Preparation and Potentiometric Study of Promethazine Hydrochloride Selective Electrodes and Their Use in Determining Some Drugs

摘要

Promethazine hydrochloride selective electrodes were constructed based on promethazine-phosphotun-gstic acid ion pair in PVC matrix membrane.The plasticizers used were di-butyl phosphate(DBP),tri-n-butyl phosphate(TBP),o-nitro phenyl octyl ether(ONPOE),and di-n-butyl phthalate(DBPH).The electrodes based on DBP,TBP,and ONPOE gave the same linear range between 1 X 10~(-4)and 1 X 10~(-1)M,while the one based on DBPH ranged between 5 X 10~(-4)and 1 X 10~(-1)M.The slopes for linear range ranged from 40 to 56 mV/decade with correlation coefficients lying between 0.9984 and 0.9993.The best detection limit was 2 X 10~(-5)M for the electrode based on DBPH.The standard deviation of potential drift ranged from ±1 to ±9 mV.The measurement interferences in the presence of Li,Na~+,K~+,Mg~(2+),Ca~(2+),Zn~(2+),Fe~(3+),Cr~(3+),and Al~(3+)were studied using separate and match methods for selectivity coefficient determination.The pH and life time of the electrodes were also studied.