Determination of 1-tryptophan and inosinic acid in fermentation solutions (spectrophotometric analysis of compounds in the presence of an optical background)

1985 ◽  
Vol 19 (12) ◽  
pp. 872-880
Author(s):  
E. R. Roshal' ◽  
A. F. Sholin
1985 ◽  
Vol 33 (7) ◽  
pp. 729-732 ◽  
Author(s):  
R A Clark ◽  
G L Krueger

The triammonium salt of aurin tricarboxylic acid, commonly referred to as aluminon, forms a dye that has been used for the colorimetric determination of Al(III) species. We have reviewed the pertinent literature on the reaction of aluminon with respect to the metallic species that form colored aluminon complexes. The effects of experimental variables, such as time, temperature, and pH, upon the color development of the aluminon complex are also presented. Organic and inorganic species, particularly Be(II) and Fe(III), which can affect color formation, are described. The use of aluminon as a histochemical staining agent for the detection of aluminum requires verification by atomic absorption spectrophotometric analysis or other quantitative techniques.


2002 ◽  
Vol 67 (11) ◽  
pp. 777-782 ◽  
Author(s):  
Dragutin Drazic ◽  
Jovan Popic

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1M Na2SO4 + H2SO4 (pH1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II):Cr(III)?7:1. This process was stable over 4h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, "anomalous" dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process.


Author(s):  
LIPSA SAMAL ◽  
AMARESH PRUSTY

Objective: The aim of the present work was to develop and validate a simple UV spectroscopic method for the determination of duloxetine, which is a thiophene derivative and a selective neurotransmitter reuptake inhibitor for serotonin, norepinephrine, and to lesser degree dopamine. Methods: The UV Spectrophotometric analysis was performed using Shimadzu UV-1800 and Shimadzu UV-1700 spectrophotometer by using solvent system acetonitrile and water in the ratio of 8:2. Detection was performed at a wavelength of 290 nm. Method validation was carried out according to ICH Q2R1 guidelines by taking the parameters linearity, accuracy, precision, ruggedness, and robustness, LOD and LOQ. Results: The UV Spectrophotometric method was found linear in the range of 10-50 μg/ml. The method was rugged and robust with % relative standard deviation less than 2. The extraction recoveries were found to be higher than 99% in all experimental conditions. Conclusion: Based upon the performance characteristics, the proposed method was found accurate, precise and rapid and suitable for the determination of Duloxetine for routine analysis.


1977 ◽  
Vol 60 (1) ◽  
pp. 16-20 ◽  
Author(s):  
Paul R Mathewson ◽  
Yeshajahu Pomeranz

Abstract A method is described for the rapid, convenient detection or estimation of sprout-damaged wheat by determining its α-amylase content colorimctrically. A commercially available substrate in the form of dyed amylose tablets is used. The extent of sprout damage can be determined qualitatively, or quantitatively when actual α-amylase concentration is required. Amylase content is determined by visual comparison with prepared colored standards or by spectrophotometric analysis. The method requires only 5 min incubation time and no elaborate equipment, and is sufficiently simple for use at locations having minimal laboratory facilities.


2001 ◽  
Vol 84 (2) ◽  
pp. 368-375 ◽  
Author(s):  
Mohammed Rizk ◽  
Fathalla Belal ◽  
Fawiza Ibrahim ◽  
Soad Ahmed ◽  
Zeinab A Sheribah

Abstract A derivative UV-spectrophotometric analytical procedure was developed for determination of three 4-quinolone antibacterials: norfloxacin (NFX), ciprofloxacin (CFX), and sparfloxacin (SFX). The method depends on the complexation of Cu(II) with the studied compounds in aqueous medium. A third order, measurement was applied for their quantification. A linear correlation was established between the amplitude of the peak and concentration for all the studied drugs in the range of 15–80, 35–120, and 200–700 ng/mL, with minimum detectability (S/N = 2) of 1.0, 1.3, and 5.1 ng/mL for NFX, CFX, and SFX, respectively. The method was successfully applied for accurate, sensitive, and selective determination of the studied drugs in bulk and tablets formulation with average percentage recoveries of 99.22 ± 0.55 to 100.33 ± 1.60. The results obtained were favorably compared with those of the reference method. The method was also used to determine sparfloxacin in spiked human plasma and urine. The results obtained were satisfactory, accurate, and precise.


2009 ◽  
Vol 92 (6) ◽  
pp. 1673-1680 ◽  
Author(s):  
marinês J E Souza ◽  
Natália Canedo ◽  
Paulo S Souza Filho ◽  
Ana M Bergold

Abstract A UV spectrophotometric method was developed for determination of ceftiofur sodium in the drug substance and sterile powder for injection. The method validation, which yielded good results, included evaluation of the range, linearity, intraand interday precision, accuracy, recovery, specificity, robustness, LOQ, and LOD. The UV spectrophotometric determinations were performed at 292 nm. Good linearity was obtained between 2.5 and 20.0 g/mL. A prospective validation showed that the method is linear (r = 0.9999) and precise, with RSD values of 0.3 for product A and 0.4 for product B. The intraand interday precision values were <2 for all samples analyzed. Comparison of UV spectrophotometry and LC by analysis of variance and Student's t-test showed no significant difference between methodologies. Moreover, the accuracy and precision obtained with the UV method correlated well with the values obtained with the LC method, and this correlation suggests that UV spectrophotometric analysis can be an inexpensive, reliable, and less time-consuming alternative to chromatographic analysis. The results demonstrated the validity of the proposed method as a simple and useful alternative for the determination of ceftiofur in routine QC analyses.


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