Electrochemical evaluation of a boron-doped diamond electrode for simultaneous determination of an antihypertensive ternary mixture of amlodipine, hydrochlorothiazide and valsartan in pharmaceuticals
The simultaneous voltammetric determination of a ternary mixture containing antihypertensive drugs amlodipine (AML), hydrochlorothiazide (HCTZ) and valsartan (VAL) by square-wave voltammetry using a cathodically pretreated boron-doped diamond electrode is reported for the first time. Three very well-resolved and reproducible oxidative processes of AML, HCTZ and VAL were found at 0.781 V, 1.14 V and 1.41 V, respectively, in Britton–Robinson buffer solution (pH 5.0). The linearity ranges were 4.9 × 10−7–7.2 × 10−6 mol L−1, 2.9 × 10−6–4.5 × 10−5 mol L−1, and 9.7 × 10−6–1.3 × 10−4 mol L−1 for AML, HCTZ and VAL, with detection limits of 2.3 × 10−7 mol L−1, 7.5 × 10−7 mol L−1, and 6.2 × 10−6 mol L−1, respectively. The proposed method was successfully applied to the simultaneous analysis of these antihypertensive drugs in their combined pharmaceutical tablets available in the market.
- This article is part of the themed collection: Analytical Chemistry in South America