Metrohm is continuously expanding its range of columns and improving existing separation column types by means of the latest production methods and materials. The new Metrosep C 4 separation column can be used for the determination of the standard cations, of amines and transition metals. It is available as iColumn, i.e. as an intelligent separation column, in column lengths of 50 mm, 100 mm, 150 mm and 250 mm. The standard eluent for the C 4 column is composed of 1.7 mmol/L nitric acid (HNO3) and 0.7 mmol/L dipicolinic acid (DPA). All the other standard parameters have also been optimised for this eluent. This, together with the low standard flow of 0.9 mL/min not only increases the columns lifetime but also ensures optimal analytical results.