Hierarchical porous zeolitic imidazolate framework‑8 supported hollow-fiber liquid-phase microextraction of nine typical phenolic pollutants in water samples followed by electrophoretic analysis.

Hierarchical porous zeolitic imidazolate framework‑8 (HpZIF-8) have not only good chemical and thermal stability, but also pore structures of different sizes. In this work, HpZIF-8 supported hollow-fiber liquid-phase microextraction (HpZIF-8@HF-LPME) co-modified with tributyl phosphate and 2-nitroethyl benzene was firstly developed for purification and enrichment of nine typical phenolic pollutants followed by electrophoretic separation and amperometric detection (CE-AD). The key enrichment parameters were optimized by full factorial experimental and central composite designs. Under the optimum conditions, the maximum enrichment factors for the nine analytes were 479 (phenol), 249 (2-chlorophenol), 821 (4-chlorophenol), 1253 (3-methylphenol), 1376 (2,4-dichlorophenol), 1078 (2,4,6-trichlorophenol), 200 (pentachlorophenol), 614 (4-nitrophenol) and1827 times (bisphenol A), respectively. The limits of detection were 0.060-1.5 µg L-1 (S/N = 3) in real sample matrixes. This proposed method has been successfully applied to water samples with high ionic strength, and the average recoveries were in the range of 80.2-118.0%. This developed method of HpZIF-8@HF-LPME/CE-AD needs no desorption and derivatization, providing an alternative for monitoring typical phenolic pollutants in water samples.