[Column chromatography purification and analysis of biodiesel by transesterification].

In the present paper, crude biodiesel prepared with sorbifolia oil as raw material by transesterification was purified by column chromatography, then the composition of biodiesel was analyzed by gas chromatography, FTIR, GC-MS and 1H NMR. Column chromatography can separate the crude biodiesel into two fractions: petroleum ether eluted fraction (A1) and methanol eluted fraction (A2). Petroleum ether eluted fraction was mainly biodiesel fraction, which was produced from sorbifolia oil by transesterification, including methyl linoleate, methyl cis-9-octadecenoate and so on; methanol eluted fraction was mainly glycerol fraction, which came from the side reaction of transesterification. The results show that the purity of refined biodiesel increased from 77.51% to 93.872, and the product recovery rate reached up to 91.04% after the purification by column chromatography. The results obtained by FTIR and 1H NMR further showed that the column chromatography can effectively improve the purity of biodiesel. This paper provides a basis for industrialization of purification of biodiesel.

[Study on of deferrization mechanism of apoferritin and the effect of spectra variation with holoferritin].

The deferrization mechanism of apoferritin was established, and the spectra variation of apoferritin was compared with that of holoferritin. Sodium hyposulfite is a strong reducing agent, therefore, was applied to deoxidize holoferritin to release iron ion, and connection of iron of buffer was measured by the 2,2-dipyridyl. Apoferritin was detected by ICP-MS. Holoferritin was found to have no absorption compared with apoferritin by UV analysis, and have no fluorescence emission spectra in contrast with apoferritin by fluorescence analysis.

Effect of purple sweet potato on lipid metabolism and oxidative stress in hyperlipidemic rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of purple sweet potato on lipid metabolism and oxidative stress in hyperlipidemic rats.</p><p><b>METHODS</b>Forty male SD rats were randomly divided into 4 groups: normal control group, high-fat control group, high purple sweet potato groups, low purple sweet potato group. The rats were fed with different diets for 6w respectively.</p><p><b>RESULTS</b>Serum TC, TG levels were significantly lower in high dosage group than in high-fat control group; while only serum TG was significantly lower in low dosage group than in high-fat control group, these changes started at the third week and lasted to the end of experiment. Serum LDL-C and AI levels were significantly lower in high and low dosage group than in high-fat control group, whereas, serum HDL-C was significantly higher than that in high-fat control group at w3 and lasted to the end of experiment. Serum SOD was significantly higher in high and low dosage group than in high-fat control group, whereas, serum MDA was significantly lower than that in high-fat control group at w6.</p><p><b>CONCLUSION</b>Purple sweet potato can decrease serum lipids and reduce hepatic oxidative stress in hyperlipidemic rats.</p>