ASTM D6277 Method for Determination of Benzene in Spark-Ignition Engine Fuels
ASTM D6277 Standard Test Method for Determination of Benzene in Spark-Ignition Engine Fuels Using Mid Infrared Spectroscopy
4. Summary of Test Method
4.1 A sample of spark-ignition engine fuel is introduced into a liquid sample cell. A beam of infrared light is imaged through the sample onto a detector, and the detector response is determined. Wavelengths of the spectrum, that correlate highly with benzene or interferences, are selected for analysis using selective bandpass filters or by mathematically selecting areas of the whole spectrum. A multivariate mathematical analysis converts the detector response for the selected areas of the spectrum of an unknown to a concentration of benzene.
5. Significance and Use
5.1 Benzene is a compound that endangers health, and the concentration is limited by environmental protection agencies to produce a less toxic gasoline.
5.2 This test method is fast, simple to run, and inexpensive.
5.3 This test method is applicable for quality control in the production and distribution of spark-ignition engine fuels.
6. Interferences
6.1 The primary spectral interferences are toluene and other monosubstituted aromatics. In addition, oxygenates can interfere with measurements made with filter apparatus. Proper choice of the apparatus, proper design of a calibration matrix, and proper utilization of multivariate calibration techniques can minimize these interferences.
