The presently disclosed subject matter provides methods for analyzing complex mixtures with ultra high resolution mass spectrometry. In particular, the presently disclosed subject matter provides methods for identifying and monitoring the presence of a compound within a complex mixture. In certain embodiments, the method includes providing a sample of the complex mixture; performing mass spectrometry on the sample of the complex mixture to obtain a mass spectrum; and identifying one or more peaks from the mass spectrum corresponding to the compound. In certain embodiments, the sample is obtained during production of the complex mixture, e.g., a pet food product. In certain embodiments, the sample is prepared by a single alcohol/water extraction step.
