A new ytterbium(III) PVC membrane electrode based on 6-methy-4-{[1-(1H-pyrrol-2-yl)methylidene]amino}-3-thioxo-3,4dihydro-1,2,4-triazin-5(2H)-one.

This study presents the development of an original electrode, employing 6-methy-4-{[1-(1H-pyrrol-2-yl)methylidene]amino}-3-thioxo-3,4dihydro-1,2,4-triazin-5(2H)-one (PMTO) as a suitable ionophore. Interestingly, the electrode performance provided a very good response for Yb(3+) in a wide concentration range (from 1.0x10(-6) to 1.0x10(-1)molL(-1)) with a detection limit of 4.6x10(-7)molL(-1) and a slope of 19.5+/-0.3mV per decade of Yb(3+) concentration. Furthermore, it possessed a fast response time of about 10s and it functioned in the pH range of 3.3-8.0 with a usage of at least 2 months without observing any deviations. Noticeably, the proposed electrode revealed an excellent selectivity for Yb(3+) over a broad variety of alkali, alkaline earth, transition and heavy metal ions. The practical applicability of the electrode was demonstrated by its utilization as an indicator electrode in the potentiometric titration of Yb(3+) ions with EDTA and in the determination of F(-) in mouth wash samples. Additionally, it was also applied for the determination of Yb(3+) ions in binary mixtures.