An investigation into three alternative gas chromatographic based methods for providing simulated distillation curves, up to a final boiling point of 538°C, on total crude oils is described. The first and simplest method employs a single chromatographic run with a known weight of an n-paraffin added to quantify the amount of crude oil analyzed. The second procedure involves the use of two chromatographic runs, one with and one without a known weight of an internal standard. In the third method, the flash distillate of the crude oil from a miniature flash still is analyzed. In this procedure, an accurate weight balance of distillate and residue can be obtained.

The advantages and disadvantages of the three techniques in terms of speed, accuracy, and simplicity are discussed. The results obtained for various crudes by these procedures are compared with the true boiling point data obtained by conventional 15-plate distillation.