Sephadex G-25用于YML-1脱盐条件优化   总被引：1，自引：0，他引：1  

廖铭能  苏伟明  于立坚  马润娣 《广东海洋大学学报》2006,26(4):94-95

凝胶过滤(或称分子筛)层析是一种由限制分子通过多孔基质,按分子大小分离混合分子的技术[1]。凝胶过滤方法常用于生物样品脱盐,其操作简便易行,脱盐效果可靠[2]。由于可通过紫外和电导检测器监控整个层析过程、产品的纯度和回收率,又可连续自动进样和收集样品,自动化程度高,容易放大[3],所以,自上世纪60年代初始,随着层析介质技术的发展,Sephadex G-25系列凝胶过滤介质常用于实验室乃至工业规模的脱盐、小分子物质去除及缓冲液的置换。一般实验室脱盐常用透析方法,但其耗费时间长、缓冲液消耗量大,又易损失宝贵样品。笔者采用凝胶过滤法研…  相似文献   

Use of ultrasonic treatment for extraction of humic acid with inorganic reagents from soil     

A.U. Ramunni  F. Palmieri 《Organic Geochemistry》1985,8(4):241-246

The use of ultrasonic vibrations (1 hr) on the extraction of humic acids (HA) from a brown soil has been compared with the extraction by mechanical stirring (24 hr) with two extractants: 0.5 N and 0.1 M Na₄P₂O₇, followed by extraction with 0.5 N NaOH. In the pyrophosphate extraction, ultrasonic and mechanical treatments produced the same yield of HA. Further extraction with NaOH and mechanical stirring gave higher yields.The elemental composition of HA changed remarkably with both ultrasonic and mechanical systems. The HA extracted with ultrasonic treatment showed a higher ash content and a lower content of COOH and phenolic OH groups. These HA's showed higher optical density at 260 and 450 nm when pyrophosphate-extracted, and lower optical density when NaOH-extracted. Moreover the ultrasonic-treated HA in both extractants showed a lower E₄₀₀/E₆₀₀ ratio.Infrared examination confirmed the difference in chemical characteristics of extracted HA. The HA distribution in the different classes of nominal molecular weights by Sephadex gel filtration was influenced by both ultrasonic and mechanical systems, specially for molecular weights between 5000 and 150,000. It has been noted that the differences due to both systems are less marked than those caused by ssing different extractants.  相似文献