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When acetate buffer was used in chiral separation of d , l -serine derivatives using a γ-cyclodextrin (CD) column, both retention factor and resolution were high below the pKa of acetic acid and decreased sharply as the pH approached the pKa. A similar result was obtained by increasing the buffer concentration at a fixed pH. These observations suggest that hydrogen bonding interaction between the carboxylate group of the amino acid and the secondary hydroxyl groups at the CD rim plays an important role in chiral separation and is disrupted by the buffer anion.

5-Hydroxymethylfurfural (HMF) was determined without interferences in juices, honey, syrup, tomato paste, grape juice concentrate and dehydrated pear by anion-exclusion chromatographic separation and UV detection at 285 nm. The samples were mixed with water, filtered and injected without extensive sample treatment, which is normally required in conventional spectrophotometric or reversed-phase high-performance liquid chromatographic methods, HMF at the 50 ppb level was determined with a signal-to-noise ratio of 6. The recovery of HMF added to honey was 98% at the 10 ppm level and 91% at 30 ppm.