title: [Multi-residue determination of 15 phenylurea herbicides in vegetables using solid phase extraction and online post-column ultraviolet decomposition-fluorescent derivatiztion-high performance liquid chromatography].
abstract: A high performance liquid chromatographic (HPLC) method for multi-residue analysis of phenylurea herbicides in vegetables was developed. The sample was extracted with acetonitrile and cleaned up by solid phase extraction (SPE) using a Florisil cartridge. The target compounds were separated on a C18 column (250 mm x 4.6 mm, 5 microm) and detected by a fluorescence detector (FLD) after online post-column ultraviolet (UV) decomposition with a UV lamp with 254 nm wavelength and fluorescent derivatization. The elution gradient, sample pretreatment and conditions of decomposition and derivatization were also studied. The elution gradient was as follows: the mobile phase started with 70% A (water) and 30% B (acetonitrile), which was increased linearly to 50% B in 15 min, and increased 90% B in the next 15 min and held for 2 min, then returned to the initial conditions in 0.5 min. The column was equilibrated for 10 min at 25 degrees C. The flow rate was 0.75 mL/min for HPLC and 0.2 mL/min for derivatization reagent. In the linear ranges of concentrations, the correlation coefficients were between 0.998 6 and 1.0000. The 15 herbicides were measured in fortified onion, spinach and cucumber samples at three spiked levels, the average recoveries (n=3) were in the range of 75.3%-121.6% with relative standard deviations of 0.4%-11.6%. The limits of detection (LOD) were 0.005-0.05 mg/kg. The method is simple, sensitive, selective and qualified for phenylurea herbicide multi-residue analysis.
authors.affiliation: Rice Product Quality Inspection and Supervision Center, Ministry of Agricultue, China National Rice Research Institute, Hangzhou 310006, China. tiger_2204@163.com
authors.forename: Jianliang
authors.initials: J
authors.lastname: Zhi
authors.forename: Renxiang
authors.initials: R
authors.lastname: Mou
authors.forename: Mingxue
authors.initials: M
authors.lastname: Chen
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D053000:Analytic Sample Preparation Methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005453:Fluorescence; D005504:Food Analysis / Q000379:methods*; D006540:Herbicides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D007700:Kinetics; D057230:Limit of Detection; D016014:Linear Models; D010671:Phenylurea Compounds / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D014466:Ultraviolet Rays; D014675:Vegetables / Q000737:chemistry*
chemical_list: D006540:Herbicides; D010671:Phenylurea Compounds