A new extraction–spectrophotometric method for the determination of phosphate

1978 ◽  
Vol 56 (13) ◽  
pp. 1729-1738 ◽  
Author(s):  
Kunnath S. Subramanian ◽  
Alfio Corsini
Keyword(s):  
Spectrophotometric Method ◽  
Natural Waters ◽  
Amyl Alcohol ◽  
Tungstophosphoric Acid ◽  
Molar Ratio ◽  
Molybdenum Blue ◽  
Phosphorus Containing ◽  
Precision And Accuracy ◽  
Ph Range

A new extraction–spectrophotometric method has been developed for the determination of trace amounts of phosphorus as orthophosphate. The method is based on the chemistry of 12-tungstophosphoric acid, H3PW12O40 (TPA). In the procedure, orthophosphate is converted quantitatively to TPA in aqueous solution at a tungstate–phosphate molar ratio ≥24, in the pH range 1.2 to 1.9 and in the temperature range 60 to 100 °C. The TPA is subsequently extracted into n-amyl alcohol and its absorbance measured at 267 nm. Beer's law is followed up to at least 25 µg/ml P. The method is less prone to solution conditions and species interference (especially As(V) and Si(IV)) than the widely used molybdenum-blue methods and is competitive in terms of sensitivity, precision, and accuracy. The TPA method was applied successfully to the determination of phosphate in a variety of phosphorus-containing specimens including natural waters, ores, and alloys.Based on potentiometric and spectrophotometric studies, a scheme which accounts for the observed heptaproticity of TPA is proposed.

scholarly journals Development of Extractive Spectrophotometric Determination of Rhodium (III) using Schiffs Base as An Analytical Reagent

2021 ◽  
pp. 1101-1105
Author(s):  
Mrs. Ritika Makhijani
Keyword(s):  
Aqueous Solution ◽  
Elemental Analysis ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Amyl Alcohol ◽  
Schiff’S Base ◽  
Analytical Reagent ◽  
Ph Range ◽  
Method Show

Rh (III) was determined by simple, sensitive & feasible spectrophotometric method by using analytical reagent N - (o - methoxy benzaldehyde) 2-aminophenol (NOMBAP) . Elemental analysis was used to characterize synthesized Schiff’s base NOMBAP. Rh (III) is extracted quantitatively (99.66%) by NOMBAP into carbon tetra chloride from an aqueous solution having pH range 5.1 – 5.9. An intense peak at 480 nm (λ max) was observed in the extract of n-amyl alcohol. Beer’s law is obeyed over the concentration range 1.0 – 10.0 µg/ml for Rh (III). The molar absorptivity and Sandel’s sensitivity for Rh - NOMBAP system is 8248.23 dm3 mole-1cm-1and 0.08332 μgcm-2 respectively. Mole Ratio & Job’s Continuous Variation and Method show that the extracted species has composition 1:3 (Rh-NOMBAP). Study has been done for interference by various ions. For determination of Rh (III) in alloy the proposed method has been used.

UV spectroscopic method for determination of phenytoin in bulk and injection forms

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Ich Guidelines ◽  
Precision And Accuracy ◽  
Routine Quality Control

Recent study was conducted to develop a simple UV spectrophotometric method to determine Phenytoin in bulk and injection form according to official requirement and validate as per ICH guidelines. λmax of Phenytoin was found 202 nm. Linearity existed perceived in the concentration assortment 2-8 μg/ml (r2 = 0.999) for the method. The method was validated pertaining to linearity, precision and accuracy studies, LOD and LOQ consistent with ICH guidelines. The existent method was establish to be simple, linear, precise, accurate as well as sensitive and can be applied for routine quality control enquiry for the analysis of Phenytoin in bulk and injection form.

scholarly journals Ultraviolet Spectrophotometric Method for Determination of Glipizide in Presence of Liposomal/Proliposomal Turbidity

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Neelkant Prasad ◽  
Roshan Issarani ◽  
Badri Prakash Nagori
Keyword(s):  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Limit Of Detection ◽  
Quantitative Estimation ◽  
Uv Detection ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Precision And Accuracy ◽  
Clear Solution

A simple and sensitive ultraviolet spectrophotometric method for quantitative estimation of glipizide in presence of lipid turbidity is described to avoid false estimation due to diffraction by turbidity. UV detection was performed at 230 nm, 225 nm, and 235 nm, and the calibration curve was plotted between resultant of absorbance of [230 nm − (225 nm + 235 nm)/2] and concentration of analyte. The calibration curve was linear over the concentration range tested (1–20 μg/mL) with limit of detection of 0.27 μg/mL and limit of quantification of 0.82 μg/mL. Percent relative standard deviations and percent relative mean error, representing precision and accuracy, respectively, for clear as well as turbid solutions, were found to be within acceptable limits, that is, always less than 0.69 and 0.41, respectively, for clear solution and 0.65 and 0.47, respectively, for turbid solution. Conclusively, our method was successfully applied for the determination of glipizide in clear as well as turbid solutions, and it was found that the drug analyte in both types of solutions can be detected from the same calibration curve accurately and precisely and glipizide entrapped in the liposomes or in proliposomal matrix was not detected.

Molybdenum-Blue Spectrophotometric Method for Determination of Lewisite Vapor in Air

1985 ◽  
Vol 18 (19) ◽  
pp. 2381-2394 ◽  
Author(s):  
William K. Fowler ◽  
Thomas T. Hancock ◽  
John J. Martin
Keyword(s):  
Spectrophotometric Method ◽  
Molybdenum Blue

scholarly journals Spectrophotometric determination of active chlorine by the color of indophenolic compounds

2019 ◽  
Vol 57 (3) ◽  
pp. 93-98
Author(s):  
Svetlana E. Pratskova ◽  
◽  
Oksana E. Sirenko ◽  
Keyword(s):  
Sodium Nitroprusside ◽  
Natural Waters ◽  
Tap Water ◽  
Active Chlorine ◽  
Molar Ratios ◽  
Spectrophotometric Methods ◽  
Organic Impurities ◽  
Ph Range ◽  
Fold Excess

Chlorination is a method of disinfection and oxidation of organic impurities in water. Chlorine is present in aqueous solutions in various forms, which are formed as a result of the chlorination of water. Spectrophotometric methods are very important for determining small amounts of chlorine and its compounds. The article presents a modification of the classical indophenolic method. Determination of active chlorine should be carried out at room temperature, maintaining the solutions for 50 minutes, the pH range is 11.9 ± 0.1. The optimal concentration of reagents: 33-fold excess of N-phenanthranilic acid, 2-fold excess of sodium nitroprusside, and the concentration of ammonium chloride should be 4 to 7 times less than the concentration of active chlorine. The following interaction scheme was proposed: oxidation of ammonia to chloramine with hypochlorite, amination of N-phenanthanilate with the formation of sodium 4-amino-N-phenylanthranilate, oxidation of 4-amino-N-phenylanthranilate with sodium hypochlorite to an indamin compound, followed by complexation with sodium nitroprusside. The linearity range of the calibration curve is 1-23 mg/l, the convergence is 2.3%, the relative error is 1%. The molar ratios of ions and oxidizing agents present in natural waters that do not interfere with the determination of active chlorine are investigated. The optimal concentrations of reagents, sequential variation of the concentration of solutions and fixing the change in light absorption were established. The ratio of the stoichiometric coefficients according to the reaction equation was: ammonium: N-phenanthranilic acid: sodium nitroprusside: hypochloride was 1: 2: 1: 1. It is proposed to use this method to determine the active chlorine in tap water. It is recommended to use the calibration schedule to determine the preliminary content, and to establish a more accurate concentration, use the method of additives.

scholarly journals DETERMINATION OF SIMULTANEOUS IRBESARTAN AND HYDROCHLOROTHIAZIDE BY ULTRAVIOLET SPECTROPHOTOMETRY WITH DUAL WAVELENGTH METHOD

1970 ◽  
Vol 7 (3) ◽  
pp. 1-4 ◽  
Author(s):  
Hafid Syahputra ◽  
M. Si. Apt Muchlisyam ◽  
M.S. Apt Masfria
Keyword(s):  
Blood Pressure ◽  
Quality Control ◽  
Spectrophotometric Method ◽  
Reduce Blood Pressure ◽  
Dual Wavelength ◽  
Good Precision ◽  
Ultraviolet Spectrophotometry ◽  
Validation Parameters ◽  
Precision And Accuracy

Objective: The present study was aimed to develop a spectrophotometric method by dual wavelength method in simultaneous analysis of irbesartan and hydrochlorothiazide on tablet preparations without separation. Irbesartan and hydrochlorothiazide are a group of anti-hypertensive drugs that are very effective and safe to use to reduce blood pressure and edema. These drugs often given in combination with these active ingredients can cause problems in quantitative analysis for the quality control of preparations. Methods: The study was carried out experimentally with a spectrophotometric method, one of which was dual wavelength method and then tested its validity based on validation parameters, namely linearity, accuracy, precision, LOD and LOQ and intraday and interday. Then, this method of irbesartan and hydrochlorothiazide in tablet preparations. Results: The results of the study were showed that the application of dual wavelength method on the concentration was carried out at λ 263.4 nm and 281 nm for irbesartan and at λ 243.4 nm and 247.6 nm for hydrochlorothiazide. The results obtained by irbesartan and hydrochlorothiazide on tablets were (108.04 ± 2.696) and (94.28 ± 4.48)% respectively, and with good precision and accuracy. Conclusions: The ultraviolet spectrophotometry method is dual wavelength method successfully applied for the determination of the concentration of irbesartan and hydrochlorothiazide in tablets.

Improved ultraviolet spectrophotometric method for determination of nitrate in natural waters

2002 ◽  
Vol 2 (2) ◽  
pp. 213-221 ◽  
Author(s):  
N. Kishimoto ◽  
I. Somiya ◽  
R. Taniyama
Keyword(s):  
Water Quality ◽  
Spectrophotometric Method ◽  
Standard Error ◽  
Coefficient Of Variation ◽  
Natural Waters ◽  
Uv Light ◽  
Rapid Determination ◽  
The Other ◽  
Extreme Conditions

An improved UV spectrophotometric method for determination of nitrate in natural waters was proposed and the determination accuracy of the method was discussed in this study. As a result of estimation of the proposed method, adoption of 215 and 220 nm for detection of nitrate and interfering substances resulted in decreasing standard error to about a half of that of a conventional spectrophotometric method. One of the reasons was thought that the coefficient of variation of relative absorbance of interfering substances (rs) at 215 nm was smaller and more stable than that at 275 nm, which was used in the conventional method. The other reason inferred was that most of the interfering substances absorbed UV light at wavelengths of 215 and 220 nm. Although rs has to be renewed when targeted water quality is under extreme conditions, the procedure of the proposed method is very simple, namely only measuring two UV absorbances of a filtrated sample, and more accurate than the conventional spectrophotometric method. Consequently, the proposed method is available for rapid determination of nitrate in natural waters.

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