A two-dimensional system composed of supercritical fluid chromatography (SFC) and reverse phase liquid chromatography (RPLC) coupled a tandem mass spectrometry (MS) was developed for the quantitative analysis of vitamin D in daily oily supplements. Two six-port switching valves are configured, allowing four different valve positions. When the valve positions were fixed at Position A, this system worked at SFC-MS mode. When the valve positions switched between Position B and C, this system worked at a SFC-LC-MS switching mode. Vitamin D3 in two kinds of oily drops, Baby Ddrops and Vitamin AD drops, was determined at both SFC-MS and SFC-LC-MS switching modes by using the same system. The linearity, repeatability and recovery were investigated using the internal and external standard methods for the two modes. The results obtained from the internal standard method are better than those of the external standard method at either mode. The coefficient of determination (r²) for the internal standard method is more than 0.999, with a linear range of 20–1000 μg/L. Both Baby Ddrops and Vitamin AD drops were analyzed with good repeatability (<3.21%) and recovery (94.1%–116.1%) using internal standard method. When calculated by the external standard method, as compared to SFC-MS mode, SFC-LC-MS switching mode has better linearity (r²>0.999), repeatability (Baby Ddrops: 4.45%, Vitamin AD drops: 1.12%) and recovery (86.3%–107.1%). The results indicate that the two-dimensional SFC-MS/SFC-LC-MS system is useful for determination of vitamin D in oily drops. If it works at SFC-MS mode, the internal standard is required. When SFC-LC-MS switching mode is used, external standard method can also obtain the accurate results with good precision.

建立了由超临界流体色谱（SFC）和反相液相色谱（RPLC）以及串联质谱（MS）组成的二维系统，用于定量分析每日油性补品中的维生素D。配置了两个六通切换阀，允许四个不同的阀位。当阀门位置固定在位置A时，该系统在SFC-MS模式下工作。当阀位在位置B和C之间切换时，该系统在SFC-LC-MS切换模式下工作。通过使用同一系统，在SFC-MS和SFC-LC-MS切换模式下测定了两种油性滴剂中的维生素D3，即婴儿滴剂和维生素AD滴剂。使用内部和外部标准方法对两种模式的线性，重复性和回收率进行了研究。在任何一种模式下，通过内标方法获得的结果均优于通过外标方法获得的结果。测定系数（r²）对于内标法，其值大于0.999，线性范围为20–1000μg/ L。使用内标方法对婴儿滴剂和维生素AD滴剂的重复性（<3.21％）和回收率（94.1％–116.1％）进行了分析。通过外部标准方法计算时，与SFC-MS模式相比，SFC-LC-MS切换模式具有更好的线性度（r ² > 0.999），可重复性（婴儿D下降：4.45％，维生素AD下降：1.12％）和恢复（86.3％–107.1％）。结果表明，二维SFC-MS / SFC-LC-MS系统可用于测定油滴中的维生素D。如果它在SFC-MS模式下工作，则需要内部标准。当使用SFC-LC-MS切换模式时，外标方法也可以得到精度较高的准确结果。