Separation of carcinogenic aromatic amines in the food colourants plant wastewater treatment

A new method of separation of carcinogenic aromatic amines in wastewater is given. With SDS (C12H25O4SNa) and beta-CD (beta-cyclodextrin) addition, it is effective to improve separation. At the same time, it forms mixed micelle. As a result, a micellar electrokinetic capillary chromatography (MECC) system was established. Nine aromatic amines were separated by the MECC with added lower concentration of beta-CD. In the system, the sample entered the capillary at the in positive electrode and was detected at the negative electrode. The experiment revealed that the separation of aromatic amines increased quickly with a slight increase in beta-CD concentration in MECC. Nine analytes reach the baseline separation in 13 min. The retention order of peaks of aromatic amines is related to the number of carbon atoms of the solute molecules and the numbers of amino. When the number of amino groups gets larger, the number of carbon atoms of the solute molecules becomes smaller, and the peaks elute earlier, the 110 mmol/L SDS and 10 mmol/L P-CD were chosen. When the NaH2PO4 concentration is from 20 to 60 mmol/L, the separation of aromatic amines increased quickly. And then the 40 mmol/L is chosen. The optimal conditions were 40 mmol/L NaH2PO4 (pH 9.6).