Determination of Trace Chromium by Square-Wave Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode

Abstract

A square-wave adsorptive cathodic stripping voltammetric protocol coupled with an improved bismuth film electrode (BiFE) for the determination of trace chromium in the presence of 4-(2-pyridylazo) redorcinol (PAR) has been investigated. A well-defined and sensitive stripping peak of the Cr(III)-PAR complex was observed at −0.57 V (versus SCE) in a 0.1 mol/L acetate buffer solution (pH 5.0) at a deposition potential of −0.45 V. The experimental variables as well as potential interferences were studied. Compared with the BiFE plated in the solution prepared based on HAc-NaAc without trisodium citrate, the improved BiFE electrodeposited in the solution of HAc-NaAc prepared based on containing trisodium citrate displayed a better electroanalytical performance for the determination of chromium(III). Under the optimized conditions, the limit of detection for chromium was 2.0 × 10−10 mol/L and the relative standard deviation was 4.35% at the 1.0 × 10−8 mol/L level (n = 7). This method was applied to determine the trace amount of chromium in several environmental samples.

Square‐Wave Voltammetry: A Review on the Recent Progress

“…In the recent years, the SW voltammetry has emerged as a viable and cheap alternative to the expensive and time-consuming techniques (such as chromatography, or spectrophotometry, for example) for the determination of inorganic and biologically important compounds. The simple working set-up, the quick time of performing the measurements, the different modes that can be applied, together with its sensitivity, make the SWV a technique of choice for quantification of important classes of compounds such as proteins [82], vitamins [83], phenols [84][85][86][87][88], benzoquinones [89], pesticides, herbicides and fungicides [90][91][92][93][94][95][96][97][98], alkaloids [99], terpenoids [100], heavy metals [101][102][103][104][105][106][107][108][109][110][111][112][113][114][115][116], and drugs [117,118]. One of the most valuable ability of SWV is its application for simultaneous determination of compounds with similar structures present in various pharmaceutical and physiological samples.…”

Disposable plastic electrode for electrochemical determination of total chromium and hexavalent chromium

“…Determination of total Cr was carried out according to a modification of our previous work [34] by replacing a bismuth film electrode with the Au-PET electrode.…”

Determination of Total Germanium in Chinese Herbal Remedies by Square-Wave Catalytic Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode

“…And it was obvious that the BiFE (d) electrodeposited in HAc-NaAc medium containing sodium citrate also showed a better electroanalytical performance for determination of Ge(IV) than the BiFE (c). According to Zhang et al [25] and Nunes and Faria [26], the significant improvement was due to the addition of trisodium citrate that helped form a homogeneous structure by aggregates of spherical particles with a few nanometers in diameter. We also investigated the effect of KBrO 3 on the electrochemical behavior of germanium(IV)-pyrogallol complex at the improved bismuth film electrode.…”

“…However, there is no report about the determination of germanium in Chinese herbal remedies by using BiFEs so far. And our group found that the analytical performance of bismuth film electrode was significantly improved by adding citrate to a relatively higher pH electrodeposition solution [25].…”