紫外光降解-离子色谱法测定液晶化合物中的阴离子

 采用紫外光降解 离子色谱法测定了液晶材料中的阴离子。建立了样品前处理的方法 ,研究了样品光降解的条件及样品测定的最佳色谱参数。结果表明 ,该液晶材料样品中含有F-,Cl-,NO2 -,Br-和I-等 5种阴离子。用DionexOnGuardRP及P型前处理柱过滤可有效去除光解后样品基体中的有机物。光解时加入H2 O2 可显著提高光解效率 ,在样品基体中加入NaOH使该方法可准确测定样品中的I-。F-,Cl-,NO2 -和Br-在光解时间约为 2 0h时达到最大离解效率 ,I-在光解 1 5h时达到最大离解效率。采用DionexIonPacAS16色谱柱 ,整个样品的测定可在 2 5min内完成。

Determination of Anions in Liquid Crystal Samplesby UV-Photolysis-Ion Chromatography

A new method for the determination of anions in liquid crystal samples by UV photolysis ion chromatography was developed The sample pretreatment method, the photolytic conditions and the chromatographic parameters were optimized The results indicate that there have five anions (F -,Cl -,NO 2 -,Br -,I -) in the liquid crystal sample By the filtration with the Dionex OnGuard RP and P cartridges, most of the organic compounds in the photolyzed sample solution can be removed In the process of photolysis, the efficiency can be remarkably enhanced by the adding of H 2O 2 Iodide in the liquid crystal sample can be accurately determined by adding of 0 1 mmol/L NaOH In the five anions, fluoride, chloride, nitrite and bromide can get their maximal responses when the photolysis time is 2 h With the strongest reducibility, iodide only needs 1 5 h to get the highest response The separation of the five anions was accomplished with Dionex IonPac AS16 column and the determination can be completed in 25 min The recoveries for the five anions were between 85 1% and 111 5%