Clark C C
J Assoc Off Anal Chem. 1975 Jul;58(4):852-5.
Fifteen laboratories collaboratively studied a method for the quantitative ultraviolet determination of ephedrine sulfate in sirups. Ephedrine is separated from water-soluble impurities and strong acids by elution from a weakly basic Celite column. Further cleanup is accomplished by retention of the ephedrine on a weakly acidic column while the weak acids, weak bases, and organic-soluble neutral compounds are eluted. Ephedrine is eluted from the column after neutralization with NH3 and is converted to benzaldehyde via an on-column periodate reaction. The samples collaboratively studied consisted of 2 commericial ephedrine-containing sirups and 2 commercial non-ephedrine-containing sirups to which ephedrine was added. Recoveries for the spiked sirups averaged 100.7 and 100.3% for mixtures containing 2.5 and 5.0 mg ephedrine sulfate/ml, respectively. The means and standard deviations for the commercial preparations were 4.088 plus or minus 0.068 and 2.375 plus or minus 0.053 mg/ml. The method has been adopted as official first action and has been incorporated into the official method for phenylpropanolamine hydrochloride, 38.199-38.203.
十五家实验室合作研究了一种定量测定糖浆中硫酸麻黄碱的紫外分光光度法。麻黄碱通过从弱碱性硅藻土柱上洗脱，与水溶性杂质和强酸分离。进一步的净化是通过将麻黄碱保留在弱酸性柱上，同时洗脱弱酸、弱碱和有机可溶性中性化合物来实现的。用氨中和后，麻黄碱从柱上洗脱，并通过柱上高碘酸盐反应转化为苯甲醛。合作研究的样品包括两种市售含麻黄碱糖浆和两种添加了麻黄碱的市售不含麻黄碱糖浆。对于分别含有2.5和5.0mg硫酸麻黄碱/毫升的混合物，加标糖浆的回收率平均分别为100.7%和100.3%。市售制剂的平均值和标准差分别为4.088±0.068和2.375±0.053mg/毫升。该方法已被采用为官方首次行动方法，并已纳入盐酸苯丙醇胺的官方方法（38.199 - 38.203）。
