N-rich hypercrosslinked porous polymers for highly efficient preconcentration and sensitive detection of chlorophenols.

Three novel N-rich hypercrosslinked porous polymers (NHCP1, NHCP2, and NHCP3) were facilely developed using Friedel-Crafts alkylation. NHCP1 with a remarkably large surface area (2066 m g) showed the best adsorption performance for chlorophenol pollutants. A sensitive and simple method was developed by using NHCP1 as a sorbent for solid-phase extraction to preconcentrate several chlorophenols in honey, water, and peach beverage samples followed by determination using a high-performance liquid chromatography-ultraviolet detector. The detection wavelength was 280 nm. Under the optimized conditions, the linear ranges were 1.67-1000 ng g for honey, 0.170-100 ng mL for water, and 0.330-100 ng mL for peach beverage samples. The detection limits (S/N = 3) were 0.500-2.00 ng g, 0.0500-0.100 ng mL, and 0.100-0.200 ng mL, respectively. Recovery values were 89.3-111% with relative standard deviations <9.4%. The proposed extraction/preconcentration and quantitative analysis method provides an affordable and effective alternative for the preconcentration and determination of low levels of chlorophenols in real samples.