peaks of o-CIPF and its coordination compound with Ga(I)is only 48nm apart in the presence of CTMAB micelle alone.Although the absorption peaks of both o-CIPF and its coordination compound with Ga(I)all shift batho- chromically in the presence of mixed micelle of CTMAB and Tween-80,but they situate at 530nm and 578nm respectively and their separation still remains at 48nm.The laboratory data are shown in Fig.1. 2.2 Optimum Chromophoric Conditions (1)Acidity:In the presence of CTMAB alone,a maximum and constant absorbance is obtained within the pH range of 7.2~7.6;but in the presence of mixed micelle of CTMAB and Tween-80,it is extended to pH 6.8~7.6; furthermore,its sensitivity is improved. (2)Amount of o-CIPF:To cause a maximum and constant absorbance, 0.3~0.5ml of o-CIPF solution is suitable for the ternary system of (Ga(I) -o-CIPF-CTMAB)but it is extended to 0.4~0.8m1 for the quarternary system of《Ga(I)—o-C1PF—Tween--80》. (3)Choice of surfactants:The sensitizing effect of 16 kinds of cationic and 8 kinds of nonionic surfactants have been tested.It has been found that the cationic surfactants shows obvious sensitization for the colouration of Ga (I)with o-CIPF,especially the CTMAB is most effective.After comparing various nonionic surfactants which belong to Triton X series,Tween series and emulsifier,it is found that the addition of Tween-80 to CTMAB can intro- duce a most sensitive colouration;moreover,it shows wider chromophoric conditions and better stability than with CTMAB alone. From the laboratory data shown in Fig.2,it has been found that the suitable amount of CTMAB solution and Tween-80 solution for 25.00ml of coloured solution should be 1.0~7.0ml and 3.0~6.0ml respectively.In the following experiments,2.5ml of CTMAB solution and 4.0ml of Tween-80 solu- tion are chosen;thus,a concentration of CTMAB is larger than the C.M.C. value of CTMAB alone. (4)Order of reagents adding:If the working solution of Ga(I)is mixed with o-CIPF before the presence of micelle,the absorbance is reduced.Besides, if the working solution of Ga()is mixed with buffer solution at first,the absorbance decreases markedly with the hydrolysis of Ga(),and reproduci- bility is also poor.Only after the micelle of one or two surfactants has already existed,will the colouration develop with a maximum and constant absorbance,.The order of“Ga(I)—CTMAB-Tween-80一o-ClPF buffer"has been proved to be most suitable for a rapid and complcte coloura- tion. 388一 位 一 一 ， 五 犷 口 。 。 。 。 ， 。 一 。 妞 一 ， 。 。 ， · 一 ， 。 一 。 一 《 — 一 — 》 。 《 — 一 — 一 五 。 一 ， 住 ， ， 百 一 ， · ， 五 往 一 。 扭 。 。 。 。 ， 。 。 一 ， · · 。 一 ， · ， ， ， ， “ — — 一 — 一 ” —