scholarly journals A Square-Wave Adsorptive Stripping Voltammetric Method for Determination of Fast Green Dye

2009 ◽  
Vol 92 (6) ◽  
pp. 1714-1719
Author(s):  
Ali F Al-Ghamdi
Keyword(s):  
Soft Drink ◽  
Supporting Electrolyte ◽  
Pulse Amplitude ◽  
Fast Green ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Square Wave ◽  
Carbonate Buffer ◽  
Enhanced Sensitivity

Abstract Square-wave adsorptive stripping voltammetric (SW-AdSV) determinations of trace concentrations of the coloring agent fast green were described. The analytical methodology used was based on the adsorptive preconcentration of the dye on the hanging mercury drop electrode, and then a negative sweep was initiated. In pH 10 carbonate supporting electrolyte, fast green gave a well-defined and sensitive SW-AdSV peak at 1220 mV. The electroanalytical determination of this dye was found to be optimized in carbonate buffer (pH 10) with the following experimental conditions: accumulation time (120 s); accumulation potential (0.8 V); scan rate (800 mV/s); pulse amplitude (90 mV); frequency (90 Hz); surface area of the working electrode (0.6 mm2); and the convection rate (2000 rpm). Under these optimized conditions, the AdSV peak current was proportional over the concentration range 2 1086 107 M (r = 0.999), with an LOD of 1.63 1010 M (0.132 ppb). This analytical approach possessed more enhanced sensitivity than conventional chromatography or spectrophotometry, and was simple and quick. The precision of the method in terms of RSD was 0.17, whereas the accuracy was evaluated via the mean recovery of 99.6. Possible interferences by several substances usually present as food additive azo dyes (E110, E102, E123, and E129), natural and artificial sweeteners, and antioxidants were also investigated. Applicability of the developed electroanalysis method was illustrated via the determination of fast green in ice cream and soft drink samples.

scholarly journals A Square-Wave Adsorptive Stripping Voltammetric Method for the Determination of Amaranth, a Food Additive Dye

2005 ◽  
Vol 88 (3) ◽  
pp. 788-793 ◽  
Author(s):  
Ahmad H Alghamdi
Keyword(s):  
Soft Drink ◽  
Supporting Electrolyte ◽  
Pulse Amplitude ◽  
Food Additive ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Square Wave ◽  
Carbonate Buffer ◽  
Relative Standard

Abstract Square-wave adsorptive stripping voltammetric (AdSV) determinations of trace concentrations of the azo coloring agent Amaranth are described. The analytical methodology used was based on the adsorptive preconcentration of the dye on the hanging mercury drop electrode, followed by initiation of a negative sweep. In a pH 10 carbonate supporting electrolyte, Amaranth gave a well-defined and sensitive AdSV peak at −518 mV. The electroanalytical determination of this azo dye was found to be optimal in carbonate buffer (pH 10) under the following experimental conditions: accumulation time, 120 s; accumulation potential, 0.0 V; scan rate, 600 mV/s; pulse amplitude, 90 mV; and frequency, 50 Hz. Under these optimized conditions the AdSV peak current was proportional over the concentration range 1 × 10−8 − 1.1 × 10−7 mol/L (r = 0.999) with a detection limit of 1.7 × 10−9 mol/L (1.03 ppb). This analytical approach possessed enhanced sensitivity, compared with conventional liquid chromatography or spectrophotometry and it was simple and fast. The precision of the method, expressed as the relative standard deviation, was 0.23%, whereas the accuracy, expressed as the mean recovery, was 104%. Possible interferences by several substances usually present as food additive azo dyes (E110, E102), gelatin, natural and artificial sweeteners, preservatives, and antioxidants were also investigated. The developed electroanalyticals method was applied to the determination of Amaranth in soft drink samples, and the results were compared with those obtained by a reference spectrophotometric method. Statistical analysis (paired t-test) of these data showed that the results of the 2 methods compared favorably.

Square-wave adsorptive stripping voltammetric determination of an antihistamine drug astemizole

2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Ahmad Alghamdi
Keyword(s):  
Biological Fluids ◽  
Supporting Electrolyte ◽  
Reduction Process ◽  
High Sensitivity ◽  
Pulse Amplitude ◽  
Analytical Methodology ◽  
Square Wave ◽  
Pharmaceutical Tablets ◽  
Method Accuracy

AbstractThe square-wave voltammetric technique was used to explore the adsorption properties of the astemizole drug. The analytical methodology used was based on the adsorptive preconcentration of the drug on a hanging mercury drop electrode (HMDE), followed by the electrochemical reduction process which yielded a well-defined cathodic peak at −1.184 V (vs. the Ag/AgCl electrode). To achieve high sensitivity, various experimental and instrumental variables were investigated such as the supporting electrolyte, pH, accumulation time and potential, drug concentration, scan rate, SW frequency, pulse amplitude, convection rate, and the working electrode area. Under the optimized conditions, the AdSV peak current was proportional over the analyte concentration range of 5 × 10−7 to 2.5 × 10−6 mol L−1 (r = 0.998) with the detection limit of 1.4 × 10−8 mol L−1 (6.4 ng mL−1). The precision of the proposed method in terms of RSD was 2.4 %, whereas the method accuracy was indicated by the mean recovery of 100.1 %. Possible interferences of several substances usually present in the pharmaceutical tablets and formulations were also evaluated. The applicability of this electroanalytic approach was illustrated by the determination of astemizole in tablets and biological fluids.

Adsorptive Stripping Voltammetric Determination of Aluminium Using Arsenazo III

2001 ◽  
Vol 66 (3) ◽  
pp. 456-464 ◽  
Author(s):  
Alena Komersová ◽  
Martin Bartoš ◽  
Kurt Kalcher ◽  
Karel Vytřas
Keyword(s):  
Supporting Electrolyte ◽  
Pulse Amplitude ◽  
Arsenazo Iii ◽  
Pulse Interval ◽  
Divalent Metal Ions ◽  
Experimental Conditions ◽  
Accumulation Time ◽  
Indirect Determination ◽  
Calibration Dependence

A new analytical method for the indirect determination of trace amounts of aluminium(III) is based on the adsorptive accumulation of an azo dye, Arsenazo III, on the hanging mercury drop electrode. In the presence of Al(III) forming complexes with the dye, its peak occurring at -330 mV decreases. Optimized experimental conditions were found as follows: supporting electrolyte, acetate or chloroacetate-acetate buffer (pH 3.6); accumulation potential, -50 mV vs SCE; accumulation time, 120 s; Arsenazo III concentration, 5 · 10-7 mol l-1; scan rate, 20 mV s-1; initial potential, -500 mV; final potential, 0 mV; FSDPV mode; pulse amplitude, 50 mV; pulse duration, 100 ms; pulse interval, 10 ms. Under these experimental conditions, the calibration dependence was linear in the concentration range 0-6 μmol l-1 with a detection limit of 3.7 · 10-8 mol l-1 (1 ppb, calculated as 3σ for n = 10). Interference of iron(III) can be suppressed by addition of L-ascorbic acid, the effect of numerous divalent metal ions is negligible. Serious interfering effects were observed for U(VI) as UO22+, both Cr(III) and Cr(VI), and F-. The method developed was verified using a certified reference material (SRM 1575 Pine Needles); no statistically significant differences between the determined and declared contents were found.

scholarly journals Square-wave voltammetric determination of drospirenone and ethinylestradiol in pharmaceutical dosage form using square wave technique

2019 ◽  
Vol 10 (4) ◽  
pp. 305-316
Author(s):  
Ibrahim Hassan Habib ◽  
Mohammed Salem Rizk ◽  
Maha Sultan ◽  
Dalia Mohamed ◽  
Rehab Moussa Tony
Keyword(s):  
Supporting Electrolyte ◽  
Reference Method ◽  
Pulse Amplitude ◽  
Voltammetric Determination ◽  
Pharmaceutical Dosage Form ◽  
Square Wave ◽  
Significant Difference ◽  
Scan Rate ◽  
Wave Technique

Cathodic voltammetric behaviors of drospirenone and ethinylestradiol were used for the simultaneous determination of both drugs in bulk and in pharmaceutical formulation (Yasmin® tablets) without the interference of excipients. The determinations were made on hanging mercury dropping electrode using square-wave technique in a voltammetric cell containing 10 mL of 0.04 mole/L Britton-Robinson. After every aliquot addition, the solution was stirred for 10 s at 1000 rpm, rested for 10 s then square wave voltammetry mode was ramped from +100 to -1700 mV with scan rate of 100 mV/s, pulse amplitude of 50 mV and measurement time of 5 ms. Several factors such as pH, type of supporting electrolyte, pulse amplitude and scan rate were studied to optimize the condition for voltammetric determination of these drugs. With optimized experimental parameters, a good linearity was obtained for both drugs over a range of 1.36×10-6 to 1.91×10-7 mole/L and 6.75×10-8 to 6.07×10-7 mol/L of drospirenone and ethinylestradiol, respectively. Characterization of the proposed method was done according to International Conference on Harmonization, Q2B: Validation of Analytical procedures. The proposed method was statistically compared with the reference method and the results revealed no significant difference regarding accuracy and precision.

scholarly journals Determination of Carmine Food Dye (E120) in Foodstuffs by Stripping Voltammetry

2009 ◽  
Vol 92 (5) ◽  
pp. 1454-1459 ◽  
Author(s):  
Ahmad H Alghamdi ◽  
Hamed M Alshammery ◽  
Mohamed A Abdalla ◽  
Ali F Alghamdi
Keyword(s):  
Supporting Electrolyte ◽  
Reduction Process ◽  
Stripping Voltammetry ◽  
Pulse Amplitude ◽  
Acetate Buffer ◽  
Experimental Conditions ◽  
Accumulation Time ◽  
Food Dye ◽  
Voltammetric Technique

Abstract The behavior of the food colorant agent carmine (E120) was studied by square-wave adsorptive stripping voltammetry (SW-AdSV) at the hanging mercury drop electrode. It was observed that carmine gave a sensitive stripping voltammetric peak at 350 mV in pH 3 acetate buffer. The cyclic voltammetric technique was also used to characterize the electrochemical reduction process of carmine. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions, and the optimized values were supporting electrolyte, acetate buffer; buffer acidity, pH 3; dye concentration, 3 107 M; accumulation time, 150 s; accumulation potential, 0.2 V; scan rate, 300 mV/s; pulse amplitude, 185 mV; SW frequency, 20 Hz; working electrode area, 0.6 mm2; and convection rate, 2600 rpm. The SW-AdSV peak currents depended linearly on the concentration of carmine from 5 108 to 1.25 107 mol/L (r 0.99). A detection limit of 1.43 109 mol/L with an RSD of 2.2 and a mean recovery of 97.9 were obtained. Possible interferences by several substances usually present in food products such as food additive dyes (E102, E100, E123, E127, and E129), artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of carmine food dye in spiked commercially available ice cream and soft drinks.

scholarly journals Application of Bar Adsorptive Microextraction for the Determination of Levels of Tricyclic Antidepressants in Urine Samples

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3101
Author(s):  
Mariana N. Oliveira ◽  
Oriana C. Gonçalves ◽  
Samir M. Ahmad ◽  
Jaderson K. Schneider ◽  
Laiza C. Krause ◽  
...  
Keyword(s):  
Tricyclic Antidepressants ◽  
Matrix Effects ◽  
Activated Carbons ◽  
Process Efficiency ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Low Efficiency

This work entailed the development, optimization, validation, and application of a novel analytical approach, using the bar adsorptive microextraction technique (BAμE), for the determination of the six most common tricyclic antidepressants (TCAs; amitriptyline, mianserin, trimipramine, imipramine, mirtazapine and dosulepin) in urine matrices. To achieve this goal, we employed, for the first time, new generation microextraction devices coated with convenient sorbent phases, polymers and novel activated carbons prepared from biomaterial waste, in combination with large-volume-injection gas chromatography-mass spectrometry operating in selected-ion monitoring mode (LVI-GC-MS(SIM)). Preliminary assays on sorbent coatings, showed that the polymeric phases present a much more effective performance, as the tested biosorbents exhibited low efficiency for application in microextraction techniques. By using BAμE coated with C18 polymer, under optimized experimental conditions, the detection limits achieved for the six TCAs ranged from 0.2 to 1.6 μg L−1 and, weighted linear regressions resulted in remarkable linearity (r2 > 0.9960) between 10.0 and 1000.0 μg L−1. The developed analytical methodology (BAμE(C18)/LVI-GC-MS(SIM)) provided suitable matrix effects (90.2–112.9%, RSD ≤ 13.9%), high recovery yields (92.3–111.5%, RSD ≤ 12.3%) and a remarkable overall process efficiency (ranging from 84.9% to 124.3%, RSD ≤ 13.9%). The developed and validated methodology was successfully applied for screening the six TCAs in real urine matrices. The proposed analytical methodology proved to be an eco-user-friendly approach to monitor trace levels of TCAs in complex urine matrices and an outstanding analytical alternative in comparison with other microextraction-based techniques.

Electrochemical Determination of Brilliant Blue and Tartrazine Based on an Ionic Liquid-Modified Expanded Graphite Paste Electrode

2015 ◽  
Vol 98 (3) ◽  
pp. 817-821 ◽  
Author(s):  
Wenchang Wang ◽  
Ye Chen ◽  
Jing Zhang ◽  
Xue Wang ◽  
Zhidong Chen
Keyword(s):  
Ionic Liquid ◽  
Simultaneous Determination ◽  
Soft Drink ◽  
Expanded Graphite ◽  
Brilliant Blue ◽  
Experimental Conditions ◽  
Graphite Composite ◽  
Graphite Paste Electrode ◽  
Paste Electrode

Abstract A sensitive electrochemical method was developed for the simultaneous determination of Brilliant Blue (BB) and tartrazine (Tz) using an ionic liquid-modified expanded graphite paste electrode (IL-EGPE). The IL-EGPE was prepared by mixing ionic liquid-expanded graphite composite (IL-EG) with solid paraffin. Compared with the EGPE, the IL-EGPE remarkably enhanced the electrocatalytic oxidation signals of BB and Tz. Under optimal experimental conditions, the designed IL-EGPE exhibited wide linear responses to BB and Tz ranging from 5.0 × 10–9 to 4.0 × 10–6 M and 1.0 × 10–8 to 1.0 × 10–6 M, respectively. The detection limits for BB and Tz were 2.0 × 10–9 M (1.6 ng/mL) and 3.3 × 10–9 M (1.8 ng/mL) at an S/N of 3, respectively. This electrode showed good reproducibility, stability, and reusability. The proposed method was successfully applied in the simultaneous determination of BB and Tz in a soft drink with satisfactory results.

Analysis of the Electrode Kinetics of Ni(II) Reduction in Thiocyanate Media on the Dropping Mercury Electrode

2000 ◽  
Vol 65 (3) ◽  
pp. 326-342
Author(s):  
María S. Crespo-Pinilla ◽  
Fernando Mata-Pérez ◽  
Rosa M. Villamañán
Keyword(s):  
Ionic Strength ◽  
Compensation Effect ◽  
Supporting Electrolyte ◽  
Mercury Electrode ◽  
Electrode Kinetics ◽  
Surface Process ◽  
Experimental Conditions ◽  
Dropping Mercury Electrode ◽  
Kinetics Of

A study of two prewaves of the Ni(II)-SCN- system was carried out under the experimental conditions when the influence of electroreduction of SCN- is negligible. Kinetics of Ni(II) reduction in thiocyanate media on the dropping mercury electrode was studied by DC Tast Polarography (DCTP) via determination of Koutecký's parameter χ; the influence of different variables was analyzed. The study of prewaves was performed using various polarographic techniques. Values of χ depend on the SCN- concentration, pH, ionic strength (Ψ-effect) and on the nature of the supporting electrolyte. The number of electrons n, the transfer coefficient α, the stoichiometric number ν, ∆H≠, and ∆S≠ were determined (compensation effect). The first prewave has character of a reaction in the solution, the second prewave is a surface process. Main features of both mechanisms are common: catalytic nature, one-electron step discharge and the rate-determining process between species of opposite charges.

scholarly journals Simple Atomic Absorption Spectroscopic and Spectrophotometric Methods for Determination of Pioglitazone Hydrochloride and Carvedilol in Pharmaceutical Dosage Forms

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Afaf A. Abdelmonem ◽  
Gamal H. Ragab ◽  
Hisham Hashem ◽  
Eman A. Bahgat
Keyword(s):  
Atomic Absorption ◽  
Acidic Medium ◽  
Methylene Chloride ◽  
Ion Pair ◽  
Fast Green ◽  
Experimental Conditions ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Orange G

This study represents simple atomic absorption spectroscopic and spectrophotometric methods for determination of pioglitazone hydrochloride (PGZ-HCl) and carvedilol (CRV) based on formation of ion-pair associates between drugs and inorganic complex, bismuth(III) tetraiodide (Method A) and between drugs and organic acidic dyes, fast green and orange G (Method B). Method A is based on formation of ion-pair associate between drugs and bismuth(III) tetraiodide in acidic medium to form orange-red ion-pair associates, which can be quantitatively determined by two different procedures. The formed ion-pair associate is extracted by methylene chloride, dissolved in acetone, dried, and then decomposed by hydrochloric acid, and bismuth content is determined by direct atomic absorption spectrometric technique (Procedure 1) or extracted by methylene chloride, dissolved in acetone, and quantified spectrophotometrically at 490 nm (Procedure 2). Method B is based on formation of ion-pair associate between drugs and either fast green dye or orange G dye in acidic medium to form ion-pair associates. The formed ion-pair associate is extracted by methylene chloride and quantified spectrophotometrically at 630 nm (for fast green dye method) or 498 nm (for orange G dye method). Optimal experimental conditions have been studied. Both methods are applied for determination of the drugs in tablets without interference.

scholarly journals Determination of Zalcitabine in Medicaments by Differential Pulse Voltammetry

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Katia Christina Leandro ◽  
Josino Costa Moreira ◽  
Pércio Augusto Mardini Farias
Keyword(s):  
Pulse Amplitude ◽  
Differential Pulse ◽  
Active Principle ◽  
Reduction Peak ◽  
Hanging Mercury Drop Electrode ◽  
Analytical Methodology ◽  
Scan Rate ◽  
Pulse Voltammetry ◽  
Antiretroviral Activity

The zalcitabine (ddC) has been extensively used in the treatment of HIV patients due to its antiretroviral activity. The quality control of this active principle in medications is of outstanding importance to public health. The principal objective of the current study was the development of an alternative analytical methodology for the zalcitabine determination using a voltammetric process. The zalcitabine gives a reduction peak (at -1.22 V versus Ag/AgCl) at the hanging mercury drop electrode (HMDE). The differential pulse voltammetric response is evaluated with respect to the scan rate (20 mV/s), pulse amplitude (50 mV), support electrolyte (Clark-Lubs buffer), pH (2.0), and other variables. The response is linear over the 10.0 to 28.0 mg/L (47 to 133 μM) concentration range, and the detection limit is 2.08 mg/L. The validation of this method was realized using a governmental Brazilian document (Inmetro, 2007) and the results are reported for medication drugs.

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