Abstract: 6-[N-(4-aminobutyl-N-ethyl)-N-ethyl]-amino-2,3-dihydrophthalazine 1,4-dione (ABEI) is a kind of common labelled compounds in luminescence immunodiagnosis.We have made a study of the various conditions of electrochemiluminescence of ABEIand found that the optimal rectangular electric pulse parameters are: pulse space 0.45, pulse length 20 ms, pulse amptitude +1.6 V(vs.SCE), and that the medium condition is: 0.12 mol/L KOH-0.080 mol/L H₃BO₃-0.080 mol/LKCl (pH 12.0).Under these conditions, the range of the linear relationship between light intensity and concentration of ABEIis 1.0×10^-8 mol/Lto 9.0×10^-5 mol/L.Our study also shows that Cl^- in the solution was oxidized to ClO^-, and ClO^- acts on ABEIand then gives out luminescence.

Key words: Electrochemiluminescence, ABEI, Luminescence immunodiagnosis