A lutetium PVC membrane sensor based on (2-oxo-1,2-diphenylethylidene)-N-phenylhydrazinecarbothioamide
Based on the former experience on the design and construction of metal ions sensors, especially those of high sensitivity for lanthanides, (2-oxo-1,2-diphenylethylidene)-N-phenylhydrazinecarbothioamide (PHCT) was used to construct a Lu(3+) PVC sensor exhibiting a Nernstian slope of 19.8 +/- 0.3 mV dec(-1). The sensor was found to function well over a concentration range of 1.0x10(-2) and 1.0x10(-6) mol L(-1) of the target ion with a detection limit of 6.8x10(-7) mol L(-1). The sensor selectivity against many common alkaline, alkaline earth, transition, heavy metals and specially lanthanide ions was very good and it functioned well in the pH range 2.5-8.7. Having a lifetime of at least 2 months and a short response time of approximate to 5 s, the sensor was successfully used as an indicator electrode in the potentiometric titration of Lu(3+).