A rapid procedure for the determination of residual hexane in oilseed meals and flours

A rapid and direct gas chromatographic procedure is described for the quantitative determination of residual hexane in finely ground oilseed meals and flours. A 0.04 g sample of meal or flour is added between two small plugs of glass wool in a liner of the injection port of a gas chromatograph. The liner with the sample is placed in the heated injection port and firmly secured, and 80 μl of water is immediately injected just above the glass wool which covers the sample. Volatiles which are rapidly eluted from the sample are then analyzed by temperature-programmed gas chromatography on a 2 ft × 1/4 in. Porapak P column. The results are comparable to the results obtained by the simple and efficient but more time consuming volatilization procedure. Since results are obtained within 20 min, this rapid procedure is very useful in monitoring desolventization processes.