Effect of ring size variation within lipophilic crown ether carboxylic acids on the selectivity and efficiency of competitive alkali-metal cation solvent extraction into chloroform

Journal Article · Sat Sep 15 04:00:00 EDT 1990 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00217a023· OSTI ID:5407771

Walkowiak, W; Kang, Sang Ihn; Stewart, L E; Ndip, G; Bartsch, R A ^[1]

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1. Texas Tech Univ., Lubbock (USA)

Competitive solvent extraction of alkali-metal cations from aqueous solutions into chlororform by a series of lipophilic crown ether carboxylic acids with varying ring sizes is reported. Extraction selectivity for Li{sup +} is observed for lipophilic crown ether carboxylic acids with 12-15-membered polyether rings containing four oxygen atoms. For lipophilic 14-crown-4-carboxylic acids, very high Li{sup +}/Na{sup +} selectivity coefficients of 17-20 are observed with no detectable extraction of K{sup +}, Rb{sup +}, or Cs{sup +}. Lipophilic crown ether carboxylic acids which contain 15-crown-5, 18-crown-6, and 21-crown-7 rings exhibit good selectivities for Na{sup +}, K{sup +}, and Cs{sup +}, respectively. In contrast, poor extraction selectivity is observed for lipophilic crown ether carboxylic acids with 24-crown-8, 27-crown-9, and 30-crown-10 rings.

• OSTI ID: 5407771
• Journal Information: Analytical Chemistry (Washington); (United States), Journal Name: Analytical Chemistry (Washington); (United States) Journal Issue: 18 Vol. 62:18; ISSN 0003-2700; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400105* -- Separation Procedures
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
CARBOXYLIC ACIDS
CHLORINATED ALIPHATIC HYDROCARBONS
CHLOROFORM
DISPERSIONS
EFFICIENCY
EXTRACTION
HALOGENATED ALIPHATIC HYDROCARBONS
MIXTURES
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
SEPARATION PROCESSES
SOLUTIONS
SOLVENT EXTRACTION