LAUSR

An analytical method was developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) and 15 nitrated PAHs (NPAHs) in ambient air particulates by applying an in-house built integrated ultrasonic extraction device followed by gas chromatography coupled with mass spectrometry (GC–MS). After integrated ultrasonic extraction in the extraction cell, the extract solution was released through the opened valve into a purification tube containing adsorbents for purification, then concentrated and analyzed by GC–MS. Compared to previously reported methods, such as Soxhlet extraction and accelerated solvent extraction, this method has greatly shortened the pretreatment time, simplified the pretreatment process, and reduced experimental costs. A series of experimental conditions, including extraction solvent, adsorbents, and elution solvent, were systematically studied and optimized. Owing to its superior ability in purifying particulate matter samples, a combination of flower-like-texture Mg–Al layered double oxide (Mg–Al-LDO) and silica gel was selected as the optimized adsorbent. To our knowledge, few reports on this combination of materials exist. The limits of detection (LODs) of 16 PAHs and 15 NPAHs ranged from 0.018 to 1.7 and from 0.035 to 0.60 ng g−1, respectively. Limits of quantifications (LOQs) were from 0.061 to 5.7 and 0.12 to 2.0 ng g−1 for 16 PAHs and 15 NPAHs, respectively. Recoveries at three spiked concentration levels ranged from 81.6 to 116%. The relative standard deviations (RSDs) were less than 6.5% in all cases. The proposed analytical method was proved to be practical and suitable technique for PAH and NPAH analysis in real ambient air particulate samples.Graphical Abstract