Date of Award
Master of Science (MS)
A gas chromatographic-mass spectrometric (GC-MS) method has been developed for the determination of a broad range of aldehydes (including, hydroxylated and aromatic aldehydes) in particulate matter (PM). In this method, the aldehydes are derivatized with O-2, 3, 4, 5-pentafluorobenzyl hydroxylamine hydrochloride (PFBHA) using various solvents for extraction and derivatization including acetonitrile, water, methanol, and acetonitrile/dichloromethane/methanol. An ACN/DCM/MeOH mixture with sonication was shown to be optimal as it increased the derivatization efficiency in addition to efficient extraction for all tested aldehydes. The optimal derivatization conditions were determined and then tested on a variety of oxy-PAHs which resulted in a complete derivatization of carboxaldehydes but only incomplete derivatization of quinonic species. Application of the extraction protocol to wood smoke (WS) PM and comparison to the traditional EPA buffer method resulted in higher recoveries (up to 150%) of several aldehydes. This artifact was shown to be due to the presence of organics like syringol and levoglucosan in WS PM at higher concentrations and not be caused by which were not due to completeness/incompleteness of the analyte derivatization. This effect was attributed to a matrix-assisted response enhancement, i.e., loss of analytes upon injection due to its adsorption, which may be masked by organics as blocking agents. Further application of the optimized method to particulate matter in GC-MS EI and NCI methods resulted in identification of up to 30 compounds. The NCI method proved to be more sensitive, with up to 28 compound detected with LODs in a range of 0.06 Âµg – 1.47 Âµg and comparable quantities (mean Â± SD) of
aldehydes in all concentrations of WS PM used. By contrast, the EI method was shown to be less sensitive, with only 16 compounds being detected.
Chintapalli, Manikyala Rao, "Determination Of Aldehydes In Particulate Matter Using Gas Chromatography-Mass Spectrometry" (2015). Theses and Dissertations. 1754.