Study on the Colour Reaction of a New Reagent 1-(2,6-dichloro-4-nitrophenyl)-3-(4-nitrophenyl)- Triazene with Cadmium and Its Application
YANG Ming-hua 1,ZHENG Yun-fa 1,GONG Chu-ru 2 (1. Department of Chemistry, Lishui Teachers College, Lishui, 323000; 2. Department of Chemistry, Hubei Normal University, Huangshi, 435002)
The coluor reaction of 1-(2,6-dichloro-4-nitrophenyl)-3-(4-nitrophenyl)-triazene (DCNPNPT) with cadium (Ⅱ) was studied. Results show that the yellow complex(1∶3) appears at pH=9.8～11.0 buffer solution of Na 2B 4O 7-NaOH in the presence of Triton X-100. The maximum absorption is at 445 nm, whereas the maxmium negative absorption is at 525 nm. The molar absorptivity is 2.85×10 5 L·mol -1·cm -1 by using dual-wavelength spectrophotometry. This method has been used for the determination of Cd(Ⅱ) in waste water and human hair with satisfactory results.