Simultaneous determination of four active ingredients of dinocap in crops by high-performance liquid chromatography

A procedure for high-performance liquid chromatographic (HPLC) determination of four active ingredients of dinocap, 2,4-dinitro-6-octylphenyl crotonate, 2,6-dinitro-4-octylphenyl crotonate, 2,4-dinitro-6-octylphenol and 2,6-dinitro-4-octylphenol, in crops was examined. The four compounds were extracted with acetone and re-extracted into hexane. After clean-up successively by hexane-acetonitrile partition and silica gel column chromatography, the compounds were determined by HPLC with an UV detector (245 nm). The column was Cosmosil 5C18 (ODS, 5 micron) and the eluent was methanol-water-acetic acid (330:70:1). The limit of detection was 0.02 ppm and the recoveries from crops (spiked with 0.5 ppm) were 85-100%. The four compounds were determined simultaneously and the method was shown to be applicable to residue analysis of these compounds in crops sprayed with dinocap.