Determination of sulfadimethoxine in milk with aptamer‐functionalized Fe₃O₄/graphene oxide as magnetic solid‐phase extraction adsorbent prior to HPLC

Abstract

An aptamer (Apt) functionalized magnetic material was prepared by covalently link Apt to Fe3O4/graphene oxide (Fe3O4/GO) composite by 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide hydrochloride and N‐hydroxysuccinimide, and then characterized by FTIR spectroscopy, X‐ray diffraction, and vibration sample magnetometry. The obtained composite of Fe3O4/GO/Apt was employed as magnetic solid‐phase extraction adsorbent for the selective preconcentration of sulfadimethoxine prior to analysis by high‐performance liquid chromatography. Under the optimal conditions (sample pH of 4.0, sorbent dosage of 20 mg, extraction time of 3 h, and methanol‐5% acetic acid solution as eluent), a good linear relationship was obtained between the peak area and concentration of sulfadimethoxine in the range of 5.0 to 1500.0 µg/L with correlation coefficient of 0.9997. The limit of detection (S/N = 3) was 3.3 µg/L. The developed method was successfully applied to the analysis of sulfadimethoxine in milk with recoveries in the range of 75.9‐92.3% and relative standard deviations less than 8.1%. The adsorption mechanism of Fe3O4/GO/Apt toward sulfadimethoxine was studied through the adsorption kinetics and adsorption isotherms, and the results show that the adsorption process fits well with the pseudo‐second‐order kinetic model and the adsorbate on Fe3O4/GO/Apt is multilayer and heterogeneous.

Microfluidic flow-injection aptamer-based chemiluminescence platform for sulfadimethoxine detection

“…Not only for antibiotics but this approach can also be suggested as a new flow-injection strategy for the detection of analytes whose aptamers have been confirmed. For application in physiological conditions, detection of analyses in complex matrices with purification systems still needs to be explored [ 51 ].…”

Aptamer-based assays: strategies in the use of aptamers conjugated to magnetic micro- and nanobeads as recognition elements in food control

“…Despite the large number of aptamers selected for different targets, their reliable applications in MSPE are still in their infancy as well as limited to few small molecules. As for food safety and quality monitoring, published articles focus exclusively on mycotoxins or antibiotic residues [36][37][38][39][40][41].…”

“…Guo et al developed an MSPE procedure using aptamer-functionalized magnetic Fe 3 O 4 /graphene oxide/aptamer composite for the determination of sulfadimethoxine in milk; parameters such as extraction time, sample pH, amount of adsorbent, elution solvent, and elution time were studied in binding buffer [ 40 ]. The selectivity of the method was investigated by comparing the HPLC–UV chromatogram of a standard solution of four sulfanilamide antibiotics after MPSE procedure with that acquired before MSPE: the only signal showing a significant increase was that of the target analyte, whereas the peak areas of other compounds remained unchanged or one of them was not detectable.…”

A novel and sensitive electrochemical aptasensor for sulfadimethoxine detection based on the triple helix/exonuclease I-assisted double-amplification strategy

“…Many methods have been developed for the detection of SDM residues in food and the environment, such as high performance liquid chromatography (HPLC), 5,6 capillary electrophoresis (CE), 7 fluorescence, 8 liquid chromatography-mass spectrometry (LC-MS) 9,10 and spectrophotometry. 11 Although all the above methods possess high accuracy, they often involve expensive instruments, complex sample preparation processes and demanding experimental operations.…”