title: Effect of paste processing on residue levels of imidacloprid, pyraclostrobin, azoxystrobin and fipronil in winter jujube.
abstract: The changes of imidacloprid, pyraclostrobin, azoxystrobin and fipronil residues were studied to investigate the carryover of pesticide residues in winter jujube during paste processing. A multi-residue analytical method for winter jujube was developed based on the QuEChERS approach. The recoveries for the pesticides were between 87.5% and 116.2%. LODs ranged from 0.002 to 0.1 mg kg(-1). The processing factor (Pf) is defined as the ratio of pesticide residue concentration in the paste to that in winter jujube. Pf was higher than 1 for the removal of extra water, and other steps were generally less than 1, indicating that the whole process resulted in lower pesticide residue levels in paste. Peeling would be the critical step for pesticide removal. Processing factors varied among different pesticides studied. The results are useful to address optimisation of the processing techniques in a manner that leads to considerable pesticide residue reduction.
authors.affiliation: a Department of Applied Chemistry, College of Science , China Agricultural University , Beijing 100193 , China.
authors.forename: Wei
authors.initials: W
authors.lastname: Peng
authors.forename: Liuwei
authors.initials: L
authors.lastname: Zhao
authors.forename: Fengmao
authors.initials: F
authors.lastname: Liu
authors.forename: Jiaying
authors.initials: J
authors.lastname: Xue
authors.forename: Huichen
authors.initials: H
authors.lastname: Li
authors.forename: Kaiwei
authors.initials: K
authors.lastname: Shi
mesh_terms: D002219:Carbamates / Q000737:chemistry; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D007093:Imidazoles / Q000737:chemistry; D007306:Insecticides / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D015394:Molecular Structure; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000737:chemistry; D010573:Pesticide Residues / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry; D011743:Pyrimidines / Q000737:chemistry; D000073739:Strobilurins; D031957:Ziziphus / Q000737:chemistry*
chemical_list: D002219:Carbamates; D007093:Imidazoles; D007306:Insecticides; D008689:Methacrylates; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010573:Pesticide Residues; D011720:Pyrazoles; D011743:Pyrimidines; D000073739:Strobilurins; C082359:imidacloprid; C513428:pyrachlostrobin; C087670:azoxystrobin; C082360:fipronil
keywords: paste; pesticide residues; processing factor; winter jujube