Separation Of Chloramphenicol Research Articles

Core-shell magnetic molecularly imprinted polymers prepared by self-polymerization of bifunctional monomers for efficient enrichment and separation of chloramphenicol in water samples

Chloramphenicol (CAP) is a potent antibiotic used to treat infections in livestock and humans, but its residues can be hazardous to human health. In this study, amino-modified Fe3O4 nanoparticles were prepared by a single-pot method, and magnetic molecularly imprinted materials were prepared by self-polymerization for imprinting with CAP. The imprinted thin layer was prepared by polymerization of dopamine (DA) and 3-aminophenylboronic acid (APBA) copolymers, which improved the elution efficiency of the template. Dopamine generated under alkaline conditions replaces the crosslinker and can be adsorbed on the surface of magnetic carriers. The aromatic groups in dopamine make it difficult to degrade and fall off after adsorption on the magnetic carrier surface. The maximum adsorption amount of CAP on magnetic materials was 6.5 mg/g. After several adsorption cycles, the CAP-MMIPs still had good stability. The results showed that the method can both specifically recognize and enrich the separation of the target antibiotics, which greatly reduced the pretreatment time of the samples and provided a new approach for the pretreatment of CAP.

Fabrication of porous molecularly imprinted polymer using halloysite nanotube as template for selective recognition and separation of chloramphenicol

In this research, porous molecularly imprinted polymers (PMIPs) with thin wall were prepared using halloysite nanotube (HNT) hard template, which has a unique hollow tubular structure, for selective recognition and removal of the chloramphenicol (CAP) antibiotic frequently detected in water environment. PMIPs had the good porous structure replicated from the HNT template. The adsorption equilibrium, kinetics, selectivity and regeneration properties of CAP by PMIPs were systematically studied by static adsorption experiments. The maximum adsorption capacity of PMIPs toward CAP increased from 91.26 μmol g−1 at 25 °C to 102.5 μmol g−1 45 °C. The adsorption was in accordance with Freundlich isothermal model, indicating the multi-molecular layer adsorption. The adsorption could reach equilibrium basically within 80 min with a quick kinetic property and was confirmed by the pseudo-second-order kinetics model, indicating the chemical adsorption was rate-controlling step. The high contact temperature was beneficial to the CAP adsorption, thus which was belonged to the endothermic process. Importantly, adsorption selectivity experiments showed PMIPs had the high recognition ability for template molecule CAP whether in one- or two- component antibiotic solutions. Besides, PMIPs exhibited good thermal and chemical stability and reproducibility for practical application in further.

Microwave-assisted preparation of boron acid modified expanded graphite for the determination of chloramphenicol in egg samples

A rapid and simple method for the synthesis of boron acid modified expanded graphite (B-EG) with the assist of microwave irradiation was developed. The synthesis process can be completed in one-step, where H2SO4 and H3BO3 were used as intercalating agent and KMnO4 was used as oxidizing agent. The obtained B-EG was worm-like and lamellar structure with plenty of small dispersed particles. The B-EG was successfully used as solid phase extraction absorbent for the enrichment and separation of chloramphenicol in egg samples, followed by liquid chromatography tandem mass spectrometry analysis. The predominant conditions affecting extraction efficiency were optimized. Under optimal conditions, the detection limit of the method was 0.27 ng g−1. The relative standard deviations of within-day and between-day were in the range of 2–6% and 2–8%, respectively. The method was successfully used to detect chloramphenicol in five egg samples. At the spiked concentration of 50 ng g−1, the satisfactory recoveries (87–94%) were obtained.

Hollow imprinted polymer nanorods with a tunable shell using halloysite nanotubes as a sacrificial template for selective recognition and separation of chloramphenicol

Hollow imprinted polymer nanorods with excellent regeneration property were prepared for selective recognition and separation of chloramphenicol.

Molecularly imprinted polymers for the selective solid-phase extraction of chloramphenicol

A variety of bulk polymers for the selective separation of chloramphenicol were synthesised from 2-vinylpyridine, diethylaminoethyl methacrylate or methacrylic acid monomers. Chromatographic evaluation indicated that chloramphenicol was retained under nonpolar elution conditions (k = 58.65) through selective hydrogen bonding and ionic interactions. The retention of chloramphenicol under aqueous elution conditions (k > 100) results from nonselective hydrophobic interactions. Under nonpolar elution conditions, the functional monomer employed imparted a significant influence on the recognition properties of the corresponding polymer. After solid-phase extraction using a molecularly imprinted polymer as sorbent and either an organic or aqueous washing solvent, nearly 100% recovery from the chloramphenicol standard solution was achieved, and nearly 90% recovery could be attained from spiked honey samples. The molecularly imprinted polymer was well suited to suppress matrix effects, and provided optimal preconcentration of the target molecule (chloramphenicol) prior to chromatographic analysis.

Determination and separation of chloramphenicol and its hydrolysate in eye-drops by capillary zone electrophoresis with amperometric detection

The amperometric detection of chloramphenicol and its hydrolytic product, 2-amino-1-(4-nitrophenyl)-propane-1,3-diol, following their separation by capillary zone electrophoresis is described in this paper. A carbon disk electrode used as working electrode for two analytes exhibits good response at +1175 mV (vs. Ag/AgCl). The method was validated, and reproducibility, linearity, and recovery for both components was assessed. Under the optimum conditions, the two analytes were baseline resolved within approximately 11 min. The limits of detection were 0.5 and 0.2 μg/ml for chloramphenicol and its hydrolysate, respectively. The method was successfully applied to analyze the stability of four batches of chloramphenicol ophthalmic solutions stored at room temperature. The suggested procedure was found to have a high accuracy and was less time-consuming.

Spectrophotometric Determination of Chloramphenicol and Its Esters in Complex Drug Mixtures

When aromatic nitro compounds are reduced with zinc and calcium chloride and reacted with trisodium pentacyanoaminoferrate they give a purple product having an absorbance maximum between 480 and 540 nm. Applying this reaction, a quantitative method has been developed for the determination of chloramphenicol and its esters. Various reaction conditions have been standardized. Beer's law is obeyed in the concentration range of 4 to 32 micrograms/mL reaction mixture. Average recoveries and standard deviations were 99.78 +/- 0.627 and 99.90 +/- 0.660; 101.06 +/- 0.702; and 99.90 +/- 0.880% for chloramphenicol, chloramphenicol sodium succinate, and chloramphenicol palmitate, respectively. The method has also been applied to determine chloramphenicol and its esters as well as chloramphenical in the presence of combination drugs in dosage forms. The presence of benzocaine, lignocaine, sulfadiazine, nitrofurantoin, ascorbic acid, hydrocortisone, prednisolone, streptomycin, and tetracycline does not interfere with the proposed spectrophotometric procedure. The method does not require prior separation of chloramphenicol from combination drugs.