Determination of Dibromochloropropane and Related Fumigants in Citrus Fruit.

A simple and systematic procedure for determination of 1,2-dibromo-3-chloropropane (DBCP), 1,3-dichloropropene (DCP), chlorobutol (TCB) and seven related compounds in citrus fruits was established. Since these compounds have extremely high volatility, the distillation apparatus for volatile oil determination was used. These compounds were trapped into cyclohexane (more than 94.2-98.4% at spiking levels of 0.5-50 ppm) by this distillation. The distillate was purified by Florisil column chromatography. All compounds except TCB were eluted with n-hexane:ether(93:7) and TCB was eluted with ether. Each eluate was injected into an ECD-gas chromatograph directly for determination. Their recoveries from lemon, orange and grapefruit were within 91.5-98.6% at the spiking levels of 0.01-1 ppm.