Newly designed molecularly imprinted 3-aminophenol-glyoxal-urea resin as hydrophilic solid-phase extraction sorbent for specific simultaneous determination of three plant growth regulators in green bell peppers

A method based on solid-phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC) was developed to determine the content of 4-chlorophenoxy acetic acid (PCPA), naphthylacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in green bell peppers. A molecularly imprinted 3-aminophenol-glyoxal-urea resin (MIAGUR) was first synthesized as a specific SPE adsorbent, which exhibited special selectivity and multiple adsorption interactions including hydrogen bonding and π-π interactions. The quantities of PCPA, NAA and 2,4-D in green bell peppers from 20 samples scattered throughout Baoding city (Hebei province, China) were determined using the proposed method. The results suggested that the use of PCPA, NAA and 2,4-D in green bell peppers from Baoding’s markets is almost in fair. Moreover, MIAGUR-SPE-HPLC is suitable for the specific simultaneous monitoring of PCPA, NAA, and 2,4-D in green bell peppers and has potential applications in determination of PCPA, NAA, and 2,4-D of other plant products.