Abstract
The residue analysis of benzomate in orange and apple was investigated. Benzomate in samples was extracted with methanol and reextracted with methylene chloride. The extract was evaporated under a reduced pressure, diluted with acetonitrile and then washed with n-hexane. The acetonitrile phase was evaporated to dryness. The residue was dissolved in a small portion of methylene chloride and then streaked on a tlc plate (Merck Art. 5554). Benzomate on the plate was eluted with methanol after developing with methylene chloride. After evaporating the solvent, the residue was dissolved in 1ml of acetonitrile and then 10μl of the solution was injected into a high performance liquid chromatograph fitted with a column (φ4.6mm×25cm) packed with Zorbax C8. The column was eluted with an acetonitrile and water mixture (8:2, v/v) at a flow rate of 1ml/min. The absorbance was monitored at 254nm with a 8μl flow cell. The limit of the detection using 50g of sample was 0.04ppm and recovery was about 80%.
