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.

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.

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 Determination of Etofibrate, Fenofibrate, and Atorvastatin in Pharmaceutical Preparations and Plasma Using Differential Pulse Polarographic and Square Wave Voltammetric Techniques

2008 ◽  
Vol 91 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Mohamed A Korany ◽  
Ismail I Hewala ◽  
Karim M Abdel-Hay
Keyword(s):  
Reference Electrode ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Pulse Amplitude ◽  
Differential Pulse ◽  
Square Wave ◽  
Voltammetric Techniques ◽  
Irreversible Reduction ◽  
Relative Standard

Abstract Etofibrate, fenofibrate, and atorvastatin were determined in their pharmaceutical preparations and human plasma using differential pulse polarographic and square wave voltammetric techniques by reduction at a dropping-mercury working electrode versus Ag/AgCl reference electrode. The reversibility of the electrode reactions was tested using cyclic voltammetry, and they were found to be irreversible reduction reactions. Optimum conditions such as pH, scan rate, and pulse amplitude were studied, and validation of the proposed methods was performed. The proposed methods proved to be accurate, precise, robust, and specific for determination of the 3 drugs. The relative standard deviation values were <2, indicating that these methods are precise. Limits of detection and quantitation were in the ranges of 0.0370.21 and 0.120.71 g/mL, respectively, indicating high sensitivity.

scholarly journals New Spectrofluorimetric Method with Enhanced Sensitivity for Determination of Paroxetine in Dosage Forms and Plasma

2008 ◽  
Vol 3 ◽  
pp. ACI.S1053 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Sawsan M. Amer ◽  
Heba H. Abdine ◽  
Lama I. Al-Rayes
Keyword(s):  
High Sensitivity ◽  
Dosage Forms ◽  
Official Method ◽  
Factors Affecting ◽  
Pharmaceutical Tablets ◽  
Enhanced Sensitivity ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Optimized Conditions

New simple spectrofluorimetric method with enhanced sensitivity has been developed and validated for the determination of the antidepressant paroxetine (PXT) in its dosage forms and plasma. The method was based on nucleophilic substitution reaction of PXT with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in an alkaline medium (pH 8) to form a highly fluorescent derivative that was measured at 545 nm after excitation at 490 nm. The factors affecting the reaction was carefully studied and optimized. The kinetics of the reaction was investigated, and the reaction mechanism was presented. Under the optimized conditions, linear relationship with good correlation coefficient (0.9993) was found between the fluorescence intensity and PXT concentration in the range of 80-800 ng ml-1. The limits of detection and quantitation for the method were 25 and 77 ng ml-1, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 3%. The proposed method was successfully applied to the determination of PXT in its pharmaceutical tablets with good accuracy; the recovery values were 100.2 ± 1.61%. The results obtained by the proposed method were comparable with those obtained by the official method. The proposed method is superior to the previously reported spectrofluorimetric method for determination of PXT in terms of its higher sensitivity and wider linear range. The high sensitivity of the method allowed its successful application to the analysis of PXT in spiked human plasma. The proposed method is practical and valuable for its routine application in quality control and clinical laboratories for analysis of PXT.

High sensitivity ELISA determination of taxol in various human biological fluids

1999 ◽  
Vol 20 (3) ◽  
pp. 549-555 ◽  
Author(s):  
Stan R Svojanovsky ◽  
Kamal L Egodage ◽  
Jun Wu ◽  
Milan Slavik ◽  
George S Wilson
Keyword(s):  
Biological Fluids ◽  
High Sensitivity

Clinical and Diagnostic Value of Cardiac Markers in Human Biological Fluids

Kardiologiia ◽  
2019 ◽  
Vol 59 (11) ◽  
pp. 66-75 ◽  
Author(s):  
A. M. Chaulin ◽  
L. S. Karslyan ◽  
E. V. Bazyuk ◽  
D. A. Nurbaltaeva ◽  
D. V. Duplyakov
Keyword(s):  
Blood Serum ◽  
Oral Fluid ◽  
Biological Fluids ◽  
High Sensitivity ◽  
Diagnostic Value ◽  
Cardiac Markers ◽  
Methods Of Analysis ◽  
Clinical Diagnostic

The article is devoted to problems of clinical-diagnostic value of determination of cardio-specific troponins in human biological fluids. Improvement of laboratory instrumentation and emergence of high sensitivity methods of analysis have allowed to identify troponins in urine, dialysate, and oral fluid. In the review we present actual information related to measurement of troponins in blood serum, data on testing of cardio-specific troponins in urine, dialysate, and oral fluid. Special attention is paid to determination of some cardiomarkers in oral fluid with thorough analysis of diagnostic value and effectiveness of the conducted studies.

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