Measurement of temperature dependence for the vapor pressures of twenty-six polychlorinated biphenyl congeners in commercial Kanechlor mixtures by the knudsen effusion method

Katsuhiko Nakajoh, Etsuro Shibata, Tomohiro Todoroki, Atsushi Ohara, Katsushi Nishizawa, Takashi Nakamura

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

The vapor pressures of the major congeners in commercial polychlorinated biphenyl (PCB) mixtures (Kanechlors; Kanebuchi Chemical Industry, Tokyo, Japan) have been experimentally determined by Knudsen mass loss effusion. We obtained vapor pressures for the individual PCBs in the crystalline solid, liquid, and subcooled liquid forms as a function of temperature. We derived the thermodynamic parameters, such as the enthalpies of sublimation and vaporization, from the temperature dependence of the vapor pressure by the Clausius-Clapeyron equation. To decide whether the commercial PCB mixtures were ideal solutions, we obtained the activity coefficients by comparing our experimental vapor pressures for pure PCB congeners with those calculated from Kanechlor molar compositional data and vapor pressure values. In many cases, we found that, at 298 K, the values of the activity coefficients of major PCBs in Kanechlor 300 and 500 ranged from 1 to 2. Thus, we suggested that the commercial PCB mixtures show slight positive deviations from ideal solution (Raoult's Law) behavior at ambient temperatures.

Original languageEnglish
Pages (from-to)327-336
Number of pages10
JournalEnvironmental Toxicology and Chemistry
Volume25
Issue number2
DOIs
Publication statusPublished - 2006 Feb

Keywords

  • Knudsen effusion method
  • Polychlorinated biphenyls
  • Raoult's Law
  • Thermodynamic parameters
  • Vapor pressure

ASJC Scopus subject areas

  • Environmental Chemistry
  • Health, Toxicology and Mutagenesis

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