Experimental Analysis was carried out by using a JEOL AccuTOFDART™ mass spectrometer operated in positive-ion mode at a resolving power of >6000 (FWHM). The DART source was operated with helium and the gas heater was set to 375°C. Melting point tubes were dipped in oil samples and placed in front of the DART ion source for a few seconds. A cotton swab dipped in dilute ammonium hydroxide was placed nearby to enhance formation of [M+NH 4 ] + from triglycerides. A spectrum of PEG 600 was measured between samples to permit exact mass measurements.