EXPLANATION
See the discussion under Test Method ASTM D4815. This infrared method is faster, simpler, less expensive and more portable than the current methods. It measures MTBE and other alcohols in the concentration ranges from about 0.1 to about 20 mass %. This test method, however, cannot be used for compliance with federal regulations.
Oxygenates in gasoline can be determined using the Test Method ASTM D5599.
TEST SUMMARY
A sample of gasoline is analyzed by infrared spectroscopy. A multivariate mathematical analysis is carried out which converts the detector response for the selected regions in the spectrum of an unknown to a concentration of each component.
TEST PRECISION
Biases were observed in the round robin; however, it is not possible to make a definitive statement on this issue.