Analysis of Sodium Diphenylhydantoin and Phenobarbital Combinations by Nonaqueous Titration

1968 ◽  
Vol 51 (5) ◽  
pp. 1013-1016
Author(s):  
Sura J P Agarwal ◽  
Martin I Blake
Keyword(s):  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Ammonium Hydroxide ◽  
Butyl Alcohol ◽  
Dosage Forms ◽  
Direct Titration ◽  
Titration Procedure ◽  
Tert Butyl Alcohol ◽  
Preliminary Separation

Abstract A simple, nonaqueous titration procedure is described for the determination of sodium diphenylhydantoin and phenobarbital combinations. Preliminary separation of the components is unnecessary. The phenobarbital content is determined by direct titration in tert.-butyl alcohol, using sodium methoxide or triethyl n-butyl ammonium hydroxide as the titrant. The total acidity is determined by titration of the sample after passage through a cation exchange resin (Amberlite IRC-50). The sodium diphenylhydantoin content is obtained by difference. Quantitative recoveries were obtained for synthetic mixtures and commercially available dosage forms

The determination of mimosine and 3,4-dihydroxypyridine in biological material

1964 ◽  
Vol 15 (1) ◽  
pp. 168 ◽  
Author(s):  
MP Hegarty ◽  
RD Court ◽  
PM Thorne
Keyword(s):  
Hydrochloric Acid ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Ammonium Hydroxide ◽  
Mesityl Oxide ◽  
Specific Method ◽  
Fresh Material ◽  
First Time ◽  
Hydrolysis Of

A simple, specific method is described for the determination of mimosine and 3,4-dihydroxypyridine (DHP) in extracts of leaves and seeds of Leucaena glauca Benth. and in urine. Plant material is extracted with cold 0.1 N hydrochloric acid, and interfering substances are removed by chromatography on a cation-exchange resin. Organic cations are displaced from the resin with 2N ammonium hydroxide and the concentrated eluate chromatographed in one direction with the use of mesityl oxide : formic acid : water (41 : 7 : 6 by volume). The spots of mimosine and DHP, revealed with a ferric chloride spray, are cut out and the colour fully developed and measured. Urines are analysed in the same way except for a preliminary hydrolysis of the conjugated DHP. The method is satisfactory for estimating amounts of mimosine and DHP in the range 10–160 µg applied to the paper. Recoveries of these substances added to various extracts and to urine have varied between 98–102%. Appreciable destruction of mimosine, with the formation of some DHP, occurred when fresh L. glauca leaves were dried even under mild conditions. In fresh material no loss of mimosine occurred when it was placed immediately in 0.1 N hydrochloric acid. The ready hydrolysis of mimosine to DHP by boiling 0. I N hydrochloric acid has been demonstrated for the first time.

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 Determination of the dipole moments of some polar liquids dissolved in polar solvents

1969 ◽  
Vol 47 (20) ◽  
pp. 3767-3771 ◽  
Author(s):  
H. A. Rizk ◽  
N. Youssef ◽  
H. Grace
Keyword(s):  
Dipole Moments ◽  
Butyl Alcohol ◽  
Polar Solvents ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Initial Decrease ◽  
Interacting Systems ◽  
Solvent Molecules ◽  
Onsager Equation

The application of a modified form of the Onsager equation at the condition of infinite dilution of a polar solute in a polar solvent leads to reasonable dipole moments for water, pyridine, acetone, tert-butyl alcohol, n-butyl alcohol, and β-octyl alcohol, except in the case of water in tert-butyl alcohol at 30 and 40 °C and the case of acetone in n-butyl alcohol at 30 to 50 °C. The initial decrease of the dielectric constant of solvent by addition of solute in each of these two cases is associated with a reduction in the Kirkwood g-factor of solute. In all 12 systems investigated, strong hydrogen bonding occurs between solute and solvent molecules and often between solvent molecules themselves. It is thought that this equation must fail when short-range interactions assume predominant importance, but why it works so well for those cases which are also strongly interacting systems is not clear.

An improved separation scheme for Sr through fluoride coprecipitation combined with a cation-exchange resin from geological samples with high Rb/Sr ratios for high-precision determination of Sr isotope ratios

2020 ◽  
Vol 35 (5) ◽  
pp. 953-960
Author(s):  
Wen-Gang Liu ◽  
Shuang Wei ◽  
Jian Zhang ◽  
Cong Ao ◽  
Fu-Tian Liu ◽  
...  
Keyword(s):  
Cation Exchange ◽  
High Precision ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Separation Scheme ◽  
Geological Samples ◽  
Sr Isotope ◽  
Precision Determination ◽  
High Precision Determination

A new separation method for Sr involving HF coprecipitation combined with AG50 resin from samples with high Rb/Sr ratios.

Ion Exchange Method for Rapid Determination of Alkalinity of Water-Soluble Tea Ash Containing High Levels of Manganese

1980 ◽  
Vol 63 (3) ◽  
pp. 460-461
Author(s):  
Saidul Z Qureshi ◽  
Fadhil M Najib ◽  
Fahmi A Mohammed
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Exchange Resin ◽  
Rapid Determination ◽  
Cation Exchange Resin ◽  
Water Soluble ◽  
Exchange Method ◽  
Strong Cation Exchange ◽  
Ion Exchange Method

Abstract An ion exchange method to determine the alkalinity of water-soluble tea ash containing high levels of manganese is described. A chromatographic column containing a strong cation exchange resin (20–50 mesh) in Na+ form, with a bed volume of 5 mL is used. The present ion exchange method is compared to pH titrations and also to the official AOAC methods (31.012, 31.015, 31.016). Results with the new method are accurate and precise.

Simultaneous Analysis of Nivalenol and Deoxynivalenol in Cereals by Liquid Chromatography

1987 ◽  
Vol 70 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Denis R Lauren ◽  
Roy Greenhalgh
Keyword(s):  
Liquid Chromatography ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Relative Standard ◽  
Phase Liquid ◽  
Cereal Samples ◽  
Sensitive Method

Abstract A sensitive method is described for determination of nivalenol (NIV) and deoxynivalenol (DON) in cereals by using reverse phase liquid chromatography and UV detection at 222 nm. The sample is extracted with acetonitrile-water (85 + 15) and an aliquot is purified by passage through a combined column of cation exchange resin and alumina-carbon (20 + 1). Analysis at this stage is possible with some samples but the method recommends passing an aliquot through a carbon minicolumn after evaporation and solubilization in methanol. Interference from coextracted compounds at this point is negligible. Recoveries of both NIV and DON from spiked extracts taken through the full method were in the range 83-94%. The relative standard deviation, based on 5 replicate determinations from each of 2 corn samples, was approximately 5% for both NIV and DON. With a 10 fiL injection, the minimum contamination (3 x signal/noise ratio) able to be detected in cereal samples was about 0.015 μ NIV/g and 0.05 μ DON/g. The cleaned up extracts are also suitable for analysis by gas chromatography.

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