关键词: 特殊医学用途配方食品, 胆碱, 固相萃取, 离子色谱-电导检测法

Abstract: [Objective] To establish a solid-phase extraction-ion chromatography conductivity detection method for the determination of choline content in food for special medical purpose. [Method] The samples were re-solubilized in 1.0 mol/L hydrochloric acid solution,and then hydrolyzed in an 80 ℃ water bath for 4 hours. The solution was purified using SAX strong anion exchange column. It was eluted isocratically with a 15 mmol/L methanesulfonic acid solution. The separation was achieved on an IonPac™ CS12A cation exchange chromatographic column（4 mm×250 mm,4 μm）equipped with an IonPac™ CG12A cation exchange guard column（4 mm×50 mm,4 μm）. The column temperature was 40 ℃,and qualitative and quantitative analysis was carried out using a CDRS 600 inhibitory conductivity detection. [Result] The choline concentration was in the range of 0.02~5.00 mg/L,exhibited a good linear relationship with the peak area,with a correlation coefficient of 0.999 8. The detection limits for liquid and solid samples were 0.3 and 1.0 mg/100g respectively,and the quantification limits were 1.0 and 3.0 mg/100 g respectively. The average recovery rate of 12 different formulations actual samples was 95.0%~103.8%,and the relative standard deviation of the determination results was 0.384%~2.970%（n=6）. [Conclusion] This method was highly efficient,simple,had a low detection limit,and high accuracy. It was suitable for the determination of choline in food for special medical purpose.

Key words: food for special medical purpose, choline, solid-phase extraction, ion chromatography-conductivity detection method