石油类测试中不同品牌四氯乙烯试剂的稳定性

多年来四氯乙烯试剂的稳定性一直是业内关注的难题,其稳定性显著影响《水质 石油类和动植物油类的测定 红外分光光度法》(HJ 637—2018)的实施。针对市场上8个品牌四氯乙烯试剂开瓶后的吸光度开展测试,研究四氯乙烯试剂稳定性。结果显示:科密欧化学试剂有限公司、国药集团化学试剂有限公司、南京化学试剂股份有限公司、天津基准化学试剂有限公司、天津傲然精细化工研究所和吉林市吉联油脂化工有限公司6家厂商生产的"环保级"等相关级别四氯乙烯试剂稳定性较好,在开瓶7周时间内可以满足《水质 石油类和动植物油类的测定 红外分光光度法》(HJ 637—2018)标准中针对四氯乙烯试剂的要求。Sigma Aldrich和Alfa Aesar品牌四氯乙烯试剂虽然稳定性较好,但吸光度不满足上述标准中针对该试剂的要求,不可用于该方法检测。通过采取相关工艺(如提高纯度、调整溶剂的酸碱度、添加稳定剂等),可提升四氯乙烯试剂稳定性。该研究成果可为《水质 石油类和动植物油类的测定 红外分光光度法》(HJ 637—2018)标准中四氯乙烯试剂的保存时间及使用等提供一定参考。

Stability Study on the Application of Different Brands of Tetrachloroethylene Reagents in Petroleum Testing

The stability of tetrachloroethylene reagents has been a concern in the industry for many years.It affects the smooth advancement of the Water Quality-Determination of Petroleum,Animal Fats and Vegetable Oils-Infrared Spectrophotometry (HJ 637-2018) significantly.The absorbance of 8 brands of tetrachloroethylene reagents in the market after opening the bottle was tested to study the stability of tetrachloroethylene reagents.The results showed that tetrachloroethylene reagents with "Environmental Protection Grade" and other related grade produced by 6 manufacturers,including Kermel Chemo Chemical Reagent Co,Ltd,Sinopharm Chemical Reagent Co,Ltd,Nanjing Chemical Reagent Co,Ltd,Tianjin Benchmark Chemical Reagent Co,Ltd,Tianjin Aoran Fine Chemical Research Institute and Jilin City Jilian Grease Chemical Co,Ltd,had good stability.These reagents could meet the requirements of HJ 637-2018 within 7 weeks of bottle opening.Sigma Aldrich and Alfa Aesar,the two brands of tetrachloroethylene reagents had good stability,but their absorbance did not meet the requirements of the HJ 637-2018 and could not be used for this method of detection.The improvement of tetrachloroethylene reagent can be achieved by adopting relevant processes to improve purity,adjusting the acidity and alkalinity of solvents,and adding stabilizers.The research can provide some reference for the storage time and the use of tetrachloroethylene reagents in the HJ 637-2018 standard.