Application of multi-walled carbon nanotube-agarose/chitosan composite film microextraction-HPLC-UV to the determination of anthracene in lake water

Abstract

This study investigates a new approach in m-solid phase extraction (m-SPE) combined with high performance liquid chromatography ultraviolet detection (HPLC-UV) for the analysis of polycyclic aromatic hydrocarbon (PAHs) namely anthracene in water samples. The m-SPE method utilized multi-walled carbon nanotubes (MWCNTs) immobilized in agarose-chitosan film to serve as the sorbent. The presence of amino functional group in chitosan offered a good dispersion of MWCNTs in a agarose/chitosan matrix and prevent deactivation of sorbent via agglomeration. Ionic interaction between amino groups of chitosan with MWCNTs produce more stable composite film and prevent leaching of sorbent during application. The film was prepared by mixing MWCNTs, agarose and chitosan, followed by drying in an oven. The prepared film was characterized by Fourier transform infrared spectroscopy (FTIR). Microextraction of anthracene was performed by inserting a hypodermic needle through circular MWCNTs-agarose/chitosan film discs (5 mm diameter) and the assembly was dipped into an agitated sample solution prior to HPLC-UV analysis. Important parameters studied included extraction time, desorption time and amount of adsorbent loading. Calibration curves prepared showed good linearity with r ≥ 0.9932 over the concentration range of 10−500 mg L¯¹. The limits of detection (LODs) and limits of quantification (LOQs) of anthracene were 0.657 mg L¯¹ and 2.192 mg L¯¹, respectively, with satisfactory recoveries in the range of 85.23% to 119.05% and acceptable reproducibility, RSD ≤ 10.90%. The proposed method showed good sensitivity and was successfully employed in the analysis of PAHs in lake water samples.