TPH GRO by EPA 8015 & TPH DRO Chromatograms comparing various fuel and oil types The EPA 8015 TPH GRO and DRO method is the primary tool for quantifying petroleum in the “gasoline range” and the “diesel range”. However, these method also detect other types of fuels and oils. Whereas the analysis provides quantification, there is often more useful information that can be obtained by reviewing the chromatogram. Read More The EPA 8015 TPH GRO and DRO method is the primary tool for quantifying petroleum in the “gasoline range” and the “diesel range”. However, these method also detect other types of fuels and oils. Whereas the analysis provides quantification, there is often more useful information that can be obtained by reviewing the chromatogram. The following chromatograms provide a comparison of various analytical standards standards analyzed on the TPH DRO instrument. As with the previous chromatograms, the yellow arrow delineates the beginning of quantitation (C10) and the purple arrow delineates the end of the quantitation (C28). Weathered diesel fuel is on the left compared to a fresh diesel fuel on the right. Notice that the weathered diesel fuel has lost much of the lighter hydrocarbons on the left side which is the beginning of the diesel range (yellow arrow). The hydrocarbons are lighter on the left side of the chromatogram and heavier on the right side. Number 4 fuel oil is on the left compared to a fresh diesel fuel on the right. Notice that the # 4 pattern starts later and continues beyond where the diesel fuel pattern ends. This particular diesel fuel chromatogram also illustrates the fact that diesel fuel constituents exist outside the range (both heavier and lighter) that the method allows quantitation. Jet A fuel is on the left compared to a fresh diesel fuel on the right. Jet A is a lighter fuel comparable to kerosene. Jet A fuel is on the left compared to a kerosene on the right. The patterns are very similar making it difficult to differentiate Jet A from kerosene. Biodiesel on the left compared to a fresh diesel fuel on the right. Creosote oil on the left compared to a fresh diesel fuel on the right. Hydraulic oil on the left compared to a fresh diesel fuel on the right. Most hydraulic oils have relatively little hydrocarbons in the diesel range and are best quantified using a TPH ORO (Oil Range Organics). Used motor oil on the left compared to a fresh diesel fuel on the right. Once again, there are relatively little hydrocarbons in the diesel range. Better quantification can be obtained using the TPH ORO (Oil Range Organics) analysis. Used motor oil on the left compared to a hydraulic oil on the right.