Enhanced solubilization of bovine serum albumin in reverse micelles by compressed CO2

The effect of compressed CO2 on the solubilization of bovine serum albumin (BSA) in water/sodium bis-(2-ethylhexyl) sulfosuccinate (AOT)/isooctane reverse micelles was studied by observing phase behavior and recording UV-visible spectra under different conditions. The pH values within the water cores of reverse micelles at different CO2 pressures were also determined. The solubilization capacity of the reverse micelles for the protein increased considerably as CO2 pressure increased within the low-pressure range, but decreased at higher CO2 pressures, so that the micelles eventually lost their ability to solubilize the protein. The effect of CO2 on the stability of the reverse micelles played an important role in the relationship between pressure and protein solubility. A "multicomplex" model was proposed to explain these effects. The different solublization capacities within different pressure ranges demonstrates the unique advantage of using compressed CO2 in the extraction of proteins with reverse micelles.     

Synthesis and growth mechanism of zirconia nanotubes by anodization in electrolyte containing Cl−

The formation and growth of a self-organized zirconia porous layer can be achieved directly by anodization of Zr in chloride containing electrolytes. The morphology of the porous layers is affected by electrochemical conditions such as Cl⁻ concentration. Zirconia nanotubes with diameters ranging from 250 to 300 nm and a length of 33 μm were formed under proper conditions. The nanotubes have smooth and straight walls. The composition of the nanotubes was characterized by using an energy dispersive spectrometer. Selected area electron diffraction investigation reveals that the as-anodized zirconia nanotubes have an amorphous structure. Crystal phase transition and structural stability of the ZrO₂ nanotubes after heat treatment were characterized. A possible growth mechanism is presented.     

2,4-二硝基酚分光光度法测定氯氮卓

在水溶液中 ,氯氮卓与 2 ,4 二硝基酚发生荷移反应 ,生成稳定的 1∶1的配合物 .最大吸收波长为 44 4nm ,表观摩尔吸光系数为ε =1.48× 10 3L/ (mol·cm) ,线性范围 3～ 96 μg/mL ,回收率为 99.95 %～ 99.97% ,相对标准偏差为 0 .5 5 %     

硫化铵溶样催化极谱法快速测定硫磺中痕量硒

提出硫化铵溶解,氨性介质过氧化氢氧化分解硫磺试样,在0.48mol·L~(-1)HClO_4-4.76×10~(-3)mol·L~(-1)Na_2SO_3-2.96mol·L~(-1)NH_3·H_2O-6.81×10~(-3)mol·L~(-1)(NH_4)_2SO_4-8.41×10~(-4)mol·L~(-1)KIO_3-1.18×10~(-2)mol·L~(-1)硫脲-0.02g·L~(-1)动物胶体系中以催化极谱法测定痕量硒的方法.硒浓度在0.02～9.0ng·ml~(-1)范围内与极谱峰电流有良好的分段线性关系,检出限为0.01ng·ml~(-1).方法的RSD为3.4%～3.9%,加标回收率为91%～97%.此法仪器试剂简单,操作快速简便.用于硫磺样品的测定,结果满意.