ASTM D4291 standard test method for trace ethylene glycol in used engine oil
3. Summary of Test Method
3.1 The sample of oil is extracted with water and the analysis is performed on the water extract. A reproducible volume of the extract is injected into a gas chromatograph using on-column injection and the eluting compounds are detected by a flame ionization detector. The ethylene glycol peak area is determined and compared with areas obtained from the injection of freshly prepared known standards.
4. Significance and Use
4.1 Leakage of aqueous engine coolant into the crank case weakens the ability of the oil to lubricate. If ethylene glycol is present, it promotes varnish and deposit formation. This test method is designed for early detection to prevent coolant from accumulating and seriously damaging the engine.