GC法研究碱式氯化铝——有机酸溶液配合物的耐酸性

Studies on Acid-Resistance of Masked Basic Aluminium Cloride by GC

用凝胶过滤色谱法（ＧＣ）洗脱分离有机酸与６０％碱度的氯化铝形成的溶液配合物，通过比较ＧＣ图来研究它们在酸性介质中的变化。用ＳｅｐｈａｄｅｘＧ２５（Ｓｕｐｅｒｆｉｎｅ）柱（８０×２．４ｃｍ）作分离柱，铬天青Ｓ比色法测流份的铝含量。结果表明，不同浓度的碱式氯化铝与有机酸形成的溶液配合物的分子尺寸随介质ｐＨ值的降低而变小，且ｐＨ值越低，变化越大，这与有机酸种类和它们与铝盐的比例有关。试验结果说明，用较常规的ＧＣ法代替有很大局限性的水系高压洗脱的粒子排除色谱法（ＳＥＣ－ＨＰＬＣ）洗脱分离，进而研究Ａｌ（Ⅲ）－有机酸溶液配合物的耐酸性等是可行的。

Gel-filtration was carried out with Sephadex G25(Superfine) class column 80×2.4cm to analyze the organic acid masked 60% basic alum. chloride solutions which were stored in the different acidic medium (pH 3.5 to 1.5)for 1.5h. The column was eluted with 0.1M NaCl solution, the color of aluminium was developed with Chrome Azurol S. Tests showed that the molecular size of the alum. complexes masked with the organic acids became small considerably by the addition of acid. The lower the medium pH volume was, the smaller the molecular size was, but the change was related to the ratio of Morg.acid/M Al . and the organic acids. So, the experimental results indicated that gel-filtration chromatography could replace the water system size exclusion type HPLC to analyse the acid-resistance of masked alum. complex in solution, and so on.