摘要
建立了饮料中痕量维生素B12（VB12）的在线净化/固相萃取-高效液相色谱（HPLC）测定方法.在双梯度HPLC系统上,以磷酸盐缓冲溶液-乙腈为流动相,将2.5mL样品在线注入SPE柱（Acclaim PAⅡ,3 μm,3.0 mm× 33mm）以富集VB12,通过改变流动相梯度在SPE柱上以正向淋洗方式预分离VB12.被切入分析流路中的VB12在Acclaim PAⅡ分析柱（3μm,3.0mm×150 mm）上以磷酸盐缓冲溶液-乙腈为流动相,0.5 mL/min流速梯度洗脱分离,使用紫外检测器在361 nm波长下检测,整个分析过程在20 min内完成.VB12峰面积的相对标准偏差（RSD）为2.2％,其保留时间的RSD为0.027％.方法在0.1～ 5.0 μg/L质量浓度范围内与其峰面积呈良好的线性关系,线性系数为0.9999.方法的加标回收率为91％～ 109％,检出限为0.046 μg/L.该方法简单、快速、重现性好,相比于直接大体积进样和传统在线SPE模式,其去除杂质的效率更高、灵敏度更好,是一种测定饮料中痕量VB12的简单、有效方法.
A high performance liquid chromatographic （HPLC）method combined with on-line cleanup and solid-phase extraction （SPE） was developed for the fast and effective determination of trace amount of vitamin B12 （VB12） in beverages.A small change in the flow scheme of the traditional on-line SPE system reverses the flush direction on the SPE column,and creates an online SPE system with dual function （trapping the analytes and partially separating it from interferences prior to the analytical column） that eliminates interferences much more efficiently.The trapping of VB12 was completed by injecting 2.5 mL beverage sample into the SPE column （Thermo Scientific Acclaim PA Ⅱ,3 μm,3.0 mm ×33 mm）,using phosphate buffer-acetonitrile as mobile phase,and then the VB12 was partially separated on the SPE column by changing mobile phase gradient.Therefore,only those interferences co-eluting with VB12 entered the analytical column,and more interferences were removed.The volume of VB12 cut from the SPE column was separated on the analytical column（Thermo Scientific Acclaim PA Ⅱ,3 μm,3.0 mm × 150 mm） using phosphate buffer-acetonitrile as mobile phase,and detected with UV detector at 361 nm.The complete analysis only took 20 min.The relative standard deviation （RSD） of VB12 was 0.027％ for retention time,and 2.2％ for peak area.Good linearity was obtained in the range of 0.1-5.0 μg/L with correlation coefficient of 0.999 9.The spiked recoveries for 4 beverage samples were in the range of 91％-109％,and the limit of detection for this method was 0.046 μg/L.Compared with the direct large-volume injection and the traditional on-line SPE system,this method was better expression in easy manipulation and effective clean-up.
出处
《分析测试学报》
CAS
CSCD
北大核心
2014年第1期39-44,共6页
Journal of Instrumental Analysis
关键词
在线固相萃取
在线净化
双梯度高效液相色谱系统
阀切换
饮料
维生素B12
on-line solid-phase extraction （SPE）
on-line clean-up
dual-gradient high performance liquid chromatography （HPLC）
valve-switching
beverage
vitamin B12
