A sensitive method is described for the on-line determination and preconcentration of nickel using the coupling of a flow system (continuous flow and flow injection) with transversely heated electrothermal atomic absorption spectrometry. The method is based on the volatilization of nickel as nickel tetracarbonyl and its trapping on a graphite surface. The carbonyl generation is optimized by usi...

An electrothermal atomic absorption spectrometric procedure for the determination of nickel in active pharmaceutical ingredients was developed. Since the recoveries of nickel by the direct dissolution of samples in diluted nitric acid were low and caused errors in the determination of Ni in pharmaceutical samples, different approaches for sample pre-treatment were examined. It was found that th...

A method for the determination of nickel(II) by stripping voltammetry is described. The method is based on the adsorptive accumulation of nickel(II) calconcarboxylic acid complex onto a hanging mercury drop electrode (HMDE), followed by the reduction of the adsorbed complex using differential pulse voltammetry. The optimum operating conditions and parameters were found to be 0.05 M NH3/NH4Cl bu...

This study describes the application of an empirical method to estimate the energy consumption in laboratory of the primary grinding of nickel ore with a specific mineralogical texture. This method developed by Donda was previously used in iron ore from the Iron Quadrangle (Minas Gerais, Brasil) with the same purpose. Through the grinding test, performed under standard conditions and based on t...

A novel analytical reagent, 4-(2-hydroxyphenylethamino)benzene-1,3-diol was synthesized for determination of nickel(II) in biological samples and plant materials by extractive differential pulse polarography. The analysis of nickel(II) was carried out by extracting the nickel(II)-(4-(2-hydroxyphenylethamino)benzene-1,3-diol) complex from chloroform prior to injecting into the instrument. The el...

in this work, a selective method for separation and preconcentration of nickel ions at trace level on modified multiwalled carbon nanotubes columns and determination by flame atomic absorption spectrometry (faas) has been developed. multiwalled carbon nanotubes were oxidized with concentrated hno3 and then modified with loading 1-(2-pyridylazo)-2-naphtol. the sorption of ni(ii) ions was quantit...

Numerous apex locator studies have been performed. Generally, they use only stainless-steel hand files for testing purposes. Today many clinicians use both stainless-steel and nickel-titanium files during the treatment of a case. Given the widespread use of nickel-titanium files, a comparison of the accuracy in determining length with an apex locator using stainless-steel and nickel-titanium fi...

Two rapid and simple methods have been developed for determining the approximate cooling rates of iron and stony-iron meteorites in which kamacite formed by diffusion-controlled growth along planar fronts. The first method requires only measurements of the mean kamacite bandwidth and the bulk nickel content. The second method requires the determination of the nickel composition near the taenite...

In the present paper, a solid phase extraction system for separation and preconcentration of nickel (ng g(-1)) in saline matrices is proposed. It is based on the adsorption of nickel(II) ions onto an Amberlite XAD-2 resin loaded with 1-(2-pyridylazo)-2-naphthol (PAN) reagent. Parameters such as the pH effect on the nickel extraction, the effect of flow rate and sample volume on the extraction, ...