scholarly journals Spectrophotometric Determination of Trace Amount of Nitrite in Water with p-Nitroaniline and 1-Naphthol

2015 ◽  
Vol 19 (2) ◽  
pp. 89-93 ◽  
Author(s):  
Deba Bahadur Khadka ◽  
Laxmi Pachhai
Keyword(s):  
Waste Water ◽  
Hydrochloric Acid ◽  
Spectrophotometric Determination ◽  
Water Samples ◽  
Trace Amount ◽  
Azo Dye ◽  
Molar Absorptivity ◽  
Analytical Wavelength ◽  
Sensitive Method

A simple, selective and sensitive method for the spectrophotometric determination of nitrite in different natural and waste water samples is applied. Nitrite reacts with p-nitroaniline in the presence of hydrochloric acid to form diazonium cation which is subsequently coupled with 1-naphthol to form a stable azo dye. The ?max for the azo dye is found to be 610 nm. At analytical wavelength 610 nm the Lambert-Beer’s law obeys over the concentration range 0.035-0.123 ?g/ml of nitrite. The correlation coefficient, molar absorptivity and Sandell’s sensitivity of the method were found to be 0.99, 5.24×104 lit.mol-1cm-1 and 8.77×10-4?g cm-2 respectively. The percentage recovery was found to range from 93-109% and the interference of foreign ions was also studied.Journal of Institute of Science and Technology, 2014, 19(2): 89-93

scholarly journals Difference spectrophotometric method for the determination of Fluphenazine hydrochloride in tablets using peroxomonosulfate

2021 ◽  
Vol 9 (2) ◽  
pp. 64-71
Author(s):  
Mykola Blazheyevskiy ◽  
◽  
Valeriy Moroz ◽  
Olena Mozgova ◽  
◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Present Method ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Derivatizing Agent ◽  
Sensitive Method

The oxidative derivatization method using potassium hydrogenperoxomonosulfate for the indirect spectrophotometric determination of Fluphenazine hydrochloride is presented. Potassium hydrogenperoxomonosulfate is introduced as a derivatizing agent for Fluphenazine hydrochloride, yielding the sulfoxide. This reaction product was successfully used for the spectrophotometric determination of the Fluphenazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Fluphenazine hydrochloride in the concentration range of 0.2-30 µg mL-1. The molar absorptivity at 349 nm is 5.6×103 (dm3cm-1mol-1). The limit of quantification, LOQ (10S) is 0.24 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Fluphenazine hydrochloride in tablets 5.0 mg was demonstrated. The present method is precise, accurate and excipients did not interfere. RSD for Fluphenazine Hydrochloride 5.0 mg tablets was 1.37 %.

Spectrophotometric Determination of p-aminobenzoic acid via Diazotization and Coupling reaction

2021 ◽  
pp. 5313-5318
Author(s):  
Rana S. Al-Saffar ◽  
Safaa A. Zakaria ◽  
Nabeel S. Othman
Keyword(s):  
Folic Acid ◽  
Hydrochloric Acid ◽  
Sodium Nitrite ◽  
Azo Dye ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Good Sensitivity ◽  
Aminobenzoic Acid

A simple and accurate spectrophotometric method to assay p-aminobenzoic acid (PABA) has been suggested. The method based on the diazotization of PABA via reaction with nitrite ions which liberated in the medium through the reaction of sodium nitrite with hydrochloric acid, then coupling the dizotised-PABA(D-PABA)with 1-naphthylamine -7-sulphonic acid (1-NASA) to form an intense colored pink azo dye ,it is water-soluble , very stable and has a maximum absorbance at 525 nm. The absorbance was increase with the increasing of PABA amounts in the solution, and the linearity from 2.5 to70 µg in 10 ml (0.25to7 µg.ml-1).The molar absorptivity and Sandell ҆s sensitivity values have been calculated they equal to 3.6057x104 L.mol-1 cm -1 and 0.0037993 µg. cm-2 respectively. The two values above demonstrated a good sensitivity of the suggested method. The method has been used in estimated PABA resulted from analysis of folic acid in tablet.

Selective determination of tantalum in ores by extraction with N-phenylbenzohydroxamic acid in toluene

1990 ◽  
Vol 55 (7) ◽  
pp. 1686-1690 ◽  
Author(s):  
José Aznarez ◽  
Juan Carlos Vidal ◽  
Cecilia Vaquero
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Aqueous Phase ◽  
Spectrophotometric Determination ◽  
Absorption Maximum ◽  
Good Accuracy ◽  
Molar Absorptivity ◽  
Selective Determination ◽  
Accuracy And Precision

A method for tantalum(V) spectrophotometric determination in a non-aqueous phase is proposed. Tantalum(V) is extracted with N-phenylbenzohydroxamic acid into toluene from a 5M hydrochloric acid solution. The colour is then developed by addition of 4-(2-pyridylazo)-resorcinol (PAR) solution in N,N-dimethylformamide and pyridine to an aliquot of the extracted phase. The Ta(V)-PAR complex gives an absorption maximum at 547 nm with a molar absorptivity of 3.88 ± 0.04 . 104 l mol-1 cm-1. The method has been applied to the selective determination of tantalum in ores with good accuracy and precision.

Spectrophotometric Determination of Al(III) in Environment Water with p-Carboxyarsenazo

2013 ◽  
Vol 830 ◽  
pp. 363-366 ◽  
Author(s):  
Lin Gao ◽  
Bo Yan ◽  
Fang Chen ◽  
Jun Long Yao
Keyword(s):  
Detection Limit ◽  
Linear Regression ◽  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Water Samples ◽  
High Sensitivity ◽  
Molar Absorptivity ◽  
Linear Regression Equation ◽  
Color Reagent

Spectrophotometry determination of Al (III) with new color reagent p-Carboxyarsenazo(CAA) was reported, and the chromomeric reaction between CAA and Al (III) was studied. In a buffer medium of pH=4.6 HAc-NaAc, CAA reacts with Al (III) to form a red complex and exhibits an absorption maxima at 614nm; Beer,s law is obeyed for 0.10~0.80 μg/mL of Alumium in color solution, the color reaction exhibited high sensitivity (the apparent molar absorptivity obtained is 1.61×104 L/(mol.cm)), and the absorbance fit linear regression equation is A=0.0105+0.561X(μg/mL), the correlation coefficient is 0.9998, the detection limit of the method is 0.36 μg/L. The results obtained by this method in the determination of environment water samples were rapid, accurate and satisfactorily.

scholarly journals Spectrophotometric determination of ceftazidime in pharmaceuticals using resorcinol and 2-methylphenol

2021 ◽  
pp. 35-44
Author(s):  
O. Kostiv ◽  
◽  
O. Korkuna
Keyword(s):  
Hydrochloric Acid ◽  
Alkaline Medium ◽  
Spectrophotometric Determination ◽  
Molar Absorptivity ◽  
Azo Compounds ◽  
Azo Coupling ◽  
Spectrophotometric Methods ◽  
Maximum Absorbance ◽  
Stoichiometric Ratios

We developed two fast, simple and sensitive spectrophotometric methods for the determination of ceftazidime in drugs by using phenolic reagents resorcinol and 2-methylphenol. The methods are based on a previous antibiotic diazotization in the medium of hydrochloric acid (CHCl=12 M) and its following azo coupling with reagents in an alkaline medium with the formation of effective analytical forms that allow determining ceftazidime and have maximum absorbance at 519 nm and 516 nm for resorcinol and 2- methylphenol, respectively. The azo coupling products of diazotized ceftazidime exhibit effective molar absorptivity in the range of (6.31–6.84)103 M–1 cm–1. Stoichiometric ratios of the azo compounds components were established using continuous variations methods and they were the same in both cases (1:1). The developed methods allow determining from 2.75 to 185.5 g mL–1 of ceftazidime with resorcinol (LOQ=2.54 g mL–1) and 0.32191.3 g mL–1 of ceftazidime with 2-methylphenol (LOQ=0.28 g mL–1). The developed methods have been successfully tested in the analyses of one-component preparations (powders for injection solutions).

scholarly journals Spectrophotometric Determination of Carbofuran with Diazotized Benzidine in Environmental Water Samples

2016 ◽  
Vol 13 (3) ◽  
pp. 498-510
Author(s):  
Baghdad Science Journal
Keyword(s):  
Water Samples ◽  
Azo Dye ◽  
Absorption Maximum ◽  
Concentration Level ◽  
Environmental Water ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Reagent Blank ◽  
Blank Solution

A simple, rapid, accurate and sensitive spectrophotometric method has been developed for the determing carbamate pesticides in both pure and water samples. The method is appropriate for the determination of carbofuran in the presence of other ingredients that are usually available in dosage forms. The effect of organic solvents on the spectrophotometric properties of the azo dye and the structure of the resulting product have also been worked out and it is found to be 1:1 benzidine :carbofuran. The method can be successfully applied to determination of carbofuran in water samples. The method is based on diazotization of Benzidine (4, 4 – diamino biphenyl) with sodium nitrite and hydrochloric acid followed by coupling with carbofuran in alkaline medium to form a yellow colored azo dye having the absorption maximum at 429nm against reagent blank solution. Beer’s law is obeyed in the concentration range of (0-14) ?g of 10mL carbofuran. Molar absorptivity of 1×104 L.mol-1.cm-1 which depend on the concentration level of carbofuran.

4, 4’-Diantipyrylmethane (DAM): A tool for spectrophotometric microdetermination of cerium (IV)

2021 ◽  
Vol 25 (7) ◽  
pp. 49-55
Author(s):  
Amita Garg ◽  
Radhika Khanna ◽  
Parveen Rathi
Keyword(s):  
Spectrophotometric Determination ◽  
Trace Amount ◽  
Acidic Medium ◽  
Absorption Maximum ◽  
Molar Absorptivity ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Good Reproducibility ◽  
Beer’S Law

A simple and hasty method has been employed for the direct spectrophotometric determination of trace amount of Ce(IV) using a complexing agent 4,4’-diantipyryl methane (DAM) with absorption maximum at 445-455nm in acidic medium at 1.3 -1.5 pH. Molar absorptivity and Sandell’s sensitivity were calculated to be 9.1 × 103 l mol-1 cm-1 and 0.015 μg Ce cm-2. Beer’s law was found to be defensible over the cerium concentration range of 0-5.5 μg ml-1. Effect of large number of cations, anions and complexing agents was also studied and several analytically important ions do not cause interference in the procedure except thiourea and EDTA. The method has good reproducibility and has been satisfactorily applied in the determination of cerium in samples.

Optimization of an analytical method for the spectrophotometric determination of copper in tea and water samples after ultrasonic assisted cloud point extraction using a benzothiazole fluorescein derivative complexing agent

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65321-65327 ◽  
Author(s):  
Chunlei Fan ◽  
Shengxu Luo ◽  
Rong Liu
Keyword(s):  
Cloud Point ◽  
Spectrophotometric Determination ◽  
Water Samples ◽  
Analytical Method ◽  
Cloud Point Extraction ◽  
Complexing Agent ◽  
Ultrasonic Assisted ◽  
Determination Of Copper

BTF is exists with spirolactone species with adding Cu2+, which leads to the absorbance intensity is decreased gradually and the decrease of the absorbance value is linear for Cu2+.

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