The method of claim 2 wherein the 1,2-dioxetane is of the formula: ##STR21## wherein R5 and R6 are alkyl groups which may be combined together to form a spiro-fused cyclic or polycyclic ring alkyl group containing 6 to 30 carbon atoms, wherein R3 is selected from alkyl and aralkyl groups containing 1 to 20 carbon atoms and wherein R4 is an aryl group substituted with an X-oxy group which forms an