叶酸水分测定方法的研究

Study on the determination of water content in folic acid

目的:采用热重分析法(TG)、差示扫描量热法(DSC)等方法对叶酸的热力学行为进行研究,并建立了一个新的卡式炉-卡尔费休法测定水分的方法。方法:卡式炉自动进样器温度为150℃,加热时间为10 min,载气流速为80 mL min^-1,终点相对漂移为20μg min^-1,滴定终点为延迟时间终止模式。结果:采用新建立的方法测定中国食品药品检定研究院与美国药典会(USP)叶酸对照品水分,结果分别为8.13%与8.00%,标准偏差分别为0.74%与0.28%(n=3)。结论:经方法学验证本文建立的卡式炉-卡尔费休法方法适合批量样品水分的测定,为叶酸对照品的标定及其原料的质量控制提供了依据。

Objective:The thermodynamics of the folic acid was studied by differential scanning calorimetry(DSC)and thermogravimetric analysis(TG).And a new Oven samplechanger/Karl Fisher method was established.Methods:The experimental conditions were as follows:drying temperature was 150℃,the heating time was 10 min,the carrier gas flow rate was 80 mL min^-1,the relative drift of end points was 20μg min^-1 and titration end point was delayed time termination mode.Results:The results of the NIFDC and USP folic acid reference standard(RS)and were 8.13%and 8.00%[RSD:0.74%,0.28%(n=3)]respectively.Conclusion:The established Oven samplechanger/Karl Fisher method isverified and suitable for the water analysis of batches of samples,it also provides a basis for calibration of folic acid reference substance and quality control of raw materials.