No abstract

The increasing use of panthenol has emphasized the need for a more efficient assay method. Hence, the microbiological assay has been modified to eliminate the ether extraction for removal of pantoyl lactone or the separate assay required to correct for preformed pantoic acid. In the present procedure, these interfering products of hydrolytic cleavage of

Abstract. A capillary extrusion rheometer has been developed which circumvents many of the problems of traditional hypodermic principle rheometers. The capillary is enclosed in a hollow plunger driven at a series of fixed rates into a barrel containing the test sample. Drawbacks observed with traditional viscometers have been obviated, for example, entrapment of air between the sample and the plunger leading to gas compression effects, gross motion of the fluid in the barrel leading to fluid structure breakdown and difficulties in determining plunger/barrel friction contributions. With strict temperature control, it has been shown that absolute values for fluid flow properties could be determined on small samples quickly and easily with an accuracy of ±0.5%.

High ABSTRACTThe oxidation of a low erucic rapeseed oil was compared to the oxidation of a high erucic rapeseed oil in the temperature range 100 to 140 C. The two oils were found to be very similar in the rate of peroxidation, viscosity increase, change of refractive index, oxidation of the individual fatty acids, and hydroperoxide decay. Rate constants and activation energies for the change of these quantities were determined. The rate of hydroperoxide decomposition was found to be of first order for both oils, but there was evidence that a second order mechanism becomes important at temperatures less than 100 C. Butylated hydroxy anisole (BHA) caused decomposition of hydroperoxide and reacted with fatty acid and possibly with natural antioxidants in the oil. It did not react with oxygen. BHA decomposed thermally between 110 and 140 C. BHA is not an effective antioxidant at these temperatures in an oil which contains esters of highly reactive fatty acids.

In order to ensure success with Chaney's method for the determination of protein-bound iodine, a study was made of the factors involved. The chemistry of the reactions was studied, and the effect of variations in method and the kinetics of the ceric sulfate-arsenious acid reaction was determined. The resulting information makes possible successful use of the method, even by technicians with limited training in chemistry.