Characteristics of Voltammetric Determination and Speciation of Chromium – A Review

Abstract

This article reviews the voltammetric methods of chromium determination, including adsorptive and catalytic adsorptive stripping voltammetry at liquid mercury, metallic films, and modified carbon paste electrodes. The principle applications of the catalytic adsorptive stripping voltammetric method of chromium(VI) determination in the presence of DTPA and nitrate, most useful in the analysis of chromium traces and its speciation, is presented in detail. Special emphasis is put on the presentation and characterization of the voltammetric procedures which make it possible to conduction speciation studies of chromium(VI) in the presence of a great excess of chromium(III) and surfactants. This survey is based on 173 articles.

Chromium–protein complexation studies by adsorptive cathodic stripping voltammetry and MALDI-TOF–MS

“…This has also been previously observed for glycine [6]. This catalytic effect is known for nitrate which therefore is a component of the supporting electrolyte with the function to enhance the signal by oxidizing Cr(II)-DTPA back to Cr(III)-DTPA [41].…”

“…Standard analysis (described in [39] and developed in [40]) was performed with a pre-purging (argon) time of 300 s at the HMDE, followed by deposition (60 s, at -1.0 V) in the differential pulse mode (pulse amplitude 50 mV), starting and ending at -1.0 and -1.45 V, respectively, (sweep rate 33.3 mV s -1 ) and an equilibrium time after each addition of Cr(VI) of 300 s. Chromium determination using DTPA and nitrate is well established and reviewed in [41]. The equilibrium time period after addition of Cr(VI) to the protein solution may be important for complexation as metal-protein complexation is time dependent [42].…”

“…No significant complexation was observed either with Cr(VI) or with Cr(III) [linearly increasing signal with addition of Cr(III) (R 2 = 0.993) and for Cr(VI) (R 2 = 0.995)] at a protein concentration of 0.6 nM (0.004 g L -1 ) (data not shown). The measurements were performed with a significantly shorter equilibrium time after the addition of Cr(III), only 5 s compared with 300 s [for Cr(VI)], due to a decreasing signal of Cr(III) with time [41]. Even though these findings imply similar results independent of chromium speciation in the case of BSM, the situation may be different for LYS, HSA, and/or BSA (not investigated in this study) as suggested by Tkaczyk et al for BSA [3].…”

Sequential voltammetric determination of chromium, thallium, cadmium, lead, copper and antimony in saline hemodialysis concentrates using electrolyte pH gradient

“…19 Among the chromium species, DTPA builds the most stable complex (pK stb 15.3) with Cr(III). 20 Considering the complexing agents used in AdCSV for chromium determination, 21 DTPA presents good performance for the sequential method. This is because it starts to be desorbed from the HMDE surface at a potential around -800 mV by changing the pH of the supporting electrolyte.…”

Simultaneous Determination of Cr(III) and Cr(VI) by Differential Pulse Voltammetry Using Modified Screen‐Printed Carbon Electrodes in Array Mode

“…Many instrumental techniques have been used for the determination of the total content of chromium, such as ultraviolet-visible spectrophotometry [7], electrothermal atomic absorption spectrometry (ETAAS), flame atomic absorption spectrometry (FAAS) [3,7,8] inductively coupled plasma-mass spectrometry (ICP-MS) [9], inductively coupled plasma optical emission spectrometry (ICP-OES) [7] and electrochemical techniques including anodic stripping voltammetry (ASV) [10,11], differential pulse adsorptive stripping voltammetry (DPAdSV) [12] and catalytic adsorptive stripping voltammetry (CAdSV) [13][14][15]. These methods involve the determination of chromium after tedious separation steps.…”