Lyman G W, Johnson R N
J Assoc Off Anal Chem. 1979 Jan;62(1):71-4.
A gas-solid chromatographic procedure is described for the analysis of low levels of moisture in individual lyophilized vials of pharmaceutical products. Dry ethanol, which contains methanol as the internal standard, is injected through the septum of the vial to dissolve the lyophilized contents. An aliquot of this solution is then withdrawn and injected onto a Porapak QS column at 110 degrees C where the components are separated and detected using thermal conductivity detection. A solvent blank correction allows quantitation of the water in the individual vial. The method is conveniently applied to samples containing as little as 50 microgram water/vial, and as many as 25 vials can be assayed/day. A simple technique is also described for removing water from the ethanol solvent to less than 100 ppm, using a molecular sieve.
本文描述了一种气固色谱法，用于分析药品冻干小瓶中低含量的水分。含有甲醇作为内标的无水乙醇通过小瓶的隔膜注入，以溶解冻干的内容物。然后取出该溶液的一份等分试样，并在110℃下注入到Porapak QS柱上，在该柱上各组分被分离，并使用热导检测进行检测。通过溶剂空白校正可对单个小瓶中的水进行定量。该方法可方便地应用于每个小瓶中仅含50微克水的样品，并且每天可分析多达25个小瓶。还描述了一种使用分子筛将乙醇溶剂中的水去除至低于100 ppm的简单技术。
