[Determination of niclosamide ethanolamine residue in rice and paddy field by high performance liquid chromatography]

A high performance liquid chromatographic (HPLC) method was established for the analysis of niclosamide ethanolamine residue in rice and paddy field. The paddy water and plant were extracted with alkaline ethylacetate, while the paddy soil, rice husk and unpolished rice were first extracted with alkaline ethanol, and then with ethylacetate. The extracts were then cleaned-up by a Florisil column and detected by high performance liquid chromatography with an ultraviolet detector (UVD) on a Welchrom C18 column (250 mm x 4.6 mm, 5 microm). The calibration curve showed good linearity from 0.01 mg/L to 10.00 mg/L with the correlation coefficient more than 0. 999 8. The average recoveries of this method were from 93.47% to 100.9% with the relative standard deviations of 1.46% - 5.82% at the spiked levels of 0.01 - 5.00 mg/kg. This method is fast, simple, sensitive, reproducible and practical for the determination of niclosamide ethanolamine residue in paddy fields, and can meet the requirement of the determination of pesticide residues.