The determination of six different isoquinoline alkaloids from Chelido
nium majus (leaves and roots) using capillary electrophoresis is descr
ibed. Analyses were performed on fused silica capillaries with 66 mM p
hosphate buffer at pH 2.4 containing 10% methanol. The analytes were m
onitored by on-line ultraviolet (UV) detection to identify sanguinarin
e, chelerythrine, berberine and chelidonine. Both coptisine and DL-sty
lopine were isolated by semi-preparative high performance liquid chrom
atography (HPLC), and their structure assessed by UV and mass spectrom
etry. Capillary electrophoresis is confirmed as a useful complementary
technique to HPLC.