Lead-selective PVC membrane electrodes based on bis(crown ether)s

Lead-selective PVC membrane electrodes based on newly synthesized bis(crown ether)s containing 18-crown-6 moiety was prepared using standard PVC membr ane composition. In order to monitor lead in environmental samples by lead sensor, especially good selectivity over alkali and all;aline earth metals has to be obtained. Thus, responses of the PVC membrane prepared with new b is(crown ether)s and Fluka ionophore V (crown ether) base to various cation s include lead, alkali and alkaline earth metal ions were investigated for their use as a lead sensor. The polymeric Liquid membrane based on trans-18 -crown-6 ether exhibits the best overall potentiometric performances as a l ead-selective electrode in terms of a wide linear dynamic range (between 10 (-6) and 10(-2) M, Pb2+), excellent detection limit (less than 10(-6) M) an d good durability within limited error. The preferences of lead over other cations, such as Ag+, Hg2+, Na+, Ca2+ and even K+ in the aforementioned ele ctrode are much better than the Fluka ionophore V system.