APPLICATIONS OF MEKC IN THE DETERMINATION OF BENZIDINES FOLLOWING EXTRACTION FROM WATER, SOIL, SEDIMENT, AND CHROMATOGRAPHIC ADSORBENTS

Micellar electrokinetic chromatography (MEKC) with ultra-violet detection is used to determine benzidine (4,4′-di-aminobiphenyl) and three substituted analogues (3,3′-dimethoxybenzidine, 3,3′-dimethylbenzidine, and 3,3′-dichlorobenzidine) in water, soil, and sediment. Recovery of benzidines from chromatographic adsorbents is also determined by MEKC. The use of short capillaries makes possible the determination of benzidines in soil extracts in about 2 minutes after solid-phase extraction cleanup with C18 cartridges. Although benzidines are determined down to 10 ng/g in water, problems are encountered in the extraction of benzidines from soil and sediment matrices and from chromatographic adsorbents. Several solvent systems are investigated with moderate success for extraction of benzidines at contaminant levels in the µg/g range for soil. MEKC of additional aromatic amines is carried out, allowing assessment of the specificity of the determination. © 1994 Oxford University Press.