New Application Note on Oxygenate Trace analysis in C2-C5 Hydrocarbons Streams
Hydrocarbon mixtures may contain trace amounts of oxygenates, such as alcohols and ethers, which could poison the catalyst during processing. To determine these compounds at trace levels, the standardized method ASTM D7423 is used.
As this method suffers from discrimination of high boiling compounds such as Propanol, Da Vinci Laboratory Solutions has developed the Liquefied Gas Injector (LGI). A new application note describes the analysis of the ASTM D7423 method using the Liquefied Gas Injector, which improves the detection limits and resolves the discrimination for the ASTM D7423 determination.
To compare the ASTM D7423 analyses one GC system is configured with a Liquid Sampling Valve (LSV) and the second system is configured with the Liquefied Gas Injector (LGI). A gravimetric blend of individual oxygenates in Heptane is diluted with LPG and analyzed on both systems.
The analysis results of the LGI and LSV injection are shown in the application note. All compounds have an LOD below 20 µg/kg for the D7423 method with LGI injection, except for Diethyl ether and Methanol which have an LOD below 50 µg/kg. For the LSV injection, the detection limits for the heavy alchohols exceed the 500 µg/kg scope of the method.