Electrophoretic deposition of graphene oxide onto carbon fibers for in-tube solid-phase microextraction

- Electrophoretic deposition was introduced as a preparation method of extraction materials.
- Graphene oxide-coated carbon fibers were developed for in-tube SPME.
- Graphene oxide-coated carbon fibers showed enhanced extraction efficiency than carbon fibers for PAHs.
- Online SPME-HPLC method had good application towards PAHs in environmental sample.

Carbon fibers (CFs) were functionalized with graphene oxide (GO) by an electrophoretic deposition (EPD) method for in-tube solid-phase microextraction (SPME). GO-CFs were filled into a poly(ether ether ketone) (PEEK) tube to obtain a fibers-in-tube SPME device, which was connected with high performance liquid chromatography (HPLC) equipment to build online SPME-HPLC system. Compared with CFs, GO-CFs presented obviously better extraction performance, due to excellent adsorption property and large surface area of GO. Using ten polycyclic aromatic hydrocarbons (PAHs) as model analytes, the important extraction conditions were optimized, such as sample flow rate, extraction time, organic solvent content and desorption time. An online analysis method was established with wide linear range (0.01-50 μg L−1) and low detection limits (0.001-0.004 μg L−1). Good sensitivity resulted from high enrichment factors (1133-3840) of GO-CFs in-tube device towards PAHs. The analysis method was used to online determination of PAHs in wastewater samples. Some target analytes were detected and relative recoveries were in the range of 90.2-112%. It is obvious that the proposed GO-CFs in-tube device was an efficient extraction device, and EPD could be used to develop nanomaterials functionalized sorbents for sample preparation.