Sandra P, Medvedovici A, Zhao Y, David F
Department of Chemistry, University of Stellenbosch, CENSSUS, Private Bag X1, Matieland 7602, South Africa.
J Chromatogr A. 2002 Oct 18;974(1-2):231-41. doi: 10.1016/s0021-9673(02)01311-0.
Characterization of triglycerides in vegetable oils was achieved by silver-ion packed-column supercritical fluid chromatography (SI-pSFC) with mass spectrometric detection. Hyphenation was made using commercially available liquid chromatography-mass spectrometry (LC-MS) interfaces without any modification. A make-up fluid was delivered through a T-piece placed before or after the SFC restrictor by means of a high pressure pump. Atmospheric pressure chemical ionization (APCI) and coordination ion spray (CIS) with silver ions were used as ionization modes. Compared to UV detection, the sensitivity was increased by a factor of 100. Both ionization modes are generating similar structural information. Molecular ions [M-H]+ or [M-Ag(-)] are observed in the mass spectra with exception of the saturated triglycerides for which only CIS gives intense molecular ions. The position at which the fatty acids are esterified to the glycerol backbone can be elucidated by pSFC-APCI although it remains speculative whether this is valid for highly unsaturated triglycerides because reference compounds are not available to proof this.
采用配有质谱检测的银离子填充柱超临界流体色谱法（SI-pSFC）对植物油中的甘油三酯进行了表征。联用采用市售的液相色谱 - 质谱（LC-MS）接口，无需任何修改。通过高压泵经置于SFC限流器之前或之后的三通管输送补充液。采用大气压化学电离（APCI）和含银离子的配位离子喷雾（CIS）作为电离模式。与紫外检测相比，灵敏度提高了100倍。两种电离模式产生的结构信息相似。在质谱图中观察到分子离子[M-H]+或[M-Ag(-)]，但饱和甘油三酯除外，对于饱和甘油三酯只有CIS能给出强分子离子。虽然由于没有参考化合物来证明这一点，对于高度不饱和甘油三酯是否有效仍存在推测，但通过pSFC-APCI可以阐明脂肪酸酯化到甘油主链的位置。
