Developing a new ion selective electrode based

In this study, developing of a new solid state ion selective electrode based calcium fluorapatite (Ca10(PO4)6(F)2) purposed. The electrodes was made with mixed different mass ratio of Ca10(PO4)6(F)2 (calcium fluorapatite), Ag2S and Cu2S salts. Some of electrodes was used the ground human teeth instead of Ca10(PO4)6(F)2. Ion selectivity of electrode was researched with using a lot of ions by potentiometric method.It was observed that electrode has sensitivity to fluoride ions, chloride ions and pH variation in high and low pH. The measurements were made at constant ionic strength (0,1 M NaNO3, medium) and at room temperature(220C). It was achieved best performance from the electrode that composition is % 20 Ca10(PO4)6(F)2 + % 5 Cu2S + % 75 Ag2S. It was established that this electrode have selectivity with slope 10 ± 3,4 mV/pF for fluoride ions; 20 ± 3,5 mV/pCl for chloride ion at 1x10-6-1x10-2 M ion concentration range and pH 6. In addition to, It was protected that the electrode has a slope with 25± 3,2 mV/pH at the range of pH:1-5 and 39 ± 5,8 mV/pH at the range of pH 10-13 to changing of pH in the cell solution. It was researched the interferences effect of K+, Mg2+, Ca2+, Ni2+, Cu2+, Cr3+, OH-, F-, I-, PO43- and identified the selectivity coefficients in presence of 1x10-3 M Cl-.This electrode has been used for the determination of chloride concentration in samples of synthetic tear and top water by applying standard addition method. The concentration of chloride was determinated (0,6 ± 0,1) mgCI-/L in tear and (0,7 ± 1,2) mgCI-/L in top water.