目的  优化层析-比色法，并对该方法进行分析方法验证；比较优化层析-比色法和层析-积分法，评价两方法测定伤寒Vi精制多糖分子大小的适用性。方法  优化比色法O-乙酰基标准曲线浓度范围，对该方法进行准确度、重复性、中间精密度、线性和耐用性的验证；应用优化层析-比色法和层析-积分法检测多批次伤寒Vi精制多糖分子大小，对结果进行统计学分析。结果 优化层析-比色法准确度回收率均为100%；样品的重复性相对标准偏差（relative standard deviation，RSD）分别为2.4%和0.0%，中间精密度RSD均为3.4%，连续5次测定标准曲线，决定系数均大于0.999 0，耐用性RSD为4.6%。优化层析-比色法和层析-积分法在检测伤寒Vi精制多糖分子大小时，差异无统计学意义（t=-1.372，P＞0.05）。结论  优化的比色法具有良好的准确度、重复性、中间精密度、线性和耐用性，两种方法均可用于检测伤寒Vi精制多糖分子大小。

 Objective  To optimize the chromatography colorimetry method and verify by analytic methodology, to compare optimized chromatography colorimetry with chromatography integration, and to evaluat the applicability of the two methods to determine the molecular size of typhoid Vi refined polysaccharide. Methods  The concentration range of O-acetyl standard curve of colorimetry was optimized, and its accuracy, repeatability, intermediate precision, linearity and durability were verified. The molecular size of multiple batches typhoid Vi was tested using chromatography colorimetry and chromatography integration, and the results were statistically analyzed. Results  The accuracy recovery rates of the optimized chromatography colorimetry were all 100%. The relative standard deviations（RSDs) of corresponding repeatability of samples were both＜5.0%, the RSDs of intermediate precision were both 3.4%. The standard curve was analyzed for 5 time, and coefficients of determination were all greater than 0.9990. The RSD of durability was 4.6%. There was no statistically significant difference between optimized chromatography colorimetry and chromatography integration in the detection of molecular size of typhoid Vi refined polysaccharide (t=-1.372, P > 0.05). Conclusions  The optimized chromatography colorimetry has good accuracy, repeatability, intermediate precision, linearity and durability. Both methods are applicable in detecting the molecular size of typhoid Vi refined polysaccharide.