Ingenious introduction of aminopropylimidazole to tune the hydrophobic selectivity of dodecyl-bonded stationary phase for environmental organic pollutants

Nowadays, the efficient detection of environmental organic pollutants has been a research focus in the field of chromatographic analysis. In this work, aminopropylimidazole was designedly introduced to adjust the hydrophobicity of the long-chain alkyl group, and a novel chromatographic stationary phase for the separation and analysis of environmental organic pollutants was specially prepared. Specifically, the waste aminopropyl silica gel (5 mu m) was first recycled as the raw material, which was calcined at high temperature and then acidified with hydrochloric acid solution to obtain the activated silica gel. Afterwards, a new type of aminopropylimidazole/ dodecyl dual-functionalized silica stationary phase (Sil-API-DD) was synthesized via one-pot reaction of the activated silica gel with 3-chloropropyltrimethoxysilane, dodecyltrimethoxysilane and 1-(3-aminopropyl)imidazole. The separation performance of Sil-API-DD was evaluated using environmental organic pollutants as the model analytes, and the results showed that an effective separation of seven alkylphenols, five bisphenols, six phthalates, seven steroid hormones and six benzophenones in reversed-phase chromatography was achieved. Moreover, the developed Sil-API-DD was found to exhibit more flexible selectivity and superior separation efficiency compared with the commercial C18 column under the tested conditions, suggesting a good application prospect.

Automated summary

Efficient detection of environmental organic pollutants is a hot topic in chromatographic analysis. In this study, a novel chromatographic stationary phase was prepared by introducing aminopropylimidazole to adjust the hydrophobicity of the alkyl group. Waste aminopropyl silica gel was recycled and activated to serve as the raw material. A one-pot reaction of the activated silica gel with 3-chloropropyltrimethoxysilane, dodecyltrimethoxysilane, and 1-(3-aminopropyl)imidazole was conducted to synthesize the aminopropylimidazole/dodecyl dual-functionalized silica stationary phase (Sil-API-DD). The Sil-API-DD exhibited effective separation of various environmental organic pollutants in reversed-phase chromatography, with flexible selectivity and superior separation efficiency compared to commercial C18 column.