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2010
Conference Paper
Title
Beyond phthalates - Analytical and modeling tasks of modern plasticizers
Abstract
Due to the increased health debate about plasticizers basing on the esters of phthalic acid a slow shift to other acid esters (e.g.,adipic acid) occurred in the past years. Another modern plasticizer is derived from diisononylphthalate (DINP) via catalytic hydration: DINCH (diisononylcyclohexane-1,2-dicarboxylate). The latter two compounds are applied in industry as isomer mixtures. In most cases, DINCH or DINP contain a number of ~ 20 - 30 structural isomers. Thus, the analytical effort is significantly elevated against the analysis of pure compounds like, e.g. di(2-ethylhexyl)phthalate (DEHP). The present study describes measurements of selected modern plasticizers in air via thermal desorption - gas chromatography/mass spectrometry (TD-GC/MS). The different isomers of DINCH and DINP cannot be identified via low-resolution mass spectrometry but the differences in retention time allow the estimation of the difference of physical parameters of the governing isomers. Liquid samples of six plasticizers were conditioned in a microchamber (µ-CTE, Markes Ltd.) and air samples were taken on Tenax TA. The experimental setup allowed the determination of the emission rate (area or mass specific) of the six compounds and a rough estimation of the vapor pressure. Furthermore, two different prediction algorithms - SPARC and EPIWIN - for the estimation of compound properties are applied on a variety of different plasticizers. The distribution of the compound between airborne particles, settled particles (dust), and gas phase is calculated on the basis of the predicted partitioning coefficients and compared to published data (when available) as well as the microchamber results.
Language
English