固相萃取-超高效液相色谱-串联质谱法测定乳粉和果冻中的氯化胆碱

Determination of choline chloride in milk powder and jelly by solid phase extraction-ultra high performance liquid chromatography-tandem mass spectrometry

建立了固相萃取-超高效液相色谱-串联质谱测定乳粉和果冻中氯化胆碱的分析方法。样品在10 mL 0.02mol/L乙酸铵溶液(冰乙酸调节pH至3.0)中水解3 h后离心,上清液经DIKMA ProElut PLS固相萃取柱(60 mg/3 mL)净化后,用Agilent ZORBAX 300 SCX色谱柱(150 mm×2.1 mm,5μm)进行分离,通过电喷雾正离子(ESI^+)模式电离,多反应监测(MRM)模式进行定性和定量分析。方法的检出限(LOD,S/N=3)和定量限(LOQ,S/N=10)分别为0.15 mg/kg和0.50 mg/kg,加标回收率为70.8%~100.2%,相对标准偏差(RSD)均不大于6.83%(n=6)。目标化合物在0.05~8.0 mg/L范围内线性关系良好,线性方程为Y=2.05×10~5X+3.24×10~4,相关系数(r)为0.996。对市售乳粉和果冻中的氯化胆碱进行检测,结果表明,乳粉和果冻中氯化胆碱的含量分别为251.0~2 448 mg/kg和0.261~0.314 mg/kg。该法准确可靠、灵敏度高,适用于乳粉和果冻中氯化胆碱的测定。

An analytical method was developed for the determination of choline chloride in milk powder and jelly by solid phase extraction-ultra high performance liquid chromatography- tandem mass spectrometry （UPLC-MS/MS）. The samples were centrifuged after hydrolyzation 3 h in 10 mL 0. 02 mol/L ammonium acetate （ glacial acetic acid adjust pH to 3.0）. The supernatant was cleaned up by a DIKMA ProElut PLS column （60 mg/3 mL）. The target com-pounds were separated by an Agilent ZORBAX 300 SCX column （150 mm×2. 1 mm,5 μm）. Qualitative and quantitative analyses were carried out by multiple reaction monitoring （MRM） mode with positive electrospray ionization （ESI＋）. The limit of detection （LOD, S/N =3） and the limit of quantitation （LOQ, S/W=10） were 0. 15 mg/kg and 0. 50 mg/kg, respectively. The recoveries of choline chloride spiked in milk powder and jelly were 70. 8% -100. 2%,with RSDs no more than 6. 83% （n = 6）. The standard curves showed good linearity in the concentration range from 0. 05 to 8. 0 mg/L with correlation coefficient （r ） of 0. 996. The method was applied to detection of commercially available choline chloride in milk powder and jelly. The contents of choline chloride in real milk power and jelly samples were 251. 0-2 448 mg/kg and 0. 261-0. 314 mg/kg, respectively. The developed method is accurate,reliable,sensitive,and suitable for the determination of choline chloride in milk powder and jelly.