Determination of subnanomolar concentrations of cobalt by adsorptive stripping voltammetry at a bismuth film electrode

Abstract

Procedures for trace cobalt determinations by adsorptive stripping voltammetry at in situ and ex situ plated bismuth film electrodes are presented. These exploit the enhancement of the cobalt peak obtained by using the Co(II)-dimethylglyoxime-cetyltrimethylammonium bromide-piperazine-N,N'-bis(2-ethanesulfonic acid) system. The calibration graph for an accumulation time of 120 s was linear from 2 x 10(-10) to 2 x 10(-8) mol L(-1). The relative standard deviation from five determinations of cobalt at a concentration of 5 x 10(-9) mol L(-1) was 5.2%. The detection limit for an accumulation time of 300 s was 1.8 x 10(-11) mol L(-1). The proposed procedure was applied to cobalt determination in certified reference materials and in tap and river water samples.

Pyrolyzed Photoresist Carbon Electrodes for Trace Electroanalysis of Nickel(II)

“…This value is comparable to the one obtained with bulk gold substrate and lower with respect to other electroanalytical methods reported in the literature [29][30][31][32][33][34]. It is well known that DMG complexes other metal cations, such as Co(II) [37,40]; for this reason, cobalt is usually considered an interference in the determination of nickel. In order to verify the possible interference of Co(II), the above described analytical procedure was applied for analyzing Ni(II) in the presence of Co(II).…”

“…Briefly, the PPCE was dipped into a 0.1-mol•L −1 ammonium buffer solution containing 10 mg•L −1 Bi(III) in the form of its complex with tartrate and 1 × 10 −5 mol•L −1 dimethylglyoxime (DMG) as the complexing agent. Tartrate was selected in order to avoid the precipitation of bismuth at the pH value necessary for Ni(II) and Co(II) determination [37].…”

Simultaneous Adsorptive Cathodic Stripping Voltammetric Determination of Nickel(II) and Cobalt(II) at an In Situ Bismuth‐Modified Gold Electrode

“…Tartrate was selected in order to avoid the precipitation of bismuth at the pH value necessary for Ni(II) and Co(II) determination [32]. A twostep accumulation protocol, i.e.…”

“…Recently, M. Korolczuk et al [31,32], and Sopha et al [33] proposed the use of in situ prepared BiFE and antimony film electrode (SbFE) for measuring solely nickel ions. The only example of simultaneous determination of nickel and cobalt was reported by Korolczuk et al using an in situ prepared lead film electrode (PbFE) [34], but lead is also a toxic element.…”

Fabrication of Bismuth/Multi‐walled Carbon Nanotube Composite Modified Glassy Carbon Electrode for Determination of Cobalt

“…7 These electrodes have been applied to determination of many heavy metals such as cadmium, 8 lead, 8 tin, 9 nickel 3,4 and cobalt. 3,4,10,11 Carbon nanotubes (CNT) have attracted much attention in electroanalysis due to the unique mechanical, electronic, geometrical and chemical properties. [12][13][14] In recently years, it has been found that combining metal particles, such as platinum, 15 nickel, 16 copper 17 and palladium, 18 with CNT-modified electrodes can provide a promising way for fabrication of novel electrodes with largely improved performances.…”