scholarly journals A Simple Spectrophotometric Determination of Phosphate in Sugarcane Juices, Water and Detergent Samples

2007 ◽  
Vol 4 (4) ◽  
pp. 467-473 ◽  
Author(s):  
Mahadevaiah ◽  
M. S. Yogendra Kumar ◽  
Mansour S. Abdul Galil ◽  
M. S. Suresha ◽  
M. A. Sathish ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Official Method ◽  
Sodium Sulphide ◽  
Cane Juice ◽  
Sulfuric Acid Medium ◽  
Sugar Cane Juice

A simple spectrophotometric method is developed for the determination of phosphate in sugar cane juice, water and detergent samples. The method is based on the formation of phosphomolybdate with added molybdate followed by its reduction with sodium sulphide in aqueous sulfuric acid medium. The system obeys Lambert-Beer’s law at 715 nm in the concentration range 0.3-12.24 ppm. Molar absorptivity, correlation coefficient and Sandell’s sensitivity values were found to be 6.1x103mol-1cm-1, 0.999 and 0.0156 µg cm-2respectively. The results obtained were reproducible with acceptable standard deviation 3.7% and relative error 3.4%. For a comparison of the method phosphate present in various samples were also determined separately following an official method. The results of the developed method compare well with those of the official method.

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 Simple Spectrophotometric Method for Determination of Paroxetine in Tablets Using 1,2-Naphthoquinone-4-Sulphonate as a Chromogenic Reagent

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Heba H. Abdine ◽  
Sawsan M. Amer ◽  
Lama I. Al-Rayes
Keyword(s):  
Spectrophotometric Method ◽  
Correlation Coefficients ◽  
Molar Absorptivity ◽  
Official Method ◽  
Calibration Data ◽  
Pharmaceutical Tablets ◽  
Relative Standard ◽  
Label Claim ◽  
Colored Product

Simple and rapid spectrophotometric method has been developed and validated for the determination of paroxetine (PRX) in tablets. The proposed method was based on nucleophilic substitution reaction of PRX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium to form an orange-colored product of maximum absorption peak () at 488 nm. The stoichiometry and kinetics of the reaction were studied, and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance (A) with PRX concentration (C) was obeyed in the range of 1–8 g . The regression equation for the calibration data was: A = 0.0031 + 0.1609 C, with good correlation coefficients (0.9992). The molar absorptivity () was L  1 . The limits of detection and quantitation were 0.3 and 0.8 g , respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the determination of PRX in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was %. The results obtained by the proposed method were comparable with those obtained by the official method.

scholarly journals Development and validation of spectrophotometric method for phenylephrine hydrochloride estimation in nasal drops formulations

2008 ◽  
Vol 27 (2) ◽  
pp. 149 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Vladimir Banković
Keyword(s):  
Standard Deviation ◽  
Sodium Hydroxide ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Phenylephrine Hydrochloride ◽  
Relative Standard ◽  
Development And Validation

Simple, accurate and reproducible UV-spectrophotometric method was developed and validated for the estimation of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. Phenylephrine hydrochloride was estimated at 291 nm in 1 mol⋅dm-3 sodium hydroxide (pH 13.5). Beer’s law was obeyed in the concentration range of 10–100 μg⋅cm−3 (r2 = 0.9990) in the sodium hydroxide medium. The apparent molar absorptivity was found to be 1.63×103 dm3⋅mol−1⋅cm−1. The method was tested and validated for various parameters according to the ICH (International Conference on Harmonization) guidelines. The detection and quantitation limits were found to be 0.892 and 2.969 μg⋅cm−3, respectively. The proposed method was successfully applied for the determination of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 1 %), while being simple, cheap and less time consuming, and hence can be suitably applied for the estimation of phenylephrine hydrochloride in different dosage forms.

scholarly journals Spectrophotometric Method for Determination of Paraquat in Food and Biological Samples

1997 ◽  
Vol 80 (2) ◽  
pp. 388-391 ◽  
Author(s):  
Ritu Kesari ◽  
Manish Rai ◽  
Vinay Kumar Gupta
Keyword(s):  
Standard Deviation ◽  
Metal Ions ◽  
Relative Standard Deviation ◽  
Alkaline Medium ◽  
Spectrophotometric Method ◽  
Biological Samples ◽  
Molar Absorptivity ◽  
Relative Standard ◽  
Sensitive Spectrophotometric Method

Abstract A sensitive spectrophotometric method was developed for determination of paraquat, a widely used herbicide. Paraquat was reduced with glucose in an alkaline medium, and the blue radical ion obtained was measured at 600 nm. Beer’s law was obeyed at 0.1–1.2 ppm paraquat. The molar absorptivity was 1.26 × 105 L mol-1 cm-1. The standard deviation and relative standard deviation were ± 0.007 and 2.0%, respectively, for 5 μg paraquat/10 mL analyzed over 7 days. The method was free from interference by other commonly used pesticides and metal ions. The method may be used to the determine paraquat in plants, fruits, grains, water, blood, and urine.

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.

Spectrophotometric Determination of Boron in Dates of Some Cultivars Grown in Saudi Arabia

1993 ◽  
Vol 76 (3) ◽  
pp. 601-603 ◽  
Author(s):  
A A Al-Warthan ◽  
S S Al-Showiman ◽  
S A Al-Tamrah ◽  
A A BaOsman
Keyword(s):  
Saudi Arabia ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Relative Standard ◽  
Sensitive Spectrophotometric Method

Abstract The formation of a red complex between boron and the quinalizarin reagent was investigated and used as the basis for a simple and sensitive spectrophotometric method for boron in date cultivars. At 620 nm, the absorbance was linear (r= 0.999) over the 0.25-2.5 μg/mL concentration range. The molar absorptivity was found to be 2.23 x 103mol-1cm-1 and the relative standard deviation for 10 replicates (1.0 μg/mL) was 0.97%.

scholarly journals Spectrophotometric Method for the Determination of Paracetamol

1970 ◽  
Vol 24 ◽  
pp. 39-44 ◽  
Author(s):  
Buddha Ratna Shrestha ◽  
Raja Ram Pradhananga
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Trace Amount ◽  
Pharmaceutical Preparation ◽  
Chemical Society ◽  
Molar Absorptivity ◽  
Coupling Agents ◽  
Clinical Samples ◽  
Relative Standard

Paracetamol with 1-napthol or resorcinol gave azodye and the concentration of paracetamol was investigated spectrophotometrically. The azodyes formed with both 1-napthol and resorcinol as coupling agents follow Lambert Beer's law in the range of 0 to 10 µgmL-1 of paracetamol. The molar absorptivity and Sandell's sensitivity for azodye coupled with 1-napthol were found to be 1.68×104 Lmol-1cm-1 and 9.0 ngmL-1cm-2, respectively. The molar absorptivity and Sandell's sensitivity for azodye coupled with resorcinol were found to be 2.86×104 Lmol-1cm-1 and 5.3 ngmL-1cm-2, respectively. Both coupling agents had been applied successfully in the analysis of paracetamol in pharmaceutical preparation. The relative standard deviation for all five samples ranged from 2.2-6.4% at 95% confidence. The percentage recoveries were found to range from 97.8 to 103.4. Both methods used in the present study may be applied to the determination of trace amount of paracetamol in different clinical samples. Keyword: Paracetamol; Spectrophotometric; 1-napthol; Resorcinol DOI: 10.3126/jncs.v24i0.2389 Journal of Nepal Chemical Society Vol. 24, 2009 Page: 39-44

Spectrophotometric Method for Microdetermination of Nitrogen in Kjeldahl Digest

1989 ◽  
Vol 72 (6) ◽  
pp. 953-956 ◽  
Author(s):  
Muljibhai B Devani ◽  
Chamanlal J Shishoo ◽  
Shailesh A Shah ◽  
Bhanubhai N Suhagia
Keyword(s):  
Standard Deviation ◽  
Nitrogen Content ◽  
Spectrophotometric Method ◽  
Acidic Medium ◽  
Molar Absorptivity ◽  
Nitrogen Compounds ◽  
Relative Standard ◽  
Kjeldahl Method ◽  
Aoac Method

Abstract A new spectrophotometric method for the determination of nitrogen in Kjeldahl digest has been developed. The method is based on the reaction of ammonia with acetylacetone-formaldehyde reagent in aqueous medium to yield yellow 3,5-diacetyl- 1,4-dihydrolutidine with a characteristic absorption maxima at 412 nm. The effect of several experimental variables on the determination of nitrogen was studied. The method was suitable for determination of nitrogen in acidic medium without interference from the usual catalysts employed for the digestion in Kjeldahl method. Lambert-Beer’s law is obeyed in the concentration range of 0.5-6.0 ng nitrogen/mL in the reaction mixture. The molar absorptivity in terms of nitrogen was 1.4 X 103L mol-1 cm-1. The standard deviation and relative standard deviation were ±0.0447 and ±0.896% (n = 10), respectively. The method is simple, rapid, and precise. A variety of carbocyclic and heterocyclic nitrogen compounds have been analyzed for nitrogen content. The results are comparable with those obtained by AOAC method, 47.021.

Utility of π-acceptor reagents for spectrophotometric determination of sulphonamide drugs via charge-transfer complex formation

2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Faten Nour El-Dien ◽  
Gehad Mohamed ◽  
Eman Frag
Keyword(s):  
Charge Transfer ◽  
Standard Deviation ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Official Method ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Chloranilic Acid ◽  
Relative Standard

AbstractA simple, sensitive and accurate spectrophotometric method for the determination of sulphonamides (sulphamethoxazole (SMZ), sulphaguanidine (SGD), sulphaquinoxaline sodium (SQX), sulphametrole (SMR), and sulphadimidine sodium (SDD)) has been developed. The charge-transfer reactions between sulphonamides as n-electron donors and 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid, p-CLA) as π-acceptors resulting in highly coloured complexes were studied. Experimental conditions for these CT reactions were carefully optimised. Beer’s law is valid over the concentration ranges from 4–280 µg mL−1, 4–260 µg mL−1, 4–200 µg mL−1, and 4–200 µg mL−1 of SMZ, SGD, SQX, and SDD using DDQ reagent, respectively. While the calibration curves are linear in the concentration ranges from 4–180 µg mL−1, 4–80 µg mL−1, 4–60 µg mL−1, 4–180 µg mL−1, and 4–60 µg mL−1 of SMZ, SGD, SQX, SMR, and SDD, respectively, using TCNQ reagent and from 4–380 µg mL−1 and 4–300 µg mL−1 of SQX and SDD, respectively, using p-CLA reagent, respectively. Different analytical parameters, namely molar absorptivity (ε), standard deviation, relative standard deviation, correlation coefficient, limit of detection, and limit of quantification, were calculated. The results obtained by the proposed methods are in good agreement with those obtained by the official method as indicated by the percent recovery values.

scholarly journals Pyrocatechol Violet in Pharmaceutical Analysis Part II. A Spectrophotometric Method for the Determination of Paracetamol in Pure and in Pharmaceutical Dosage Forms

2001 ◽  
Vol 69 (2) ◽  
pp. 179-188 ◽  
Author(s):  
Alaa Amin
Keyword(s):  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Ion Pair ◽  
Official Method ◽  
Pyrocatechol Violet ◽  
Pharmaceutical Dosage Forms ◽  
Selective Determination ◽  
Significant Difference

A spectrophotometric method for the selective determination of paracetamol based on its reaction with pyrochatechol violet under basic conditions to form an ion-pair complex is described. The absorption maximum of the coloured ion-pair formed is observed at 652 nm and the molar absorptivity is 4.54 x10-3l mol-1 cm-1. Beer's law is obeyed over the concentration range 0.5-34.0 μg ml-1, while that obtained using Ringbom method is in the range 3.5 -32.0 μg ml-1. There is no interference from common additives, excipients and commercial drugs present in their formulations suggesting a highly selective procedure compared with others. Statistical analysis of the obtained results showed that there is, no significant difference and absence of any systematic error in the method compared with the official one. The method is simple, rapid and convenient and was applied successfully to the determination of paracetamol in pure and in its dosage forms compared with the official method.

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