Schenk Jamie, Nagy Gabe, Pohl Nicola L B, Leghissa Allegra, Smuts Jonathan, Schug Kevin A
Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX 76019, United States.
Department of Chemistry, Indiana University, Bloomington, IN 47405, United States.
J Chromatogr A. 2017 Sep 1;1513:210-221. doi: 10.1016/j.chroma.2017.07.052. Epub 2017 Jul 18.
Methodology for qualitative and quantitative determination of carbohydrates with gas chromatography coupled to vacuum ultraviolet detection (GC-VUV) is presented. Saccharides have been intently studied and are commonly analyzed by gas chromatography-mass spectrometry (GC-MS), but not always effectively. This can be attributed to their high degree of structural complexity: α/β anomers from their axial/equatorial hydroxyl group positioning at the C1-OH and flexible ring structures that lead to the open chain, five-membered ring furanose, and six-membered ring pyranose configurations. This complexity can result in convoluted chromatograms, ambiguous fragmentation patterns and, ultimately, analyte misidentification. In this study, mono-, di, and tri-saccharides were derivatized by two different methods-permethylation and oximation/pertrimethylsilylation-and analyzed by GC-VUV. These two derivatization methods were then compared for their efficiency, ease of use, and robustness. Permethylation proved to be a useful technique for the analysis of ketopentoses and pharmaceuticals soluble in dimethyl sulfoxide (DMSO), while the oximation/pertrimethylsilylation method prevailed as the more promising, overall, derivatization method. VUV spectra have been shown to be distinct and allow for efficient differentiation of isomeric species such as ketopentoses and reducing versus non-reducing sugars. In addition to identification, pharmaceutical samples containing several compounds were derivatized and analyzed for their sugar content with the GC-VUV technique to provide data for qualitative analysis.
本文介绍了采用气相色谱-真空紫外检测联用技术（GC-VUV）对碳水化合物进行定性和定量测定的方法。糖类已得到深入研究，通常采用气相色谱-质谱联用技术（GC-MS）进行分析，但效果并不总是理想。这可归因于其高度的结构复杂性：由于C1-OH处的轴向/赤道羟基定位，糖类存在α/β异头物，且具有灵活的环状结构，可导致开链、五元环呋喃糖和六元环吡喃糖构型。这种复杂性可能导致色谱图复杂、碎片模式模糊，最终导致分析物误识别。在本研究中，单糖、二糖和三糖通过两种不同方法进行衍生化——全甲基化以及肟化/全三甲基硅烷基化——并采用GC-VUV进行分析。然后比较了这两种衍生化方法的效率、易用性和稳健性。结果表明，全甲基化是分析酮戊糖和可溶于二甲基亚砜（DMSO）的药物的有用技术，而肟化/全三甲基硅烷基化方法总体上是更有前景的衍生化方法。VUV光谱已被证明具有独特性，能够有效区分酮戊糖以及还原糖与非还原糖等异构体。除了鉴定之外，还对含有多种化合物的药物样品进行衍生化，并采用GC-VUV技术分析其糖含量，以提供定性分析数据。
