scholarly journals Analytical application of the reaction system disulphonated hydroquinone-hydrogen peroxide for the kinetic spectrophotometric determination of iron traces in acidic media

2019 ◽  
Vol 73 (6) ◽  
pp. 387-396
Author(s):  
Snezana Tosic ◽  
Snezana Mitic ◽  
Aleksandra Pavlovic ◽  
Emilija Pecev-Marinkovic ◽  
Danijela Kostic ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Limit Of Detection ◽  
Reaction System ◽  
Absorption Spectrometry ◽  
Acidic Media ◽  
Experimental Conditions ◽  
Method Effects ◽  
Kinetic Spectrophotometric ◽  
White Radish

A simple, rapid, sensitive and selective kinetic spectrophotometric method for determination of Fe(III) traces was elaborated in this paper. It is based on the catalytic effect of Fe(III) ions on oxidation of potassium salt of disulphonated hydroquinone (K2S2Hy) by hydrogen peroxide in acidic media, at a constant ionic strength. At the working temperature of 20?C and the wavelength of 450.0 nm, optimal conditions for determination of iron were found so that iron (III) can be determined by the proposed method in the concentration range of 1.87 to 18.7 ng cm-3. Corresponding RSD values were determined to be in the range 4.22 to 10.33 %. The limit of detection (LOD) calculated in two ways was found to be 1.07 ng cm-3 i.e. 1.11 ng cm-3 Fe(III). In order to assess the selectivity of the method effects of different ions on the reaction rate were also determined. It was found that presence of oxalates and citrates in the w/w ratio to Fe(III) 1:1 under selected experimental conditions interferes with determination of iron. Then the method was applied for determination of Fe(III) traces in white radish juice. The results agreed well with those obtained by atomic absorption spectrometry.

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.

scholarly journals Kinetic spectrophotometric determination of Bi(III) based on its catalytic effect on the oxidation of phenylfluorone by hydrogen peroxide

2009 ◽  
Vol 74 (8-9) ◽  
pp. 977-984
Author(s):  
Sofija Rancic ◽  
Snezana Nikolic-Mandic
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Determination ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Kinetic Method ◽  
Limit Of Quantification ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A new reaction was suggested and a new kinetic method was elaborated for determination of Bi(III) in solution, based on its catalytic effect on the oxidation of phenyl-fluorone (PF) by hydrogen peroxide in ammonia buffer. By application of spectrophotometric technique, a limit of quantification (LQ) of 128 ng cm-3 was reached, and the limit of detection (LD) of 37 ng cm-3 was obtained, where LQ was defined as the ratio signal: noise = 10:1 and LD was defined as signal 3:1 against the blank. The RSD value was found to be in the range 2.8-4.8 % for the investigated concentration range of Bi(III). The influence of some ions upon the reaction rate was tested. The method was confirmed by determining Bi(III) in a stomach ulcer drug ('Bicit HP', Hemofarm A.D.). The obtained results were compared to those obtained by AAS and good agreement of results was obtained.

scholarly journals A New Technique for Quantitative Determination of Dexamethasone in Pharmaceutical and Biological Samples Using Kinetic Spectrophotometric Method

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ali Mohammad Akhoundi-Khalafi ◽  
Masoud Reza Shishehbore
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Method ◽  
Biological Samples ◽  
Reaction System ◽  
Calibration Graph ◽  
Experimental Conditions ◽  
Orange G ◽  
A New Technique ◽  
Kinetic Spectrophotometric

Dexamethasone is a type of steroidal medications that is prescribed in many cases. In this study, a new reaction system using kinetic spectrophotometric method for quantitative determination of dexamethasone is proposed. The method is based on the catalytic effect of dexamethasone on the oxidation of Orange G by bromate in acidic media. The change in absorbance as a criterion of the oxidation reaction progress was followed spectrophotometrically. To obtain the maximum sensitivity, the effective reaction variables were optimized. Under optimized experimental conditions, calibration graph was linear over the range 0.2–54.0 mg L−1. The calculated detection limit (3sb/m) was 0.14 mg L−1for six replicate determinations of blank signal. The interfering effect of various species was also investigated. The present method was successfully applied for the determination of dexamethasone in pharmaceutical and biological samples satisfactorily.

Kinetic Spectrophotometric Determination of Selenium (IV) by its Catalytic Effect on the Oxidation of Acid Chrome Blue K by Hydrogen Peroxide

2012 ◽  
Vol 538-541 ◽  
pp. 2358-2363 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Acid Chrome Blue K ◽  
Good Agreement

Based on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid solution, while 1,10-phenanthroline (phen) acts as an activator, a simple kinetic spectrophotometric method was developed for the determination of trace amounts of Se(IV).The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of ACBK at 524 nm with a fixed-time method. The decrease in the absorbance of ACBK is proportional to the concentration of Se (IV) in the range 0.06–1.0 µg/L with a fixed time of 4–10 min from the initiation of the reaction. The limit of detection is 0.018 µg/L Se (IV). The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 62.30 kJ/mol. The relative standard deviation for 11 replicate determination of 0.01 and 0.02 µg/25mL selenium (III) was calculated to be 2.3 % and 2.0 %, respectively. Combined with sulphydryl dextrane gel (SDG) separation and enriching, the method has been successfully applied to the determination of Se (IV) in foodstuff samples with the relative standard deviation of 1.1 %–3.7 % and the recovery of 99.0 %–104.0 %, the results are in good agreement with those provided by HG-AAS method.

scholarly journals Application of the reaction system methylene blue B-(NH4)2S2O8 for the kinetic spectrophotometric determination of palladium in citric buffer media

2017 ◽  
Vol 71 (2) ◽  
pp. 97-104
Author(s):  
Sofija Rancic ◽  
Snezana Nikolic-Mandic ◽  
Aleksandar Bojic ◽  
Snezana Djoric-Veljkovic ◽  
Aleksandra Zarubica ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Reaction System ◽  
Icp Oes ◽  
Limit Of Quantification ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A new, simple, rapid, sensitive and selective kinetic spectrophotometric method for Pd(II) traces determination was elaborated in this paper. It is based on the catalytic effect of palladium ions upon the oxidation of methylene blue B (MBB) by (NH4)2S2O8 (APS) in citric buffer (BUF) solution. At the working temperature of 25 ?C and the wavelength of 662.4 nm, the optimal conditions for palladium determination were found. RSD value was found to be 2.6 to 4.9% for the investigated concentration range of Pd(II). Limit of detection (LD) was found to be 2.0 ng cm?3 Pd(II), and limit of quantification (LQ) is 6.9 ng cm?3 Pd(II). Only the presence of Pb2+, Hg2+ and Sn2+ in the reaction mixture interferes the determination of palladium by this method, while Au3+ and Ag+ have the catalytic effect upon the reaction rate. By this method, it is possible to determine the Pd(II) traces in the concentration range of 3.3x10?8 to 1.0x10?6 g cm?3. The method was confirmed by determination of Pd(II) traces in alloy PtRhG as well as in the powder of Pt. The obtained results were compared to those obtained by ICP-OES method and good agreement of results was found.

scholarly journals New Methylene Blue Covalently Functionalized Graphene Oxide Nanocomposite as Interfacial Material for the Electroanalysis of Hydrogen Peroxide

2021 ◽  
Vol 9 ◽  
Author(s):  
Jifang Chen ◽  
Ziqing Gao ◽  
Ruonan Yang ◽  
Huiling Jiang ◽  
Lin Bai ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Limit Of Detection ◽  
Crosslinking Agent ◽  
Spectroscopic Techniques ◽  
Experimental Conditions ◽  
Functionalized Graphene Oxide

New methylene blue (NMB), a phenothiazine dye, was covalently bonded to graphene oxide (GO) using glutaraldehyde as a crosslinking agent, which was characterized by spectroscopic techniques and electrochemistry. The obtained GO–NMB nanocomposite was used as interface material to construct a novel electrochemical sensor for the determination of hydrogen peroxide (H2O2). The electrochemical sensor based on GO–NMB nanocomposite exhibited excellent electrocatalytic activity for the reduction of hydrogen peroxide (H2O2), which was also enhanced by GO within the GO–NMB nanocomposite. With the optimized experimental conditions, the developed sensor showed high sensitivity (79.4 μA mM−1 cm−2) for electrocatalytic determination of H2O2 at the applied potential of −0.50 V in the concentration range of 0.000333 to 2.28 mΜ. The low limit of detection (1.35 μM), good reproducibility, and high stability of the sensor suggests that the electrochemical sensor based on the GO–NMB nanocomposite possesses obvious advantages, which paves a new avenue to functionalize GO for obtaining electrode interface materials.

scholarly journals Analytical application of the reaction system phenyl fluorone-hydrogen peroxide for the kinetic determination of cobalt and tin traces by spectrophotometry in ammonia buffer media

2013 ◽  
Vol 67 (6) ◽  
pp. 989-997
Author(s):  
Sofija Rancic ◽  
Snezana Nikolic-Mandic ◽  
Aleksandar Bojic
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction System ◽  
Inhibitory Effect ◽  
New Method ◽  
Kinetic Determination ◽  
Spectrophotometric Methods ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results ◽  
Oxidation By Hydrogen Peroxide

The present paper describes two new, simple, rapid, selective and sensitive kinetic spectrophotometric methods for Co(II) and Sn(II) determination in solution at room temperature, based on their effect on phenyl fluorone (PF) oxidation by hydrogen peroxide in ammonia buffer. The new method was elaborated for nano amounts of Co(II) determination, based on its catalytic effect on the oxidation of PF by H2O2 in the presence of citric acid (CA) as an activator. Also, the new method for micro amounts of Sn(II) determination was developed based on its inhibitory effect upon the same reaction. Comparison of the results showed that the activated catalytic reaction has better sensitivity than the inhibitory one. Methods were validated by the analyze of chemical substances and results were improved by examining the same samples by AAS method.

scholarly journals An Improved Methodology for Determination of Fluorine in Biological Samples Using High-Resolution Molecular Absorption Spectrometry via Gallium Fluorine Formation in a Graphite Furnace

2021 ◽  
Vol 11 (12) ◽  
pp. 5493
Author(s):  
Andrzej Gawor ◽  
Andrii Tupys ◽  
Anna Ruszczyńska ◽  
Ewa Bulska
Keyword(s):  
High Resolution ◽  
Limit Of Detection ◽  
Graphite Furnace ◽  
Absorption Spectrometry ◽  
Biological Tissues ◽  
Biologically Active ◽  
Molecular Absorption ◽  
Biological Origin ◽  
Molecular Absorption Spectrometry

Nowadays growing attention is paid to the control of fluorine content in samples of biological origin as it is present in the form of various biologically active organic compounds. Due to the chemically-rich matrix of biological tissues, the determination of fluorine becomes a very difficult task. Furthermore, a required complex sample preparation procedure makes the determination of the low contents of F by ion chromatography UV-Vis or ion-selective electrodes not possible. High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) seems to be the best option for this purpose due to its high robustness to matrix interferences, especially in the presence of carefully selected modifiers. In this work the possibility of quantitative F determination in water and animal tissues was examined by measuring the molecular absorption of gallium monofluoride (GaF) at 211.248 nm with the use of a commercially available HR-CS GF MAS system. Experimental conditions for the sensitive and precise determination of fluorine were optimized, including the time/temperature program as well as addition of gallium and modifier mixture in combined mode. Under these conditions the fluoride present in the sample was stabilized up to 600 °C, and the optimum vaporization temperature for GaF was 1540 °C. Palladium and zirconium deposited onto the graphite surface served as solid modifiers; sodium acetate and ruthenium modifiers were added directly to the sample. The limit of detection and the characteristic mass of the method were 0.43 μg/L and 8.7 pg, respectively. The proposed procedure was validated by the use of certified reference materials (CRMs) of lake water and animal tissue; the acceptable recovery was obtained, proving that it can be applied for samples with a similar matrix.

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