Jump to main content
Jump to site search

Issue 6, 2001
Previous Article Next Article

High-resolution determination of H+ by ion chromatography. Application to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain

Author affiliations

Abstract

An ion chromatographic (IC) method was developed for the high-resolution determination of a sample’s free hydrogen ion concentration (H+). Highly purified lithium dodecyl sulfate was used as the stationary phase, a slightly acidified aqueous LiCl solution was used as the mobile phase and conductivity was used for analyte detection. An electrical double layer (EDL) containing H+ was established on the stationary phase by using a slightly acidified electrolyte solution as the eluent. H+ in the EDL protonated any weak acid groups (i.e., silanols) on the stationary phase so that H+ from the sample could be retained/separated purely by dodecyl sulfate. The optimum molar ratio of H+∶Li+ in the EDL for this IC system was obtained by using an aqueous solution containing 40.0 mM LiCl and 0.07 mM H2SO4 as the eluent. After separation, H+ was detected by direct conductimetric measurement. An H+ detection limit of better than 8.2 × 10−6 M was obtained from the analysis of standard aqueous H2SO4 solutions. Other monovalent cations could also be separated with this method, giving detection limits of 7.4 × 10−5, 4.3 × 10−5 and 4.2 × 10−5 M for Na+, NH4+ and K+, respectively. The method was applied to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain. The results obtained showed a significant improvement in reproducibility when compared with those from a conventional pH-meter. Acid rain samples with a pH <5 could be analyzed with this IC system.

Back to tab navigation

Article information


Submitted
12 Mar 2001
Accepted
05 Apr 2001
First published
18 May 2001

Analyst, 2001,126, 821-824
Article type
Paper

High-resolution determination of H+ by ion chromatography. Application to the simultaneous determination of H+, Na+, NH4+ and K+ in acid rain

W. Hu, K. Hasebe, A. Iles and K. Tanaka, Analyst, 2001, 126, 821
DOI: 10.1039/B102292J

Social activity

Search articles by author

Spotlight

Advertisements