Determination of Copper in Black,Red Pepper and the Waste Water Samples by a Highly Selective Sensitive Cu(II)Microelectrode Based on a New Hexadentates Schiff's Base

摘要

A Cu~(2+)ion-selective membrane microelectrode has been fabricated from poly vinyl chloride(PVC)matrix membrane containing a new symmetrical hexadentate Schiffs base 2-{1-(E)-2-((Z)-2-{(E)-2-[(Z)-1-(2-hydroxyphenyl)ethylidene] hydrazono}-1-methylpropylidene)hydrazono]ethyl}phenol(HDNOS)as a neutral carrier,Potassium tetrakis(4-chlorophenyl)borate(KTpClPB)as an anionic excluder and o-nitrophenyloctyl ether(NPOE)as a plasticizing solvent mediator.The microelectrode displays linear potential response in the concentration range of 1.0 X 10~(-5)-1.0 X 10~(-11)M of Cu~(2+).The microelectrode exhibits a nice Nernstian slope of 25.9 +-0.3 mV decade-1 in the pH range of 3.1-8.1.The sensor has a relatively short response time in whole concentration ranges(approx 5 s).The detection limit of proposed sensor is 5.0 X 10~(-12)M(320 pg/L),and it can be used over a period of eight weeks.The practical utility of the sensor has been demonstrated by using it as an indicator electrode in the potentiometric titration of Cu~(2+)with EDTA.The proposed membrane electrode was used for the direct determining of Cu~(2+)content in black and red pepper,and in waste water samples.