Highly sensitive determination of α-lipoic acid in pharmaceuticals on a boron-doped diamond electrode

Abstract

A simple, highly sensitive, and selective differential pulse voltammetry method for the determination of α-lipoic acid (LA) in pharmaceutical preparations was developed and validated. The method is based on a quasi-reversible, diffusion-controlled, one-electron anodic oxidation of LA on a boron-doped diamond electrode (BDDE) in a McIlvaine (citrate-phosphate, C-PB) buffer solution at pH 3.0. For the first time, this environment was used for LA determination. A linear calibration curve was obtained within the concentration range 5.82 × 10−8 to 4.00 × 10−4 mol L−1 with a correlation coefficient of 0.9999. The limits of detection was estimated to be 1.94 × 10−8 mol L−1, which is one of the lowest values characteristic of voltammetric and chromatographic methods of LA determination. The proposed procedure is sensitive, accurate, and precise. Its utility was demonstrated in the determination of LA in pharmaceuticals without the need for its separation from the matrices. The results were comparable to those obtained by high performance liquid chromatography reference method and were in good accordance with the once declared by manufacturers. Thus, our method can be considered as an alternative to the dominant chromatographic determinations of α-LA in real samples.

Recent Advances in Electrochemical Sensors for Sulfur-Containing Antioxidants

“…α-Lipoic acid shows higher electrochemical activity and can be determined using platinum [ 39 ], glassy carbon (GCE) [ 40 , 41 ], carbon fiber microelectrode [ 42 , 43 ] or boron-doped diamond [ 44 , 45 ] electrodes. The linear dynamic ranges are mainly from dozens to hundreds of μM excluding boron-doped diamond electrodes, for which a 0.3–105 μM linear dynamic range with a detection limit of 0.088 in Britton–Robinson buffer pH 3.0 [ 44 ] and 0.0582–400 μM with a detection limit of 0.0194 μM in McIlvaine buffer pH 3.0 [ 45 ] have been achieved in differential pulse voltammetry (DPV).…”

Quantification of alpha-lipoic acid in pharmaceutical samples using Pd(II) catalyzed ligand substitution reaction in SLS micellar medium

“…Different methods are frequently employed to quantify thio compounds in analytical, biological, and pharmacological materials. The quantifica,tion methodology includes potentiometry [31], spectrophotometry [32,33], chromatography [34][35][36], fluorimetry [37], NMR-spectrometry [38], flow injection analysis [39], colorimetry [29], and voltammetry [40,41]. Table 1 describes the various analytical methods used for the determination of ALA with their detection limit.…”

A new Approach for the Voltammetric Sensing of the Phytoestrogen Genistein at a Non‐modified Boron‐doped Diamond Electrode

“…Optimizing the voltammetric method's effectiveness necessitates the development of an improved electrode material. Various comprehensive studies conducted throughout the last two decades have observed that boron-doped diamond (BDD) electrode, the relatively new carbon-based form, has sparked enormous fascination as such an environment-friendly electrode material in such a variety of sectors, including chemical analysis, environmental research, biological scientific method, materials science, and etc [29][30][31][32][33][34][35][36][37][38]. BDD electrode has an extraordinarily broad potential windows in both aqueous and non-aqueous mediums, structure stability at extremes anodic & cathodic potentials, and then a great resistant to deactivation by surfaces fouling (the existence of sp 3 hybridized atoms of carbon in diamonds structures).…”