原文发表于Anal Chem. 2012 Oct 16;84(20):8642-9. doi: 10.1021/ac301759q. Epub 2012 Oct 2.


DART质谱法实时直接监测固体聚合物样品中的助剂作用：聚乙烯中 irgafos 168实例

Direct monitoring of the role played by a stabilizer in a solid sample of polymer using direct analysis in real time mass spectrometry: the case of irgafos 168 in polyethylene.

Fouyer K, Lavastre O, Rondeau D.

Institut d'Electronique et de Télécommunication de Rennes (IETR UMR CNRS 6164), Université de Rennes 1 , Campus de Beaulieu, 263 Avenue du General Leclerc, 35042 Rennes Cedex, France.

摘要

在没有任何样品制备的情况下，使用实时直接分析（DART）离子化方法配合飞行时间质谱（TOF）来直接分析无添加助剂或含有 Irgafos 168助剂的工业聚乙烯颗粒。该方法采用了邻苯二甲酸二异（2-乙基己基）辛酯（俗称塑化剂）的 [M + H](+) 离子来校准 AccuTOF 质谱仪的精确质量，并使用随机附带的质量漂移补偿功能，来测定助剂及聚合物的精确离子质量。实际上，邻苯二甲酸二异辛酯（DEHP）是一种塑料污染物，总会在样品的质谱图上出现。不论聚乙烯还是Irgafos都出现特征的质谱信号。热处理样品分析结果表明，当足够量的 Irgafos 存在于材料中时聚合物不会降解，而 Irgafos 168 在这其中起了氧气捕获剂的作用。聚乙烯颗粒暴露在紫外线环境下，用 DART-TOF MS 能显示出，Irgafos 168 对紫外辐射的反应有所不同，通过其 P-O 键的断裂防止了聚合物的降解。所测离子的元素组成验证了这一解释。

Direct analysis in real time (DART) ionization method is used with a time-of-flight (TOF) mass spectrometer to perform the analysis of industrial polyethylene pellets free of additives or containing Irgafos 168 as stabilizing agent without any sampling step. The developed analytical method uses the [M + H](+) ion of the bis(2-ethylhexyl) phthalate (DEHP) for performing the exact mass measurements of the stabilizer and polymer ions using the mass drift compensation procedure available on the AccuTOF mass spectrometer. DEHP is in fact a plastic contaminant always presents on the mass spectra of the analyzed samples. The mass spectra allow one to characterize either the ions of the polyethylene and that of the Irgafos. The analysis of thermally treated samples show that the polymer does not undergo any degradation when the Irgafos is present in the bulk of the material, and the role played by the Irgafos 168 is that of an oxygen trapping agent. Under UV exposure, the DART-TOF MS analyses performed on the exposed polyethylene pellets shows that the Irgafos 168 behavior toward the UV radiations is different since this one reacts by cleavages of its P-O bonds to prevent the degradation of the polymer. These interpretations are supported by all the elemental formula determination of the detected ions.

编译: Echo Jia

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pubs.acs.org/doi/abs/10.1021/ac301759q