ION IMPRINTING IS A UNIQUE TECHNIQUE USED FOR PREPARING POLYMERS WITH SYNTHETIC RECOGNITION SITES HAVING A PREDETERMINED SELECTIVITY FOR ANALYTES OF INTEREST. IN RECENT YEARS, ION IMPRINTED POLYMERS (IIPS) HAVE GAINED WIDE ACCEPTANCE AS NEW ION RECOGNITION MATERIALS IN CHEMICAL SENSORS. POTENTIOMETRIC TECHNIQUE IS ALSO WELL-KNOW VERSATILE, SIMPLE, RAPID AND INEXPENSIVE METHOD FOR DETERMINATION OF TARGET ION. POTENTIOMETRIC TECHNIQUE IS ANOTHER APPROACH TO ELECTROCHEMICAL TRANSDUCTION OF ION SELECTIVE SENSORS BASED ON IIP.WITH THE POTENTIOMETRIC TRANSDUCTION MODE, POLYMERIC MEMBRANE ION SELECTIVE ELECTRODES (ISES) HAVE FOUND WIDESPREAD USE IN INDUSTRIAL, CLINICAL AND ENVIRONMENTAL ANALYSIS OWING TO THEIR ADVANTAGES SUCH AS GOOD SELECTIVITY, LOW COST OF PREPARATION, RAPIDITY AND EASINESS OF MEASUREMENT AND HIGH RELIABILITY.IN THIS STUDY, A POLYMERIC MEMBRANE ION-SELECTIVE ELECTRODE FOR DETERMINATION OF MERCURY (II) IS DESCRIBED. IT IS BASED ON A ION IMPRINTED POLYMER FOR ION RECOGNITION, WHICH CAN BE SYNTHESIZED WITH MERCURY (II) ACETATE AS MERCURY SALT, METHACRYLIC ACID AND 1, 3_DIMETHYLBARBITURIC ACID AS FUNCTIONAL MONOMERS, ETHYLENE GLYCOL DIMETHACRYLATE AS CROSS-LINKING AGENT AND AZOBISISOBUTYRONITRILLE AS AN INITIATOR. AND A NEW COATED WIRE ELECTRODE HAS BEEN DEVELOPED AS A MERCURY ION-SELECTIVE SENSOR. THE OPTIMIZED MEMBRANE INCORPORATING DOP, PVC AND IIP WAS DIRECTLY COATED ON THE SURFACT OF A PLATINUM WIRE ELECTRODE. THE EFFECTS OF THE PH AND POSSIBLE INTERFERING IONS WERE INVESTIGATED AND THE OPTIMIZED CONDITIONS FOR ELECTROD WERE EVALUATED.

THERE ARE MANY REPORT FOR DETERMINATION OF MERCURY ION IN ARTICLES.CHELEX IS A CHELATING ION EXCHANG RESIN THAT CAN BE USED FOR PRECONCENTRATION OF IONS. IN THIS REPORT, NEW ELECTRODE FOR MESURMENT OF MERCURY (II) WERE PREPARED BY INCORPORATING CHELEX INTO SOL-GEL MATRIX. CALIBRATION PLOT WITH NERNSTIAN SLOPE (58.6 ± 0.5 MV/DECADE) FOR HG ION WAS OBSERVED OVER A LINEAR RANGE OF ABOUT FOUR DECADES OF CONCENTRATION (1.0 × 10-6 TO 1.0 × 10-2 M, AT 25OC). THE SOL-GEL ELECTRODE SHOWS DETECTION LIMIT OF 5.4 × 10-7 M. THE RESPONSE OF ELECTRODE FOR HG ION IN PRESENCE OF OTHER CATION HAS BEEN STUDIED AND IT SHOWED HIGH SELECTIVITY FOR MERCURY (II) ION. THE EFFECT OF TEMPERATURE ON THE ELECTRODE RESPONSE SHOWED THAT THE TEMPERATURE HIGHER THAN 60°C DETERIORATES THE ELECTRODE PERFORMANCE. THE PROPOSED ELECTRODE HAS HIGH MECHANICAL AND THERMAL STABILITY.IT HAS A SHORT RESPONSE TIME (10 S) AND CAN BE USED FOR MORE THAN 3 MONTHS WITHOUT ANY CONSIDERABLE DIVERGENCE IN THE POTENTIALS. THE RESULTS OF APPLICATION SHOW THAT THE ELECTRODE CAN BE USED SUCCESSFULLY IN DETERMINATION OF HG IONS IN VARIOUS WATER SAMPLES.

RAW AND OXIDIZED CARBON NANOTUBES (CNTS) UNABLE TO ADSORPTION OF HG (II) IONS. THEN CARBON NANOTUBES WERE OXIDIZED WITH HNO3 AND OXIDIZED CNTS WERE AMIDIZED WITH AMMONIUM ACETATE SOLVED IN ACETONITRILE. THEIR PHYSICOCHEMICAL PROPERTIES WERE INVESTIGATED BOEHM’S TITRATION, RAMAN SPECTROSCOPY, FT-IR, THERMAL ANALYSIS (TGA & DTA) AND ZETA POTENTIAL MEASUREMENT. IN THIS WORK, AMIDIZED CNTS USED AS A NEW ADSORBENT FOR SOLID PHASE EXTRACTION (SPE) OF HG (II) FROM AQUEOUS SOLUTIONS. THE EFFECT OF PH, TYPE OF BUFFER AND FLOW RATE FOR QUANTITATIVE ENRICHMENT WAS ALSO INVESTIGATED. THE EXPERIMENTAL RESULTS SUGGEST THAT HG (II) ADSORPTION CAPACITIES AMIDIZED CNTS INCREASE DUE TO THE FUNCTIONAL GROUPS INTRODUCED BY OXIDATION COMPARED WITH THE AS-GRAWN CNTS. A DETECTION LIMIT OF 5.00×10-4 NG/ML AND A RELATIVE STANDARD DEVIATION 2.4% WERE OBTAINED. THE CNT–SPE PRECONCENTRATION PROCEDURE SHOWED A LINEAR CALIBRATION CURVE WITHIN CONCENTRATION RANGE FROM 0.003 TO 0.3 NG/ML FOR HG (II).

EXPOSURE TO EVEN VERY LOW LEVELS OF TOXIC HEAVY METALS SUCH AS LEAD, MERCURY AND CADMIUM IS KNOWN TO CAUSE NEUROLOGICAL, REPRODUCTIVE, CARDIOVASCULAR, AND DEVELOPMENTAL DISORDERS, WHICH ARE MORE SERIOUS PROBLEMS FOR CHILDREN PARTICULARLY. ACCORDINGLY, GREAT EFFORTS HAVE BEEN DEVOTED TO THE DEVELOPMENT OF FLUORESCENT AND COLORIMETRIC SENSORS, WHICH CAN SELECTIVELY DETECT THESE METAL IONS [1]. IN THIS STUDY, A NEW FLUORESCENT PROBE 1, 5- (4- (N-OCTYL-NPHENYLAMINO) BENZYLIDENE) -DIHYDRO-2 THIOXOPYRIMIDINE-4, 6 (1H, 5H) -DIONE, AS AN ELECTRON DONOR–ACCEPTOR SUPRAMOLECULAR COMPOUND, WAS DESIGNED AND SYNTHESIZED FOR A HIGHLY SELECTIVE COLORIMETRIC IDENTIFICATION OF MERCURY IONS [2].