Preparation and characterization of molecularly imprinted polymer for di(2-ethylhexyl) phthalate: Application to sample clean-up prior to gas chromatographic determination

• Published in: Journal of Chromatography A Vol. 1247; pp. 125 - 133
• Main Authors: Shaikh, Huma, Memon, Najma, Khan, Hamayun, Bhanger, M.I., Nizamani, S.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.07.2012
• Subjects: Acrylamides - chemistry; Adsorption; Chromatography, Gas - methods; desorption; Di(2-ethylhexyl) phthalate; dibutyl phthalate; Diethylhexyl Phthalate - analysis; Diethylhexyl Phthalate - chemistry; Diethylhexyl Phthalate - isolation & purification; dimethyl phthalate; Equipment Reuse; Fourier transform infrared spectroscopy; Gas chromatography; Kinetics; Linear Models; Molecular imprinting; Molecular Imprinting - methods; polymerization; polymers; Polymers - chemical synthesis; Polymers - chemistry; river water; rivers; Rivers - chemistry; Sample clean-up; scanning electron microscopy; Solid Phase Extraction - instrumentation; Solid Phase Extraction - methods; Solid-phase extraction; water analysis; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Di(2-ethylhexyl) phthalate; Gas chromatography; Molecular imprinting; Solid-phase extraction; Sample clean-up
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2012.05.056

► Synthesis of water compatible molecularly imprinted polymer (MIP) for di(2-ethylhexyl) phthalate(DEHP). ► Characterization of MIP by FT-IR, SEM, Scatchard analysis and LF-isotherm. ► Selectivity experiments over other homologues of DEHP. ► Clean-up of environmental waters prior to GC determination of DEHP. The molecularly imprinted polymer (MIP) selective for di(2-ethylhexyl) phthalate (DEHP) an environmental endocrine disruptor was prepared by suspension polymerization using methacrylamide as functional monomer and N,N′-methylene-bis-acrylamide as cross-linker. The imprinted polymer was employed for solid-phase extraction of DEHP from water samples of environmental importance and characterized by FT-IR and SEM. The adsorption properties of the imprinted polymer were demonstrated by equilibrium rebinding experiments, Pseudo-second-order kinetic model, Sips isotherm and Scatchard analysis. The reusability of MIP was checked for at least six repeated batch adsorption cycles and the results showed almost no deterioration in the adsorption capacity. The competitive recognition studies were performed with DEHP and structurally similar compounds; dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP). The imprinting factor (IF) of DEHP was found to be 12.86 which was much higher than the imprinting factors (IF) of other phthalates. A method constituted by molecularly imprinted solid-phase extraction (MISPE) with GC-FID was developed for DEHP analysis in water samples under very simple conditions. Sample loading and desorption conditions were also optimized. The MISPE method's linearity ranged from 0.035 to 3.0μgml−1 with r2=0.9998. Intra-assay, interassay precision and accuracy ranged from 0.0168% to 1.017%, 1.130% to 4.799% and 94.98% to 99.35%, respectively. The LOD and LOQ were found to be 0.011 and 0.035μgml−1, respectively. Synthesized MIP was employed in MISPE for cleaning up the spiked river water samples prior to gas chromatographic analysis. The river samples were found to contain DEHP in the range of 1.4×10−3 to 0.349μgml−1.