2011年9月23日星期五

Determination of Butachlor and Pencycuron Residues in Vegetables and Rice:Application of the Macroporous Diatomaceous Earth Column

Butachlor and pencycuron are commonly used pesticides in Taiwan. but still lack official methods for determining butachlor and pencycuron residues in agricultural products. An analytical method using a macroporous diatomaceous earth (MDE) column and florisil cartridge for cleanup procedure was developed for determination of butachlor and pencycuron in vegetables and rice. Butachlor and pencycuron were extracted from crops with acetone and the concentrated extract was transferred into the MDE column. eluted with n-hexane.
The eluate was concentrated and applied on a florisil cartridge. The cartridge was washed with 5% diethyl ether in n-hexane (E/H), and
then eluted with 15% E/H (fraction l) and 15% ethyl acetate in n-hexane (EA/H) (fraction iD. Butachlor residue in fraction I was determined by GC-ECD. Pencycuron residue in fraction Il was determined by HPLC-UV at 248 nm. Chinese mustard and rice samples were
fortified with butachlor and pencycuron at levels of 0.25-0.75 ppm and analyzed. The recoveries of butachlor and pencycuron were
between 84.9_94.g% and 88.3-94.8%, respectively. The detection limits of both pesticides in Chinese mustard and rice were 0.05 ppm.
   MDE liquid/liquid extraction cartridges provide a means of simplifying and speeding up multiple liquid/liquid extractions.
Yangzhou pioneer chemical CO.,LTD

没有评论:

发表评论