DEVELOPMENT OF AN ANALYTICAL METHOD FOR THE QUANTIFICATION OF 26 POLYCYCLIC AROMATIC HYDROCARBONS FROM AMBIENT AIR PARTICULATE MATTER

Abstract

Several compounds have been classified into the priority organic pollutants (POPs) class such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/PCDFs) and related polychlorinated compounds, and polyclic aromatic hydrocarbons (PAHs). Ambient air particulate matter contains numerous organic compounds, including POPs and particularly several polyaromatic hydrocarbons (PAHs) that are known or suspected carcinogens. A method for the determination of 26 polyaromatic hydrocarbons (PAHs) in particulate matters in urban is presented. In this study, the 16 priority pollutant EPA-PAHs and few other PAH compounds which were few studied in air before such as 3,6-Dimethylphenanthrene (36MeP), Benzo[b]fluorene (B[b]F), Benzo[j]fluoranthene (B[j]Flua), TriPhe (Triphenylene), Benzo[e]pyrene (B[e]Py), Perylene (Pery), Dibenzo(aj)anthracene (B[aj]A), Anthanthrene (Anthan), Coronene (Coro) and especially B[al]Pyre were used to investigate. The method was evaluated for sensitivity, recovery, precision, and agreement of paired air samples. Sample collection and pretreatment, analyte extraction, clean-up procedures, determination techniques are summarized and discussed.  Experimental design was used to investigate the effects of solvent of extraction, time of extraction and filters of PAHs collection. The highest recoveries were obtained at extraction time 30 minute and 10 mL mixture of n-hexane and petroleum ether (v/v = 9/1). PAHs are extracted from quartz micro-fiber filters and teflon fiber filters, concentrated and measured at trace levels using gas chromatography–mass spectrometry. The optimum procedures for clean up particulate matters in C₁₈-solid-phase extraction (SPE) cartridge prior to the analysis of polyaromatic hydrocarbons (PAHs) by PTV injection system integrated to a gas chromatograph–mass spectrometer (GC/MS) have been investigated.

Separation of non-polar, aromatic and polar fractions solid-phase extraction with C₁₈ was carried out and PAHs were eluted with 3 mL dichloromethane/ n-hexane (1:5,v/v). n-hexane and dichloromethane/n-hexane (1:5,v/v) as a solvent were tested. The best separations of monitored fractions were obtained, when extract was dissolved in dichloromethane/ n-hexane (1:5,v/v). Validation was carried out in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. LOD values ranging from 0.203 to 16.659 μg L^-1 were carried out. This study yielded that the range of LOQs for the 26 PAH compounds fell 0.687–63.215 µg/L. Precision was evaluated testing two concentration levels. Good results were obtained both in terms of intra-day repeatability and intermediate precision: RSD% lower than 5% at the highest concentration and lower than 15% at the lowest one were calculated for intra-day repeatability. Known volume of standard solutions was spiked onto the filters to get the efficiency of the analysis procedure. Recoveries of PAHs for this method were between 63.33 % for Napht and 103.2% for Ace with RSD lower than 11%. A method for the determination of 26 polyaromatic hydrocarbons (PAHs) from ambient air particulate matter in urban, industrial or rural zones was presented. PAHs were extracted by ultrasonic extraction method. Purification of extracts was carried out by solid-phase extraction with C18 and PAHs were eluted with mixture of n-hexane and dichloromethane. PAHs were determined by gas chromatography with electron impact mass spectrometric detection in the selected ion-monitoring mode (GC-MS-SIM), using deuterated PAHs as internal standards. The limits of detection ranged from 0.2 to 16.65 μg L^-1.