Determination of Some Kinetic Parameters by Respirometry

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2535-2538 ◽  
Author(s):  
M. Roš ◽  
M. Dular
Keyword(s):  
Reaction Time ◽  
Activated Sludge ◽  
Kinetic Parameters ◽  
Oxygen Transfer ◽  
Dynamic Method ◽  
Research Work ◽  
Substrate Utilisation ◽  
Relative Standard ◽  
Temperature Constant

Individual kinetic parameters such as BOD, biodegradation of wastewater, reaction time, maximal substrate rate can be determined by respirometry. For the determination of main respirometric parameters (STBOD, BODr, reaction time, etc.) overall oxygen transfer coefficient, KLa, is needed. This parameter can be determined with dynamic method in an open respirometer at limited conditions (constant temperature, constant stirring conditions). It was found out that KLa is dependent upon concentration of the activated sludge; it can be determined with about 2% of relative standard deviation. The objective of our research work was determination of maximal exogenous oxygen uptake, re max and maximal substrate utilisation, µmax, which is very important kinetic parameter at wastewater treatment. These parameters show us the maximal substrate (wastewater) utilisation for appointed activated sludge.

Novel Determination of Anti-Hypertensive Combination; Benidipine Hydrochloride and Nebivolol Hydrochloride by High Performance Chromatographic Method

2021 ◽  
pp. 5433-5438
Author(s):  
V.L.N. Balaji Gupta Tiruveedhi ◽  
Venkateswara Rao Battula ◽  
Kishore Babu Bonige ◽  
Tejeswarudu B.
Keyword(s):  
High Performance ◽  
Degradation Products ◽  
Research Work ◽  
Hplc Method ◽  
Assay Method ◽  
Injection Quantity ◽  
Relative Standard ◽  
Nebivolol Hydrochloride ◽  
Concentration Series

This research work was designed to establish and validate a novel stability indicating RP-HPLC method for the combined determination of Benidipine hydrochloride (BHE) and Nebivolol hydrochloride (NHE) in bulk and tablets, dependent on ICH guidelines.The assay method to analyse BHE and NHE was optimized with isocratic elution using acetonitrile: 0.1M acetate buffer (45:55, pH 5.1), Lichrospher ODS RP-18 column and flow pace of 1 ml/min. Total time for single run was 14 min. The injection quantity was 20μl, and was detected at 249nm. The method was verified on a concentration series of 1.25-10μg/ml (NHE) and 1.0-10μg/ml (BHE) for precision, accuracy and linearity. The LOD values were 0.059µg/ml and 0.028µg/ml for NHE and BHE, respectively. The LOQ values were 0.196µg/ml for NHE and 0.094µg/ml for BHE. The recovery percentages were 98.60-100.11% (BHE) and 98.94-101.50% (NHE) with relative standard deviation 0.250-0.694% (BHE) and 0.183-0.400% (NHE). The method was also observed to be efficient, and was sufficiently specific to measure BHE and NHE in the presence of stress-produced degradation products.

Chemiluminescence determination of chromium(VI), molybdenum(VI), and vanadium(V) with bis-(2,4,6-trichlorophenyl) oxalate and perylene

1982 ◽  
Vol 47 (6) ◽  
pp. 1606-1612 ◽  
Author(s):  
Záviš Holzbecher ◽  
Lubomír Kábrt ◽  
Lubomír Janšta
Keyword(s):  
Hydrogen Peroxide ◽  
Standard Deviation ◽  
Oxygen Transfer ◽  
Methyl Acetate ◽  
Catalytic Effect ◽  
Metal Salts ◽  
Experimental Conditions ◽  
Chromium Vi ◽  
Relative Standard

The effect of the experimental conditions (pH, ionic strength, hydrogen peroxide concentration) and of various metal salts on the chemiluminescence occurring during oxidation of bis-(2,4,6-trichlorophenyl) oxalate (TCPO) with hydrogen peroxide in the presence of perylene was studied in water-methyl acetate solutions. The spectrum of the emitted radiation was found practically identical with the fluorescence spectrum of perylene. The observed catalytic effect of Cr(IV), Mo(VI), and V(V) on the chemiluminescence reaction in question can be explained so that these elements form peroxo acids with hydrogen peroxide, thereby facilitating the oxygen transfer from the latter to TCPO. Based on this phenomenon, a method is suggested for the determination of the above elements in concentrations about 10-3 to 10-4 mol l-1; its precision, represented by the relative standard deviation, is about 3-4%, the limits of determination of Cr(VI), Mo(VI), and V(V) are approximately 5-10 μg.

Colorimetric Determination of Arprinocid in Feed

1978 ◽  
Vol 61 (5) ◽  
pp. 1078-1082
Author(s):  
David W Fink ◽  
Kobert P Martin ◽  
James V Pivnichny ◽  
Jung-Sook K Shim
Keyword(s):  
Standard Deviation ◽  
Reaction Time ◽  
Analytical Method ◽  
Acidic Solution ◽  
Feed Additives ◽  
Colorimetric Determination ◽  
Colorimetric Measurement ◽  
Relative Standard ◽  
Zinc Reduction

Abstract An analytical method has been developed for the determination of arprinocid (9-(2-chloro- fluorophenylmethyl) -9ff-purin-6-amine) in feed, based upon measurement of the absorbance of the diazo chromophore formed from product of zinc reduction of the drug in acidic solution. The analyte is extracted from the feed into chloroform in the presence of a pH 7 phosphate buffer and isolated by adsorption chromatography on alumina, followed by partitioning between hexane and 0.15M HC1. The reduction product in the aqueous phase is then treated for colorimetric measurement. This procedure has been applied to determining 0.0010-0.0080% arprinocid in feed with precision of <5% relative standard deviation near the middle of this concentration range. Of 32 feed additives examined, only zoalene and sulfamethazine were serious interferences. study and discussion of several factors, e.g., reaction time, pH, and amount of zinc metal, that affect the analytical reactions are also included.

Biodegradability of industrial textile wastewater – batch tests

2016 ◽  
Vol 74 (5) ◽  
pp. 1079-1087 ◽  
Author(s):  
Katarzyna Paździor ◽  
Anna Klepacz-Smółka ◽  
Julita Wrębiak ◽  
Ewa Liwarska-Bizukojć ◽  
Stanisław Ledakowicz
Keyword(s):  
Activated Sludge ◽  
Kinetic Parameters ◽  
Organic Contaminants ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Batch Tests ◽  
Half Saturation Constant ◽  
Batch Bioreactors ◽  
Parameter Values

Following new trends we applied oxygen uptake rate (OUR) tests as well as long-term tests (in two batch bioreactors systems) in order to assess the biodegradability of textile wastewater. Effluents coming from a dyeing factory were divided into two streams which differed in inorganic and organic contaminants loads. Usefulness of the stream division was proved. Biodegradation of the low-loaded stream led to over 97% reduction of biochemical oxygen demand (BOD5) together with 80% reduction of chemical oxygen demand (COD) and total organic carbon (TOC). Most of the controlled parameter values were below the levels allowed by legislation for influents to surface water, whereas the high-loaded stream was so contaminated with recalcitrant organic compounds that despite the reduction of BOD5 by over 95%, COD, TOC, total nitrogen and total phosphorus levels exceeded permissible values. OUR tests were aimed at determination of the following kinetic parameters: maximum specific growth rate (μMax), half-saturation constant, hydrolysis constant and decay coefficient for activated sludge biomass for both types of textile wastewater studied. The values of kinetic parameters will be applied in activated sludge models used for prediction and optimisation of biological treatment of textile wastewater.

scholarly journals Characterization of camptothecin by analytical methods and determination of anticancer potential against prostate cancer

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sunil T. Galatage ◽  
Rahul Trivedi ◽  
Durgacharan A. Bhagwat
Keyword(s):  
Prostate Cancer ◽  
Mass Spectrometry ◽  
Cell Lines ◽  
Lncap Cell ◽  
Research Work ◽  
Spectrometric Method ◽  
Resonance Spectroscopy ◽  
Relative Standard

Abstract Background Objective of present research work is to develop and validate cost-effective analytical tool for determination of camptothecin (CPT) and determine its anticancer potential against prostate cancer LNCaP cell lines. Structural elucidation has been performed by mass spectrometry, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and MTT assay utilized for in vitro cytotoxicity where spectrometric method was used for estimation of camptothecin. Results Mass spectra showed peak at 349.2 which matches to standard molecular weight of camptothecin. FTIR and NMR spectra conformed functional moieties and structure of isolated camptothecin which was nearly equal to values mentioned in standard structure of camptothecin. IC50 values of CPT against LNCaP cell lines was found to be 3.561 μg/ml. Lambda max of CPT was found to be at 225 nm and calibration curve found to be linear over the concentration range from 2 to 70 μg/ml of camptothecin. Developed method was found to be linear, accurate, and precise. LOD and LOQ were found to be 0.0524 μg/ml and 0.1614 μg/ml, respectively. Developed method has % relative standard deviation less than one which is reproducible hence % recovery was found to be 99.80%. Conclusions FTIR, NMR, and mass spectrometry results conforms isolated compound was camptothecin; cytotoxicity study proves it has strong potential in treatment of prostate carcinoma as competent alternative to chemotherapy in the form of herbal medicine and the developed UV method proves to be valid, sensitive, and applicable for rapid, accurate, precise, and economical determination of camptothecin.

scholarly journals UV-ANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR SIMULTANEOUS ESTIMATION OF DAPOXETINE HYDROCHLORIDE AND SILDENAFIL CITRATE IN TABLET DOSAGE FORM

2019 ◽  
Vol 12 (1) ◽  
pp. 328
Author(s):  
Hemesh Gadiya ◽  
Monika Maheshwari ◽  
Ashok Dashora
Keyword(s):  
Simultaneous Determination ◽  
Method Development ◽  
Research Work ◽  
Dual Wavelength ◽  
Sildenafil Citrate ◽  
Simultaneous Estimation ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Dapoxetine Hydrochloride

Objective: The objective of this research was to develop and validate a simple ultraviolet (UV) spectrophotometric method for simultaneous determination of sildenafil citrate and dapoxetine hydrochloride in a pharmaceutical formulation.Methods: Two simple UV spectrophotometric methods have been developed for simultaneous determination of sildenafil citrate and dapoxetine hydrochloride. For both methods, stock solutions were prepared in methanol followed by the further required dilutions with methanol. Proposed dual-wavelength method and ratio derivative method, the wavelength of maximum absorption for sildenafil citrate and dapoxetine hydrochloride was 292 nm and 231 nm, respectively.Results: In both methods, the linearity range lies between 10 and 60 μg/ml for sildenafil citrate and 2–12 μg/mL for dapoxetine hydrochloride with their respective wavelengths. By dual-wavelength method, the percentage of sildenafil citrate and dapoxetine hydrochloride was found to be 101.3% and 100.3%, respectively.Conclusion: Result obtained in this research work clearly indicated that both these methods were found to be accurate, precise, stable, and robust as indicated by low values of percentage relative standard deviation. Thus, the present study gives an excellent method for the determination of both the drugs in combined tablet formulation.

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