A glassy carbon electrode modified with cerium phosphate nanotubes for the simultaneous determination of hydroquinone, catechol and resorcinol

Abstract

A nafion film containing cerium phosphate nanotubes was pasted onto a glassy carbon electrode (GCE) to obtain a sensor for hydroquinone (HQ). The morphologies and components of the coating were characterized by transmission electron microscopy, scanning electron microscopy and energy-dispersive spectroscopy. Cyclic voltammetry and differential pulse voltammetry (DPV) showed the specific surface of the electrode to be significantly increased and the electron transfer rate to be accelerated. The modified GCE was applied to the determination of hydroquinone (HQ) via DPV. The oxidation current increases linearly in the 0.23 μM to 16 mM HQ concentration range which is as wide as five orders of magnitude. The limit of detection is 0.12 μM (based on a signal-to-noise ratio of 3), and the sensitivity is 1.41 μA·μM cm. The method was further applied to the simultaneous determination of HQ, catechol and resorcinol. The potentials for the three species are well separated (20, 134, and 572 mV vs SCE). Average recoveries from (spiked) real water samples are between 95.2 and 107.0%, with relative standard deviations of 0.9~2.7% (for n = 3) at three spiking levels. The method was validated by independent assays using HPLC. Graphical abstract ᅟ.

Mesoporous Carbon and Ceria Nanoparticles Composite Modified Electrode for the Simultaneous Determination of Hydroquinone and Catechol

“…These relationships indicate that the electrochemical process of HQ and CC on MC–CeNPs–CS/GCE is typical adsorption–controlled [48]. Laviron theory [49] was used to study the reaction mechanism:Ip = nFQν/4RT where n is the number of electrons, F is the Faraday constant (96485 C mol −1 ), Q is the electric quantity, R is the universal gas constant (8.314 J K −1 mol −1 ), and T is the temperature in kelvin. The n can be calculated, the values are 1.69 and 1.85 for HQ and CC, indicating that the reaction of HQ and CC in modified electrode is complex, which is not a simple two–electron process [46,47,48].…”

“…The linear regression equations were E pa = 0.21 + 0.020 log ν (R 2 = 0.996) and E pc = 0.071–0.034 log ν (R 2 = 0.996), E pa = 0.32 + 0.021 log ν (R 2 = 0.996) for HQ, and E pc = 0.21–0.020 log ν (R 2 = 0.995) for CC. The electrochemical parameters, such as charge transfer coefficient (α) and electron transfer coefficient (K s ), were calculated by following Laviron’s eq [31,49] Epa = Eθ +(2.3RT(1−α)nF)log ν Epc = Eθ–(2.3RTαnF)log ν logks = αlog(1−α)+(1−α)logα−log(RTnFv)−(1−α)αnFΔE2.3…”

Electrochemical Sensing Platforms of Dihydroxybenzene: Part 2 – Nanomaterials Excluding Carbon Nanotubes and Graphene

“…A pre‐treated carbon paste electrode (PCPE) was used to prepare MgO nanoparticles based on the DHB sensor. Li and co‐workers [128] prepared a paste of cerium phosphate nanotubes (CePO 4 ) in Nafion film and subsequently deposited it on the GCE surface. The as‐developed sensor CePO 4 @GCE exhibited excellent catalytic activity towards the three DHB isomers.…”

Multivariate standard addition for the analysis of overlapping voltammetric signals in the presence of matrix effects: Application to the simultaneous determination of hydroquinone and catechol

“…[19] to multicomponent analysis in the presence of overlapped signals. For this purpose, we have selected two dihydroxybenzene isomers, hydroquinone and catechol, which show a clear overlapping of their oxidation signals in voltammetric measurements [20][21][22][23]. In the last years, many efforts have been devoted to develop modified electrodes able to increase the separation between both peaks [20][21][22] but, as far as we know, a perfect resolution of both signals has not been achieved yet.…”

“…For this purpose, we have selected two dihydroxybenzene isomers, hydroquinone and catechol, which show a clear overlapping of their oxidation signals in voltammetric measurements [20][21][22][23]. In the last years, many efforts have been devoted to develop modified electrodes able to increase the separation between both peaks [20][21][22] but, as far as we know, a perfect resolution of both signals has not been achieved yet. In contrast, the use of relatively simple electrodes combined with a common multivariate calibration method like partial least squares (PLS) allowed a satisfactory determination of both analytes [23].…”