Thiacloprid residues and its safety evaluation in Darjeeling tea.
In order to examine the persistence behavior, safety evaluation and utilization of residue data for fixation of thiacloprid MRL, a supervised field trial in tea was conducted at Darjeeling. The HPLC analysis of thiacloprid in green tea leaves indicates that the initial deposits of 2.14 and 3.95 mg kg(-1), which declined gradually and persisted until day 14 to the tune of 0.23 and 0.45 mg kg(-1) respectively. The residues in processed tea samples prepared from green tea leaves of 7 and 14th day were 3.0-3.8 times less. Thiacloprid did not infuse to tea liquor from processed tea. The half-life value in green tea leaves ranged from 4.29 to 4.31 days. Considering the EU MRL value of 10 mg kg(-1) and risk assessment calculation, thiacloprid at 30 g a.i. ha(-1) appears to be safe in plant protection schedules and first round of plucking of green tea leaves on day 7 is recommended.
All India Network Project on Pesticide Residues, Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, 741235, West Bengal, India.
Devottam
D
Banerjee
Hemanta
H
Banerjee
D002851:Chromatography, High Pressure Liquid; D006207:Half-Life; D000073943:Neonicotinoids; D010573:Pesticide Residues / Q000032:analysis* / Q000633:toxicity; D011725:Pyridines / Q000032:analysis* / Q000633:toxicity; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet; D013662:Tea / Q000737:chemistry*; D013843:Thiazines / Q000032:analysis* / Q000633:toxicity
D000073943:Neonicotinoids; D010573:Pesticide Residues; D011725:Pyridines; D013662:Tea; D013843:Thiazines; C417209:thiacloprid