Conductivity measurements chromatography gradients

Separation of a purified hydrolyzate of demineralized bovine dentin by cation exchange chromatography at pH 5.25. Gradient 0.0 - 0.5 M NaCl in 0.05 M HAc/NaAc, 1 mM NaNs, pH 5.25. Column SP Sephadex C25 (34 x2.6cm). Flow rate approx. 30 ml/h. The 4-ml fractions were assayed for amino acids by ninhydrin reaction (—) and for NaCl by electric conductivity measurement after 75-fold dilution (—). Fractions collected for further characterization are denoted by bars and Roman numerals. 

Conductivity detectors respond to all ions. In suppressed-ion chromatography, it is easy to measure analyte because eluenl conductivity is reduced to near 0 by suppression. Suppression also allows us to use eluent concentration gradients. 

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