title: A method for improving the calculation accuracy of acid-base constants by inverse gas chromatography.
abstract: In this paper, studies were conducted in order to improve the calculation accuracy of acid-base constants measured by inverse gas chromatography. The conventional a·(γ(d)(l))(0.5) parameters of DCM (dichloromethane), TCM (trichloromethane), and EtAcet (ethyl acetate) were corrected as 185, 212, and 235 Å(2)(mJ/m(2))(0.5) by analyzing the relationship between a·(γ(d)(l))(0.5) and the boiling temperature of the probe solvents, where a is molecular area and γ(l)(d) is surface dispersive free energy of the probe solvents, respectively. To validate the availability of the new a·(γ(d)(l))(0.5) values, the acid-base constants of polystyrene were measured. It was found that when the new a·(γ(d)(l))(0.5) parameters were adopted, the final linear fit degree for the plot of -ΔH(a)(s)/AN* versus DN/AN* was enhanced from 0.993 to 0.999, and the standard deviation was decreased from 0.344 to 0.156. In addition, the availability of general application to improving the calculation accuracy of acid-base constants with the new a·(γ(d)(l))(0.5) parameters was also proved with a mathematical justification.
authors.affiliation: Department of Chemistry, College of Science, Northeast Forestry University, Harbin, Heilongjiang 150040, China. shi baoli@yahoo.com
authors.forename: Baoli
authors.initials: B
authors.lastname: Shi
authors.forename: Dawei
authors.initials: D
authors.lastname: Qi
mesh_terms: D000143:Acids / Q000737:chemistry*; D000465:Algorithms; D002849:Chromatography, Gas / Q000379:methods*; D013816:Thermodynamics
chemical_list: D000143:Acids