This article studies the chromogenic reaction of cobalt(Ⅱ) with 5 Br PADAP in a nonionic micromemulsion containing appropriate amounts of emulgent:OP

n butanol n hepane and 90% water

under the ambient temperature.The results of the photometric analysis are as follows:the maximum wave length of absorption of the complex is 588nm;the molar absorptivity is 1.13\+*10\+5L·mol\+\{-1\}·cm\+\{-1\}

and when the amount of cobalt(Ⅱ)ranges from 0 to 30 μg/25 mL

it obeys the Beer′s law.Compared with the micelle system with only one kind of emulgent

op

and the same amount of water

the method used here improve the sensiveness dramatically.