validated for estimating fluopyram and tebuconazole in onion on LC-MS/MS using dispersive QuEChERS. Three sprays of a combination fungicide fluopyram + tebuconazole (Luna experience, 400 SC) were applied @ 75 + 75 and 150 + 150 g a.i. ha-1at an interval of 10 days on onion using Knapsack sprayer. First spray was made at bulb setting stage. Spring onion samples were drawn at 0 (1 h), 1, 3, 5, 7, 10, 15, and 20 days and matured onion bulb at harvest (52 days) after the last spray. Soil samples were also drawn at harvest. Foliar application of the combination product resulted in 1.14 and 2.86 mg kg-1fluopyram residues on spring onion at standard and double dose, respectively, one hour after the last application. The levels of fluopyram residues gradually declined and recorded 0.25 and 0.58 mg kg-1on 20th day of application with half-lives of 8.8 and 9.1 days at standard and double dose, respectively. For tebuconazole, the corresponding residues observed after 1 h (0 day) of application were 0.92 and 2.29 mg kg-1. The levels declined gradually to 0.12 and 0.33 mg kg-1on 20th days with half-life of 6.7 to 7.7 days at standard and double dose, respectively. Here, we are proposing a pre-harvest interval of 7 day for fluopyram and tebuconazole in spring onion when applied at 75 + 75 g a.i. ha-1(400 SC). Risk assessment was done by calculating hazard quotient and by comparing theoretical maximum residue intake (TMRI) with maximum permissible intake (MPI). In all the cases, results of the study showed that HQ (Hazard Quotient) ≤1 and TMDI < MPI. Hence, the use of this combination product can be recommended with pre harvest interval of 7 days. The data can be used in establishing MRLs (maximum residue limits) for spring onion after considering multilocation trials.
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India.
authors.forename: Badal V
authors.initials: BV
authors.lastname: Patel
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India. suchisood10@yahoo.co.uk.
authors.forename: Suchi
authors.initials: S
authors.lastname: Chawla
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India.
authors.forename: Hetal
authors.initials: H
authors.lastname: Gor
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India.
authors.forename: Payal
authors.initials: P
authors.lastname: Upadhyay
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India.
authors.forename: Kaushik D
authors.initials: KD
authors.lastname: Parmar
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India.
authors.forename: Anil R
authors.initials: AR
authors.lastname: Patel
authors.affiliation: Pesticide Residue Laboratory, AINP on Pesticide Residues, Anand Agricultural University, Anand, Gujarat, -388110, India.
authors.forename: Paresh G
authors.initials: PG
authors.lastname: Shah
mesh_terms: D001549:Benzamides / Q000032:analysis*; D006207:Half-Life; D019697:Onions / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D011725:Pyridines / Q000032:analysis*; D018570:Risk Assessment; D012989:Soil Pollutants / Q000032:analysis; D053719:Tandem Mass Spectrometry; D014230:Triazoles / Q000032:analysis*
chemical_list: D001549:Benzamides; D010573:Pesticide Residues; D011725:Pyridines; D012989:Soil Pollutants; D014230:Triazoles; C087114:tebuconazole; C572868:N-(2-(3-chloro-5-(trifluoromethyl)-2-pyridyl)ethyl)-alpha,alpha,alpha-trifluoro-o-toluamide
keywords: ADI; Dissipation; EDI; Fluopyram; Hazard quotient; LC-MS/MS; Onion; Risk assessment; TMDI; Tebuconazole