scholarly journals Microdetermination of Methenamine in the Presence of Formaldehyde by Solid Phase Spectrophotometry

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Mehdi Taghdiri ◽  
Yadollah Yamini ◽  
Ali Moloudi
Keyword(s):  
Industrial Wastewater ◽  
Solid Phase ◽  
Sample Volume ◽  
Ion Pair ◽  
Pair Formation ◽  
Bromocresol Green ◽  
Green Is ◽  
Relative Standard ◽  
Solid Phase Spectrophotometry

A sensitive spectrophotometric method for the determination of methenamine has been developed without any separation steps. Bromocresol green is adsorbed on Sephadex LH-20 gel but the sorption decreases in the presence of methenamine due to ion-pair formation between bromocresol green and methenamine in solution. This attenuation was used to the microdetermination of methenamine by measurement of absorbance of the solid phase (Sephadex LH-20 gel) in a 1.0 mm cell at 625 nm. Methenamine could be determined in the concentration range of 0.42–1.68 μg mL−1 (10-mL Sample volume) with a relative standard deviation (RSD) of 0.03% (n=4). The detection limit obtained was 50 μg L−1 for 10 mL sample volume. The method was used for determination of methenamine in industrial wastewater and a satisfactory result was obtained.

scholarly journals Application of Sephadex LH-20 for Microdetermination of Dopamine by Solid Phase Spectrophotometry

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Mehdi Taghdiri ◽  
Arash Mohamadipour-taziyan
Keyword(s):  
Solid Phase ◽  
Sample Volume ◽  
Ion Pair ◽  
Pair Formation ◽  
Bromocresol Green ◽  
Green Is ◽  
Relative Standard ◽  
Solid Phase Spectrophotometry ◽  
Sensitive Spectrophotometric Method

A sensitive spectrophotometric method for the determination of dopamine was carried out without any separation steps. Bromocresol green is adsorbed on Sephadex LH-20 gel but the sorption decreases in the presence of dopamine due to ion-pair formation between bromocresol green and dopamine in solution. This attenuation was used to the microdetermination of dopamine by measurement of absorbance of the solid phase (Sephadex LH-20 gel) in a 1.0 mm cell at 625 nm. Dopamine could be determined in the concentration range of 0.4–1.6 μg mL−1 (10-mL Sample volume) with a relative standard deviation (RSD) of 0.03% (). The detection limit was obtained, 0.26 μg mL−1 (1.7 μM). The method was used for determination of dopamine in pharmaceutical injection sample and satisfactory result was obtained.

scholarly journals An Eco-Concerned Development of a Fast, Precise and Economical Spectrophotometric Assay for the Antiviral Drug Simeprevir based on Ion-Pair Formation

2021 ◽  
Vol 11 (5) ◽  
pp. 13474-13489
Keyword(s):  
Limit Of Detection ◽  
Ion Pairs ◽  
Antiviral Drug ◽  
Ion Pair ◽  
Pair Formation ◽  
Bromocresol Green ◽  
Bromocresol Purple ◽  
Acid Dyes ◽  
Ion Pair Formation ◽  
Relative Standard

Simeprevir sodium (SMV) is one of the antiviral drugs used for the treatment of virus C. The current strategy develops and validates a new eco-concerned tool for its quantification in the pure and pharmaceutical formulations. Sulfonephthalein acid dyes were used for this purpose, applying visible analyses based on ion-pair formation. A linear relation between the absorbed signal and the drug concentration is obtained up to 67.0 μg mL-1 with r2 of 0.9989-0.9999. The measurement is carried out at 410, 415, 410, and 403 nm for bromocresol green, bromoxelenol blue, bromothymol blue, and bromocresol purple, respectively, in dichloromethane as a solvent. The drug structure was confirmed utilizing different tools; mass spectrometry, FT-IR, 1H NMR, and thermal analysis. Association, formation constants, molar absorptivity, and free energy change for SMV-ion-pairs were calculated. The limit of detection reaches 50.0 ng mL-1 with a quantification limit of 180.0 ng mL-1. The recovery values are 96.44-104.39%, with a relative standard deviation 0.15-1.37%. For confirmation of the obtained results, they were statistically compared with a previously published HPLC method utilizing t- and F- tests.

scholarly journals Solid phase extraction and determination of indium using multiwalled carbon nanotubes modified with magnetic nanoparticles

2018 ◽  
Vol 1 (01) ◽  
pp. 5-10 ◽  
Author(s):  
Ehsan Zolfonoun
Keyword(s):  
Inductively Coupled Plasma ◽  
Solid Phase ◽  
Optical Emission ◽  
Environmental Water ◽  
Sample Volume ◽  
Emission Spectrometry ◽  
Multiwalled Carbon ◽  
Inductively Coupled ◽  
Relative Standard

In this work MWCNTs-Fe3O4 nanocomposite was used as an adsorbent for extraction and preconcentration of indium from aqueous solutions. The magnetic MWCNTs with adsorbed analytes were easily separated from the aqueous solution by applying an external magnetic field. After elution of the adsorbed analytes, the concentration of indium was determined using inductively coupled plasma optical emission spectrometry determination. The effects of pH, sorbent amount, eluent type, chelating reagent concentration, sample volume and time on the recovery of the In(III) were investigated. Under the optimum conditions, the detection limit for In(III) was 0.28 μg L−1. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of ten replicates, was 3.1 %. The method was successfully applied for the determination of In(III) in environmental water samples.

Determination of Sulfite in Rainwater by Solid-Phase Spectrophotometry

1994 ◽  
Vol 77 (5) ◽  
pp. 1224-1229 ◽  
Author(s):  
Juan M Bosque-Sendra ◽  
Francisca Molina ◽  
Mounir Nechar
Keyword(s):  
Calibration Curve ◽  
Solution Method ◽  
Solid Phase ◽  
Specific Method ◽  
Similar Reaction ◽  
Analytical Sensitivity ◽  
Limit Values ◽  
Relative Standard ◽  
Solid Phase Spectrophotometry

Abstract A simple and specific method was developed for the determination of sulfite in rainwater based on solid-phase spectrophotometry (SPS). Rainwater was collected on morpholine, sulfite was stabilized by forming an adduct that reacted with pararosanil-ine and formaldehyde, and the reaction product was fixed on Dowex 1-X8 resin. The absorbance of the solid phase was measured directly at 565 and 700 nm. The calibration curve was linear in the concentration range of 1-50 μg/L in solution (relative standard deviation = 1.7%); the International Union of Pure and Applied Chemistry detection limit was 0.8 μg/L. In simulated rainwater, the values of the calibration curve slopes were similar to that of the standard calibration curve slope, and recoveries for 40-497 μg/L sulfite ranged from 97 to 105%. Linearity, analytical sensitivity, and precision were better for the SPS method than the solution method, and the detection and quantitation limit values were lower for the SPS method than the solution method based on the similar reaction. The SPS method was subsequently used to determine sulfite in real rainwater.

scholarly journals Spectrophotometric determination of some pharmaceutical piperazine derivatives by charge-transfer and ion-pair complexation methods

2002 ◽  
Vol 70 (3) ◽  
pp. 253-269 ◽  
Author(s):  
Issa Y.M. ◽  
Abou-Attia F.M. ◽  
Abdel-Gawad F.M. ◽  
Abdel-Hamid S.M.
Keyword(s):  
Charge Transfer ◽  
Ion Pair ◽  
Bromocresol Green ◽  
Basic Drug ◽  
Yellow Colour ◽  
Piperazine Derivatives ◽  
Relative Standard ◽  
Coloured Complex ◽  
Complexation Reactions

Simple and sensitive spectropliotometric methods are described for the assay of three piperazine derivatives ketoconazole, trimetazidine hydrochloride and piribedil based on cliarge-transfer and ion-pair complexation reactions. The first method is based on the reaction of the basic drug with iodine as o-acceptor in dry 1,2-dichloroethane to form a yellow colour due to the formation of charge-transfer complex showing maximum absorbence at 363, 364 and 359 nm for ketoconazole, trimetazidine hydrochlorid and piribedil, respectively. The second method is based on the reaction of basic drug with bromocresol green (BCG) in dry 1,2- dichloroethane to form a stable yellow coloured complex with maximum absorbance at 407, 408 and 410 nm for ketoconazol, trimetazidine hydrochloride and piribedil, respectively. Beer's law was obeyed for both methods and the relative standard deviations were found to be less than 1%. The two methods can be applied for the analysis of tablets and cream, with no evidence of interference from excipients. A more detailed investigation of the complex was made with respect to its composition association constant and free energy cliange.

scholarly journals DETERMINATION OF MIANSERIN USING TROPAEOLIN-OOO BY ION PAIR FORMATION

2019 ◽  
Vol 11 (1) ◽  
pp. 168 ◽  
Author(s):  
Giri Prasad Gorumutchu ◽  
Venkata Nadh Ratnakaram
Keyword(s):  
Treatment Process ◽  
Ion Pair ◽  
Pair Formation ◽  
Reaction Conditions ◽  
Organic Layers ◽  
Ich Guidelines ◽  
Relative Standard ◽  
Satisfactory Precision ◽  
Pre Treatment

Objective: The present study was aimed at the development of a simple visible spectrophotometric method for the assay of mianserin, a drug used for the treatment of depression.Methods: The method was developed using tropaeolin-ooo (TPooo) as an ion associative complex forming a chromophore. Developed the chromophore by sequential mixing of aqueous solutions of mianserin, hydrochloric acid, and TPooo. Chromophore was extracted into an organic solvent (chloroform) and absorbance values of organic layers were measured. As per the existing guidelines of an international conference on harmonization (ICH), various parameters of the method were tested for validation.Results: At the optimized reaction conditions, the formed chromophore (λ max 524 nm) was stable and sensitive. Regression analysis (r>0.9999) shows that the plotted calibration curve exhibits good linearity in the studied range of concentration (4–24 µg/ml). Accuracy of the method was evident from the % recovery values (99.50–99.87 range). Satisfactory precision (both intra and inter day) for the proposed method was clear as ranges of percentage of relative standard deviation (%RSD) values were 1.382-1.781 and 1.128-1.765 respectively. Since RSD is less than 2 %, this method was reproducible and accurate.Conclusion: Due to lack of pre-treatment process for this method, it was simple. All the tested parameters of the method were validated as per ICH guidelines.

Utilization of solid phase spectrophotometry for the determination of trace amounts of copper using 5-(2-benzothiazolylazo)-8-hydroxyquinoline

2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Alaa Amin
Keyword(s):  
Solid Phase ◽  
Standard Addition ◽  
Environmental Water ◽  
Sample Volume ◽  
Molar Absorptivity ◽  
Accurate Procedure ◽  
Solid Phase Spectrophotometry ◽  
Dowex 1 ◽  
Detection And Quantification

AbstractA simple, selective, highly sensitive and accurate procedure for the determination of trace amounts of copper has been developed based on solid-phase spectrophotometry. Copper reacts with 5-(2-benzothiazolylazo)-8-hydroxyquinoline (BTAHQ) to give a complex with high molar absorptivity (3.17 × 107 L mol−1 cm−1, 3.07 × 108 L mol−1 cm−1, 1.22 × 109 L mol−1 cm−1, and 1.80 × 109 L mol−1 cm−1), fixed on a Dowex 1-X8 type anion-exchange resin for 10 mL, 100 mL, 500 mL, and 1000 mL, respectively. The absorbance at 667 nm and 800 nm packed in a 1.0 mm cell was measured directly. Calibration is linear over the range 0.2–3.7 µg L−1 with RSD of < 1.28 % (n = 10). The detection and quantification limits of the 500 mL sample method are 79 ng L−1 and 260 ng L−1 when using 60 mg of Dowex 1-X8. For a 1000 mL sample, the detection and quantification limits are 67 ng L−1 and 220 ng L−1 using 60 mg of the exchanger. Increasing the sample volume can enhance the sensitivity. The proposed method was applied to the determination of copper in different environmental water samples (tap, pit, spring, and river), food products (rice, corn flour, and tea), and mushrooms, using the standard addition technique.

scholarly journals Visible color changes estimation in colorimetric determination of chromium (VI) using polymeric sensors

ACTA IMEKO ◽  
2016 ◽  
Vol 5 (3) ◽  
pp. 95 ◽  
Author(s):  
Nataliya A. Gavrilenko ◽  
Sergey V. Muravyov ◽  
Nadezhda V. Saranchina ◽  
Alexey V. Sukhanov
Keyword(s):  
Solid Phase ◽  
Tap Water ◽  
Color Difference ◽  
Colorimetric Determination ◽  
Color Analysis ◽  
Color Coordinates ◽  
Color Changes ◽  
Relative Standard ◽  
Solid Phase Spectrophotometry

<p class="Abstract"><span lang="EN-US">The paper describes an application of a kind of optical analytical method, digital color analysis (DCA), using colorimetric polymethacrylate sensors (optodes) in order to determine Cr (VI). The optodes are made of optically transparent polymethacrylate matrix (PMM) with 1.5-diphenylcarbazide immobilized. The developed optode can be used in determination of the analytes using solid phase spectrophotometry and calculating color coordinates as functions of absorbance spectra. Also color coordinates can be represented as basic color (e.g. RGB) data after the optode image digitizing. Then one can determine the content of an analyte in a sample by an appropriate color difference calculated for these coordinates. Experimental results of Cr (VI) determination in tap water show that the DCA relative standard deviation is 8-17 % and recovery is &lt; 12 % at the range of determined concentrations 0.05-1.0 </span><span lang="EN-US">mg·L<sup>–1</sup></span><span lang="EN-US">. The characteristics are comparable with those of the solid phase spectrophotometry.</span></p>

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