Residue evaluation of imidacloprid, spirotetramat, and spirotetramat-enol in/on grapes (Vitis vinifera L.) and soil

• Published in: Environmental monitoring and assessment 2015-10, Vol.187 (10), p.632-632, Article 632
• Main Authors: Mohapatra, Soudamini, Kumar, Sampath, Prakash, G.S.
• Format: Article
• Language: English
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Aza Compounds - analysis; Chromatography; Chromatography, High Pressure Liquid; Crops; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental Monitoring - methods; Fruits; Gas chromatography; Half-Life; Horticulture; Imidazoles - analysis; Insecticides; Insecticides - analysis; Insects; Liquid chromatography; Mass spectrometry; Metabolites; Monitoring/Environmental Analysis; Neonicotinoids; Nitro Compounds - analysis; Pest control; Pesticide Residues - analysis; Pesticides; Residues; Soil Pollutants - analysis; Spiro Compounds - analysis; Vitaceae; Vitis - chemistry; Vitis vinifera
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-015-4859-x

A combination of imidacloprid and spirotetramat effectively controls sucking pests on grapevines. Residues of these insecticides on grapes were evaluated after treatment with spirotetramat 12 % + imidacloprid 12 % (240 SC) three times at 90 and 180 g a.i. ha −1 . The samples were extracted and purified by QuEChERS method and analyzed by high-performance liquid chromatography with a photodiode array detector (imidacloprid) and gas chromatography mass spectrometry (spirotetramat and its metabolite spirotetramat-enol). Satisfactory results were obtained with ranges of 80.6–98.6 % for the recovery, 3.1–10 % for the relative standard deviation range, and 9.8–15.6 % for the uncertainty. The limits of detection and quantification were 0.015 μg mL −1 and 0.05 mg kg −1 , respectively. Initial residue concentrations of imidacloprid after the 90 and 180 g a.i. ha −1 treatments were 0.912 (half-life 11 days) and 1.681 mg kg −1 (half-life 12.4 days), respectively. For spirotetramat + spirotetramat-enol, the residue concentrations were 1.337 (half-life 5.6 days) and 2.0 mg kg −1 (half-life 7.6 days) for the 90 and 180 g a.i. ha −1 treatments, respectively. Spirotetramat degraded faster than spirotetramat-enol. After treatment at 90 g a.i. ha −1 , the initial residues of both insecticides were within European Union maximum residue limits and a 1-day pre-harvest interval (PHI) was adequate for safe consumption of grapes. After treatment at 180 g a.i. ha −1 , the required PHI was 7 day. Therefore, a PHI of 7 day should be used after treatment with imidacloprid and spirotetramat.