禁用偶氮染料所释放2,4-二氨基甲苯的检测分析

Analysis for Detection Method of 2,4-Diaminotoluene Derived from Banned Azo Colorants

纺织品中禁用偶氮染料释放的芳香胺2,4-二氨基甲苯检出率较高,检测难度大。检测标准ISO 14362-1:2017和GB/T 17592-2011技术条件存在差别,实际检测结果不一致,存在假阴性和假阳性。为提高2,4-二氨基甲苯检测的回收率及样品检测的准确性,以阳性样品为研究对象,通过对比实验,对影响2,4-二氨基甲苯检测结果的关键步骤进行探讨。结果表明:碱化样品还原后的溶液,控制硅藻土柱流速在2~3 mL/min,可以提高2,4-二氨基甲苯提取效率;24 h内阳性样品溶液进行延迟检测实验,发现部分阳性样品中目标物损失严重,应尽快检测。含有聚氨酯和胶黏剂的样品在气相色谱进样口高温下会产生2,4-二氨基甲苯,导致假阳性结果,需要用液相色谱法进行验证。

The detection rate of 2,4-diaminotoluene derived from banned azo colorants in textiles is high, but the detection itself is difficult. Different technical conditions in test standards ISO 14362-1:2017 and GB/T 17592-2011 cause inconsistent outcomes,potentially resulting in false positives and false negatives. In order to improve the recovery rate of 2,4-diaminotoluene and accuracy of samples detection results, the pretreatment process of the positive samples was studied in detail by comparative experiments. The extraction efficiency of 2,4-diaminotoluene can be effectively improved by controlling alkalization of samples solution and column flow rate of in diatomaceous earth at 2-3 mL/min. Through the delayed detection experiment of the positive sample within 24 h, the content of 2,4-diaminotoluene in some positive-samples greatly decreased, so it should be tested as soon as possible. For the samples containing polyurethane and adhesive, 2,4-diaminotoluene will be produced at high injector temperature of gas chromatograph, and the result of 2,4-diaminotoluene is maybe false-positive, which needs to be analyzed by liquid chromatography.