Fig. 1. Effect of sulfosalicylic acid concentration on retention
acid was larger than the column void volume be- volumes (V ) of (A) anions and (B) cations. Eluent pH 2.9; R
sample: mixture of 0.5 mM Na SO , NH NO , KNO , CaCl , and cause of hydrophobic interactions of the eluent 2 4 4 3 3 2 22 2 2 1 1 MgSO (0.1 ml). (1) SO , (2) Cl , (3) NO , (4) Na , (5) NH , species with the unfunctionalised portions of the 4 4 3 4 1 21 21 (6) K , (7) Mg , (8) Ca .