320 



T. V. Shcherbakova 



400 440 480 520 560 600 



Fig. 3. Luminescence spectra of petroleums of different specific gravity: 1 — 0.797; 

 2—0.801; 3—0.813; 4—0.820; 5—0.831; 6—0.853; 7—0.861. 



Figure 4 shows the results of determining the luminescence of solutions of 

 petroleum in chloroform. 



As can be seen, the luminescence spectrum of petroleum changes Httle 

 with addition of chloroform, but the intensity of the radiation increases 

 considerably. The intensity of the green radiation changes in proportion to 

 the concentration of petroleum in the chloroform up to one hundredth of 

 one per cent (Fig. 5). With further increase of the amount of petroleum m 

 the chloroform the intensity of the luminescence changes little and even 

 begins to decrease (region of concentration extinction [1, 3, 6]). 



Figure 6 shows the dependence of instrumental readings (in ^A) on the 



