离子色谱法与比色法测定浓维磷糖浆中总磷量的比较

Comparisom of Ion Chromatography and Colorimetry for the Determination of Amount of Total Phosphorus in Concentrated Divitamins and Sodium Phosphate Syrup

目的建立测定浓维磷糖浆中有效成分总磷量的离子色谱法,并以比色法进行比较。方法采用IonPac AS18-HC离子分析柱,以50%氢氧化钾溶液梯度淋洗,流速为1.0mL·min^(-1),进样量为25μL,抑制电导检测器。结果在该色谱条件下,甘油磷酸根峰与PO_4^(3-)峰均能有效分离,线性范围分别为1.054~84.35μg·mL^(-1)(r=0.9994)及0.3168~25.35μg·mL^(-1)(r=0.9998);平均回收率分别为99.3%(RSD:1.16%,n=9)和98.9%(RSD:2.61%,n=9);精密度的RSD均小于1.08%;样品在8h内稳定。离子色谱法与比色法测得的4批样品总磷量均在合格范围。结论离子色谱法测定结果与比色法测定结果有差异,来源为甘油磷酸钠的量与PO_4^(3-)的量;离子色谱法专属性强,更适合作为浓维磷糖浆中总磷量的质量控制的方法。

OBJECTIVE To establish a ion chromatography method for the Amount of total phosphorus of the active ingredient in concentrated divitamins and sodium phosphate syrup and compare it with the colorimetry. METHODS Using IonPac AS18-HC（ 250 mm × 4 mm） ion analysis column and the AG19-HC（ 50 mm × 4 mm）guard column,Using a gradient eluent with gradient of 50% potassium hydroxide solution as mobile phase,the flow rate was 1. 0 mL·min^-1,the injection volume was 25μL,the conductance detector,suppression conductometric detection. RESULTS Sodium glycerophosphate and phosphate could be separated well under the chromatographic conditions. The linear ranges were 1. 054 - 84. 35μg·mL^-1（ r = 0. 9994） for sodium glycerophosphate and 0. 3168 -25. 35μg· mL^-1（ r = 0. 9998） for phosphate. Their average recoveries were 99. 3%（ RSD： 1. 16%,n = 9） and 98. 9%（ RSD： 2. 61%,n = 9）,respectively. The precision RSD was less than 1. 08%; The stability of solution was less than 8 hours. The amount of total phosphorus of four samples measured by ion chromatography and colorimetry was in the qualified range; CONCLUSION There were significant differences between ion chromatography and colorimetry,the difference is the amount of sodium glycerophosphate and Amount of total phosphorus; Ion chromatography was more specific and more suitable for the determination and quality control of concentrated divitamins and sodium phosphate syrup.