DIANTIPYRYLPROPYLMETHANE AS ELECTRODE-ACTIVE COMPONENTS OF MEMBRANE OF LEAD SELECTIVE ELECTRODE

Abstract

The possibility of approbation of an ion-selective electrode based on diantipyrylpropylmethane for determination of lead is considered in the work. Optimization of the membrane composition of an ion-selective electrode was carried out with the change of weight ratios of membrane components. The best results were obtained with the addition of potassium tetraphenylborate by weight of 1.35%. According to the obtained experimental steepness, a membrane of composition (wt.%) was chosen: PVC (32.62), o-PFOE (65.25), DAPPM (1.35), NaTPB (0.78). The linearity interval of the electrode with an optimized composition of the membrane was observed in the concentration range of 10-6 -10-1 M, with a response of 10 s. The slope of the Pb-SE function is 27.4 ± 0.5 mV / pC. The influence of the acidity of the medium on the Pb-SE response was studied. At the pH=3-5 a potential of the Pb-SE for the compositions remains stable with a drift not more than 2 mV. For a given electrode, the selectivity coefficients were determined by the method of bionic potentials with respect to some d-elements, as well as alkaline and alkaline-earth metals. The influence of zinc, cadmium, mercury and copper ions on the membrane response is significant, which requires the use of various masking reagents in potentiometric analysis in the presence of these ions. To increase the selectivity of the membrane to lead ions, 0.1 M NH4SCN was introduced into the solution under analysis to bind Cu (II), Zn (II), Hg (II) and Cd (II) ions to stronger ammonium complexes. The proposed electrode favorably differs by the interval of the determined concentrations (M) - 10-6 - 10-1; high selectivity, and also increases in the stability of the membrane due to high lipophilicity relative to diantipyrylmethane.Forcitation:Tataeva S.D., Ramazanov A.Sh., Magomedova V.S., Magomedov K.E., Zeynalov R.Z. Diantipyrylpropylmethane as electrode-active components of membrane of lead selective electrode. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 23-28