Distribution coefficients and ion-exchange selectivities for 46 elements with a macroporous cation-exchange resin in hydrochloric acid-acetone medium

Mixtures of the radionuclides Na22 and Na24, as the chloride salts, have been partially separated by chromatographic methods. A column 102 cm. in length containing the cation exchange resin Dowex 50 was used. The eluant was 0.7 M hydrochloric acid. Na22 is held more strongly by the resin than is Na24. The most effective separations were obtained at 25 °C and 5.5 °C.; experiments at 48 °C and 68 °C showed much smaller isotope effects.

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

Clinical Chemistry ◽

10.1093/clinchem/23.10.1921 ◽

1977 ◽

Vol 23 (10) ◽

pp. 1921-1924 ◽

Cited By ~ 1

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.

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

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/63.3.460 ◽

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.

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Collaborative Study of an Ion Exchange Method for Ephedrine in Ephedrine Sulfate Sirup NF

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/52.4.854 ◽

1969 ◽

Vol 52 (4) ◽

pp. 854-857

Author(s):

Donald J Smith

Keyword(s):

Hydrochloric Acid ◽

Ion Exchange ◽

Positive Charge ◽

Exchange Resin ◽

Collaborative Study ◽

Cation Exchange Resin ◽

Polystyrene Sulfonate ◽

Resin Column ◽

Exchange Method ◽

Ion Exchange Method

Abstract An ion exchange procedure for Ephedrine Sulfate Sirup NF, based on the ability of ephedrine to be retained on a polystyrene sulfonate cation exchange resin column, was studied collaboratively by eight laboratories. The compound is held on the column by a positive charge located in the cationic center of the molecule, it is then eluted with hydrochloric acid, and its ultraviolet absorption is measured. The addition of 57.88 mg ephedrine sulfate to Ephedrine Sulfate Sirup NF resulted in recoveries of 58.39 and 57.72 mg, or 101 and 100%, respectively. Recoveries for collaborative samples, each containing 19.22 and 19.33 mg/5 ml, were 99.8 ± 1.83 and 101 ± 4.09%, respectively.

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