Spectrophotometric method for the determination of demeclocycline using sodium molybdate as analytical reagent

1991 ◽  
Vol 103 (1-2) ◽  
pp. 65-70 ◽  
Author(s):  
Milena Jelikić-Stankov ◽  
Dejan Stankov ◽  
Dušan Malešev ◽  
Zorica Radović
2011 ◽  
Vol 8 (2) ◽  
pp. 587-593 ◽  
Author(s):  
Maliheh Barazandeh Tehrani ◽  
Effat Souri

A simple and sensitive derivative spectrophotometric method for simultaneous determination of nickel and copper using 6-(2- naphthyl)-2,3-dihydro-1,2,4-triazine-3-thione (NDTT) as a selective analytical reagent was developed. The complexes of metal ions with NDTT were formed immediately in basic media and extracted with chloroform. The zero-crossing measurement technique was found suitable for the direct measurement of the third-derivative value of Ni-NDTT and Cu-NDTT at 501 and 472 nm respectively. Beer’s law is obeyed in the concentration range 1-30 μg/mL for both cations with different ratios. The limit of detection was 0.26 μg/mL and 0.13 μg/mL for copper and nickel respectively. The within day and between day variations showed coefficient of variation (CV%) values less than 2.80 and 2.97 for copper and nickel respectively. The error of the determination method did not exceed 6.50%. Analysis of alloy sample showed that this method can be successfully used for simultaneous determination of Cu and Ni in real samples.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Oleksandr S. Tymoshuk ◽  
Orest S. Fedyshyn ◽  
Lesia V. Oleksiv ◽  
Petro V. Rydchuk ◽  
Vasyl S. Matiychuk

The simple, rapid spectrophotometric method for palladium(II) ions determination using a new analytical reagent is described. The interaction of Pd(II) ions with a reagent, of the class of azolidones, 4-(N′-(4-imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic acid, in water medium results in the formation of a complex. The Pd(II)-p-ITYBA complex shows maximum absorbance at a wavelength of 450 nm. The molar absorptivity is 4.30 × 103 L·mol−1·cm−1. The optimal pH for complex formation is 7.0. The developed method has a wide linearity range of 0.64–10.64 µg·mL−1 for Pd(II). The detection limit is 0.23 µg·mL−1. It was found that Co(II), Ni(II), Zn(II), Fe(III), Cu(II), Al(III), and many anions do not interfere with the Pd(II) determination. The proposed method was tested in the analysis of model solutions and successfully applied for the determination of palladium in catalyst. The obtained results show that this method can be used for serial determinations of palladium in various objects.


Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Fe(III) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into ethyl acetate at pH 6. The method obeys Beer’s law over arrange from 1 to 7 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.31 × 104 L mol-1cm-1 and 0.13 μg cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


2006 ◽  
Vol 3 (3) ◽  
pp. 154-158 ◽  
Author(s):  
P. Venkata Reddy ◽  
B. Sudha Rani

A simple and reproducible spectrophotometric method has been developed for the determination of two recent antiviral drugs namely Valacyclovir (drug A) and Famciclovir (drug B) in bulk and pharmaceutical dosage forms. The method is based on the extraction of the drugs into organic layer of the dye TPooo in presence of 0.1 N hydrochloric acid and the absorbances were measured at 490 nm. The method was optimized using eight parameters.


2011 ◽  
Vol 8 (3) ◽  
pp. 1362-1370 ◽  
Author(s):  
D. Venkataramana Reddy ◽  
P. V. Chalapathi ◽  
A. Varada Reddy

A rapid, sensitive and fairly selective spectrophotometric method has been developed for the determination of molybdenum(VI) using gallacetophenone phenylhydrazone (GPPH) as an analytical reagent. The GPPH forms an orange red species of molybdenum(VI) at a pH range of 3.0-4.0 and the complex is soluble in 20% ethanol. The Mo(VI)-GPPH complex shows maximum absorbance at 375 nm with molar absorptivity and Sandellʼs sensitivity being 1.539x104L/mol cm and 1.5x10-3μg cm-2respectively. The system obeys Beerʼs law in the range of 1.0-6.0 μg/mL. The repeatability of the method was checked by finding the relative standard deviation. The composition of the Mo(VI)-GPPH complex is established as 1:2 by slope analysis method. The instability constant of the complex calculated from Edmond and Birnbaumʼs method is 6.785x10-8at room temperature. The interfering effect of various cations and anions has also been studied. The method has been applied for the determination of Mo(VI) in alloy steel samples.


2009 ◽  
Vol 20 (5) ◽  
pp. 993-998 ◽  
Author(s):  
Manpreet Kaur ◽  
Varinder Kaur ◽  
Ashok K. Malik ◽  
Neelam Verma ◽  
Baldev Singh ◽  
...  

Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Cu(II) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into n-butanol at pH 9.2. The method obeys Beer’s law over arrange from 1 to 10 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.97 × 104 L mol-1cm-1 and 0.26 µg·cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


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