Abstract

Automated amino acid analysis by low pressure ion chromatography separation and conductivity detection has been investigated. The method is characterized by separating amino acids under the low pressure of 1.97 – 2.94 x 10-5 Pa (30 – 40 psi) and detecting them by sensitive conductivity without pre-column or post-column derivatisation. The chromatography parameters were investigated, i.e. the capacity of the resin, the size of the resin, the length of separation column, elution solution and flow rate. The results show that 10 amino acids, Asp, Hyp, Ser, Glu, Pro, Gly, Ala, Val, Met and Leu have been separated and detected successfully using a 5mm x 100mm long column filled with 25μm – 30μm size and 0.02mmol/g capacity cationic exchange resin. The elution solution is 0.8mmol/L nitric acid solution and the flow rate 0.6ml/min. The method is linear in the concentration range of 10-3 – 10-4 mol/L and 10-4 – 10-5 mol/L. The variation coefficient is 1%-5% and the detection limit which can be achieved is 1.0 x 10-5 mol/L.