Sorption of hydrophobic organic compounds on nonpolar SPME fibers and dissolved humic organic matter—Part III: Application of the solubility parameter concept to interpret sorption on solid phase microextraction (SPME) fiber coatings
✍ Scribed by Juergen Poerschmann
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 152 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1040-7685
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✦ Synopsis
Hydrophobic organic compounds HOCs sorption on nonpolar poly Ž . Ž . Ž . dimethylsiloxane PDMS and polar polyacrylate PA fiber coatings is based on partitioning. By applying solubility parameter concept, explaining HOCs' sorption on amorphous polymers including ''liquid'' SPME coatings, Hildebrand solubility Ž . parameters ␦ of these fiber coatings can be calculated using fiber distribution Ž . coefficients K . Hildebrand solubility parameters turned out to be decisive f parameters for describing sorption on both coatings under study. Calculated solubility parameters of PDMS and PA coatings are within a very narrow range Ž 0.5 y1.5 . Ž 0.5 y1.5 . ␦ s 15.0 " 1.0 J cm and ␦ s 22.2 " 1.0 J cm when PAH PDMS PA and PCB fiber distribution coefficients are used to calculate data. Solubility parameter of the 7 m PDMS coating is slightly, but significantly higher than the 100 m coating. Once calculated, coating solubility parameter may serve to calculate K values of hydrophobic analytes based on available physicochemical f Ž . Ž . data including octanol᎐water coefficients K and molar volumes V . Sorption OW m coefficients on nonpolar PDMS and polar PA fiber coatings, available in the literature, fit well in this universal one-parameter solubility concept. Fiber distribution coefficients and corresponding octanol᎐water coefficients follow a strong correlation for analytes of the same ''family.'' For analytes possessing ␦ ( i 21.5 J 0.5 cm y1.5 , relation Log K s Log K is valid.