Adsorptive Voltammetry of 2-(5-Bromo-2-pyridyl)azo-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol on a Carbon Paste Electrode in the Presence of Organic Cations and Polycation

Abstract

The adsorption of ion-association complexes on a carbon paste electrode (CPE) was investigated by cyclic voltammetry using an electroactive hydrophobic anion probe. The redox reactions of 2-(5-bromo-2-pyridyl)azo-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS), the analytical probe, were irreversible. The reduction of the azo group and the oxidation of the phenol were observed at -0.1 V and 0.9 V vs. SCE, respectively, in a 0.1 mol L -1 H2SO4 solution. The peak currents for the redox reaction increased with the concentration of the cationic surfactant and the accumulation time. The increase in the ratio of the peak current to the concentration of cationic surfactants was proportional to the hydrophobicity. The peak current for 5-Br-PAPS also increased when a polycation, polyhexamethylene biguanide hydrochloride, was added and was strongly dependent on the ionic strength and pH, in contrast to cationic surfactants.

Potentiometric Titration of Polyhexamethylene Biguanide Hydrochloride with Potassium Poly(vinyl sulfate) Solution Using a Cationic Surfactant-selective Electrode

“…All experimental results described below were obtained using the HTA ion as the indicator ion and the HTA-ISE. According to the colloidal titration of PHMB-HCl by TB indicator at less than pH 2, 34 the result agreed with the total value of non-aqueous titration and argentometric titration. Thus, one mole of the unit concentration of PHMB-HCl quantitatively reacted with two moles of the unit concentration of PVSK.…”

“…So far, many determination methods for polyelectrolytes, such as a poly(diallyldimethylammonium chloride) (Cat-floc), were developed by using conductometry, 1 turbidimetry, 2 potentiometry using ion-selective electrodes (ISEs), [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] colorimetric Toluidine Blue (TB) method, [22][23][24] fluorometry, [25][26][27][28] photometric titration method [29][30][31] and a voltammetric method. [32][33][34] However, only a few determination methods of PHMB-HCl have been reported. Hattori et al 34 have reported an indirect determination of PHMB by using adsorptive voltammetry of 2-(5-bromo-2-pyridyl)azo-5-[N-npropyl-N-(3-sulfopropyl)amino]phenol on a carbon paste electrode.…”

“…[32][33][34] However, only a few determination methods of PHMB-HCl have been reported. Hattori et al 34 have reported an indirect determination of PHMB by using adsorptive voltammetry of 2-(5-bromo-2-pyridyl)azo-5-[N-npropyl-N-(3-sulfopropyl)amino]phenol on a carbon paste electrode.…”

Determination of polyhexamethylene biguanide hydrochloride

“…Because PHMB-HCl is a polycation, an organic redox anion is useful to the determination of PHMB-HCl using adsorption voltammetry. Here we used 2-[(5-bromo-2-pyridyl)azo]-5-[N-n-propyl-N-(3-sulfopropyl)amino] phenol (5-Br-PAPS) as the analytical probe (Hattori et al 2006). The adsorptive voltammograms of 5-Br-PAPS in 0.01 m H 2 SO 4 solution indicated two waves, reduction of the azo at -0.1 V vs. SCE and oxidation of the phenol at 0.9 V vs. SCE (Figure 9, broken line).…”

Electrochemical Sensing of Anions and Heparin by an Alkyl-chain Ferrocene Cationic Surfactant

“…11-2210, f3 mm, BSA) with TGP-2 carbon powder and bis(2-ethylhexyl)phtalate was used. 10,17 All measurements were performed using freshly prepared electrode surfaces. A platinum wire and a saturated calomel electrode (H type SCE, BAS) or KCl Ag/AgCl electrode (RE-5B, BAS) were used as counter and reference electrodes, respectively.…”