Abstract:
The treated filter membrane was placed in a high-flow particulate matter sampler for continuous sampling for 22 h at a flow rate of 800 L · min
−1. The filter was cut into 8 equal pieces, one of which was shredded and placed in a 50 mL- centrifuge tube. 15 mL of acetonitrile was added, and the mixture was vortexed for 30 s, ultrasonic extracted for 30 min at 20 ℃ and centrifugated for 10 min. 10 mL of acetonitrile was added and the extraction was repeated once. The two extraction solutions were combined and filtered through 0.45 μm filter membrane, and the filtrate was concentrated to near dryness by vacuum centrifugation at 50 ℃. The solution was diluted to 1.0 mL with acetonitrile and mixed well. The solution was passed through 0.45 μm filter membrane, and 16 polycyclic aromatic hydrocarbons in the filtrate were determined by ultra-high performance liquid chromatography. Agilent Eclipse PAH RRHD chromatographic column was used as the stationary phase and the mixed solution composed of water and acetonitrile at different volume ratios was used as the mobile phase for gradient elution. As shown by the results, linear relationships between the corresponding peak areas and mass concentrations of 16 polycyclic aromatic hydrocarbons were kept in the range of 0.02-1.0 mg · L
−1, with detection limits (3
s) in the range of 0.003-0.033 ng · m
−3. Test for recovery was made by the standard addition method, giving results in the range of 80.8%-111%, with RSDs (
n=8) of the determined values in the range of 2.6%-7.1%. This method was used for analysis of annual PM
2.5 samples at a monitoring site. The total detection amounts of the 16 polycyclic aromatic hydrocarbons in different seasons were in the range of 0.52-2.53 ng · m
−3, and the total detection amounts decreased in the order of winter, autumn, spring, and summer.