AAT – Amino Acid Trap
- Efficient trapping of amino acids/small peptides
- Easy installation, as a precolumn
- 4 x 50 mm column, 5 µm resin
In compositional analysis of monosaccharides from glycoproteins using HPAEC-PAD, the presence of amino acids and small peptides can interfere with the quantification of the analytes of interest. These amino acids and small peptides are generated during the acid hydrolysis of glycoproteins to release the monosaccharides from the protein backbone. If the concentration of amino acids, in particular lysine and glutamine, is high enough compared to that of the released monosaccharides, they will interfere with the monosaccharide quantification because of coelution. Moreover, amino acids are less efficiently removed from the Au electrode surface due to the suboptimal potential waveform applied for monosaccharide detection, which might lead to fouling and loss of response. To eliminate the interference of amino acids and to assure optimal performance of your monosaccharide analysis using HPAEC-PAD, Antec Scientific introduces an amino acid trap column.
The amino acid trap column is based on a novel monodisperse 5 µm polymeric resin functionalized with active groups which temporarily trap or delay the elution of amino acids and small peptides under the separation conditions (10 – 20 mM NaOH) used in HPAEC-PAD monosaccharide analysis. Subsequently, the trapped amino acids are eluted during the wash/regeneration step at high pH (typically 100 – 200 mM NaOH), without fouling the Au working electrode surface.
The performance of the amino acid trap is demonstrated in figure 1. A mix of 6 monosaccharides and 4 amino acid standards was injected onto a SweetSep™ AEX20 column with and without trap column. Without an amino acid trap in the system, in particular lysine and glutamine, are coeluting with the monosaccharides of interest. It is evident that with amino trap column, the problem of coelution of amino acids is effectively eliminated.
Fig 1. Analysis of carbohydrates with and without a SweetSep™ amino acid trap. Interfering peaks of lysine and glutamine are no longer an issue in the top chromatogram.
Conditions: separation on SweetSep™ AEX20 column using a 20 mM NaOH eluent (30°C, 0.7 mL/min). The amino acid trap column is used as a pre-column. Injected sample: 10 µL of standards in DI water of 10 µM monosaccharides (fucose, galactosamine, glucosamine, galactose, glucose and mannose) and 1 mM amino acids (arginine, lysine and glutamine). Top (red): with amino acid trap; Bottom (black): without amino acid trap. Amino acids marked in red.