Affiliations: National Key Laboratory of Elemento-Organic Chemistry,
Nankai University, Tianjin 300071, China | College of Science, China Agricultural University, Key
Laboratory of Pesticide Chemistry & Application Technology of Ministry of
Agriculture, Beijing 100094, China | College of Life Science, Sichuan University, Chengdu
610065, China
Abstract: HPLC-UV residue analytical method for monosulfuron [N-[(4'-methyl)
pyrimidin-2'-yl]-2-nitrophenylsulfonyl urea] in soil and wheat was developed.
Monosulfuron residues were recovered by solvent extraction, followed by
liquid-liquid partition, and C_{18} column clean-up.
Excellent method recoveries ranging from 95%–104% for both fortified soil
and wheat grain were obtained with coefficients of variation 1.5%–11.8%.
The minimum detectable quantities in soil and wheat were both 4 ng, the limit
of detection was 0.02 mg/kg. When monosulfuron was applied according to double
dosage of maximum recommended use direction (120 g ai/hm^2
of 10% monosulfuron wettable powder sprayed for once during development of
wheat) in field studies conducted in Shandong Province and near Beijing,
monosulfuron residues was not detected in soil and wheat samples collected 75 d
after application. Laboratory soil degradation studies showed that monosulfuron
degraded faster in acidic soil and strong alkaline soil than in neutral or weak
alkaline soil. Half lives in Jiangxi soil, Shijiazhuang soil, Jiangsu soil and
Heilongjiang soil were 41, 48, 87 and 84 d respectively. Monosulfuron residues
dissipated rapidly in Shandong and Beijing field test sites with half-lives of
less than 14 d.
