Simple Flow Injection Analysis System for Simultaneous Determination of Phenolic Antioxidants with Multiple Pulse Amperometric Detection at a Boron-Doped Diamond Electrode

Abstract

A method for simultaneous determination of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in food was developed that uses multiple pulse amperometry (MPA) with flow injection analysis (FIA). Determination of these phenolic antioxidants was carried out with a cathodically pretreated boron-doped diamond electrode and an aqueous ethanolic (30% ethanol, v/v) 10 mmol L⁻¹ KNO₃ solution (pH(cond) = 1.5) as supporting electrolyte. A dual-potential waveform, at E(det1) = 850 mV/200 ms and E(det2) = 1150 mV/200 ms versus Ag/AgCl (3.0 mol L⁻¹ KCl), was employed. The use of E(det1) or E(det2) caused the oxidation of BHA or of BHA and BHT, respectively; hence, concentration subtraction could be used to determine both species. The respective analytical curves presented good linearity in the investigated concentration range (0.050-3.0 μmol L⁻¹ for BHA and 0.70-70 μmol L⁻¹ for BHT), and the detection limits were 0.030 μmol L⁻¹ for BHA and 0.40 μmol L⁻¹ for BHT. The proposed method, which is simple, quick, and presents good precision and accuracy, was successfully applied in the simultaneous determination of BHA and BHT in commercial mayonnaise samples, with results similar to those obtained by HPLC, at a 95% confidence level.

Differential pulse voltammetric determination of albendazole in pharmaceutical tablets using a cathodically pretreated boron-doped diamond electrode

“…whether they are predominantly hydrogen or oxygen terminated [21]; the predominance of a termination type can be attained by proper electrochemical pretreatments. This effect of surface termination was observed, for instance, in the determination of additives in food products [22][23][24] and of drugs in pharmaceutical formulations [25][26][27][28], when cathodically pretreated (predominantly hydrogen-terminated) BDD electrodes presented better performances.…”

Flow‐Injection Amperometric Method for Determination of Diclofenac in Pharmaceutical Formulations Using a Boron‐Doped Diamond Electrode

“…When conventional amperometry is substituted by multiple pulse amperometry, two additional characteristics can be noted: the improved in the selectivity [22][23][24][25] and the possibility of measuring more than one analyte at the same time [26][27][28][29][30]. In addition, this technique also allowed for the use of a potential pulse for the constant cleaning of the electrode surface.…”

Análise por injeção em fluxo com detecção amperométrica de múltiplos pulsos: potencialidades e aplicações

“…Este trabalho apresenta a determinação simultânea de antioxidantes fenólicos (butil-hidróxi-anisol (BHA) e butil-hidroxitolueno (BHT)) de forma simples e rápida usando eletrodo de trabalho de diamante dopado com boro. 100 Foram aplicados apenas dois pulsos de potenciais na seguinte sequência: +0,85 V/200 ms: oxidação e quantificação direta da BHA sem a interferência de BHT; +1,15 V/200 ms: oxidação de ambos os analitos (BHA e BHT). A quantificação da BHT foi obtida pela diferença entre as respostas amperométricas no segundo (1,15 V) e no primeiro pulso de potencial (+0,85 V).…”