DETERMINATION OF LEAD BY DITHIZONE IN A SINGLE PHASE WATER–ACETONE SYSTEM

1957 ◽  
Vol 35 (11) ◽  
pp. 1278-1284 ◽  
Author(s):  
D. G. M. Diaper ◽  
A. Kuksis
Keyword(s):  
Single Phase ◽  
Solvent System ◽  
Complex Ions ◽  
Extraction Step ◽  
Phase Water ◽  
Barbital Buffer ◽  
Interfering Ions ◽  
Acetone System ◽  
Colorimetric Procedure

A modification of the dithizone colorimetric procedure for determination of lead has been developed. By working in an aqueous acetone system (70% acetone by volume) the usual extraction step is avoided. Aqueous ethanol or methanol may also be employed or, under suitable circumstances, water may be omitted from the solvent system. The 70% acetone system proposed is tolerant of cyanide, added to convert interfering ions into non-interfering complex ions, and the interference of copper under the conditions adopted was determined. This system was also found compatible with hydroxylamine, used as stabilizer, and with the barbital buffer. A reproducibility of about 2% was obtained when working with standards in the range from 0 to 10 μg. of lead and the technique was found to be sensitive to 0.1 p.p.m.

scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Two Phase ◽  
Cross Sectional ◽  
Flow Through ◽  
Pvc Pipe ◽  
Phase Water

Fluorometric Determination of Chlortetracycline in Mixed Feeds

1964 ◽  
Vol 47 (2) ◽  
pp. 203-208
Author(s):  
Stanley E Katz ◽  
Joseph Spock
Keyword(s):  
Ion Exchange ◽  
Exchange Resin ◽  
Ammonium Hydroxide ◽  
Solvent System ◽  
Ion Exchange Resin ◽  
Alkaline Degradation ◽  
Fluorometric Determination ◽  
Mixed Feeds ◽  
Microbiological Assays

Abstract The fluorometric procedure for chlortetracycline in mixed feeds is based upon the degradation of chlortetracycline in alkaline solution to isochlortetracycline. The fluorescence of the isochlortetracycline is directly proportional to the concentration of chlortetracycline present prior to alkaline degradation. Chlortetracycline is extracted from mixed feeds with an acidmethanol solvent system, separated from the feed extract by adsorption on a Dowex 50 ion exchange resin, and eluted from the resin by ammonium hydroxide after conversion to isochlortetracycline. The isochlortetracycline is measured fluorometrically. Recoveries from known feeds are generally greater than 90% and agreements with microbiological assays are very close.

scholarly journals Reverse phase-liquid chromatography assisted protocol for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in combined medication used to control HIV infection: an investigative approach

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vaibhav S. Adhao ◽  
Suraj R. Chaudhari ◽  
Jaya P. Ambhore ◽  
Sunil Sangolkar ◽  
Raju R. Thenge ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Hiv Infection ◽  
Simultaneous Determination ◽  
Tenofovir Disoproxil Fumarate ◽  
Solvent System ◽  
Array Detector ◽  
Technical Requirements ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract Background Human immunodeficiency virus (HIV) causes severe life-threatening condition, i.e., AIDS. HIV destabilises an individual’s ability to prevent infection. Therefore, the combine medication lamivudine (LVD) and tenofovir disoproxil fumarate (TDF) are prescribed to suppress the amount of HIV infection in individual’s body; thus, the individual’s immune system could function properly. Consequently, the objective of present research work was to investigate robust and sensitive liquid chromatography avenue for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in pure material and combined dosage form. Results The reversed-phase chromatographic separation has been performed through Hypersil BDS C18 column using solvent system composed of 10 mM potassium dihydrogen phosphate (pH 4.0): acetonitrile (60:40% v/v). The determination was executed at 30 oC at 1 mL/min rate for flow of solvent system through column. The eluents of column were monitored at 265 nm using Photodiode Array detector has revealed admirable retention times, i.e., 4.67 and 8.78 min for both drugs, respectively. The calibration curve demonstrated excellent linearity in the range of 10–50 μg/mL for lamivudine and tenofovir disoproxil fumarate with better determination coefficients was more than (r2 0.999). Conclusion The estimable method was effectively validated with respect to accuracy, precision, sensitive (limit of detection and limit of quantitation), robustness, ruggedness, and for selectivity and specificity. The value less than 2 for percentage relative standard deviation for accuracy, precision, robustness, and ruggedness satisfying the acceptance criteria as per procedure of International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use.

Gas Chromatographic Determination of Ametryn and Its Metabolites in Tropical Root Crops

1984 ◽  
Vol 67 (2) ◽  
pp. 280-284
Author(s):  
Promode C Bardalaye ◽  
Willis B Wheeler
Keyword(s):  
Anhydrous Sodium Sulfate ◽  
Residue Analysis ◽  
Gel Permeation Chromatography ◽  
Chromatographic Determination ◽  
Solvent System ◽  
Complete Separation ◽  
Flame Photometric Detector ◽  
Root Crops ◽  
Photometric Detector

Abstract Residue analysis of the herbicide ametryn (2-methyIthio-4-ethylamino-s-isopropylamino-s-triazine) is widely known but an analytical method for determining its metabolites has not yet been reported in the literature. A method has been developed for the extraction and determination of ametryn and 3 metabolites, 2-methylthio-4-amino-6-isopropylammo- s-triazine (GS-11354), 2-methylthio-4,6-diamino-.s-triazine(GS- 26831), and 2-methylthio-4-amino-6-ethylamino-s-triazine (GS-11355) in taniers, yams, cassava. Residues were extracted from crops with ethyl acetate-toluene (3 + 1 v/v), using a Polytron homogenizer and anhydrous sodium sulfate added for drying. The extracts were cleaned up by automated gel permeation chromatography on Bio-Beads SX-3 gel in the same solvent system. Quantitative determination was performed by gas chromatographic (GC) analysis on a column packed with 5% DEGS-PS on 100-120 mesh Supelcoport using either an N-P detector or a flame photometric detector (FPD) in the sulfur mode. Minimum detection by the flame photometric detector is 10 ng each for ametryn, GS-11354, and GS-11355 and 21 ng for GS-26831; by the N-P detector, 0.3 ng of each component gives easily quantitatable peaks. On a parts per million basis, starting with 25 g sample, the FPD detected a minimum level of 0.04 p.g/g each for ametryn, GS-11354, and GS-11355, and 0.08 p.g/g for GS-26831. The N-P detector could detect 0.0024 p.g/g for all 4 compounds. In addition to superior sensitivity, instrumental conditions allowed the complete separation of components in 10 min, for the N-P detector; more than 30 min was required for the FPD. Recoveries from fortified crops ranged from 67 to 111% at levels of 0.1-1.0 μg/g.

scholarly journals Single-phase determination of calcium and magnesium in biodiesel using smartphone-based digital images

Fuel ◽  
2022 ◽  
Vol 307 ◽  
pp. 121837
Author(s):  
Samara Soares ◽  
Gabriel M. Fernandes ◽  
Liz M.B. Moraes ◽  
Alex D. Batista ◽  
Fábio R.P. Rocha
Keyword(s):  
Single Phase ◽  
Digital Images ◽  
Phase Determination ◽  
Calcium And Magnesium
Sign in / Sign up

Export Citation Format

Share Document