ABSTRACT
In this study, a coordination imprinted polymer (CIP) solid-phase extraction (SPE) method was developed to determine the residues of flumequine (FLU) in fish samples. Silanized graphene oxide-doped CIP (SGO-CIP) monolithic column was prepared using FLU-Zn2+ as template in the presence of SGO. The synthesis conditions of SGO-CIP column were optimized by the response surface methodology. Under the optimum conditions, this column showed high specificity to FLU, and the adsorption capacity reached 61.74â¯ngâ¯mg-1. The enrichment factor of the monolithic column was over 40-fold. Various factors affecting the extraction efficiency of SGO-CIP column during SPE were tested to achieve optimal enrichment and to reduce non-specific adsorption. FLU in fish was detected by using a high-performance liquid chromatography-fluorescence detection system. The detection limit was as low as 0.32â¯ngâ¯g-1 and the recovery was as high as 95.2%, with relative standard deviations of below 5.9%. This simple and sensitive method may be applicable to the determination of FLU residues in foods.
Subject(s)
Drug Residues/analysis , Fluoroquinolones/analysis , Molecular Imprinting/methods , Seafood/analysis , Solid Phase Extraction/methods , Animals , Chromatography, High Pressure Liquid/methods , Fishes , Graphite/chemistry , Limit of Detection , Linear Models , Reproducibility of ResultsABSTRACT
In this study, a novel method was proposed to sensitively determine aflatoxin B1 (AFB1) in peanut sample by using a carbon quantum dots-coated dummy molecularly imprinted polymer (CDs-DMIP) monolithic column for pretreatment coupled with high performance liquid chromatography-fluorescence detection (HPLC-FLD). The CDs-DMIP monolithic column was prepared by in-situ polymerization in a water bath using 5,7-dimethoxycoumarin as dummy template molecule. The CDs-DMIP monolithic column was applied to determine AFB1 by HPLC-FLD. Satisfactory linearity was obtained over 0.5-2000ngmL-1, with a high correlation coefficient of 0.9999. The recoveries of AFB1 in peanut sample ranged from 79.5% to 91.2%, and the intraday and interday relative standard deviation ranged from 1.2% to 4.9%. Limit of detection (S/N=3) and limit of quantitation (S/N=10) were 0.118ngmL-1 and 0.393ngmL-1, respectively. Under the optimized conditions, the enrichment factor was over 71-fold. AFB1 in peanut sample and even some other samples could be sensitively determined by CDs-DMIP-HPLC-FLD method.
Subject(s)
Aflatoxin B1/analysis , Arachis/chemistry , Food Contamination/analysis , Poisons/analysis , Solid Phase Extraction/methods , Aflatoxin B1/chemistry , Aflatoxin B1/toxicity , Arachis/toxicity , Carbon/chemistry , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Coumarins/chemistry , Fluorescence , Food Contamination/prevention & control , Methacrylates/chemistry , Microscopy, Electron, Scanning , Molecular Imprinting/methods , Nitriles/chemistry , Poisons/chemistry , Poisons/toxicity , Polymers/chemistry , Quantum Dots/chemistry , Sensitivity and Specificity , Spectroscopy, Fourier Transform InfraredABSTRACT
A novel solid-phase extraction chip embedded with array columns of molecularly imprinted polymer-coated silanized graphene oxide (GO/SiO2-MISPE) was established to detect trace rhodamine B (RB) in chili powder. GO/SiO2-MISPE monolithic columns for RB detection were prepared by optimizing the supporting substrate, template, and polymerizing monomer under mild water bath conditions. Adsorption capacity and specificity, which are critical properties for the application of the GO/SiO2-MISPE monolithic column, were investigated. GO/SiO2-MIP was examined by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy. The recovery and the intraday and interday relative standard deviations for RB ranged from 83.7% to 88.4% and 2.5% to 4.0% and the enrichment factors were higher than 110-fold. The chip-based array columns effectively eliminated impurities in chili powder, indicating that the chip-based GO/SiO2-MISPE method was reliable for RB detection in food samples using high-performance liquid chromatography. Accordingly, this method has direct applications for monitoring potentially harmful dyes in processed food.
Subject(s)
Molecular Imprinting , Rhodamines/analysis , Silicon Dioxide/chemistry , Spices/analysis , Adsorption , Capsicum/chemistry , Chromatography, High Pressure Liquid , Coloring Agents , Dimethylpolysiloxanes/chemistry , Graphite/chemistry , Limit of Detection , Microfluidics , Microscopy, Electron, Scanning , Oxides/chemistry , Polymerization , Polymers/chemistry , Solid Phase Extraction , Spectroscopy, Fourier Transform InfraredABSTRACT
An analytical technique for selective, simultaneous determination of bisphenol A (BPA) and nonyl phenol (NP) in fish samples was established by a solid-phase extraction chip integrated with array columns of dual-molecularly imprinted polymer-coated silver-modified graphene oxide (Ag/GO-dual-MISPE-chip). Ag/GO dual-molecularly imprinted polymers (Ag/GO-dual-MIPs) were synthesized by in situ polymerization using Ag/GO as the supporting matrix which extracted templates easily. The affinity and specificity on the Ag/GO-dual-MISPE monolithic column were also investigated. The array extraction chip showed high binding capacity and selectivity to BPA and NP, with the imprinting factors of BPA and NP reaching 2.6 and 2.9, respectively. Ag/GO-dual-MIPs were characterized by scanning electron microscopy and Fourier transform-infrared (FT-IR) spectroscopy. As Low as 2.4ngL-1 BPA and 4.7ngL-1 NP were detected by high performance liquid chromatography coupled with fluorescence detection. The enrichment factor was 113-fold for BPA and 92-fold for NP. Therefore, the chip-based array columns are feasibly applicable to facile extraction of BPA and NP and effective clean-up of impurities in fish samples.
