ASTM D3525 Gasoline Diluent in Used Gasoline Engine Oils
ASTM D3525 Standard Test Method for Gasoline Diluent in Used Gasoline Engine Oils by Gas Chromatography
9. Procedure
9.1 Prepare the apparatus as per Table 1.
9.2 Inject the desired volume of sample.
9.2.1 Care must be taken that the sample size chosen does not allow some peaks to exceed the linear range of the detector. With hydrogen flame ionization detectors, the usual sample size ranges from 0.2 to 1.0 µL.
9.2.2 The syringe needle must remain in the injection port manifold for 5 to 10 s after injection to avoid any sample fractionation in the needle.
9.3 Immediately start programming the column temperature upward at the rate in Table 1, or at a rate that will produce the separation specified in 5.3. Turn on the recorder chart drive and integrator immediately after injection of the sample. Set the attenuation to allow maximum peak height of the area prior to and including the n-tetradecane reference peak without overloading the method of measurement.
9.4 Area accumulation and recording may be discontinued after elution of the n-tetradecane. This method is not intended to define the nature of the lubricating oil peak.
9.5 Removal of non-eluted oil from the system prior to subsequent operation may be achieved by techniques such as back flush or increased system temperatures.
