The analysis of reformulated gasolines using fast gas chromatography/mass spectrometry

The requirement that all reformulated gasoline (RFG) sold in the United States be analyzed by gas chromatography/mass spectrometry (GC/MS) for aromatic content presents a unique challenge and opportunity for petroleum analytical analyses. A fast GC/MS method was developed which encompasses or surpasses not only the basic EPA performance requirements for analysis of total aromatics, but will simultaneously measure individual aromatics and oxygenates in reformulated gasolines. Furthermore, the combined procedure requires only 10 minutes of instrument and computational time. In contrast, ASTM Method D 5769 generally takes 90 minutes just to measure total aromatic content. The measurements of oxygenates, benzene, and toluene also compare favorably to the standard ASTM methods. The method matches the precision and accuracy of ASTM Method D3606, a GC/GC method, which is the only current acceptable method for individual aromatics in RFG. Furthermore, it can measure methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) as accurately as ASTH D5599, the approved OFID method for oxygenates.