Determination of residual solvent in oilseed meals and flours: II. Volatilization procedure

A simple volatilization procedure was developed for the determination of residual hexane in oilseed meals and flours. A 2 g sample of meal or flour and 0.2 g of water are weighed into a 120 ml serum bottle, which is sealed and heated at 110 C for 2 hr in an oven. A 1 ml aliquot of the head‐space gas is then analyzed by gas chromatography. The concentration of residual hexane is easily determined by comparing the area of the appropriate peak of the chromatogram with a calibration chart. Results are reproducible within ±20%, and concentrations as low as 1 ppm can be detected. The technique is much simpler and more efficient than other procedures available. It also appears to be useful for determining other residual solvents such as acetone and isopropanol, and acetone impurities such as mesityl oxide and diacetone alcohol in oilseed meals and flours.