Comparison of column phase configurations for comprehensive two dimensional gas chromatographic analysis of crude oil and bitumen

Analyzing hydrocarbon fractions in crude oils by two-dimensional gas chromatography/time-of-flight mass spectrometry under reversed-phase column system

“…This technique is useful because it offers a large amount of information that is difficult to obtain by conventional one-dimensional GC [11][12][13][14][15]. For the best separation of crude oils and highest resolution of oil geochemistry, researchers have devoting to testing different analytical conditions, such as column lengths, modulation periods, and oven conditions [2,10,[16][17][18]. For example, in a detailed analysis of the oxygenated compounds in a coal liquefaction product, Omais et al tested and compared different analytical conditions involving innovative column configurations, and found the best one that enable an outstanding separation for the oxygenated compounds [10].…”

“…Normal-phase system has a non-polar column for the first dimension and a polar column for the second dimension, whereas a reversed-phase column system changes the sequence of column connection [16,17,19,20]. Given that a wide range of boiling points for hydrocarbon fractions in crude oils (including saturated and aromatic hydrocarbons), normal-phase column system has been widely used with effective separation of hydrocarbons, especially with high molecular weight (HMW, the compounds generally between C 25 -C 33 ) [21] and certain polarity [22][23][24][25][26].…”

“…It has been used in many researching works, such as roasted coffee beans [27], food flavor [19], middle-distillate samples [28], military smoke oil [29] and unresolved complex mixtures in petroleum [30]. Tran et al compared one-dimensional GC and GC Â GC using both the normal-phase and reversed-phase column systems, and concluded that the reversed-phase column system provides more information than the normal-phase column system [16]. Results show that using a polar-non-polar phase column configuration, the reversed-phase column system gains enhanced resolution for low polar compounds such as normal alkanes, branched alkanes, and cyclic alkanes.…”

Comprehensive two-dimensional gas chromatography with capillary flow modulation to separate FAME isomers

“…Most of the times, the first phase is non-polar and the second phase is more polar, considered as a conventional column configuration. However, the use of a polar column in the first dimension and a non-polar one in the second, it is referred to as an "inverted phase" column set up [30].…”

Comprehensive two-dimensional gas chromatography to characterize hydrocarbon mixtures in lithic materials

“…Then, a group of co-eluting components are successfully launched quickly into the short second column, where the mixture will be separated based on the different polarities. Although all types of stationary phases can be used, most of the reported applications are performed using a non-polar stationary phase in the first column, and a polar stationary phase in the second column [17]. Any separation that occurs on the first column due to a different volatility of analytes is preserved during the transfer to the second column where there is a new separation based on differences on polarity.…”