title: Preparation of an aminopropyl imidazole-modified silica gel as a sorbent for solid-phase extraction of carboxylic acid compounds and polycyclic aromatic hydrocarbons.
abstract: In this paper, a kind of aminopropyl imidazole-modified silica sorbent was synthesized and used as a solid-phase extraction (SPE) sorbent for the determination of carboxylic acid compounds and polycyclic aromatic hydrocarbons (PAHs). The resultant aminopropyl imidazole-modified silica sorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and elemental analysis (EA) to ensure the successful binding of aminopropyl imidazole on the surface of silica gel. Then the aminopropyl imidazole-modified silica sorbent served as a SPE sorbent for the enrichment of carboxylic acid compounds and PAHs. The new sorbent exhibited high extraction efficiency towards the tested compounds and the results show that such a sorbent can offer multiple intermolecular interactions: electrostatic, π-π, and hydrophobic interactions. Several parameters affecting the extraction recovery, such as the pH of sample solution, the pH of eluent, the solubility of eluent, the volume of eluent, and sample loading, were also investigated. Under the optimized conditions, the proposed method was applied to the analysis of four carboxylic acid compounds and four PAHs in environmental water samples. Good linearities were obtained for all the tested compounds with R(2) larger than 0.9903. The limits of detection were found to be in the range of 0.0065-0.5 μg L(-1). The recovery values of spiked river water samples were from 63.2% to 112.3% with relative standard deviations (RSDs) less than 10.1% (n = 4).
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources, CAS/Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China. sxjiang@lzb.ac.cn liusj@licp.cas.cn.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Guo
authors.forename: Licheng
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Liang
authors.forename: Shujuan
authors.initials: S
authors.lastname: Liu
authors.forename: Shengxiang
authors.initials: S
authors.lastname: Jiang
mesh_terms: D002264:Carboxylic Acids / Q000302:isolation & purification*; D007093:Imidazoles / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000295:instrumentation*
chemical_list: D002264:Carboxylic Acids; D007093:Imidazoles; D011084:Polycyclic Aromatic Hydrocarbons; C021611:aminopropyl silica gel; D012822:Silicon Dioxide