Simultaneous determination of 15 phenylurea herbicides in rice and corn using HPLC with fluorescence detection combined with UV decomposition and post-column derivatization.
A method was developed for the simultaneous determination of 15 phenylurea herbicides (fenuron, tebuthiuron, metoxuron, monuron, chlortoluron, fluometuron, isoproturon, diuron, monolinuron, metobromuron, buturon, siduron, linuron, chlorbromuron, and neburon) in rice and corn samples by HPLC with fluorescence detection combined with UV decomposition and post-column derivatization. After extraction with acetonitrile and evaporation, the herbicides were redissolved in n-hexane and purified on a Florisil solid-phase extraction column. HPLC separation was carried out on a C18 column with water-acetonitrile gradient elution. UV decomposition was carried out under a 254-nm UV lamp. The method was evaluated in terms of the limits of detection and quantification. The linearity was satisfactory, with a correlation coefficient of >0.9980. Precision and recovery studies were evaluated at three concentration levels for each matrix. Good precision was obtained, with relative standard deviation in the range 1.5-9.6% for spiked rice samples and 0.9-9.9% for spiked corn samples. Recovery (n=6) ranged between 75.3% and 104.3% for rice and between 75.0% and 105.1% for corn. The intra-day precision (n=5) for the 15 herbicides in rice and corn samples spiked at an intermediate level was between 1.5% and 7.1%, and the inter-day precision over 10 days (n=10) was between 6.4% and 15.6%.
Mou
Ren-Xiang
RX
China National Rice Research Institute, Zhejiang, Hangzhou 310006, PR China. renxiangmou@hotmail.com
Chen
Ming-Xue
MX
Zhi
Jian-Liang
JL
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006540:Herbicides / Q000032:analysis* / Q000302:isolation & purification; D016014:Linear Models; D012275:Oryza / Q000737:chemistry*; D010671:Phenylurea Compounds / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D013050:Spectrometry, Fluorescence; D014466:Ultraviolet Rays; D003313:Zea mays / Q000737:chemistry*; D009764:o-Phthalaldehyde / Q000378:metabolism
D006540:Herbicides; D010671:Phenylurea Compounds; D009764:o-Phthalaldehyde