A simple and rapid procedure for the purification of indole-3-acetic acid prior to gas chromatography-selected ion monitoring-mass spectrographic analysis was developed using an amino anion exchange minicolumn and a short high resolution C18 column. Since multiple samples can be prepared at one time, the procedure is more rapid and the sample preparation time is reduced to one-third that normally required. In addition, the final recovery was improved by 40 to 50% over that of a solvent partitioning procedure.

Available analytical techniques are now sufficient for the separation and identification of sterols from complex mixtures in plants. Gas and thin layer chromatography and mass spectroscopy in particular, have been used to resolve some of the confusion concerning the sterol composition of algae. Red algae (Rhodophyta) contain primarily cholesterol, although several species contain large amounts of desmosterol, and one species contains primarily 22‐dehydrocholesterol. Only a few Rhodophyta contain traces of C‐28 and C‐29 sterols. Fucosterol is the dominant sterol of brown algae (Phaeophyta), apparently the major sterol of every species examined. Most Phaeophyta also contain traces of cholesterol and biosynthetic precursors of fucosterol. The sterols of green algae (Chlorophyta) are much more varied and complex than those of other groups of algae. Whereas the Phaeophyta and Rhodophyta contain one primary sterol, many of the Chlorophyta contain a complex mixture of sterols such as occurs in higher plants. The Chlorophyta contain such sterols as chondrillasterol, poriferasterol, 28‐isofucosterol, ergosterol, cholesterol and others. Sterol composition may be of value in the systematics of plants such as the Chlorophyta. Recently (for the first time) complex mixtures of sterols have been isolated in very small amounts in the blue‐green algae (Cyanophyta). Available data on the sterols of other groups of algae are insufficient for making useful comparisons.

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g-irradiation and thermal treatments have been used to produce sterilized cross-linked films. Formulations containing variable concentrations of calcium caseinate and whey proteins (whey protein isolate (WPI) and commercial whey protein concentrate) or mixture of soya protein isolate (SPI) with WPI was investigated on the physico-chemical properties of these films. Results showed that the mechanical properties of cross-linked films improved significantly the puncture strength for all types of films. Size-exclusion chromatography showed for no cross-linked proteins, a molecular mass of around 40 kDa. The soluble fractions of the cross-linked proteins molecular distributions were between 600 and 3800 kDa. g-irradiation seems to modify to a certain extent the conformation of proteins which will adopt structures more ordered and more stable, as suggested by X-ray diffraction analysis. Microstructure observations showed that the mechanical characteristics of these films are closely related to their microscopic structure. Water vapor permeability of films based on SPI was also significantly decreased when irradiated. Microbial resistance was also evaluated for cross-linked films. Results showed that the level of biodegradation of cross-linked films was 36% after 60 d of fermentation in the presence of Pseudomonas aeruginosa. r