UV-visible spectrophotometric, adsorptive stripping voltammetric and capillary electrophoretic study of 2-(5′-bromo-2′-pyridylazo) -5-diethylaminophenol and its chelates with selected metal ions: application to the determination of Co(III) in vitamin B12

Oxspring, Darren A.; Maxwell, T.J.; Smyth, W. Franklin

doi:10.1016/0003-2670(95)00624-9

Cited by 38 publications

(10 citation statements)

References 11 publications

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“…UV-visible spectrophotometric, adsorptive stripping voltammetry and capillary electrophoretic study of metal ions have been studied and application was made to the determination of Co(III) in vitamin B12 [15]. The semi-derivate voltammetric peak current method was applied to determine the content of vitamin B12 in pharmaceutical preparations using gold modified electrode [16].…”

Section: Introductionmentioning

confidence: 99%

Determination of Vitamin B12 Using Differential Pulse Polarography

Kalaycı¹,

Ünal²,

Somer³

2020

AJAC

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Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH 3 /NH + 4 (pH = 9.8) and 1.0 M AcOH/AcO − (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10 −7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO − (pH = 4.0) buffer. B12, which is 1000 µg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 µg as a result of 95% confidence interval.

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Section: Introductionmentioning

confidence: 99%

Determination of Vitamin B12 Using Differential Pulse Polarography

Kalaycı¹,

Ünal²,

Somer³

2020

AJAC

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“…A brief overview regarding the material of the working electrode and the type of the modifier that have been used in these methods is available in previously published works 10–11, while with regards to the principle of the determination of the analyte, these methods can be classified into three main categories: the first category includes mercury electrodes and determination of the cobalt atom in the molecule of vitamin B 12 after the UV or chemical decomposition of the target. Despite the high sensitivity of these methods, issues associated with the use of toxic mercury and the time‐consuming decomposition step render them not really suitable for use in routine analysis 12–14. The second category includes methods which employ unmodified 7,9 or modified 5–8, electrodes for the direct electrochemical determination of vitamin B 12 by registering the reduction 5–8 or the oxidation 9 peak of the Co(II)/Co(I) 6–8, Co(III)/Co(II) 5 or Co(I)/Co(III) 9 redox couples, respectively.…”

Section: Introductionmentioning

confidence: 99%

Ultrasensitive Determination of Vitamin B₁₂ Using Disposable Graphite Screen‐Printed Electrodes and Anodic Adsorptive Voltammetry

2015

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A facile, rapid and ultra‐sensitive method for the determination of vitamin B12 (cyanocobalamin) at the sub‐nanomolar concentration range by using low‐cost, disposable graphite screen‐printed electrodes is described. The method is based on the cathodic preconcentration of square planar vitamin B12s, as occurred due to the electro reduction of Co(III) center in vitamin B12a to Co(I), at −1.3 V versus Ag/AgCl/3 M KCl for 40 s. Then, an anodic square wave scan was applied and the height of the peak appeared at ca. −0.73 V versus Ag/AgCl/3 M KCl, due to the oxidation of Co(I) to Co(II) in the adsorbed molecule, was related to the concentration of the vitamin B12 in the sample. EDTA was found to serve as a key‐component of the electrolyte by eliminating the background signal caused by metal cations impurities contained in the electrolyte (0.1 M phosphate buffer in 0.1 M KCl, pH 3). It also blocks trace metals contained in real samples, thus eliminating their interference effect. The method was optimized to various working parameters and under the selected conditions the calibration curve was linear over the range 1×10−10–8×10−9 mol L−1 vitamin B12 (R2=0.994), while the limit of detection for a signal‐to‐noise ratio of 3 (7×10−11 mol L−1 vitamin B12) is the lowest value of any reported in the literature for the electrochemical determination of vitamin B12. The sensors were successfully applied to the determination of vitamin B12 in pharmaceutical products.

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“…To overcome this, on-line sample preconcentration techniques, which are known to be effective approaches to improve the detection sensitivity, have been demonstrated. To date, however, all metal analyses employing on-line preconcentration, such as large-volume sample stacking [23][24][25][26][27] and isotachophoretic focusing, 28,29 and sweeping via dynamic complexation, 30 were demonstrated in the capillary zone electrophoresis (CZE) mode.…”

Section: Introductionmentioning

confidence: 99%

Metal Complex Separation with On-line Sample Preconcentration in Micellar Electrokinetic Chromatography

Isoo

Terabe

2005

ANAL. SCI.

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Micellar electrokinetic chromatography (MEKC) using a cationic surfactant as a pseudostationary phase was examined to separate anionic metal cyclohexane-1,2-diaminetetraacetic acid (CDTA) complexes. Cetyltrimethylammonium chloride (CTAC) was employed as the cationic surfactant micelle, its addition leading to EOF reversal. Cu(II), Co(II), Zn(II), Mn(II) and Pb(II) were used as test analytes, and the complete separation was obtained by MEKC. On-line sample preconcentration by sweeping was also examined to improve the detection sensitivity. From 15-to 42-fold increases in the detection sensitivity in terms of the peak heights were obtained by sweeping with a cationic micelle in the presence of high EOF. The limits of detection were in the range (0.6 -1.8) × 10 -6 M with UV detection without any off-line preconcentration step.

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UV-visible spectrophotometric, adsorptive stripping voltammetric and capillary electrophoretic study of 2-(5′-bromo-2′-pyridylazo) -5-diethylaminophenol and its chelates with selected metal ions: application to the determination of Co(III) in vitamin B12

Cited by 38 publications

References 11 publications

Determination of Vitamin B12 Using Differential Pulse Polarography

Determination of Vitamin B12 Using Differential Pulse Polarography

Ultrasensitive Determination of Vitamin B₁₂ Using Disposable Graphite Screen‐Printed Electrodes and Anodic Adsorptive Voltammetry

Metal Complex Separation with On-line Sample Preconcentration in Micellar Electrokinetic Chromatography

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UV-visible spectrophotometric, adsorptive stripping voltammetric and capillary electrophoretic study of 2-(5′-bromo-2′-pyridylazo) -5-diethylaminophenol and its chelates with selected metal ions: application to the determination of Co(III) in vitamin B12

Cited by 38 publications

References 11 publications

Determination of Vitamin B12 Using Differential Pulse Polarography

Determination of Vitamin B12 Using Differential Pulse Polarography

Ultrasensitive Determination of Vitamin B12 Using Disposable Graphite Screen‐Printed Electrodes and Anodic Adsorptive Voltammetry

Metal Complex Separation with On-line Sample Preconcentration in Micellar Electrokinetic Chromatography

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Ultrasensitive Determination of Vitamin B₁₂ Using Disposable Graphite Screen‐Printed Electrodes and Anodic Adsorptive Voltammetry