A study was conducted, which demonstrated the through-put and analytical precision of AFT columns for the analysis of real samples, such as amino acids. In prior studies we also analysed amino acids using AFT columns, but these were 4.6 mm in internal diameter, and when coupled to MS detection, the flow velocities achievable were only equivalent to conventional 2.1 mm i.d. columns [9]. In this work, AFT 2.1 mm i.d. columns have been employed, and this subsequently enables separations to be undertaken at much greater through-put than when conventional 2.1 mm i.d formats are employed