Partition coefficients of environmentally important phenols in a supercritical carbon dioxide-water system from cocurrent extraction without analysis of the compressible phase.
نویسندگان
چکیده
Partition coefficients of phenol, salicylic acid, and several environmentally important chloro- and nitrophenols in a supercritical CO2-water system were measured using direct cocurrent extraction of aqueous solutions of the individual solutes with CO2. Partitioning data on the nitrophenols and salicylic acid were obtained for the first time. To bypass the troublesome and error-prone analysis of the CO2-rich phase, the present method employed only the solute concentrations in the aqueous phase before and after extraction to determine the partition coefficient. Unlike most previous engineering studies of phenol partitioning in a CO2-water system, the concentrations of phenolic solutes approached infinite dilution in both phases. This makes the results relevant to analytical-scale SFE of environmental water samples with CO2. Because of effective infinite dilution of the solutes, the partition coefficients provide a direct measure of relative CO2-philicity/hydrophilicity of the individual phenols. Compared to the octanol-water partition coefficients of substituted phenols, the CO2-water partition coefficients are more sensitive to substitution in the position neighboring the hydroxyl group.
منابع مشابه
An Environmental Friendly Process for Extraction of Active Constituents from Herbal Plants
Conventional methods for extraction of the active constituents from herbal plants, in addition to their high processing costs, are harmful to the environment owing to their time and energy consumption, uncontrollable parameters, use of toxic and dangerous solvents, loss of the extract, thermal instability, the contamination of the product with organic solvents and the loss of water-soluble comp...
متن کاملMeasurement and Modeling of Acridine Solubility in Supercritical Carbon Dioxide
Supercritical carbon dioxide has gained increasing attention in food and pharmaceutical processing owing to the fact that it is environmentally inexpensive, not flammable, essentially non-toxic, and it has a convenient critical point. Also, it has been attracting much attention in many fields, such as extraction of sensitive materials and pharmaceutical processing and polymerization processes. ...
متن کاملSupercritical Carbon Dioxide Extraction of Bioactive Compounds from Feijoa (Feijoa sellowiana) Leaves
Background and Objectives: Supercritical fluid extraction (SFE) technique has been studied for extraction of bioactive compounds from Feijoa sellowiana leaves. Results were compared with those obtained from conventional ethanolic extraction (CE). Materials and Methods: Results: The best supercritical carbon dioxide (SC-CO2) extraction conditions was determined as 250 bar of pressure, 50 °...
متن کاملDispersion Coefficients of Supercritical Fluid in Fixed Beds
The axial dispersion coefficient of hexachlorobenzene in supercritical carbon dioxide is investigated in a fixed-bed packed with glass beads. The on-line chromatographic pulse-response experiment is used in order to study the dynamics of a packed column under supercritical conditions. The radial dispersion is assumed negligible because of the packed column geometry. To estimate the axial disper...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Analytical chemistry
دوره 74 16 شماره
صفحات -
تاریخ انتشار 2002