The invention discloses a method of detecting two impurities containing a
quinuclidine ring in a
penehyclidine hydrochloride injection. The method adopts a gas chromatographic method to detect the contents of the impurities, namely the content of 3-quinuclidone and the content of 3-quinuclidinol. During detection, a sample of the
penehyclidine hydrochloride injection is subjected to vacuum rotary
evaporation to remove the
solvent in the injection, is dissolved with an alkaline
organic solvent so as to convert all the hydrochlorides into free alkalis and is dried by blowing
nitrogen, and then
dimethylformamide is added to prepare a sample solution to be detected; and
impurity reference substances are salified by adding an acid firstly, then is processed as the same
processing manner for the sample solution to be detected, and is prepared into
impurity reference substance solutions. The sample solution to be detected and the
impurity reference substance solutions are directly injected respectively, chromatograms are collected, and the contents of the impurities are calculated based on peak areas by an external standard method. The method of detecting the impurities has characteristics of simple and convenient operation, high sensitivity, capability of quantitative measurement, high accuracy and good reproducibility, effectively controls the product quality of the
penehyclidine hydrochloride injection, and guarantees safety and effectiveness of clinical medication.