A simple conductometric method for trace level determination of brilliant green in water based on β-cyclodextrin and silver nitrate and determination of their thermodynamic parameters

A gravimetric and complexometric titration method based on conductometric technique is presented for the quantitative determination of brilliant green (BG) in water. The equilibrium constants and the thermodynamic parameters for the complex formation of β-cyclodextrin (β-CD) with brilliant green (BG) and precipitation of silver nitrate with BG have been determined by conductivity measurements in water. The results suggest that stable 1:1 complex is formed between BG and β-cyclodextrin and the thermodynamic parameters ( ΔHc°, ΔSc°) for this complexation reaction have been determined from temperature dependence of the stability constant using the van’t Hoff plots. Based on the obtained results, the conductometric method for the determination of BG in the presence of β-CD at 25 °C was developed in the range of 10−8–10−3 mol L−1 and with AgNO3 is 10−3–10−5 mol L−1.