Characterization of the sorption of gaseous and organic solutes onto polydimethyl siloxane solid-phase microextraction surfaces using the Abraham model.

Water-to-polydimethylsiloxane (PDMS) and gas-to-PDMS sorption coefficients have been compiled for 170 gaseous and organic solutes. Both sets of sorption coefficients were analyzed using the Abraham solvation parameter model. Correlations were obtained for both "dry" headspace solid-phase microextraction and conventional "wet" PDMS coated surfaces. The derived equations correlated the experimental water-to-PDMS and gas-to-PDMS data to better than 0.17 and 0.18 log units, respectively. In the case of the gas-to-PDMS sorption coefficients, the experimental values spanned a range of approximately 11 log units.

Comment on "systematic investigation of the sorption properties of polyurethane foams for organic vapors".

A method was devised for combining experimental partition coefficients measured at different temperatures into a single regression correlation. The proposed method described the 265 experimental air-to-polyurethane ether adsorption coefficients reported by Kamprad and Goss (Kamprad, I.; Goss, K.-U. Anal. Chem. 2007, 79, 4222-4227) to within a standard deviation of 0.084 log units, which is comparable in descriptive ability to the four temperature-specific correlations determined from a regression analysis of the experimental data at each of the temperatures studied.

Linear free energy relationship correlation of the distribution of solutes between water and sodium dodecyl sulfate (SDS) micelles and between gas and SDS micelles.

Data have been assembled from the published literature on the water-to-micellar sodium dodecyl sulfate (SDS) partition coefficient data for more than 200 compounds and on the gas-to-micellar SDS partition coefficient data for more than 140 compounds. It is shown that an Abraham solvation equation with only five descriptors can be used to correlate the observed partition coefficient data to within a standard deviation of 0.22 log units. Micellar electrokinetic chromatographic (MEKC) retention factor data measured on a micellar SDS pseudostationary phase was also gathered from the literature. The water-to-micellar SDS partition coefficient and MEKC retention factor data were combined into a single database and correlated with the Abraham model. The derived correlation described the 486 experimental values to within a standard deviation of 0.15 log units. The micellar SDS system has been compared to various liquid phases in terms of solubility of gases and vapors and has been shown to be a very selective system-more so than room-temperature ionic liquids.

Characterization of the retention behavior of organic and pharmaceutical drug molecules on an immobilized artificial membrane column with the Abraham model.

Data have been compiled from the published literature on the retention factors of 174 organic compounds and drug molecules eluted from a Regis Technologies IAM.PC.DD2 HPLC column using an aqueous mobile phase buffered in the pH range of pH 6.5-7.5. The logarithms of the retention factors are correlated with the Abraham solvation parameter model. The derived correlation contains the five Abraham solute descriptors plus two additional indicator descriptors (I(COOH) and I(amine)) that would be needed whenever carboxylic acid and alkylamine solutes are eluted in ionic form. The derived correlation describes the experimental capacity data of 174 neutral, acidic and basic compounds to within 0.21 log units.

Characterization of room-temperature ionic liquids by the Abraham model with cation-specific and anion-specific equation coefficients.

Gas-to-RTIL (room-temperature ionic liquid) partition coefficients have been compiled for 592 different solute-RTIL combinations. These partition coefficients were converted into water-to-RTIL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the Abraham solvation parameter model with cation-specific and anion-specific equation coefficients. The derived equations correlated the experimental gas-to-RTIL and water-to-RTIL partition coefficient data to within 0.10 and 0.14 log units, respectively. The 8 sets of calculated cation-specific equation coefficients and 4 sets of calculated anion-specific equation coefficients can be combined to yield expressions capable of predicting the partition coefficients of solutes in 32 different RTILs.