Abstract
Heterocylic aromatic amines (HAAs) are polycyclic aromatic compounds that contain imidazopyridine, imidazoquinoline, imidazoquinoxaline or pyridoindole in their chemical structures, and HAAs are carcinogenic and mutagenic. HAAs have been identified in city air, cigarette smoke, rain, cooking fumes, and river water; it is speculated that HAAs are an environmental pollutant due to their toxicity. In recent years, studies of fine particulate matter (PM2.5) have received a great deal of attention since studies have linked long term exposure to PM2.5 to severe illnesses. Currently, there are limited data on HAAs in PM2.5 since only two other research groups have studied the topic; in those studies, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) instrumentation was used for analysis. In our study, a quantitative gas chromatography-mass spectrometry (GC-MS) method was developed to measure HAAs in PM2.5 samples. This method consisted of a relatively simple sample extraction using sonication, solid phase extraction (SPE) clean-up, evaporation, and N-Methyl-N-tert-butyldimethylsilyltrifluoroacetamide (MTBSTFA) derivatization. This method also used deuterated internal standards to account for reaction and sample processing losses. The method was linear in the range from 5 to 1500 ng/mL with correlation coefficients from 0.971 to 0.999. The method detection limits based on a set of method blanks were between 9.3 and 150 ng HAAs per mL extract. This method was used to measure HAAs in PM2.5 samples that were collected from meat cooking, ambient air and NIST SRM 1648a. One of the studied HAAs, 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), was detected in the PM2.5 samples from meat cooking with concentrations between 1.09 ng/m3 and 20.1 ng/m3. None of the studied HAAs was detected in the NIST SRM 1648a samples. However, this material was used in the spiking experiments for method validation. For the 5 mg NIST SRM 1648a samples, the corrected recoveries ranged from 92 ± 8 % to 137 ± 57 % for the studied HAAs in sixteen samples.