scholarly journals Spectrophotometric Determination of Low Levels of the Orthophosphate Anion as Molybdenum Blue using Sodium Thiosulphate Reducing agent

2020 ◽  
Vol 36 (6) ◽  
pp. 1066-1077
Author(s):  
Irene Nalumansi ◽  
Grace Birungi ◽  
Brenda Moodley ◽  
Emmanuel Tebandeke
Keyword(s):  
Spectrophotometric Method ◽  
Water Samples ◽  
Limit Of Detection ◽  
Environmental Water ◽  
Molar Absorptivity ◽  
Sodium Thiosulphate ◽  
Molybdenum Blue ◽  
Low Levels ◽  
Phosphomolybdenum Blue

A simple spectrophotometric method for the determination of low levels of the orthophosphate (PO43-) in environmental water systems is reported. The method is based the formation of the phosphomolybdate from the condensation of molybdate and orthophosphate in aqueous acid medium followed by reduction with sodium thiosulphate to form phosphomolybdenum blue. The system obeys Beer’s law at 880 nm (λmax) in the 0.005–0.06 mg P mL-1 phosphate concentration range. Molar absorptivity, Sandell’s sensitivity and correlation coefficient values for the determination were 57526 L mol-1 cm-1, 0.2835 μg cm-2 and 0.9948 respectively. The limit of detection was 2.213 x 10-3 mg P mL-1. The results of PO43- determination in water samples obtained using the spectrophotometric method developed in this study, compare favourably with those generated using the Murphy and Riley method which is commonly used for this analysis. Therefore, the study ably demonstrates the suitability of the present spectrophotometric method for analysis of the orthophosphate in environmental water samples.

scholarly journals Flotation-Spectrophotometric Method for the Determination of Aluminium ion Using Xylenol Orange

2011 ◽  
Vol 8 (4) ◽  
pp. 1528-1535 ◽  
Author(s):  
F. Nekouei ◽  
Sh. Nekouei
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Limit Of Detection ◽  
Xylenol Orange ◽  
Molar Absorptivity ◽  
Relative Standard ◽  
Ion Associate ◽  
Sensitive Method

A simple, fast, reproducible and sensitive method for the flotation- spectrophotometric determination of Al3+is reported. The apparent molar absorptivity (ε) of the ion associate was determined to be 8.35×104L mol-1cm-1. The calibration curve was linear in the concentration range of 1.0-50 ng mL-1of Al3+with a correlation coefficient of 0.9997. The limit of detection (LOD) was 0.621 ng mL. The relative standard deviation (RSD) at 10 and 30 ng mL-1of aluminium were 1.580 and 2.410% (n=7) respectively. The method was applied for measuring the amount of aluminium in water samples.

scholarly journals Sensitive Spectrophotometric Determinations of Paracetamol and Protriptyline HCl Using 3-Chloro-7-hydroxy-4-methyl-2H-chromen-2-one

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Kumble Divya ◽  
Badiadka Narayana ◽  
Majal Sapnakumari
Keyword(s):  
Charge Transfer ◽  
Spectrophotometric Method ◽  
Charge Transfer Complex ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pharmaceutical Samples ◽  
Chromogenic Reagent ◽  
Detection And Quantification

A new spectrophotometric method is developed for the determination of Paracetamol (PCT) and protriptyline HCl (PTP) in pure forms and in pharmaceutical formulations. The experiment involves the use of 3-chloro-7-hydroxy-4-methyl-2H-chromen-2-one as a novel chromogenic reagent for the determination of PCT and PTP. The method is based on the formation of charge transfer complex between the drugs and chromogenic reagent. Beer's law is obeyed in the concentration ranges 10.00–60.00 µg mL−1 for PCT at 545 nm and 40.00–160.00 µg mL−1 for PTP at 468 nm. The molar absorptivity, Sandell, sensitivity, and limit of detection and quantification are also calculated. The method has been successfully applied for the determination of both PCT and PTP in pharmaceutical samples with acceptable results.

scholarly journals Determination of NH4+in Environmental Water with Interfering Substances Using the Modified Nessler Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Heonsang Jeong ◽  
Jongtaek Park ◽  
Hyunook Kim
Keyword(s):  
Polyvinyl Alcohol ◽  
Spectrophotometric Method ◽  
Water Samples ◽  
Essential Element ◽  
Environmental Water ◽  
High Concentration ◽  
Modified Method ◽  
Dispersing Agent ◽  
Treatment Facilities

Nitrogen is an essential element in the environment. If excess nitrogen includingNH4 +is present in water, however, it can result in algae blooming and eventually the destruction of the aquatic ecosystem. Therefore, the determination ofNH4 +in streams, lakes, and effluents of the treatment facilities has long been carried out. The Nessler method is the most common spectrophotometric method to measureNH4 +in water. However, the result of the method becomes inaccurate if there are interfering substances such as Cl2, Cl−, hardness-causing compounds (e.g., Mg2+), and Fe2+in target water samples. In this study, therefore, the traditional Nessler method has been modified to eliminate the effects of interfering substances; the so-called MS was added to water samples. In addition, the polyvinyl alcohol reagent as a dispersing agent was added to water samples to increase the sensitivity and reproducibility of the method. The modified method could successfully analyzeNH4 +of water samples even with the interfering substance at high concentration.

scholarly journals Rapid and Sensitive Spectrophotometric Method for the Determination of the Trace Amount of Thallium (III) in Water and Urine Samples by New Oxidative Coupling Reaction

2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Padmarajaiah Nagaraja ◽  
Naef Ghllab Saeed Al-Tayar ◽  
Anantharaman Shivakumar ◽  
Ashwinee Kumar Shresta ◽  
Avinash K. Gowda
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Urine Samples ◽  
Oxidative Coupling Reaction ◽  
Relative Standard ◽  
Student’S T

A very simple, sensitive and fairly selective direct spectrophotometric method is presented for the rapid determination of thallium(III) at trace level. The method is based on the oxidation of 2-hydrazono-3-methyl-2,3-dihydrobenzo[d]thiazole hydrochloride (MBTH) by thallium(III) in phosphoric acid medium to form a diazoniumcation, which couples immediately with 10,11-dihydro-5Hdibenzo[b,f]azepine (IDB) at room temperature giving a blue colored species having a maximum absorption at 660 nm. The reaction conditions and other important analytical parameters were optimized.The calibration curve was found to be linear over the range of 0.1-4 μg/mL with molar absorptivity of 4.5 × 104 L mol- cm-1 and Sandell’s sensitivity of 0.00454 μg cm-2. The relative standard deviation and limit of detection have been found to be 0.58% and 0.0147 μg/mL respectively. Almost all common anions and cations are found notto interfering in matrix level of the analytical process. The method has been successfully applied for the determination of thallium(III) in synthetic standard mixtures, water and human urine samples. The performance of proposed method was evaluated in terms of student’s t-test and variance ratio F-test, to find out the significance of proposed method over the reported methods.    

scholarly journals Vortex-assisted liquid–liquid microextraction combined with spectrophotometry for the determination of trace nitrite in water samples

2017 ◽  
Vol 17 (5) ◽  
pp. 1225-1231 ◽  
Author(s):  
Yang Jiao ◽  
Jianping Yu ◽  
Yaling Yang
Keyword(s):  
Organic Solvent ◽  
Water Samples ◽  
Limit Of Detection ◽  
Environmental Water ◽  
Cationic Dye ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Optimized Conditions ◽  
Liquid Microextraction

A vortex-assisted liquid–liquid microextraction (VALLME) method using isooctanol as extractant followed by spectrophotometry was developed for the extraction and determination of trace nitrite in water samples. The method is based on selective ion-pairing complex (I3− MG+) formation of triiodideanion I3− with cationic dye malachite green (MG) at pH 3.0, and its subsequent extraction in an organic solvent. The extracted organic solvent-rich phase is diluted with methanol, and its absorbance is measured against an analyte blank at 630 nm. The variables affecting VALLME efficiency were investigated, and a set of optimized conditions was obtained. Under the optimum conditions, the linear range of nitrite was from 1.0 to 100 ng mL−1. The relative standard deviations (n = 10) were 2.1–3.9% and the limit of detection was 0.5 ng mL−1 and was successfully applied to the determination of nitrite in environmental water.

scholarly journals Spectrophotometric method for determination of ranitidine hydrochloride in bulk and in pharmaceutical preparation using ninhydrin

2020 ◽  
Vol 11 (4) ◽  
pp. 291-297
Author(s):  
Hutaf Mustafa Baker ◽  
Hussam Ahmad Alsaoud ◽  
Hamzeh Mohamad Abdel-Halim
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Ranitidine Hydrochloride ◽  
Relative Standard ◽  
Reproducible Method

A simple, sensitive and reproducible method for the determination of ranitidine hydrochloride in pharmaceutical preparations was investigated. This spectrophotometric method was based on the formation of a deep red color product with ninhydrin in basic media and the absorbance measured at λmax = 480 nm. The reaction occurs at 45 °C with pH = 10 having a contact time of 38 minutes. Under the optimum conditions, Beer’s Law is obeyed in the concentration range of 8.98×103 - 9.90×104 µg/L. The coefficient of correlation was found to be 0.999 for the obtained method with molar absorptivity of 3.05×103 L/mol.cm. The calculated Sandell’s sensitivity is 0.108 μg/cm2. The limit of detection and limit of quantification are 0.0997 and 0.3023 µg/mL, respectively. The low values of the percentage relative standard deviation and percentage relative error indicate the high precision and the good accuracy of the proposed method. The stoichiometry of the reaction is determined and found to be 1:4 (Ranitidine hydrochloride:Ninhydrin). The initial rate method confirmed that this reaction is first order one.

scholarly journals A New Spectrophotometric Method for Hydrogen Sulphide Through Electrolytically Generated Mn(III) WithO-Tolidine

2008 ◽  
Vol 5 (1) ◽  
pp. 93-99 ◽  
Author(s):  
M. S. Suresha ◽  
Mansour S. Abdul Galil ◽  
Mahadevaiah ◽  
M. A. Sathish ◽  
M. S. Yogendra Kumar ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Hydrogen Sulphide ◽  
Spectrophotometric Method ◽  
Water Samples ◽  
Molar Absorptivity ◽  
Official Method ◽  
Color Intensity ◽  
Orange Yellow ◽  
Relative Standard

A simple, sensitive and economical spectrophotometric method for the determination of hydrogen sulphide is developed. The method is based on a redox reaction in that Mn(III) generated electrolytically is taken in excess, which is oxidizing a known but a less quantity of hydrogen sulphide and the unreacted oxidant will oxidize furthero-tolidine to produce an orange yellow quinonediimine absorbing cation (λ max. 455 nm). Therefore, in principle, the decrease in color intensity of the absorbing system is proportional to the concentration of hydrogen sulphide. The stoichiometry between Mn(III) ando-tolidine and stability constant of the complex were determined by Job's continuous method, the corresponding values were found to be 2:1 and 1.42X105Lmol-1. The system was obeying Lambert-Beer's law in the range 0.2-1.4 μg mL-1of hydrogen sulphide. Molar absorptivity, correlation coefficient and Sandell's sensitivity values were also calculated and found to be 4.2062X103L mol-1cm-1, 0.999 and 0.0012 μg cm-2respectively. The method was employed for the determination of hydrogen sulphide in water samples. The results obtained were reproducible with acceptable standard deviation 0.01-0.068 and relative standard deviation, less than 3.21%. For a comparison, hydrogen sulphide present in water samples were also determined separately following the methylene blue official method. The results of the proposed method compare well with the official method.

scholarly journals Determination of Metochloropramide Hydrochloride by Spectrophotometric Method by using Diazotized p-nitro aniline reagent

2020 ◽  
Vol 10 (01) ◽  
pp. 68-73
Author(s):  
Intidhar D. Sulaiman ◽  
Walaa A. Abd Alrada
Keyword(s):  
Alkaline Medium ◽  
Spectrophotometric Method ◽  
Azo Dye ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Amino Group ◽  
Primary Amino

New simple, sensitive, accurate, and inexpensive spectrophotometric technique has been developed for the estimation of Metochloropramide hydrochloride [MCP-HCl] in pure and pharmaceutical preparation. This technique is based on the diazotization of a primary amino group of Metochloropramide hydrochloride [MCP-HCl] with NaNo2 and HCl followed by coupling with p-nitro aniline in alkaline medium to obtain a stable red-colored water-soluble azo-dye, show a maximum absorption (λmax) at 513. 50nm. Bear,s low is obeyed in the concentration range of (0.2–25) μg.ml-1 with molar absorptivity of 2.313×103L.mol-1.cm-1and sandall’s sensitivity 0.0145 μg.mL-2. The limit of detection (LOD) and limit of quantitative were 0.182 μg.mL-1and 0.553 μg.mL-1, respectively. The proposed technique successfully applied to (tablets, syrup, and injection).

scholarly journals Spectrophotometric determination of Valsartan in pure form and in its pharmaceutical preparations

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Qabas Rashid ◽  
Ruwaida Farman Salih
Keyword(s):  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Chromogenic Reagent

An easy, rapid and economical spectrophotometric method for  determination of  Valsartan (Val), by reaction with 4-chloro-7-nitrobenzofurazan (NBD-Cl) as reagent in an alkaline interemediate. This method is based on the forming of product between (Val) and the chromogenic reagent (NBD-Cl), to produce a brown color at (pH 11.9) and λmax. 470 nm.  Beer’s Law is obeyed at the concentrations range of (0.4-14.8 µg/ml), with molar absorptivity of (1.05×104 L/mol.cm) and correlation coefficient 0.9827, The limit of detection was 0.557 µg/ml. The suggested method was prosperity implement to the determination of (Val) in  pure form and in its pharmaceutical formulations (tablets).

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