The increasing demand for safe and effective methods for the separation of biological materials combining the advantageous properties of polyethylene glycol (PEG) (1500 g mol−1 or 4000 g mol−1) and ionic liquid has led to attractive and promising applications of the new aqueous biphasic systems. In this work, the liquid–liquid extraction process with aqueous two-phase systems (ATPS) was studied for α-amylase partitioning. The phase diagrams composed of PEG (1500 or 4000) g mol−1 + 1-ethyl-3-methylimidazolium chloride + water, were determined experimentally by the turbidimetric method at different temperatures T = (293.15, 303.15, 313.15 and 323.15) K. The effect of temperature and polymer molar mass on the phase diagrams, as well as the phase densities, refractive indexes and electrical conductivity were evaluated. Subsequently, the α-amylase partitioning was performed, where the partition coefficient was determined, besides the activity and selectivity. It was found that a temperature decrease and a polymer molar mass increase favored the formation of two phases. It was also found that α-amylase showed a preference for the bottom phase composed of PEG and the systems composed of PEG 1500 presented better results.

中文翻译：

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用于提取 α-淀粉酶的水性两相系统（聚乙二醇 + 离子液体）：相图、系统表征和分配研究

对结合聚乙二醇 (PEG)（1500 g mol-1 或 4000 g mol-1）和离子液体的优势特性的生物材料分离安全有效方法的需求不断增加，这导致了新的具有吸引力和前景的应用。水性双相系统。在这项工作中，研究了水两相系统 (ATPS) 的液-液萃取过程中的 α-淀粉酶分配。由 PEG (1500 或 4000) g mol-1 + 1-乙基-3-甲基咪唑氯化物 + 水组成的相图通过比浊法在不同温度 T = (293.15, 303.15, 313.15 和 323.15) K 下实验确定。评估了温度和聚合物摩尔质量对相图以及相密度、折射率和电导率的影响。随后，进行α-淀粉酶分配，除了活性和选择性外，还确定了分配系数。发现温度降低和聚合物摩尔质量增加有利于两相的形成。还发现α-淀粉酶显示出对由PEG组成的底相的偏好并且由PEG 1500组成的系统呈现出更好的结果。