Purification of Crude Glycerine Obtained from Transesterification of Cottonseed Oil

The objective of this study was to purify glycerine obtained from the transesterification of cottonseed oil, using ion exchange resins. The batch process used strong cation, weak anion and a mixture of its resins. The purified glycerine was characterized as to metal content, colour and glycerol content. The experiments were conducted using the resins individually and in series. In the experiments in series, there was a constant decrease in conductivity. Analyses without the use of charcoal showed that conductivity behaved similarly to that of treatment with charcoal. For conductivity tests using activated charcoal and individual resins, the mixed resin produced the best result when compared to commercial glycerine.Considering the analysis made with activated carbon, when the glycerine solution was treated with individual resins, it was observed that the conditions established for treatment with 10 g of resin, 5 hours of contact with each resin and 50 mL of glycerine, its conductivity decreased to the cation exchange resin, increased to anionic resin and had a variable value with respect to the mixed resin. In serial processing, there was a steady decrease in the conductivity of the glycerine solution. The content of glycerol, after the solution had been passed through activated charcoal, 56% of the compound was recovered. It was also observed that the mixed resin retained a lower amount of glycerol. It can be concluded that ion exchange resins were efficient in treating the glycerine solution in all the tests, since there was little glycerol retention and high undesirable compound retention.

A Note on the Blood Analog for In-Vitro Testing of Heart Valve Bioprostheses

Glycerol solution with the viscosity coefficient similar to that of blood is used in evaluating the performance characteristics of prosthetic heart valves in the laboratory. However, physiological saline solution is used as a test fluid in testing tissue heart valves even though the viscosity coefficient does not match that of human blood. It is commonly believed that glycerol is absorbed by the tissue valves and hence the leaflets become stiff, making the test results invalid. However, in our laboratory a comparison of tissue valves exposed to glycerine solution at various times does not indicate any difference in the leaflet opening characteristics. Hence, it is suggested that glycerine solution be used as a test fluid for the evaluation of tissue valves also.

Semipermanent microscope slides of microfungi using a sticky tape technique

A technique is described for making semipermanent microscope slides of fungi using sticky tape. After being touched to a fungal colony, a modified segment of sticky tape is touched to ethyl alcohol and then immersed in a 50% glycerine solution containing cotton blue stain. Finally, it is transferred (sticky side up) to a microscope slide, covered with a cover glass, and sealed.