Simultaneous determination of levofloxacin and ciprofloxacin in human urine by ionic‐liquid‐based, dual‐template molecularly imprinted coated graphene oxide monolithic solid‐phase extraction

Abstract

A novel method was developed to simultaneously determine the ciprofloxacin and levofloxacin levels in human urine using an ionic‐liquid‐based, dual‐molecularly imprinted polymer‐coated graphene oxide solid‐phase extraction monolithic column coupled with high‐performance liquid chromatography. The molecularly imprinted monolithic column was prepared using ciprofloxacin and levofloxacin as templates, 1‐vinyl‐3‐ethylimidazolium bromide as the functional monomer, and graphene oxide as the core material. The resulting imprinted monoliths were characterized by scanning electron microscopy and fourier transform‐infrared spectroscopy. The efficiency and capacity of the ionic‐liquid‐based imprinted monolithic column were investigated by varying the synthesis conditions (ciprofloxacin/levofloxacin ratio and template/functional monomer/cross‐linker ratio). The solid‐phase extraction process was optimized by changing the washing and eluting conditions. The results suggested that the proposed ionic‐liquid‐based molecularly imprinted solid‐phase extraction monolithic‐high‐performance liquid chromatography method could separate ciprofloxacin and levofloxacin efficiently and simultaneously from human urine. The mean recoveries of ciprofloxacin and levofloxacin ranged from 89.2 to 93.8 and 86.7 to 94.6%, respectively. The intra‐ and interday relative standard deviation ranged from 0.9 to 3.2 and 0.8 to 2.9%, respectively. Under the optimized conditions, the recoveries of ciprofloxacin and levofloxacin were more than 93.8%.

Sample Preparation Using Molecularly Imprinted Polymers

“…101,102 To provide a green synthesis process, another approach consists in preventing the direct use of a toxic cross-linking agent by producing it directly in the polymerization solution, such as it was done for formaldehyde through the hydrolysis of hexamethylenetetramine. 55 The use of ionic liquids as monomer 28,73,80,88 or porogen 103,104 can also be considered as a greener approach than the used of conventional monomers. Deep eutectic solvents (DESs) are also considered as a greenlike material.…”

“…133 A MIP monolith prepared in a 6-mL cartridge in the presence of GO particles was also recently proposed. 88 Permeable monolithic MIPs were also obtained in a 2-mL extraction cartridge by the in situ synthesis with a sol-gel approach. 72 The production of MIP particles by emulsion polymerization in a cryogel directly into a cartridge reservoir was also recently reported to circumvent the problem of high back pressure generated by small-size particles.…”

“…38,54,60,72,82,87,123,124,129,130,133,137,138 It was also used to extract natural products from food or plants 39,[55][56][57]70,86,103,121,127,139 to control their occurrence, such as for toxins, or to purify them. It was also largely applied to the determination of drugs 29,60,74,75,88,93,122,135,140,141 or proteins 110,119,126 , mainly in biological fluids, and of various compounds in manufactured products. 125,128 Aqueous samples are often filtered before their percolation through the MIP.…”

“…110 Many works reported the optimization of these different parameters to obtain high extraction recoveries on MIPs. 75,88,90,122,123,127,128,131 Nevertheless, when using a MIP, the objective is to reach an optimal selectivity. Therefore, the study in parallel of the extraction recoveries of the target analyte on the NIP must be done during the optimization of the extraction parameters, as it is often the case.…”

Determination of trace hydroxyl polycyclic aromatic hydrocarbons in urine using graphene oxide incorporated monolith solid‐phase extraction coupled with LC‐MS/MS

“…Besides, the single‐layer thickness results in high pressure in packing G/GO into SPE cartridge and it is hard to confine nanothickness G/GO within the cartridge. To overcome these unexpected obstacles, various strategies including the covalent binding of G/GO sheets to silica, the coating of G on SPME fiber, and the hybrid of magnetic particles and G/GO have been proposed . The problems with G/GO in classical SPE can also be overcome by the fabrication of GO incorporated monolith, which is a convenient choice to combine the advantages of G/GO and polymeric monolithic column.…”