This work develops and applies methods to measure oxygenated organics in aerosols and fine particle matter. Such methods are needed to gain further insight into chemical processes affecting the generation and fate of oxidation products of hydrocarbon emissions, and source apportionment of fine particulate matter. We establish the power of methods that rely on employment of O- (2,3,4,5,6- pentalfuorobenzyl)-hydroxylamine (PFBHA) and bis (trimethylsilyl) triflouroeacetamide (BSTFA) to derivatize carbonyls and multifunctional carbonyls, and measurement of the derivatives by using gas chromatography / ion trap mass spectrometry (GC/ITMS). By using this approach, we report for the first time in the ambient atmospheric environment, the presence of hydroxy acetone, 3-hydroxy-butane, and 2-hydroxy-2-methylpropanal, and novel high molecular weight ( > C10) oxygenated organics in PM2.5 that may be tracers of diesel-particulate matter. We also establish the utility of using a mist chamber to sample water-soluble organics, with Henry's law constants greater than 103. We applied the method to measurements of pptv levels of isoprene and 2-methyl-3-buten-2-ol (MBO) photooxidation products in the Blodgett Forest, California. using sampling times of ten minutes to support the results of chamber studies.