Catalytic adsorptive stripping voltammetry versus electrothermal atomic absorption spectrometry in the determination of trace cobalt and chromium in human urine

Diagnostic assay of chromium (VI) in the ex vivo fluid of the urine of a smoker using a fluorine‐doped handmade sensor

“…The optimum conditions of pH 4.0 electrolyte solution, À1.0 V accumulation potential, 4 mV incremental potential, 35 mV amplitude, 15 Hz frequency, and 240 sec deposition time and a fast experiment time were obtained. Moreover, the developed sensor approached the DL of 0.008 mg L À1 , which is lower than that of the common spectrophotometric (12)(13)(14)(15) and voltammetric methods (19,20,22,26). Thus, developed method can be used for any in vivo or in vitro diagnostic application.…”

“…Concentrated in vivo chromium absorptions are associated with various diseases, such as fibroproliferative disease, airway hypersensitivity (5,6), lung cancer (7)(8)(9), nasal cancer, and various other types of cancer (10). Recently, various low analytical detection methods have been considered, such as electrothermal atomic absorption spectrometry (detection limit, DL, 0.13 mg L À1 ) (11,12), atomic absorption spectrometry (DL, 0.81 mL À1 ) (13), inductively coupled plasma mass spectrometry [DL, 8.30 pg mL À1 (Cr(VI)] (14), and flame atomic absorption spectrometry (DL, around 0.18 mg L À1 ) (15). Some of these techniques approached sensitive analytical DLs but had high DLs, owing to which they are unusable for in vivo diagnosis.…”

“…Moreover, these instruments are complicated, time-consuming, and expensive. Recently, simpler and lower-cost voltammetric analytical methods have been developed, such as those using the bismuthcoated glassy-carbon electrode [DL, 0.3 nM Cr(VI) and after a 2-min accumulation time] (16), the carbon paste modified electrode (DL, about 5.0 Â 10 À8 M) (17), the refreshable mercury film silver-based electrode (DL, 0.19 nM) (18), and the stannum film electrode (DL, 2.0 mg L À1 ) (19), as well as ion transfer voltammetry [DL, 4.8 mM of Cr(VI) or 0.25 ppm] (20); humic acid voltammetry (DL, 3 Â 10 À11 mol À1 ) (21); catalytic adsorptive stripping voltammetry (DL, 0.18 mg L À1 for Cr) (22); catalytic cathodic stripping voltammetry (DL, 0.1 nM) (23); and the pyridine-functionalized sol-gel film method (DL, 4.6 ppb) (24). Such methods have high DLs, however, and thus, cannot be used in in vivo direct assay.…”

Hybrid signal processing in voltammetric determination of chromium(VI)

“…The last progresses in catalytic systems of chromium applied in adsorptive stripping voltammetry were presented in Refs. [22,25,26,28,[30][31][32][33][34][35][39][40][41]. In this work determination of Cr(VI) will be done in the presence of DTPA and nitrate on the silver-amalgam electrode with a refreshable surface [28].…”

A Gold Electrode Modified with Self-Assembled Diethylene- triaminepentaacetic Acid via Charge-based Discrimination

“…The complexation characteristics of DTPA are well-known and it has been investigated extensively from various points of view, such as detection of Cr. 25 However, to the best of our knowledge, there is no report concerning the utilization of its negatively electrostatic interaction to provide a degree of charge-based discrimination for DA over anions.…”