Dissipation and residues of chlormequat in wheat and soil.
A specific, sensitive method was developed for the analysis of chlormequat in wheat and soil by high performance chromatography/mass spectrometry. The fortified recoveries of soil were from 75.08% to 96.55%, with RSD 3.34%-15.18%, the limit of detection of the analytical method was 0.05 ng at a signal-to-noise ratio of 3, and the limit of quantification was 0.05, 0.1, 0.5 mg/kg for soil, wheat plants and wheat grain, respectively. The degradation dynamics and final residues of chlormequat in Beijing and Changchun were investigated. The half-life of chlormequat in wheat plants were 3.15 days in Beijing and 4.56 days in Changchun, while the half-life in soil was 3.88 days in Beijing and 4.51 days in Changchun. The final residues of chlormequat in soil were not detectable, and the final residues of chlormequat in wheat grain were below 0.50 mg/kg except for 3.51 mg/kg from high dosage plot of Changchun. The fact that all the final residues were below 5 mg/kg (GB2763 in National standards of the People's Republic of China, maximum residue limits for pesticide in food, Beijing, 2005) suggested that chlormequat could be safely used in wheat crops with the suitable dosage and application.
Guo
Xing-Li
XL
Department of Applied Chemistry, College of Science, China Agricultural University, 100193 Beijing, China. gxl1026@126.com
Jia
Chun-Hong
CH
Zhao
Er-Cheng
EC
Xu
Yan-Jun
YJ
Han
Li-Jun
LJ
Jiang
Shu-Ren
SR
D002681:China; D002716:Chlormequat / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005433:Flour / Q000032:analysis; D006207:Half-Life; D013058:Mass Spectrometry; D010573:Pesticide Residues / Q000032:analysis*; D010937:Plant Growth Regulators / Q000032:analysis*; D012015:Reference Standards; D012639:Seeds / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014908:Triticum / Q000737:chemistry / Q000378:metabolism*
D010573:Pesticide Residues; D010937:Plant Growth Regulators; D012987:Soil; D012989:Soil Pollutants; D002716:Chlormequat