AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
PAHs Emissions in Diesel and Biodiesel Using LVI-PTV-GC-MS
CAROLINA SOUZA, Sergio Correa, Rio de Janeiro State University
Abstract Number: 61 Working Group: Instrumentation and Methods
Abstract This work aims to develop and validate an analytical method to measure the 16 priority polycyclic aromatic hydrocarbons (PAHs) in the gas and stratified aerosol from diesel/biodiesel vehicle exhaust using gas chromatography (GC) with programmed temperature vaporization (PTV) and large volume injection mode (LVI) coupled to mass spectrometry (MS). Five operation parameters of the injection PTV (vent time, valve vent split, initial injector heating time, sample volume and injection speed) were optimized applying factorial and central composite design with response surface. The purposes were evaluate the effect of each variable has on the signal intensity (peak area) of the target PAHs and to find a set of variables values which simultaneously maximize all analytical responses, thus obtaining lower detection limits. Among these variables, vent time showed the highest effect on the signal intensity of the target PAHs. After optimization, the method was validated using extracts of gases (from XAD-2 samples) and stratified aerosol (from 10-stage nano MOUDI) from the exhaust of a engine operating with diesel and biodiesel. Limits of detection in the range of 0.74 to 4.6 µg/L were obtained, values lower than the conventional split/splitless injection. Naphthalene, Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Fluoranthene and Pyrene were identified. Concentrations between 0.16 and 14.15 µg/m3 were obtained in the emissions. The PAHs present in aerosol were preferentially associated to particles with a diameter smaller than 0.56 µm.