Ultrasensitive hexavalent chromium determination at bismuth film electrode prepared with mediator.

Title Ultrasensitive hexavalent chromium determination at bismuth film electrode prepared with mediator.
Authors K. Tyszczuk-Rotko; K. Madejska; K. Doma?ska
Journal Talanta
DOI 10.1016/j.talanta.2018.01.053
Abstract

A bismuth film electrode prepared in situ with a reversibly deposited mediator (Zn) applied for ultrasensitive determination of Cr(VI) using differential pulse catalytic adsorptive stripping voltammetry is presented. The optimization of experimental conditions such as composition of the supporting electrolyte, potential and time of bismuth film formation as well as analyte accumulation, and DP mode parameters is reported. For 180?s accumulation time, very low limits of detection and quantification of Cr(VI) were obtained, with 5.8 × 10and 1.9 × 10mol?L, respectively. The relative standard deviation for 5.0 × 10mol?Lof Cr(VI) was 3.9% (n = 5). Finally, the proposed procedure was applied to determine Cr(VI) in the certified reference materials - NASS-6 (seawater), SLEW-3 (estuarine water) and TMRAIN-04 (rainwater) - as well as in river water samples. Furthermore, the obtained results show that the proposed voltammetric procedure employing the bismuth film electrode prepared with mediator appears to form a very promising tool for the speciation of chromium at ultratrace level.

Citation K. Tyszczuk-Rotko; K. Madejska; K. Doma?ska.Ultrasensitive hexavalent chromium determination at bismuth film electrode prepared with mediator.. Talanta. 2018;182:6268. doi:10.1016/j.talanta.2018.01.053

Related Elements

Bismuth

See more Bismuth products. Bismuth (atomic symbol: Bi, atomic number: 83) is a Block P, Group 15, Period 6 element with an atomic radius of 208.98040. The number of electrons in each of Bismuth's shells is 2, 8, 18, 32, 18, 5 and its electron configuration is [Xe] 4f14 5d10 6s2 6p3. Bismuth Bohr ModelThe bismuth atom has a radius of 156 pm and a Van der Waals radius of 207 pm. In its elemental form, bismuth is a silvery white brittle metal. Bismuth is the most diamagnetic of all metals and, with the exception of mercury, its thermal conductivity is lower than any other metal. Elemental BismuthBismuth has a high electrical resistance, and has the highest Hall Effect of any metal (i.e., greatest increase in electrical resistance when placed in a magnetic field). Bismuth is found in bismuthinite and bismite. It is also produced as a byproduct of lead, copper, tin, molybdenum and tungsten extraction. Bismuth was first discovered by Early Man. The name Bismuth originates from the German word 'wissmuth,' meaning white mass.

Chromium

See more Chromium products. Chromium (atomic symbol: Cr, atomic number: 24) is a Block D, Group 6, Period 4 element with an atomic weight of 51.9961. Chromium Bohr ModelThe number of electrons in each of Chromium's shells is 2, 8, 13, 1 and its electron configuration is [Ar] 3d5 4s1. Louis Nicolas Vauquelin first discovered chromium in 1797 and first isolated it the following year. The chromium atom has a radius of 128 pm and a Van der Waals radius of 189 pm. In its elemental form, chromium has a lustrous steel-gray appearance. Elemental ChromiumChromium is the hardest metallic element in the periodic table and the only element that exhibits antiferromagnetic ordering at room temperature, above which it transforms into a paramagnetic solid. The most common source of chromium is chromite ore (FeCr2O4). Due to its various colorful compounds, Chromium was named after the Greek word 'chroma.' meaning color.