THE ELECTROCHEMICAL METHODS USING CHEMICALLY MODIFIED ELECTRODES HAVE BEEN WIDELY USED AS SENSITIVE AND SELECTIVE ANALYTICAL METHODS FOR THE DETECTION OF TRACE AMOUNTS OF IMPORTANT COMPOUNDS [1]. AMONG DIFFERENT MODIFIER, NANOMATERIALS HAVE DRAWN A LOT OF ATTENTION IN VARIOUS ELECTROCHEMICAL SENSING SYSTEMS BASED ON THEIR UNIQUE PROPERTIES. ZNO NANOSTRUCTURES DUE TO WIDE BAND GAP (3.37 EV), LARGE EXCITATION BINDING ENERGY (60 EV), NONTOXICITY AND HIGH ELECTRON COMMUNICATION FEATURES IS PREFERRED FOR DEVELOPMENT OF SENSORS AND BIOSENSORS FOR CLINICAL DIAGNOSTICS [2].IN VIEW OF THIS, THE ELECROCATALYTIC EFFECT OF ZNO NANOPARTICLE/ MULTIWALLED CARBON NANOTUBES MODIFIED CARBON PASTE ELECTRODE (CPE) TOWARD THE OXIDATION OF NAPROXEN IN BIOLOGICAL PH WAS INVESTIGATED. THE STUDY WAS CARRIED OUT BY USING CYCLIC VOLTAMMETRY, CHRONOAMPEROMETRY, AND SQUARE WAVE VOLTAMMETRY (SWV) TECHNIQUES.SOME PARAMETERS SUCH AS THE ELECTRONTRANSFER COEFFICIENT (Α) AND DIFFUSION COEFFICIENT (D) WERE ALSO DETERMINED FOR THE NAPROXEN OXIDATION. FIGURE 1 COMPARES TYPICAL CYCLIC VOLTAMMOGRAMS OF 0.1 MM NAPROXEN IN PHOSPHATE BUFFER SOLUTION (PH 7.0) AT ZNO / MWCNT MODIFIED CPE (A) ANDBARE CPE (B) AFTER SUBTRACTED FROM THEIR BASE LINES. PRIOR TO ESTABLISH THE DETECTION METHOD, EXPERIMENTAL VARIABLES WERE OPTIMIZED. UNDER THE OPTIMUM EXPERIMENTAL CONDITIONS A DYNAMIC RANGEOF1.0 TO 200MM AND THE LIMIT OF DETECTION 0.23MM WAS OBTAINEDUSING SWV (PH=7.0). THE PREPAREDELECTRODE WAS SUCCESSFULLY APPLIED FOR THE DETERMINATION OF NAPROXEN IN REAL SAMPLES.

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A NEW CU2+CARBON PASTE ELECTRODE (CPE) USING 2, 2' - (1E, 1' E) -1, 1' - (2, 2' -AZANEDIYLBIS (ETHANE-2, 1-DIYL) BIS (AZAN-1-YL-1-YLIDENE)) BIS (ETHAN-1-YLIDENE) DIPHENOL (ADEZEDP) HAS BEEN PREPARED. THE INFLUENCE OF VARIABLES INCLUDING SODIUM TETRAPHENYLBORATE (NATPB), IONOPHORE, AND AMOUNT OF MULTIWALLED CARBON NANOTUBES (MWCNT), CDO NANOWIRES, CDS NANOPARTICLES AND PALLADIUM NANOPARTICLES LOADED ON ADEZEDP AND NUJOL ON THE ELECTRODES RESPONSE WAS STUDIED AND OPTIMIZED. AT OPTIMUM VALUES OF ALL VARIABLES, FOR EACH NANOMATERIALS THE ELECTRODES RESPONSE WAS LINEAR IN CONCENTRATION RANGE OF 1.0 × 10-8 TO 1.0 × 10-1 MOL L-1 FOR ADEZEDP WITH NERNSTIAN SLOPE. THE GOOD PERFORMANCE OF ELECTRODE VIZ. WIDE APPLICABLE PH RANGE (2.0-5.0), FAST RESPONSE TIME (»6 S), AND ADEQUATE LIFE TIME (3 MONTHS) INDICATE THE UTILITY OF THE PROPOSED ELECTRODES FOR EVALUATION OF CU2+ION CONTENT IN VARIOUS SITUATIONS. FINALLY, THESE ELECTRODES HAVE BEEN SUCCESSFULLY APPLIED FOR THE DETERMINATION OF CU2+IONS CONTENT IN VARIOUS REAL SAMPLES. THE SELECTIVITY OF PROPOSED ELECTRODE WAS EVALUATED BY SEPARATION SOLUTION METHOD AND FIXED INTERFERENCE METHOD.

BACKGROUND: DRUGS FOR TREATING ASTHMA ARE DIVIDED INTO TWO CATEGORIES: (1) QUICK-RELIEF MEDICATIONS (WHICH ARE USED TO RELIEF ACUTE ASTHMA) AND (2) LONG-TERM ASTHMA CONTROL MEDICATIONS WITH (WHICH ARE USED AS PROPHYLACTIC MEASURES). IT IS HERE ESTABLISHED THAT POTENTIOMETRIC CARBON PASTE ELECTRODES (CPE) WITH CARBON NANOTUBES (CNTS) [1, 2] ARE USEFUL ANALYTICAL TOOLS FOR ANTI-ASTHMA DRUG DETERMINATIONS...

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TRYPTOPHAN IS AN AMINO ACID NEEDED FOR NORMAL GROWTH IN FANTHS AND FOR NITROGEN BALANCE IN ADULTS. IT IS ENCODED IN THE STANDARD GENETIC CODE AS THE CODON UGG. AMONY MANY METHODS FOR DETERMINATION OF TRYPTOPHAN IN BIOLOGICAL SAMPLES...

MELAMINE, A KIND OF TRIAZINE ANALOGUE WITH THREE AMINO GROUPS, IS WIDELY USED AS AN INDUSTRIAL CHEMICAL IN THE PRODUCTION OF MELAMINE RESINS. MELAMINE CAN BE FOUND AS A CONTAMINANT IN A VARIETY OF FOODS FROM FOOD-CONTACT MATERIALS. WHEN ADDED TO MILK POWDER, MELAMINE INCREASES THE NITROGEN CONCENTRATION, WHICH SUGGESTS A FALSE INCREASE IN PROTEIN CONCENTRATION...

BACKGROUND: DETERMINATION OF COPPER CONTENTS HAS GREAT IMPORTANCE DUE TO ITS WIDESPREAD APPEARANCE AND APPLICATION IN ENVIRONMENTAL SAMPLES. [1].THE ELECTROANALYTICAL PROCEDURES ARE PREFERRED DUE TO THEIR HIGH SENSITIVITY, SIMPLE OPERATION, AND LOW COST. THE POTENTIOMETRIC METHOD USING ION SELECTIVE ELECTRODES (ISES) BENEFIT FROM ADVANTAGES SUCH AS FAST, SIMPLE INSTRUMENTATION, ETC [2]. IN THIS RESEARCH, MULTIWALLED CARBON NANOTUBES WERE MODIFIED AND APPLIED FOR CONSTRACTION OF CPE. THE EFFECT OF SIGNIFICANT VARIABLES WAS INVESTIGATED AND OPTIMIZED. FINALLY, THE PERFORMANCE OF CU2+ - CPE WAS INVESTIGATED AND SUCCESSFULLY APPLIED FOR MONITORING THE CU2+ IONS CONTENT IN REAL SAMPLES.METHODS: MWCNTS WERE MODIFIED BY CHEMICAL METHODS TO OBTAIN THE 3- METHOXY 2-((3-SILYLPROPYLIMINO) METHYL) PHENOL CHEMICALLY BONDED TO MWCNTS (MSPIMP-MWCNT) AND WERE CHARECTRIZED BY FT-IR AND OTHER RELATED TECHNIQUES AND IN THE MATRIX OF CARBON PASTE APPLIED WITH OTHER INGREDIENTS SUCH AS (NATPB). THE MIXTURE IS HOMOGENIZED, LEFT AT ROOM TEMPERATURE TO EVAPORATE THF, THEN DIFFERENT AMOUNTS OF REAGENTGRADE GRAPHITE POWDER AND NUJOL OIL IS ADDED AND MIXED THROUGHLY AND THEN PACKED INTO THE HOLE OF THE ELECTRODE BODY.RESULTS: OPTIMUM COMPOSITION OF CARBON PASTE WAS SET AS (NUJOL (9 DROP) AND GRAPHITE POWDER: NATPB: CARRIER IN THE MASS (MG) RATIO OF 150.9.60). IT WAS FOUND THAT CONSTRUCTION OF CPE AT ABOVE MENTION (SPECIFIED) CONDITION LEAD TO SIGNIFICANT ENHANCE IN THE SELECTIVITY AND SENSITIVITY TOWARD CU2+ IONS OVER A WIDE CONCENTRATION RANGE OF 4.09×10-8-1.0×10-2 MOL L-1 WITH DETECTION LIMIT OF 1.6×10-8 MOL L-1 AND A NERNSTIAN SLOPE OF 29.56±0.56 MV PER DECADE-1 OF CU2+ CONCENTRATION. THE ELECTRODE RESPONSE IS INDEPENDENT OF PH IN THE RANGE OF 3.5-5.5 WITH RESPONSE TIME LOWER THAN 20 S. THE POTENTIOMETRIC SELECTIVITY COEFFICIENTS OF PROPOSED CU2+ ION - CPE SHOW ITS MODERATE SELECTIVITY FOR CU2+ ION TOWARD OTHER METAL IONS. CONCLUSION: ON THE BASIS OF THE RESULTS DISCUSSED IN THIS PAPER, MSPIMP-MWCNT IS SUITABLE NEUTRAL CARRIER FOR THE CONSTRUCTION OF A CARBON PASTE ELECTRODE FOR DETERMINATION OF CU2+ ION IN SOLUTION. THE PROPOSED ELECTRODE HAS GOOD OPERATION CHARACTERISTICS PERFORMANCE SUCH AS HIGH SENSITIVITY, STABILITY, RESPONSE TIME, DETECTION LIMIT AND WIDE LINEAR RANGE.

PROMAZINE IS A MEDICATION THAT BELONGS TO THE PHENOTHIAZINE CLASS OF ANTIPSYCHOTICS. AN OLDER MEDICATION USED TO TREAT SCHIZOPHRENIA; IT IS STILL PRESCRIBED, ALONGSIDE NEWER AGENTS SUCH AS OLANZAPINE AND QUETIAPINE. IT HAS PREDOMINANTLY ANTICHOLINERGIC SIDE EFFECTS, THOUGH EXTRAPYRAMIDAL SIDE EFFECTS ARE NOT UNCOMMON EITHER [1]...

PYROGALLOL (1, 2, 3-TRIHYDROXYBENZENE) IS ONE KIND OF NATURAL PHENOLIC COMPOUND THAT IS ALSO AN ACTIVE INGREDIENT IN MANY INDUSTRIES SUCH AS PHARMACEUTICALS, COSMETICS AND PLASTICS. THEREFORE, PYROGALLOL IS COMMONLY FOUND IN INDUSTRIAL EFFLUENTS AND EASILY INTRODUCED INTO THE LIVING ENVIRONMENT. THE DETERMINATION OF PYROGALLOL HAS BEEN EXTENSIVELY STUDIED DUE TO THE INHERENT TOXICITY AND ENVIRONMENT THREAT. SILICA PRESENTS ATTRACTIVE PROPERTIES (ADSORPTION CAPACITY, ACID/BASE CHEMISTRY, THERMAL STABILITY) WHICH COULD BE ADVANTAGEOUSLY EXPLOITED, FOR EXAMPLE IN THE ACCUMULATION OF ELECTROACTIVE ANALYTES BEFORE THEIR ELECTROCHEMICAL DETECTION. MODIFIED CARBON PASTE ELECTRODES (MCPE) ARE COMMONLY EMPLOYED IN ELECTROCHEMICAL APPLICATIONS DUE TO THEIR EXCELLENT PROPERTIES. RECENTLY, SILICA MODIFIED ELECTRODES HAVE BEEN DEVELOPED FOR VARIOUS ANALYTES. IN THIS WORK CARBON PASTE ELECTRODES (CPE) MODIFIED WITH SIO2 WERE USED FOR THE SENSITIVE ELECTROCHEMICAL DETERMINATION OF PYROGALLOL. THE ELECTRODES PREPARED BY MIXING GRAPHITE POWDER, PARAFFIN OIL AND SIO2. THE ELECTROCHEMICAL RESPONSE CHARACTERISTICS OF THESE MODIFIED ELECTRODES TOWARD PYROGALLOL WERE INVESTIGATED BY CYCLIC VOLTAMMETRY AND DIFFERENTIAL PULSE VOLTAMMETRY. PRIOR TO ESTABLISHED THE DETECTION METHOD EXPERIMENTAL VARIABLES WERE OPTIMIZED. UNDER THE OPTIMUM EXPERIMENTAL CONDITIONS THE PEAK CURRENT WAS LINEARLY DEPENDENT ON THE PYROGALLOL CONCENTRATION IN THE RANGE OF 2×10-6 TO 3×10-4 MOL L-1 WITH SIO2 MODIFIED ELECTRODES. THE APPLICABILITY OF THE PROPOSED MODIFIED ELECTRODE WAS FURTHER EVALUATED BY THE DETERMINATION OF PYROGALLOL IN REAL SAMPLES.