Differential pulse voltammetry, glassy

Figure 4, Differential pulse voltammetry of a freshly polished, activated glassy carbon surface (a) and a digital simulation of the DPV (b). The pulse frequency vas2 Hz with an amplitude of 10 mV. The DC scan rate was 2 mV s...

Other techniques that have been used include subtractive differential pulse voltammetry at twin gold electrodes [492], anodic stripping voltammetry using glassy-carbon electrodes [495,496], X-ray fluorescence analysis [493], and neutron activation analysis [494],... 

Takamura et al. have determined chlorpromazine by the use of differential pulse voltammetry incorporating rotating glassy-carbon disc electrodes [170]. The determination was carried out after pre-treatment of vitreous carbon by anodic oxidation for two minutes in 0.5 M phosphate buffer (pH 6.3) at 1.6 V vs. Ag/AgCl reference electrode. The determination was made with the use of 50 mV pulses at 2 seconds intervals, a rotation rate of 2500 rpm, and a scan rate of 5 mV/sec. 

Figure 10.1 Differential pulse voltammetry (DPV) of guanine at pH 4.5 in 0.2 M acetate buffer at a glassy carbon microelectrode, (a) 0.5 mM guanine and (b) 50 pM guanine at a scan rate of 5 mV/s. 5 (Solid line fifth scan dotted line first scan dashed fine second scan.) Reprinted from Ref. 5a with permission from Elsevier.

Recent studies describe the use of cyclic voltammetry in conjunction with controlled-potential coulometry to study the oxidative reaction mechanisms of benzofuran derivatives [115] and bamipine hydrochloride [116]. The use of fast-scan cyclic voltammetry and linear sweep voltammetry to study the reduction kinetic and thermodynamic parameters of cefazolin and cefmetazole has also been described [117]. Determinations of vitamins have been studied with voltammetric techniques, such as differential pulse voltammetry for vitamin D3 with a rotating glassy carbon electrode [118,119], and cyclic voltammetry and square-wave adsorptive stripping voltammetry for vitamin K3 (menadione) [120]. 

Electrochemical oxidation of natural and synthetic DNA performed at pyrolytic graphite [16] and glassy carbon [3-6,17,18] electrodes showed that at pH 4.5 only the oxidation of the purine residues in polynucleotide chains is observed. Using differential pulse voltammetry, the less positive peak corresponds to the oxidation of guanine residues and the peak at more positive potentials is due to the oxidation of adenine residues. 

Cai et al. [28] have synthesised AuNPs-labelled ssDNA as a probe to be hybridised with their complementary strand on chitosan-modified glassy carbon electrode (GCE). In their experiments, SH-ssDNA was self-assembled onto an AuNP (16 nm in diameter) (details given previously in Ref. [54]). After hybridisation, the AuNPs tags were detected by differential pulse voltammetry (DPV). The detection limit was 1.0 x 10-9 mol L 1 of 32-base synthesised complementary oligonucleotide. 

Differential pulse voltammetry at rotated glassy carbon disk cathodes proved successful for the accurate determination of inor-... 

Ballantine, J. Woolfson, A.D. The application of differential pulse voltammetry at the glassy carbon electrode to multivitamin analysis. J. Pharm. Pharmacol. 1980, 32, 353-356. 

Downard el al. [9] have reported the application of a phenylacetate layer to glassy carbon macroelectrodes. Their study determined dopamine levels in the presence of ascorbic acid. Differential pulse voltammetry of dopamine and ascorbic acid at both modified and unmodified electrodes showed almost a six-fold enhancement of dopamine anodic peaks at the modified electrodes. For ascorbic acid, while the magnitude of its anodic current remained similar at modified electrodes, the peaks were no longer as well-resolved as for unmodified electrodes. 

A signal amplification was obtained by forming a network of thio-cyanuric acid/Au-NPs. The electrochemical oxidation of Au-NPs was performed at -1-1.25 V for 120 s on a glassy carbon electrode. Immediately after the electrochemical oxidation, differential pulse voltammetry was performed resulting in an anal3ftical signal due to the reduction of AuCl , which relates to the amount of the Au-NPs for the sandwich format. 

AuE gold electrode CCPE chitosan-entrapped carbon paste electrode CV cyclic voltammetry 3D-CPNE three-dimensional conducting polymer nanorods electrodes DPASV differential pulse anodic stripping voltammetry DPV differential pulse voltammetry GCE glassy carbon electrode SPE screen-printed electrode SWV square wave voltammetry. 

Also, intercalated adriamycin has been used as hybridization label in a genosensor built by modifying a glassy carbon electrode (GCE) with multiwalled carbon nanotubes with carboxyl groups and Au-NPs [23], Differential pulse voltammetry (DPV) was utilized to monitor the DNA hybridization event. Under the optimal conditions, the increase of reduction peak current of adriamycin was linear with the logarithm of the concentration of the complementary oligonucleotides from 1.0 x 10 to 5.0 x 10 M with a detection limit of 3.5 x 10 M. 

AuE gold electrode DPV differential pulse voltammetry EIS electrochemical impedance spectroscopy GCE glassy carbon electrode (Ru(NH3)sL pentaamin ruthenium [3-(2-phenanthren-9-yl-vinyl)-pyridine] complex. 

DPV = differential pulse voltammetry at glassy carbon electrode ... 

Fig. 4. Polarographic analysis of Delta-Butazolidin (the drug contains two active components). Butazolidin 50 mg (by anodic differential-pulse voltammetry at a glassy-carbon electrode 51.4 mg found per 1 coated table). Prednisone 1.25 mg (by differential-pulse polarography at a DME) 1,18 mg found per 1 coated tablet).

RP-HPLC, reversed-phase HPLC ID-PCBr, Indirect detection of post-miumn electrogenerated bromine RS-DPV, Rapid scanning differential pulse voltammetry CCE, glassy carbon working electrode SPE, Screen printed electrode DME,... 

Differential-pulse polarography was reported to evaluate the content of THBQ in edible oils (Tonmanee and Archer, 1982 Cortes et al., 1993). Differential-pulse voltammetry using a carbon paste electrode modified with nickel phthalocyanine was applied to determine BHA in potato flakes (Ruiz et al., 1995). Square-wave voltam-metric methods employing carbon-disk ultramicroelectrodes (UME) (Ceballos and Fernandez, 2000), glassy carbon electrodes (Raymundo et al., 2007), platinum electrodes... 

Note NiP-CPE carbon paste electrode modified with Ni-phthalocyanine C-UME carbon ultramicroelectrode GCE glassy carbon electrode BDDE boron-doped diamond electrode DPP differential-pulse polarography DPV differential-pulse voltammetry LSV linear-sweep voltammetry and SWV square-wave voltammetry. 

The resulting hybrid material was deposited on activated glassy carbon electrode and exhibited good electrocatalytic activity toward dopamine oxidation with no interference of ascorbic acid, as can be observed by the differential pulse voltammetry (DPV) results shown in Fig. 6b. Besides dopamine, epinephrine (EP) was another neurotransmitter smdied by the same group using aparafihn/MWCNTs/CoPc composite electrode [50]. It was possible to carry out electroanal5 tical determinations of EP in urine samples without any purification step. 

Figure 12.27 (a) Current response of methyl differential pulse voltammetry of four nitro-parathion, parathion, a-hydroxyM-nitrophenyl phenol analogues, measured with the dimethyl phosphonate, p-nitrophenol, and imprinted (black bars) and non-imprinted nitrobenzene at the imprinted (A) and non- (gray bars) hybrid film modified glassy carbon imprinted (B) film electrode. (Reproduced with electrodes. (Reproduced with permission from permission from Ref. [84].) (b) Peak current in Ref. [70].)... 

There are only two published papers dealing with the determination of hair dyes by means of electrochemical techniques. Differential-pulse voltammetry (DPV) using carbon paste electrode (Wang and Chen, 1998) or square wave voltammetry (SWV) using glassy carbon electrode (Lawrence et al, 2001), have been used to determine different hair dyes successfully. 

Trace metal analysis of mM concentrations of lead, copper, and cadmium using differential pulse voltammetry at a BDD electrode in a solution containing intentionally added Hg2+[4-5]. Here, the latter deposits onto the diamond surface as a film. Mercury films are typically coated on electrode surfaces such as glassy carbon or iridium to improve the response [6, 7]. In the conventional... 

Fig. 16.10. Differential pulse voltammetry curves for Hg(N03)2 solution (6.4 xlO M) in 0.1 M KNO3 (pH = 1) electrolyte for a) diamond and b) glassy carbon electrodes. Deposition time was 2 minutes at -0.5 V vs. SCE. pulse amphtude, 50 mV, sweep rate, 100 mV s l.

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