| Autor: |
Flieger J; Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland., Żuk N; Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland., Pasieczna-Patkowska S; Department of Chemical Technology, Faculty of Chemistry, Maria Curie Skłodowska University, Pl. Maria Curie-Skłodowskiej 3, 20-031 Lublin, Poland., Flieger M; Department of Forensic Medicine, Medical University of Lublin, ul. Jaczewskiego 8b, 20-090 Lublin, Poland., Panek R; Department of Geotechnics, Civil Engineering and Architecture Faculty, Lublin University of Technology, Nadbystrzycka 40, 20-618 Lublin, Poland., Klepka T; Department of Technology and Polymer Processing, Faculty of Mechanical Engineering, Lublin University of Technology, Nadbystrzycka 36, 20-618 Lublin, Poland., Franus W; Department of Geotechnics, Civil Engineering and Architecture Faculty, Lublin University of Technology, Nadbystrzycka 40, 20-618 Lublin, Poland. |
| Abstrakt: |
The techniques used to detect and quantify cyanocobalamin (vitamin B12) vary considerably in terms of detection sensitivity, from the most sensitive, based on radioisotopes and mass spectrometry (MS) with limits of detection (LOD) in fg mL -1 , to fluorescence (FL) and surface plasmon resonance (SPR) biosensors with LOD values in the range of a few µg mL -1 . For accurate quantification of an analyte present at trace levels in complex biological matrices, a selective separation and enrichment step is required to overcome matrix interferences and ensure sufficient detection sensitivity. In this study, iron oxide magnetic nanoparticles (IONPs) were used for the extraction and initial preconcentration of cyanocobalamin (vitamin B12). In the dependence of the magnetization on the H-field (hysteresis loop), no coercivity and remanence values were found at 300 K, indicating the superparamagnetic properties of the tested IONPs. Perfluorinated acids were used as amphiphilic agents to allow the sorption of cyanocobalamin onto the IONPs. FT-IR/ATR spectroscopy was used to confirm the sorption of cyanocobalamin on the IONPs. The influence of the addition of a homologous series of perfluorinated acids such as trifluoroacetic acid (TFAA), heptafluorobutyric acid (HFBA), and trichloroacetic acid (TCAA) to the extraction mixture was tested considering their type, mass, and time required for effective sorption. The adsorption kinetics and isotherm, described by the Freundlich and Langmuir equations, were analyzed. The maximum adsorption capacity ( q m ) exceeded 6 mg g -1 and was 8.9 mg g -1 and 7.7 mg g -1 for HFBA and TCAA, respectively, as the most efficient additives. After the desorption process using aqueous KH 2 PO 4 solution, the sample was finally analyzed spectrophotometrically and chromatographically. The IONP-based method was successfully applied for the isolation of cyanocobalamin from human urine samples. The results showed that the developed approach is simple, cheap, accurate, and efficient for the determination of traces of cyanocobalamin in biological matrices. |
