Fta. Chen et Ra. Evangelista, FEASIBILITY STUDIES FOR SIMULTANEOUS IMMUNOCHEMICAL MULTIANALYTE DRUGASSAY BY CAPILLARY ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE, Clinical chemistry, 40(9), 1994, pp. 1819-1822
We present a method for the simultaneous quantification of multiple dr
ug analytes in urine, based on combining immunochemical binding with c
apillary electrophoretic separation. Two fluorescent drug-cyanine (Cy)
dye conjugates were prepared as competing species for the immunoassay
. Morphine was derivatized with Cy5 (lambda(max) = 652 nm, epsilon = 2
15 000 mol(-1)cm(-1)), phencyclidine (PCP) with Gy5.5 (lambda(max) = 6
75 nm, epsilon = 200 000 mol(-1)cm(-1)L). The high-efficiency resolvin
g power of the capillary electrophoresis system (20 mu m x 27 cm colum
n) separated the individual labeled drugs, and the antigen-antibody co
mplexes were detected by laser-induced fluorescence (laser: 10 mW He-N
e at 632.8 nm) with Cy5 diacid as internal standard. Simultaneous comp
etitive immunoassay of morphine and PCP in urine showed that the free
labeled-drug peak areas were proportional to the concentrations of the
drug species present in the urine sample. This immunoassay can be per
formed routinely and reproducibly in <5 min with analytical detection
limits of 4 nmol/L for PCP and 40 nmol/L for morphine.