Polydopamine-graphene oxide aerogel for in-tube solid-phase microextraction of polycyclic aromatic hydrocarbons

Due to the wide distribution and potential carcinogenicity, teratogenicity and mutagenicity, polycyclic aromatic hydrocarbons (PAHs) have attracted much attention, requiring efficient and sensitive methods for detection. In order to improve the stability and extraction performance of graphene oxide aerogel, polydopamine was introduced to functionalize it. Polydopamine-hybridized graphene oxide aerogel was in-situ fabricated on the surface of titanium wire. The composite material was characterized by SEM and FT-IR. Three aerogel-coated wires were filled in a polyetheretherketone tube for in-tube solid-phase microextraction. Coupled with high performance liquid chromatography, the tube showed good extraction performance for several PAHs. Under the optimal conditions (sampling volume of 60 mL, sampling rate of 1.50 mL min −1 , sample pH of 7.3, 0.5% (v/v) of methanol and 1.0% (w/v) of NaCl in sample, desorption time of 1.0 min), an online analytical method was developed for determining trace PAHs from water samples, with low detection limits (0.01-0.05 μg/L), wide linear ranges (0.03-50 μg/L, 0.15-100 μg/L) with correlation coefficients (0.9953-0.9992) and satisfactory repeatability (RSDs, 0.22%-4.42% for intra-day, 1.42%-5.18% for inter-day). The method was applied to analyze some water samples including leaching solutions of coal ash and paper food box, some targets were found. The recoveries in these samples with different spiked levels (2.0 and 10.0 μg/L) were in the range of 81-117%.