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.

Synthesis of prednisolone molecularly imprinted polymer nanoparticles by precipitation polymerization

“…Molecularly imprinting (MI) is a technique for fabrication of the artificial receptors which provides a high selectivity in size, shape, and functionality of the target molecules . This tailor‐made polymer is the specific design of the cavities for the target analyte that currently used and collaborated in numerous applications on account of these predominant properties, for instance, sensors, chromatographic separations, artificial antibody, pretreatment, drug delivery, and catalysts . The synthesis of molecularly imprinted polymers (MIPs) is based on the complex formation between template molecule and functional monomer in a pre‐polymerization mixture including covalent, non‐covalent, and semi‐covalent imprinting strategies.…”

A simple fluorescent assay for cyromazine detection in raw milk by using CYR-stabilized G-quadruplex formation

“…Nowadays, the main methods for the detection of cyromazine in raw milk and dairy products are as follows: gas chromatography-mass spectrometry (GC-MS) with the limits of quantication (LOQs) ranging from 10 to 100 ppb [6][7][8] and liquid chromatography-mass spectrometry (LC-MS), [9][10][11][12][13][14][15] ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-MS/MS), and molecularly imprinted solid-phase extraction-ultra-performance liquid chromatography (MISPE-UPLC) with LOQs ranging from 0.05 ppm to 40 ppm. 16,17 In the national standard of China (GB29704-2013), the residues of cyromazine and melamine are determinated by an ultra performance liquid chromatography-tandem mass spectrometric method (UPLC-MS).…”

The application of pseudo template molecularly imprinted polymer to the solid‐phase extraction of cyromazine and its metabolic melamine from egg and milk

“…Recently, several research groups have used melamine [], cyromazine [], and related compounds [] as templates or pseudo templates for melamine and cyromazine recognition. However, the application of pseudo‐template‐MIP as SPE materials combined with HPLC for the cyromazine and melamine detection has not been reported.…”