Diffusion coefficients of phenylbutazone in supercritical CO2 and in ethanol

Abstract

The diffusion coefficients D(12) of phenylbutazone at infinite dilution in supercritical CO(2) were measured by the chromatographic impulse response (CIR) method. The measurements were carried out over the temperature range from 308.2 to 343.2 K at pressures up to 40.0 MPa. In addition, the D(12) data of phenylbutazone at infinite dilution in ethanol were also measured by the Taylor dispersion method at 298.2-333.2K and at atmospheric pressure. The D(12) value of phenylbutazone increased from 4.45×10(-10) m(2) s(-1) at 298.2 K and 0.1 MPa in ethanol to about 1.43×10(-8) m(2) s(-1) at 343.2 K and 14.0 MPa in supercritical CO(2). It was found that all diffusion data of phenylbutazone measured in this study in supercritical CO(2) and in ethanol can be satisfactorily represented by the hydrodynamic equation over a wide range of fluid viscosity from supercritical state to liquid state with average absolute relative deviation of 5.4% for 112 data points.

Measurement and correlation of binary diffusion coefficients of lithium acetylacetonate in supercritical carbon dioxide and in liquid ethanol

“…The validity of the Eq. (6) have been demonstrated for a variety of compounds [10,[20][21][22][23][27][28][29][30]. It was found that the values of D 12 /T for all the D 12 data of Li(acac) measured in this study were also well correlated with the Á values of fluids.…”

“…The D 12 values simply increased with decreasing P and increasing T. The greater P sensitivity of D 12 at lower P indicates that the fluid or viscosity Á is remarkable factor, because these properties change rapidly with P in this region. Similar D 12 behavior was found in sc carbon dioxide in the literature for acetone [8,9,18], alkane [18], benzene [18], caffeine [19], ␤-carotene [8,20], cobalt(III) acetylacetonate [21], 1,2-diethylbenzene [22], 1,4-diethylbenzene [22], diethyl ether [23], diisopropyl ether [23], dimethylnaphthalene [24], 2-ethyltoluene [25], 3-ethyltoluene [25], 4-ethyltoluene [25], hexachlorobenzene [26], naphthalene [19,24,27,28,26], phenol [8,9], palladium(II) acetylacetonate [21], phenanthrene [26], phenylacetic acid [28], phenylacetylene [22], phenylbutazone [10], tetrahydrofuran [23], triarachidonin [29], trinervonin [29], trierucin [29], ␣-tocopherol [8,20], ubiquinone (UQ-10) [20,30], vanillin [28], vitamin K 3 [20,31] and 5-tert-butyl-m-xylene [22]. As shown in …”

“…As shown in Fig. 5, the D 12 data of Li(acac) in sc carbon dioxide can be represented by a simple empirical correlation [10,21,22] with T and P (Eq. (4)) with the average absolute relative deviation (AARD) of 2.2% for 73 data points, while the correlation depends on the system studied.…”

“…The experimental apparatuses and the procedures for the CIR and the Taylor dispersion methods are substantially the same as those reported in our previous studies [10,11]. The temperature and pressure of the system were measured by a pressure indicator (PM digital, HEISE,USA) and a thermometer (APT-100, ANRITSU, Japan), respectively.…”

Ordered mesoporous silica microspheres for supercritical fluid chromatography

“…17 Theoretically, lower viscosity that results in higher diffusion coefficient could facilitate analytes moving more rapidly in the pores of the stationary phase. 18 Therefore, Van Deemter curves were used to evaluate the separation and kinetic efficiency of the OMS packed column in SFC. 19 Herein, uracil, a strongly retained compound (retention factors k > 20), was selected as an analyte, because its peak variance is assumed to be independent of extra-column dispersion and suitable for intrinsic column efficiency evaluation.…”