Nanofibrous polyamide homopolymers and copolymers as advanced sorbents for on-line solid phase extraction coupled with liquid chromatography determination of polycyclic aromatic hydrocarbons.

New polyamide (PA) homopolymers and copolymers nanofibers with different alkyl chain lengths as novel materials have been investigated for the automation of on-line sample preparation step and extraction of polycyclic aromatic hydrocarbons (PAHs) from the environment. PA 4/6 nanofiber copolymer showed the highest extraction yield of tested analytes and comparable performance with commercial reversed phase C18 sorbent. Our study presents an automation of on-line solid phase extraction method coupled with ultra-high performance liquid chromatography with fluorescence detection for the analysis of nine PAHs in river water. The optimal conditions included 50 μL injection volume, washing with 10 % acetonitrile at a flow rate of 1.0 mL min-1 for 1 min, followed by backflush elution of analytes using a gradient of acetonitrile (from 60 % to 74 %) in water at 1.5 mL min-1 over 12.25 min on a YMC-Triart PFP column (150 × 4.6 mm, 3 μm particle size). The total analysis time, including extraction, separation, and column equilibration, was 14 min. This method provides excellent analytical performance, with linearity ranging from 0.01 to 0.5 μg L-1 for acenaphthene, anthracene, pyrene, chrysene, and 0.05-0.3 μg L-1 for benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(c,d)pyrene and benzo(g,h,i)perylene, with coefficients of determination (R2) ranging 0.9989-0.9999. The limits of detection and quantification were 0.003-0.01 and 0.01-0.05 μg L-1, respectively. The recoveries were between 92 and 105 %, with RSD 1.53-6.66 %. The polyamide-based sorbent requires no modification and can be inexpensively prepared as homogeneous mats by electrospinning. It can be cut and manually packed into a column or filtration device, allowing for easy replacement, when needed, with inter-columns repeatability of RSD <13 %. In addition, a single extraction column can be reused repeatedly.