目的  建立检测精制肺炎链球菌多糖中甲基戊糖的方法，并进行方法学验证。方法  将经硫酸和加热处理的精制肺炎链球菌多糖与半胱氨酸盐酸盐进行反应，分别在396 nm和430 nm波长下检测合成的化合物的吸光度值，并根据差值计算甲基戊糖含量。对建立的甲基戊糖测定法进行准确度、精密度、线性、专属性和耐用性验证。 结果  该法的准确度良好，甲基戊糖加样回收率为90.2%～108.9%。该法具有较好的重复性和中间精密度，相对标准偏差分别为≤4.6%和1.2%～5.2%，均符合规定的要求。在甲基戊糖质量浓度为2～22 mg/L的检测范围，该法的标准曲线呈现良好的线性，决定系数>0.990 00。该法的专属性较好，精制肺炎链球菌多糖溶液中含有10～50 g/L乙酸钠不会对检测结果产生影响。结论  建立的甲基戊糖测定法可准确定量甲基戊糖含量，可用于对精制肺炎链球菌多糖中甲基戊糖的质量控制。

 

Objective  To establish and validate a detection method for methylpentose in refined pneumococcal polysaccharides.  Methods  Refined polysaccharides from Streptococcus pneumoniae were treated with sulfuric acid and heating, and then reacted with cysteine hydrochloride. The absorbance of the reaction compound was measured at 396 nm and 430 nm, respectively. Methylpentose concentration in polysaccharides was calculated based on difference between two absorbance values. The accuracy, specificity，precision, linearity , and durability of the detection method for methylpentose were validated.  Results  The accuracy of this method was good, and recoveries of methylpentose were 90.2%-108.9%. The relative standard deviations of repeatability and intermediate precision were ≤4.6% and 1.2%-5.2%, respectively, both meeting requirements. The standard curve of this method showed good linearity in detection range of 2-22 mg/L methylpentose, and determinate coefficient >0.990 00. The specificity of this method was good, and the presence of 10-50 g/L sodium acetate in refined pneumococcal polysaccharides had no effect on results. Conclusion  The established method can accurately and quantitatively detect the content of methylpentose, and can be used for quality control of methylpentose in refined pneumococcal polysaccharides.