Hexane Extraction Method Research Articles

A new method of detoxification of cottonseed by means of mixed solvent extraction

AbstractFor several decades, scientists in the field of vegetable oils tried unsuccessfully to detoxify cottonseed by a practical method. By using 20‐30% (by wt) of ethyl alcohol (90% in vol) with commercial hexane as a mixed solvent, we were able to extract effectively both gossypol and oil from cottonseed prepressed cake or flakes. Free gossypol in meal was reduced to ca. 0.013‐0.04%; total gossypol was reduced to 0.32‐0.55%; residual oil was reduced to ca. 0.5% or less. Any aflatoxin present also can be eliminated by this process. The detoxified cottonseed meal can be used as animal feed. Cottonseed protein can be used to substitute for soy protein. The extracted oil is of better quality than that obtained by the usual hexane extraction method, and gossypol is a valuable byproduct.

Comparison of Dieldrin, Lindane, and DDT Extractions from Serum, and Gas-Liquid Chromatography Using Glass Capillary Columns

Rats were given an oral dose of 14C-labeled chlorinated pesticides to obtain serum containing p,p'-DDT, dieldrin, or lindane. Simple hexane and formic acid-hexane extraction methods, involving pretreatment of the serum with formic acid, were compared by radiometric and by paper chromatographic and gas chromatographic analysis. In vivo binding of chlorinated pesticides to constituents of the serum does not necessarily prohibit their isolation by simple hexane extractions, provided that the extraction is very vigorous and at least 5 min long. Stable emulsions were broken by cooling in liquid nitrogen or Dry Ice-acetone. The hexane extraction method described yields quantitative recovery of the pesticides studied, whereas the formic acid-hexane method is quantitative for p,p'-DDT, 93% for dieldrin, and 89% for lindane. Gas chromatographic comparison of both methods, using human serum, shows that the hexane method extracts 16% more beta-BHC, 7% more dieldrin and HCB, and 4% more p,p'-DDE from serum than does the formic acid-hexane method. The difference for p,p'-DDT is not significant. Gas chromatography with glass capillary columns and an all-glass solids injection system yielded detection limits as low as 15 fg. Data show that the use of an internal standard considerably improves the precision of quantitation.

Quantitative Method for Determination of DDT and DDT Metabolites in Blood Serum

Abstract A new method for the extraction and determination of DDT and related materials in blood has been developed. Rats were given a single oral dose of 14C-labeled DDT, and it was demonstrated by parallel gas chromatographic and radiometric measurements that in vivointroduced DDT and related materials could not be removed quantitatively from serum by simple hexane extraction. Pre-treatment of the serum with equal volumes of formic acid released the binding of DDT and DDT metabolites and permitted the extraction of these materials with n-hexane, yielding 95% recovery. When applied to sera of men from the general population and of men who had been exposed to DDT for more than 10 years in a manufacturing plant, this method gave consistently higher results than did the simple hexane extraction method.