title: Molecularly imprinted monolith coupled on-line with high performance liquid chromatography for simultaneous quantitative determination of cyromazine and melamine.
abstract: We report a novel method for simultaneous determination of cyromazine and melamine based on a molecularly imprinted monolith on-line coupled with high performance liquid chromatography (HPLC). The imprinted monolith was prepared by in situ polymerization using 2,4-diamino-6-undecyl-1,3,5-triazine (DAUTA) as a mimic template. Due to the better solubility of DAUTA in chloroform, hydrogen bonds were effectively developed between the template and the functional monomer and resulted in the formation of highly specific cavities in the obtained imprinted monolith. With methanol as the loading solvent, cyromazine and melamine were both selectively retained by the obtained imprinted monolith, while the nonspecific adsorption on the non-imprinted monolith was negligible. The imprinted monolithic column was on-line coupled with HPLC for purification and concentration of the two analytes from milk samples. To minimize the peak broadening during the on-line transfer of the analytes from the imprinted monolith to the following analytical column, a successive desorption program was developed for the elution step, which enabled on-line stacking of the target compounds before being analyzed by HPLC. Low detection limits of 0.12 μg mL(-1) for melamine and 0.05 μg mL(-1) for cyromazine were achieved with only 0.3 mL of milk sample and a low sensitivity HPLC-UVD instrument. The method may be further extended to detect other analytes of interest in a large variety of samples.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.forename: Daomin
authors.initials: D
authors.lastname: Li
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Hua
authors.forename: Meiping
authors.initials: M
authors.lastname: Zhao
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation; D006860:Hydrogen Bonding; D054802:Molecular Imprinting / Q000379:methods*; D014227:Triazines / Q000032:analysis* / Q000737:chemistry
chemical_list: D014227:Triazines; C028704:cyromazine; C011907:melamine