Comprehensive two-dimensional gas chromatography (GC×GC) approaches with cryogenic modulation were developed for the qualitative analysis of selected low volatility compounds in raw coffee bean extracts, without derivatisation. The approaches employed short first (¹D) and second (²D) dimension columns, specifically a ¹D 65% phenyl methyl siloxane column (11 m) and a ²D 5% phenyl methyl siloxane column (1 m), which allowed elution of high molar mass compounds (e.g. > 600 Da). Solutes included hydrocarbons, fatty acids, diterpenes, tocopherols, sterols, diterpene esters, and di- and triacylglycerides. An oven temperature program up to 370 °C was employed. The effects of experimental conditions were investigated, revealing that the GC×GC results strongly depended on the cryogenic trap T, and oven T program. An appropriate condition was selected and further applied for group type analysis of low volatility compounds in green Arabica coffee beans. Retention indices were compiled for 1D GC analysis and were similar for the composite column data in GC×GC. The elution of some compounds was confirmed by use of authentic standards. The approach allowed direct analysis of coffee extract in ethyl acetate solution, with improved analyte peak capacity (approximately 200 compounds were detected) without prior fractionation or pre-treatment of the sample. This avoided potential hydrolysis of high molar mass conjugate esters as well as degradation of thermally labile compounds such as the derivatives of the diterpenes cafestol and kahweol.

开发了具有低温调制功能的综合二维气相色谱（GC×GC）方法，用于定性分析生咖啡豆提取物中的选定低挥发性化合物，而无需衍生化。的途径使用短的第一（¹ d）和第二（² d）维列，特别是¹ d 65％苯基甲基硅氧烷柱（11米）和一²D 5％苯基甲基硅氧烷色谱柱（1 m），可洗脱高摩尔质量的化合物（例如> 600 Da）。溶质包括碳氢化合物，脂肪酸，二萜，生育酚，固醇，二萜酯以及二酰基和三酰基甘油酯。使用的烤箱温度程序最高为370°C。研究了实验条件的影响，发现GC×GC结果在很大程度上取决于低温阱T和柱箱T程序。选择适当的条件，并将其进一步应用于绿色阿拉比卡咖啡豆中低挥发性化合物的组类型分析。保留指数用于一维GC分析，对于GC×GC中的复合色谱柱数据，保留指数相似。某些化合物的洗脱通过使用可靠的标准品进行了确认。该方法可以直接分析乙酸乙酯溶液中的咖啡提取物，无需事先分馏或样品预处理就可以提高分析物的峰容量（检测到约200种化合物）。这样避免了高摩尔质量的共轭酯的潜在水解以及避免热不稳定化合物（例如二萜cafestol和kahweol的衍生物）的降解。