Influence of pH Value and Ionic Liquids on the Solubility of l-Alanine and l-Glutamic Acid in Aqueous Solutions at 30 °C
Influence of pH Value and Ionic Liquids on the Solubility of l-Alanine and l-Glutamic Acid in Aqueous Solutions at 30 °C
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DOI：
10.1021/acs.jced.6b00367
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发表时间：
2017-01
影响因子：
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通讯作者：
Matthias Voges;I. V. Prikhod’ko;S. Prill;M. Hübner;G. Sadowski;C. Held
中科院分区：
文献类型：
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作者：
Matthias Voges;I. V. Prikhod’ko;S. Prill;M. Hübner;G. Sadowski;C. Held
研究了在30 °C和大气压下，在3至9的pH范围内，在离子液体（IL）1-丁基-3-甲基咪唑鎓三氟甲磺酸盐（[bmim][OTf]）和柠檬酸二氢胆碱（[ch][dhcit]）的存在下，在30 °C和大气压下，氨基酸1-丙氨酸和1-谷氨酸及其钠盐（1-谷氨酸钠一水合物）在水溶液中的溶解度。用紫外分光光度法和重量法测定了L-丙氨酸和L-谷氨酸在无IL溶液中的溶解度。在IL存在下，应用HPLC分析。固相的特点是使用拉曼光谱和粉末X-射线衍射，以区分氨基酸从它们的盐。虽然L-丙氨酸的溶解度不依赖于pH值在所考虑的pH范围内，L-谷氨酸的溶解度强烈增加，随着pH值的增加。低于pH值6.2的固相，其特征在于是L-谷氨酸，而L-谷氨酸钠一水合物被发现是固体在pH值...
The solubility of the amino acids l-alanine and l-glutamic acid and its sodium salt (sodium l-glutamate monohydrate) in aqueous solutions at 30 °C and atmospheric pressure was investigated in the pH range between 3 and 9 and in the presence of the ionic liquids (ILs) 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]) and choline dihydrogencitrate ([ch][dhcit]) at pH 7. The solubility of l-alanine and l-glutamic acid in the solutions without IL was measured by UV spectroscopy and with a gravimetrical method. In the presence of an IL HPLC-analysis was applied. The solid phases were characterized using Raman spectroscopy and powder X-ray diffraction to distinguish the amino acids from their salts. While the solubility of l-alanine did not depend on pH within the considered pH range, the solubility of l-glutamic acid strongly increased with increasing pH. Below pH 6.2 the solid phase was characterized to be l-glutamic acid, while sodium l-glutamate monohydrate was found to be the solid at pH ...