Cloud point extraction coupled with derivative of carbofuran as a preconcentration step prior to HPLC

Carbofuran can be hydrolysed to from 2,3-dihydro-2,2-dimethyl-7-benzofuranol (BF). BF is coupled with 4-aminoantipyrene (AP) in presence of potassium ferricyanide (K3Fe(CN)(6)) to generate red coloured derivative(BFAP)having lambda max 530 nm. Cloud point extraction (CPE) methodology and using surfactant Triton X-100 as extractant was applied as a preconcentration step prior to HPLC, the surfactant-rich phase containing BFAP was then analysed by HPLC in visible region. The high back ground absorbance of Triton X-100 in UV region was completely avoided. A new visible detection method with high-performance liquid chromatography (HPLC) has been developed for the determination of carbofuran. Using this method, we found that carbofuran residues could be determined with recoveries ranging from 80.4% to 84.5%, relative standard deviations in the range of 2.51-3.26% for three fortified rice levels, and the limit of detection as 5.0 x 10(-4) cJ/cK. (C) 2008 Elsevier Ltd. All rights reserved.