CHROMATOGRAPHY
CHROMATOGRAPHY, Vol. 25 (2004), No. 3, pp. 93-109
Forcusing Review
Pure silica gel as cation-exchange stationary phase in ion chromatography for mono- and divalent cations
Kazutoku Ohta
Inhomogeneity Analysis Research Group Research Institute of Instrumentation Frontier (RIIF) National Institute of Advanced Industrial Science and Technology (AIST) 2266-98 Anagahora, Simoshidami, Moriyama-ku, Nagoya 463-8560, Japan
Received for review September 21, 2004. Revised manuscript received November 23, 2004. Accepted November 26, 2004.
Abstract:
The review article describes the application of a pure silica gel (Pia Seed 5S-60-SIL), synthesized by the hydrolysis of pure teratraetoxysilane [Si(OCH2CHG3)4], as a cation.exchange stationary phase in ion chromatography for common mono. and divalent cations (Li+, Na+, NH4+, K+, Mg2+ and Ca2+). Using aromatic monoamines at pH 5.0 as eluents, the Pia Seed 5S-60-SIL silica gel acted as an advanced cation. exchange stationary phase for these mono. and divalent cations. Excellent simultaneous separation and highly sensitive indirect.photometric detection at 275 nm for these cations were achieved on a Pia Seed 5S.60.SIL column (150 ~ 4.6 mm i. d.) in 20 min with 0.75 mM tyramine [4-(2-aminoethyl)phenol]-0.25 mM oxalic acid at pH 5.0 containing 1.5 mM 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) as the eluent. Using dilute oxalic acid (0.2 mM oxalic acid) as the eluent, the Pia Seed 5S-60-SIL silica gel also behaved as an advanced cation.exchange stationary phase for these mono- and divalent cations. Excellent simultaneous separation and highly sensitive indirect.conductimetric detection for these cations were also achieved on the column in 20 min with 0.2 mM oxalic acid at pH 3.6 containing 1.5 mM 18-crown-6 as the eluent. The review article also describes the chromatographic behavior of these mono- and divalent cations on the calcinated Pia Seed 5S-60-SIL silica gel columns.
Keywords: Pure silica gel, Ion Chromatography, Cations, Indirect-photometric detection, Tyramine, Indirect-conductimetric detection, Oxalic acid, Crown ethers, Calcination.