ASTM D3606 Standard Test Method for Determination of Benzene and Toluene
ASTM D3606 Standard Test Method for Determination of Benzene and Toluene in Finished Motor and Aviation Gasoline by Gas Chromatography
12. Procedure
12.1 Preparation of Sample - Accurately measure 1.0 mL of MEK into a 25-mL volumetric flask. Fill to the mark with the sample to be tested and mix well.
12.2 Chromatographic Analysis - Chromatograph the sample, using the conditions established in 10.4 "time to backflush" and the injection technique described in 11.4. The valves must be turned to backflush mode at the time determined in 10.4 so that undesirable components do not enter Column B.
12.3 Interpretation of Chromatogram - Identify on the chromatogram the benzene, toluene, and the internal standard MEK peaks from the retention times of the standards.
NOTE 13 - The order of elution will be nonaromatic hydrocarbons, benzene, MEK, and toluene using the prescribed dimethylpolysiloxane and TCEP. Fig. 4 is an example of a typical chromatogram.
12.4 Measurement of Area - Measure the areas under the aromatic peaks and under the MEK peak by conventional methods.
NOTE 14 - The precision statement in Section 15 was developed from data obtained using electronic integrators or on-line computers. The precision statement may not apply if other methods of integration or peak area measurement are used.
13. Calculation
13.1 Calculate the ratios of the peak areas of benzene and toluene to the peak area of MEK. Determine from the appropriate calibration curve the liquid volume percent of benzene and toluene corresponding to the calculated peak ratios.
13.2 If the results are desired on a mass basis, convert to mass percent as follows:
Benzene, mass % = (VB/D) x 0.8844
where:
VB = volume percent benzene, and
D= relative density of sample at 15.6/15.6°C (60/60°F).
Toluene, mass % = (VT/D) x 0.8719
where:
VT = volume percent toluene, and
D = relative density of sample at 15.6/15.6°C (60/60°F).
