Abstract
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 ...
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
