Two different approaches were applied for the preconcentration step. In the first one (Fig. 1A) a sample was mixing with TCPP and buffer in the manifold followed by retention of the formed Mn–TCPP complex for selected interval time. In the second approach a sample was pumped through the microcolumn packed with Amberlite IRA-904 loaded with TCPP (Fig. 1B). In all cases after preconcentration step, the first injection valve was switched to its other position and 0.5 ml of 2 M HNO3 solution was injected by means of a second valve in order to release manganese directly into the nebulizer of the spectrometer. Finally, the blank carrier (deionised water) was passed through the microcolumn for 30 s (at 6.8 ml min−1) in order to prepare it for the following sample loading.