Development and validation of a method for the analysis of cafenstrole and its metabolite in brown rice grains and rice straw using high-performance liquid chromatography.
The present work reports the extraction and clean-up procedures, as well as the chromatographic conditions developed, for the determination of cafenstrole and its metabolite (CHM-03) residues in brown rice grains and rice straw using HPLC-UV detection. The method makes use of an Apollo C(18) column and acetonitrile : water : acetic acid as a mobile phase for both cafenstrole and its metabolite in rice and rice straw. Using these conditions cafenstrole and its metabolite were resolved with a retention time (R(t)) of less than 14 min. The analytes were confirmed using positive atmospheric pressure ionization LC-MS with selected ion monitoring. The average recoveries of cafenstrole were found to be 87.0-92.5 and 87.6-88.3%. However, they ranged from 81.5 to 81.6% and from 76.1 to 78.5% for cafenstrole metabolite (CHM-03), in rice grains and rice straw, respectively, with relative standard deviations ranging from 1.4 to 6.6%. The limits of detection (LODs) of both cafenstrole and its metabolite were 0.002 and 0.02 ppm and 0.025 and 0.04 ppm, respectively. Field trials with recommended or double the recommended dose revealed that the herbicide could safely be recommended for application in rice and rice straw as no residues were detected in the harvest samples.
Department of Veterinary Pharmacology and Toxicology, Konkuk University, Kwangjin-gu, Seoul, Republic of Korea.
A M
AM
Abd El-Aty
Go-Woon
GW
Lee
M I R
MI
Mamun
Jeong-Heui
JH
Choi
Soon-Kil
SK
Cho
Ho-Chul
HC
Shin
Jae-Han
JH
Shim
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry; D012275:Oryza / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013450:Sulfones / Q000378:metabolism*; D014230:Triazoles / Q000378:metabolism*
D013450:Sulfones; D014230:Triazoles; C444649:cafenstrole