Co-Al bimetallic hydroxide nanocomposites coating for online in-tube solid-phase microextraction

The Co-Al bimetallic hydroxide nanocomposites were synthesized and used as in-tube solid-phase microextraction coating. The nanocomposites-coated fibers were packed in a PEEK tube and tested for the extraction of eight polycyclic aromatic hydrocarbons (PAHs) coupled with high performance liquid chromatography. Several parameters affecting the PAHs extraction including the sampling volume, sampling flow rate, methanol content and desorption time were investigated. Under the optimized conditions, the extraction tube with nanocomposites coating exhibited remarkable extraction performance towards PAH targets. An online analysis method was achieved with the limits of detection less than 0.02 μg L−1 and the linearity in the range from 0.03 to 15 μg L−1. The recoveries of the method for two water samples with spiking levels of 1 and 10 μg L−1 ranged from 83 to 121%. Extraction repeatability and preparation repeatability were less than 4.0% and 10.9%, respectively.