Departamento de Química, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil.
Anal Bioanal Chem. 2010 May;397(2):563-70. doi: 10.1007/s00216-010-3478-1. Epub 2010 Feb 6.
In this work, three sample preparation methods were evaluated for further halogen determination in elastomers containing high concentrations of carbon black. Samples of nitrile-butadiene rubber, styrene-butadiene rubber, and ethylene-propylene-diene monomer elastomers were decomposed using oxygen flask combustion and microwave-induced combustion (MIC) for further Br and Cl determination by ion chromatography (IC), inductively coupled plasma optical emission spectrometry (ICP OES), and inductively coupled plasma mass spectrometry (ICP-MS). Extraction assisted by microwave radiation in closed vessels was also evaluated using water or alkaline solution. Digestion by MIC was carried out using 50 mmol l(-1) (NH(4))(2)CO(3) as the absorbing solution. The effect of the reflux step was also evaluated. Accuracy was evaluated using certified reference materials with polymeric matrix composition and by comparison of results using neutron activation analysis. Agreement for Br and Cl was better than 95% by MIC using 5 min of reflux, and no statistical difference was found using IC, ICP OES, and ICP-MS for determination of both analytes. For MIC, the relative standard deviation (RSD) was lower than 5%. Using extraction in closed vessels, a high amount of residues was observed, and recoveries were lower than 45% for both analytes. For oxygen flask combustion, the agreement was similar using MIC but RSD was higher (20%). The residual carbon content, an important parameter used to evaluate the digestion efficiency, was always below 1% for MIC. Using MIC, it was possible to digest elastomers with high efficiency, resulting in a single solution suitable for halogen determination by different techniques.
在这项工作中，评估了三种样品前处理方法，以进一步测定高浓度炭黑的弹性体中的卤素。使用氧弹燃烧和微波诱导燃烧（MIC）对丁腈橡胶、丁苯橡胶和三元乙丙橡胶样品进行分解，通过离子色谱（IC）、电感耦合等离子体发射光谱（ICP OES）和电感耦合等离子体质谱（ICP-MS）进一步测定 Br 和 Cl。还评估了在封闭容器中使用微波辐射辅助提取的方法，使用水或碱性溶液。MIC 消化使用 50mmol/L(NH4)2CO3 作为吸收溶液。还评估了回流步骤的效果。使用具有聚合基质组成的认证参考材料评估了准确性，并通过使用中子活化分析比较结果进行了验证。使用 MIC 进行 5 分钟回流，Br 和 Cl 的准确度优于 95%，使用 IC、ICP OES 和 ICP-MS 测定两种分析物均无统计学差异。对于 MIC，相对标准偏差（RSD）低于 5%。使用密闭容器萃取，观察到大量残留，两种分析物的回收率均低于 45%。对于氧弹燃烧，使用 MIC 的一致性相似，但 RSD 较高（20%）。作为评估消化效率的重要参数，残留碳含量对于 MIC 总是低于 1%。使用 MIC，可以高效地消化弹性体，得到一种单一的溶液，适用于不同技术的卤素测定。
