Reducing saccharides, analysis effects

Besides amino acids, traces of borate in the mobile phase can also affect monosaccharide analysis due to complexation. Borate ions are among the first to be detected in the slip of water purification systems when their mixed-bed ion exchangers approach the capacity limit (Borate can be determined with ion-exclusion chromatography and subsequent conductivity detection down to the lowest ng/L level utilizing pre-concentration see Section 5.5.) If de-ionized water used for preparing the mobile phase contains traces of borate, a significant loss of peak symmetry is observed this effect is most pronounced with mannose and other reduced saccharides. Even borate concentrations in the lowest mg/L levels are sufficient to cause this effect. With a specially-designed BorateTrap column, which is placed between the analytical pump and the injection valve, borate can be completely removed from the mobile phase. 

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