Rapid Determination of Plasma Ammonia by an Ion-Exchange Technic

1964 ◽  
Vol 10 (6) ◽  
pp. 497-508 ◽  
Author(s):  
Donald T Forman
Keyword(s):  
Ion Exchange ◽  
Exchange Resin ◽  
Rapid Determination ◽  
Cation Exchange Resin ◽  
Great Sensitivity ◽  
Ammonium Ion ◽  
Colorimetric Determination ◽  
Experimental Conditions ◽  
Colorimetric Procedure

Abstract A method is described for the colorimetric determination of ammonia in plasma by a batch ion-exchange procedure. The method combines separation of ammonium ion, using a strongly acidic cation-exchange resin, with a sensitive colorimetric procedure which simultaneously elutes and colorimetrically reacts with the ammonium ion to produce a stable color. Interference by basic amino acids is negligible, and the great sensitivity of the color reaction permits the measurement of ammonia of the order of 0.5 µg./ml. The effects of variations in the experimental conditions are examined, and the results of recovery experiments and other tests of precision and accuracy are reported. In comparison with other methods in current use, this method has distinct advantages in sensitivity, simplicity, and rapidity of determination, provided the conditions and methods of measurement are controlled carefully.

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.

The non-protein nitrogen composition of grass silages: I. The estimation of the basic amino acids and non-volatile amines by chromatography on a weak cation exchange resin

1969 ◽  
Vol 72 (3) ◽  
pp. 459-466 ◽  
Author(s):  
A. D. Hughes
Keyword(s):  
Amino Acids ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Protein Nitrogen ◽  
Weak Cation Exchange

SUMMARYInvestigations into the non-protein nitrogen composition of grass silages using the 50 cm strong cation-exchange column of Spackman, Stein & Moore (1958) to determine the basic amino acids led to difficulties in the determination of ethanolamine in the presence of high concentrations of ammonia, and of histidine in the presence of δ amino-n-valeric acid. An alternative technique for the ion exchange chromatography and estimation of histidine, lysine, ornithine, ethanolamine, arginine and ammonia on a weak cation-exchange resin has been developed. This method enables small amounts of ethanolamine to be determined in the presence of large amounts of ammonia and values for the ethanolamine content of a number of silage samples are presented. When used in conjunction with the technique of Spackman et al. (1958) the δ-amino-n-valeric acid content of grass silages could also be determined in the presence of histidine.The estimation of amines produced by the microbial decomposition of herbage proteins during ensiling has previously involved their initial separation from the amino acids followed by quantitative partition chromatography. An alternative method for the estimation of these amines by ion-exchange chromatography on a weak cation-exchange resin is described. This method permits the colorimetric determination of β-phenylethylamine, tyramine, tryptamine, 5-hydroxytryptamine, putrescine, cadaverine and histamine without interference from the amino acids. The efficiency of this technique has been investigated using standard solutions of the naturally occurring amines and samples of good quality and of high pH spoilt silages.

scholarly journals Simplified two-step column-chromatographic determination of taurine in urine.

1978 ◽  
Vol 24 (2) ◽  
pp. 321-325 ◽  
Author(s):  
M A Anzano ◽  
J O Naewbanij ◽  
A J Lamb
Keyword(s):  
Present Method ◽  
Exchange Resin ◽  
Rapid Determination ◽  
Cation Exchange Resin ◽  
Chromatographic Determination ◽  
Cysteic Acid ◽  
Chromatographic Procedure ◽  
Acidic Compounds ◽  
Column Chromatographic

Abstract A two-step column-chromatographic procedure for accurate and rapid determination of taurine in urine is described. Sulfosalicyclic-acid deproteinized samples are chromatographed on a 0.9 X 10 cm column of cation-exchange resin (AG 50W-XB), with use of a pH 2.2 sodium citrate eluting buffer such that taurine and the more highly acidic compounds in urine are eluted in the void volume, and then on a 0.9 X 8 cm column of anion-exchange resin (AG 2-X8), from which taurine is preferentially eluted with 1 mol/liter acetic acid. The color developed with ninhydrin is directly proportional to taurine amounts as low as 0.01 mumol/sample. The method is highly reproducible, with analytical recoveries greater than 95%. The presence of 333 mumol of urea and 1 mumol of cysteic acid did not interfere in the analysis. When a mixture of C14-labeled amino acids other than taurine were co-chromatographed with taurine, less than 2% of the total counts loaded were located in the taurine fraction. Values for urinary taurine excretion by rats according to the present method agreed well with values obtained with an automated amino acid analyzer. Advantages of the present method for the determination of taurine are discussed.

Collaborative Study and Ion Exchange Method for the Determination of Methyldopa, Chlorothiazide, and Hydrochlorothiazide in Drug Mixtures

1971 ◽  
Vol 54 (3) ◽  
pp. 603-608
Author(s):  
Rod Chu
Keyword(s):  
Standard Deviation ◽  
Ion Exchange ◽  
Exchange Resin ◽  
Collaborative Study ◽  
Cation Exchange Resin ◽  
Resin Column ◽  
Exchange Method ◽  
Average Recovery ◽  
Ion Exchange Method

Abstract A method for the assay of methyldopa with either chlorothiazide or hydrochlorothiazide was studied collaboratively by 8 laboratories. The method involves the use of AG50-4X, 100-200 mesh H+ cation exchange resin to resolve the compounds. The thiazides pass freely through the resin column, while methyldopa is retained and subsequently eluted with 1N methanolic HCl. The components are quantitatively measured by spectrophotometry at 280 (methyldopa), 277 (chlorothiazide), and 270 nm (hydrochlorothiazide). For the methyldopa-chlorothiazide combination, the overall average recovery for methyldopa was 98.5% with a standard deviation of 2.50; and for the methyldopa-hydrochlorothiazide combination, 96.4% with a standard deviation of 2.30. The average recoveries for chlorothiazide and hydrochlorothiazide were 99.6 (standard deviation of 1.14) and 98.8% (standard deviation of 2.92), respectively. The method has been adopted as official first action for the determination of methyldopa and chlorothiazide in combination.

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.

Simplified radioimmunoassay of urinary drugs of abuse adsorbed on ion-exchange papers.

1977 ◽  
Vol 23 (10) ◽  
pp. 1921-1924 ◽  
Author(s):  
G J Alexander ◽  
S Machiz
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Drugs Of Abuse ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Screening Procedure ◽  
Central Laboratory ◽  
Small Disc

Abstract A convenient screening procedure for presence of drugs of abuse in urine consists of two steps: adsorption of the drugs from urine onto a paper loaded with cation-exchange resin and detection of the adsorbed drugs by direct radioimmunoassay. The first step can be performed in the field, the second in a central laboratory. Storage and transport to the laboratory are simplified because specimens adsorbed on dried paper are stable and can be sent in letter-mail. In the laboratory, a small disc of the ion-exchange paper is exposed to antigen and antibody, rinsed, and tested for radioactivity. Discs treated with positive urines are more radioactive than discs from negative urines.

Sign in / Sign up

Export Citation Format

Share Document