scholarly journals DETERMINATION OF TRACE NITRITE AS 4-(4-NITROBENZENAZO)- 1-AMINONAPHTHALENE COMPLEX BY EXTRACTION-SPECTROPHOTOMETRY

2010 ◽  
Vol 9 (2) ◽  
pp. 254-260
Author(s):  
Choirul Amri ◽  
Dwi Siswanta ◽  
Mudasir Mudasir

A study of extraction-spectrophotometric method for the determination of trace nitrite as 4-(4-nitrobenzenazo)-1-aminonaphthalene complex using n-amylalcohol and chloroform as organic solvents has been done. Results of the study showed that extraction-spectrophotometric determination of nitrite using n-amylalcohol or chloroform was very sensitive and had low limit of detection. Extraction-spectrophotometric method of nitrite using n-amylalcohol gave range of linear concentration 0.000-0.054 mg/L NO2--N, detection limit of 2.09x10-4 mg/L NO2--N, and sensitivity of 34.514 ± 0.398 absorbance unit per mg/L of NO2--N. Meanwhile, extraction-spectrophotometric of nitrite using chloroform had range of linear concentration of 0.000-0.100 mg/L NO2--N, detection limit of 8.99x10-4 mg/L NO2--N, and sensitivity of 18.353 ± 0.456 absorbance unit per mg/L NO2--N.   Keywords: Nitrite Trace, 4-(4-Nitrobenzenazo)-1-Aminonaphthalene, Extraction-Spectrophotometry

1990 ◽  
Vol 73 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Ivan Chang-Yen ◽  
Keshore Bidasee

Abstract An improved visible spectrophotometric method has been developed for cyclopiazonic acid in poultry feed and corn. The method Is based on the reaction of cyclopiazonic acid with Ehrlich reagent and detection at 580 nm. Reaction conditions were optimized with respect to reaction and measurement times and acid and Ehrlich reagent concentrations. Calibration curves were linear from 1 to 20 μg cyclopiazonic acid in 3 mL Ehrlich reagent, with a lower detection limit of 0.08 mg/kg for 50 g samples of poultry feed and corn. Recoveries from 50 g samples of poultry feed spiked with cyclopiazonic ranging from 0.16 to 1.20 mg/kg averaged 93.8%. Moldy corn and poultry feed samples analyzed by this method contained between 1 and 4 mg/kg cyclopiazonic acid.


1978 ◽  
Vol 32 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Angelo Barbetta ◽  
Walter Edgell

A spectrophotometric method of trace water analysis in organic solvents is reported. It is based on the water fundamental at 2.8 µ and has been applied to hexamethylphosphoramide, nitromethane, acetonitrile, oxetane, dimethylsulfoxide, 1,1-dimethoxyethane, dimethylformamide, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydropyran, 1,2-dimethoxyethane, n-butylmethylether, and pyridine. Methods for dealing with solvent absorption and water pickup by samples, and the preparation of water-free samples for reference are discussed. Some comments are made on drying these solvents with molecular sieves.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Lea Kukoc-Modun ◽  
Njegomir Radić

A simple spectrophotometric method for the determination ofN-acetyl-L-cysteine (NAC) andN-(2-mercaptopropionyl)glycine (MPG) in pharmaceutical preparations was developed, validated, and used. The proposed equilibrium method is based on a coupled two-step redox and complexation reaction. In the first step, Fe(III) is reduced to Fe(II) by NAC or MPG. Subsequently, Fe(II) is complexed with 2,4,6-tripyridyl-s-triazine (TPTZ). Several analytical parameters of the method were optimized for NAC and MPG analysis in the concentration range from 1.0 μM to 100.0 μM. Regression analysis of the calibration data showed a good correlation coefficient (0.9999). The detection limit of the method was 0.14 μM for NAC and 0.13 μM for MPG. The method was successfully applied to quantify NAC and MPG in pharmaceutical preparations. No interferences were observed from common pharmaceutical excipients.


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.


2019 ◽  
Vol 10 (2) ◽  
pp. 1392-1396 ◽  
Author(s):  
Khalaf F Alsamarrai ◽  
Menaa Abdulsalam Al-Abbasi ◽  
Eman Thiab Alsamarrai

A new, sensitive, simple and cheap spectrophotometric method for the determination of Neomycin Sulphate (NEO) in pharmaceutical forms has been developed. The method is based on the reaction between NEO and NIN in basic medium. The maximum absorbance was at 574 nm. The conditions affecting the reaction were optimized. Under the optimal conditions, the calibration curve was linear over the range of 0.0002-0.0011 mol/L. The limit of detection and limit of quantification were 5.423×10-6 mol/L, and 1.643×10-5 mol/L, RSD% of seven replicate was 0.8217- 0.8321% and Rec% was between 99.2168-100.8857%. The proposed method was successfully applied to the determination of NEO tablets form.


Author(s):  
Muchlisyam Muchlisyam ◽  
Sudarmi Sudarmi ◽  
Cindy Caroline

 Objective: Mean centering of ratio spectra method (MCR method) is one of the simplest methods for the determination of drug mixtures. The purpose of this research is to determine the content of theophylline (THEO) and ephedrine HCl (EPH) in tablets by MCR spectra method.Methods: This research was conducted with the MCR method. It was measured at 271 nm for THEO and 257 nm for EPH using 0.1 N HCL as a solution. The calculation was conducted with Matlab application. The analytical characteristics of the method are detection limit, accuracy, precision, and selectivity. Standard addition method was used to increase the concentration of EPH in the sample until it reached the range of calibration concentration.Result: The research has showed that validations for THEO were 100.57% for accuracy, 0.68% for relative standard deviation (RSD), 0.46 μg/mL for limit of detection (LOD), and 1.52 μg/mL for limit of quantification (LOQ). Meanwhile, the validations for EPH are 100.02% for accuracy, 0.07% for RSD, 43.12 μg/mL for LOD, and 143.72 μg/mL for LOQ. The level of THEO is 97.43 ± 0.17% and the level of EPH is 101.36 ± 0.25% for brand one’s tablet. Meanwhile, brand two’s tablet contains 98.72 ± 0.14% of THEO and 103.62 ± 0.23% of EPH.Conclusion: MCR ultraviolet spectrophotometric method can be used to determine the content of THEO and EPH in tablets and meets the detection limit, accuracy, precision, and selectivity.


2018 ◽  
Vol 35 (3) ◽  
pp. 93
Author(s):  
T. V. Badiadka ◽  
Badiadka Narayana

A simple and rapid spectrophotometric method for the determination of nevirapine is described. The method is based on the reaction of nevirapine with tetrathiocyanatocobalt(II) ion in buffer of pH 4 to form the corresponding complex. Beer’s law is obeyed in the range of 0.2 – 2.0 μg mL-1 for nevirapine. The optical parameters such as molar absorptivity, Sandell’s sensitivity, detection limit and quantitation limit were found to be 1.16× 104 Lmol-1cm-1, 2.09 X 10-3 μg cm-2, 0.073 μg mL-1 and 0.222 μg mL-1 respectively. The optimum reaction conditionsand other analytical parameters were evaluated. The statistical evaluation of the method was examined by determining intra-day and inter-day precision. The proposed method has been successfully applied for the determination of nevirapine in pharmaceutical formulations.


2007 ◽  
Vol 72 (8-9) ◽  
pp. 809-819 ◽  
Author(s):  
Biljana Abramovic ◽  
Vesna Anderluh ◽  
Ferenc Gaál ◽  
Daniela Sojic

A derivative spectrophotometric method for the determination of the herbicides picloram (4-amino-3,5,6-trichloropicolinic acid) and triclopyr (3,5,6-trichloro- 2-pyridyloxyacetic acid) in mixtures was developed in this work. Derivative spectrophotometric determination of the selected herbicides was preceded by investigations concerning the influence of pH, in the pH interval from 1 to 9. At pH 3.2, picloram and triclopyr solutions are stable under daylight for nine months. This pH was used for all subsequent determinations. It was also found that the use of the first derivative of the spectra at 232 nm was optimal for the determination of picloram, while use of the second derivative of the spectra at 211 nm was best suited for the determination of triclopyr. The calibration curves are linear in the concentration range 0.8 - 13 ?g cm-3 with correlation coefficients -0.9998 for picloram and 0.9996 for triclopyr. The limit of detection of the developed method is 0.08 ?g cm-3 for picloram and 0.03 ?g cm-3 for triclopyr. Derivative spectrophotometry was shown to be an appropriate method for the determination of picloram and triclopyr in mixtures and in pesticide formulations, unlike the deconvolution method. .


2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Qabas Rashid ◽  
Ruwaida Farman Salih

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).


2011 ◽  
Vol 356-360 ◽  
pp. 920-923 ◽  
Author(s):  
Gui Qing Wen ◽  
Yan Mei Ma ◽  
Zhi Liang Jiang

The decolored reaction between cetyltrimethyl ammonium bromide (CTMAB) and nanosilver was studied, and a simple, rapid spectrophotometric method was established to determine CTMAB. In pH 7.8 Na2HPO4-NaH2PO4buffer solution, nanosilver exhibited a maximum absorption peak at 395 nm, and it reacted with CTMAB to form larger particles that resulted in the absorption decreasing. Under the chosen conditions, the decreased absorbance was linear to the CTMAB concentration in the range of 2.5×10-7-1.0×10-5mol/L, with the regression equation of ΔA395 = 0.0431C CTMAB + 0.0182, the correlation coefficient of 0.9968 and the detection limit of 0.21μmol/L CTMAB. The proposed method was applied to detect CTMAB in water samples, with simplicity, rapidity and accuracy.


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