Comprehensive two-dimensional gas chromatography analysis of high-ethanol containing motor fuels
John V Seeley1, Elise M Libby, Stacy K Seeley
1Department of Chemistry, Oakland University, Rochester, MI 48309, USA. seeley@oakland.edu
Abstract:
A comprehensive 2-D GC (GC x GC) instrument equipped with a flow-switching modulator was used to determine the concentration of ethanol and eight other alcohols in a retail pump sample of E85 fuel. E85 is a mixture of ethanol and gasoline where the ethanol concentration can range from 70 to 85 vol%. The increased peak capacity and selectivity generated by GC x GC analysis allowed the alcohols to be fully resolved from the gasoline hydrocarbons. GC x GC analysis was compared to the performance obtained with the standard analytical method for determining ethanol in fuel ethanol (ASTM D5501) and the standard method for determining oxygenate concentrations in gasoline (ASTM D4815). The GC x GC analysis required 14 min while the combined ASTM D5501 and ASTM D4815 analyses required more than 60 min. The ethanol concentration obtained by GC x GC was in excellent agreement with the value obtained by the D5501 method. Poorer agreement was observed between the GC x GC and D4815 concentrations for the other alcohols present in E85. In all cases, the differences could be attributed to deficiencies in the D4815 method that led to coelutions between the alcohols and gasoline hydrocarbons.
Related Concept Videos
Gas Chromatography: Introduction
In GC, a sample is vaporized and mixed with an inert carrier gas (the mobile phase), which transports it through a column.
Gas Chromatography–Mass Spectrometry (GC–MS)
A gas chromatograph consists of a long, narrow capillary column with a polysiloxane coating on the inner wall. The coating...
Gas Chromatography: Types of Columns and Stationary Phases
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
Gas Chromatography: Sample Injection Systems
Two primary injection methods are used...
Supercritical Fluid Chromatography
SFC utilizes a supercritical fluid mobile phase,...
Gas Chromatography: Types of Detectors-I
TCD is the earliest and most widely used detector that operates by measuring the changes in the thermal conductivity of the carrier gas. When a sample compound enters the detector,...


