Corrosion Cocktail – Part Ethanol, Part Gasoline, Part Diesel – Analyzed Using GC-VUV

In a previous post I showed how methanol and ethanol can be determined in diesel with static headspace GC-VUV to help illuminate contamination of diesel with oxygenate-containing gasoline.  As mentioned in that post, it’s possible that ethanol used in gasoline in the United States can lead to serious microbiologically-influenced corrosion problems for diesel storage and handling systems when cross-contamination of fuel supplies occurs.  Corrosion can lead to underground storage tank leaks and groundwater pollution.

200 µL of diesel in 2 mL mineral oil was analyzed for ethanol using static headspace sampling with GC-VUV (Figure 1).

Figure 1. E10 gasoline in diesel analyzed using static headspace GC-VUV. In addition to seeing ethanol, other volatile gasoline components are eluting early in the E10 chromatograms.

In addition to ethanol, other volatile hydrocarbons can act as marker compounds for gasoline contamination of diesel (Figure 2).

Figure 2. The early part of the static headspace GC-VUV chromatogram shows compounds characteristic of E10 gasoline, including ethanol.

The volatile compounds that are unique to gasoline, including ethanol, are noted by proportional decreases in their peak heights when going from higher to lower percent contamination (Figure 3).

Figure 3. E10 gasoline at various levels in diesel analyzed using static headspace GC-VUV. Ethanol and other volatile gasoline components are good indicators for gasoline contamination of diesel in the United States.

If you want a corrosion cocktail, I suggest a Rusty Nail (Drambuie and Scotch whiskey).  To avoid a bad hangover from the other version described above, monitor your diesel for ethanol with GC-VUV.