Article

Determination of iron in water samples by adsorptive stripping voltammetry with a bismuth film electrode in the presence of 1-(2-piridylazo)-2-naphthol

Departamento de Química Analítica, Facultad de Química, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
Talanta (Impact Factor: 3.51). 06/2008; 75(4):973-7. DOI: 10.1016/j.talanta.2007.12.038
Source: PubMed

ABSTRACT An adsorptive stripping voltammetry method for the determination of iron has been developed. The procedure is based on the adsorptive collection of a complex of iron with 1-(2-piridylazo)-2-naphthol (PAN) on a bismuth-coated glassy carbon electrode (BiFE). Factors affecting the stripping performance, such as pH, PAN concentration (C(PAN)), potential, accumulation time (E(ads), t(ads)), and interference by other ions were also studied. The optimum conditions were obtained in a 0.1 mol L(-1) acetate buffer at pH 4.0, C(PAN) 5.0 micromol L(-1), t(ads) 60 s, E(ads) -400 mV, pulse height 4.0 mV, pulse amplitude 25 mV, and frequency 15 Hz. The detection limit was found to be 0.1 microg L(-1) when a t(ads) of 60 s was used, and the linear range was from 0.4 to 60.0 microg L(-1). The proposed procedure was validated by determining of Fe(III) in CRM-MFD, QCS-19 and CRM-SW certified reference materials and applied in seawater samples with satisfactory results.

Download full-text

Full-text

Available from: Rodrigo Segura, Dec 19, 2013
1 Follower
 · 
184 Views
  • Source
    • "In order to solve these problems, great efforts have been taken to develop mercury-free solid electrodes. For example, solid-state gold-amalgamation [14], ion-selective membranes [15], ionomercoatings [16] [17] [18] [19], carbon paste [20], glassy carbon [21] electrodes and gold microelectrode ensembles [22] as new solid electrodes have been developed for iron determination. However, the continuous improvements of functional electrodes are still urgently required for achieving simple, rapid and sensitive detection of trace iron, especially in coastal waters. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We establish a novel nanoparticle/ion-exchange polymer-based sensor for selective and sensitive detection of trace iron (Fe3+) in coastal waters. Titanium carbide nanoparticles (nano-TiC) are used as a typical nanomaterial with promising physical and chemical properties to accelerate the electron transfer. Nafion is chosen as the widely used cation-exchange polymer to facilitate the preconcentration of Fe3+. Taking advantage of synergistic effects of nano-TiC and Nafion as well as the catalytic amplifying effect of hydrogen peroxide (H2O2), the excellent cathodic signal responses for the stripping determination of Fe3+ which is linear in the range of 0.07–70 μM with a detection limit of 7.2 nM can be obtained. This analytical method can be used to effectively and simply detect Fe3+ without using any complexing agents. The fabricated sensor has been successfully applied for the sensitive determination of Fe3+ in real coastal waters.
    Sensors and Actuators B Chemical 11/2015; 219. DOI:10.1016/j.snb.2015.05.034 · 4.29 Impact Factor
  • Source
    • "The pH of solution has a significant influence on the stability of complex.The pH and type of supporting electrolyte affect the complex formation parameters and stability of a complex (Segura et al, 2008 "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, a novel voltammetric method has been developed to determine the amount of boron in soil. 50 soil samples were collected from 5 typical sites of agricultural area. After hot water extraction of available boron in the soil samples, all boron is complexed by addition of Alizarin Red S (ARS) to the extraction solutions.Differential pulse anodic stripping voltammetry was used to determine the amount of the boron complexes. The electrochemical parameters have been optimized according to the experimental results. The optimum scan rate, stirring rate, deposition potential, deposition time and pH values were determined as 5 mVs-1 , 200 rpm, -0.5 V (vs. Ag/AgCl, sat.), 15sec. and 7.5, respectively. An oxidation peak was occurred at the peak potential of -0.45 V for Boron-Alizarin complex. The limit of detection, limit of quantification and linear working range were determined for the voltammetric soil-boron analysis. In addition, the interference effects of coexisting ions were successfully investigated. Comparison of the analytical data for analyzing real samples was carried out between the differential pulse anodic stripping voltammetric method and the Azometine H spectrophotometric method have shown good agreement. A great advantage of voltammetry over the spectrophotometric method is found to be simplicity, selectivity and shortening of the analysis time.
    08/2014; 3(3):182-188. DOI:10.18393/ejss.98434
  • Source
    • "In order to overcome these difficulties and to increase sensitivity, separation and/or preconcentration is an important and frequently applied tool [7]. There is a wide variety of possible instrumental methods, spectrophotometry [8] [9] [10], chemiluminescence [11], HPLC [12], adsorptive stripping voltammetry [13], fluorescence [14], inductively coupled mass spectrometry (ICP-MS) [15] and atomic absorption spectrometry (AAS) [16] for detection of iron. However when trace levels of the analyte is concerned, the applicable detection methods are reduced. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A method integrating a long waveguide capillary cell with a preconcentration resin in a multi-syringe flow injection analysis (MSFIA) system for iron determination in waters was developed. The determination of iron is based on a colorimetric reaction and two reagents were tested, ferrozine and ammonium thiocyanate. A liquid waveguide capillary cell (1.0 m pathlength, 550 µm i.d. and 250 µL internal volume) with a preconcentration resin were used to improve the sensitivity of the determination. Two different preconcentration resins were also tested, Chelex 100 and NTA Superflow. The developed method employing the NTA Superflow with ferrozine colorimetric reagent provided a detection limit of 0.05 µg L− 1 with a linear response up to 8 µg L− 1 and a sample throughput rate of 12 per hour. The developed system presents low reagents/sample consumptions. The accuracy was assessed using a certified reference water sample.
    Microchemical Journal 11/2009; 93(2-93):153-158. DOI:10.1016/j.microc.2009.06.003 · 3.58 Impact Factor
Show more