Rapid Nondestructive Spectrometric Measurement of Temperature-Dependent Gas鈭扡iquid Solubility Equilibria

详细信息    查看全文

• 作者：Jian Ma ; Purnendu K. Dasgupta ; Bingcheng Yang
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：February 1, 2011
• 年：2011
• 卷：83
• 期：3
• 页码：1157-1161
• 全文大小：718K
• 年卷期：v.83,no.3(February 1, 2011)
• ISSN：1520-6882

文摘

Gas鈭抣iquid solubility equilibria (Henry鈥檚 Law behavior) are of basic interest to many different areas. Temperature-dependent aqueous solubilities of various organic compounds are of fundamental importance in many branches of environmental science. In a number of situations, the gas/dissolved solute of interest has characteristic spectroscopic absorption that is distinct from that of the solvent. For such cases, we report facile nondestructive rapid measurement of the temperature-dependent Henry鈥檚 law constant (K_H) in a static sealed spectrometric cell. Combined with a special cell design, multiwavelength measurement permits a large range of K_H to be spanned. It is possible to derive the K_H values from the absorbance measured in the gas phase only, the liquid phase only (preferred), and both phases. Underlying principles are developed, and all three approaches are illustrated for a solute like acetone in water. A thermostatic spectrophotometer cell compartment, widely used and available, facilitates rapid temperature changes and allows rapid temperature-dependent equilibrium measurements. Applicability is shown for both acetone and methyl isobutyl ketone. Very little sample is required for the measurement; the K_H for 4-hydroxynonenal, a marker for oxidative stress, is measured to be 56.9 卤 2.6 M/atm (n = 3) at 37.4 掳C with 1 mg of the material available.