Academic literature on the topic 'Diferenční pulzní voltametrie (DPV)'

Voltammetric methods for the determination amphenicol antibiotic chloramphenicol (CAP) and quinolone antibiotic Ofloxacin (OFL) were developed. TTechniques differential pulse voltammetry (DPV) and DC voltammetry (DCV) for determination of both substances at boron doped diamond film electrode (BDDFE) were used. The effect of pH of Britton-Robinson buffer was tested and the stability of the signal with repeated measurements was monitored. Optimal pH 6 was used for determining of CAP by both, DPV and DCV techniques. Media of pH 4 for determining of OFL by DPV and DCV was optimal. Under these conditions linear dependences in the calibration concentration region 1.10 -6 - 1.10-4 mol.l -1 were obtained. The limit of determination for the method for CAP by DPV at 3.10 mol.l , by -6 -1 DCV at 3.10 mol.l and for -6 -1 OFL by DPV at 1.10 mol.l -6 -1 and by DCV at 4.10 mol.l -7 -1 was found. The developed methods were used for the determination of CAP in the drug samples Spersadex comp. and OFL determination in drug samples Zanocin 200. Method for solid phase extraction of OFL from samples of urine with voltammetric detection was developed with limit of determination at 7.10 mol.l . -6 -1

This Thesis deals with the construction of an electrochemical cell with two types of integrated composite electrodes based on carbon films. Using these electrodes, the voltammetric behavior of environmental pollutant triclosan (5-chlor-2-(2,4- dichlorophenoxy)phenol) was studied. For the construction of composite electrodes, graphite and glassy carbon were used as conductive microparticles. Several types of polymers served as the nonconductive binder. For the measurements, combinations of graphite with polystyrene and graphite with polycarbonate were selected as optimum materials. From the dependence of peak heights on solution composition, a mixture of a buffer of pH 7 and methanol (1:9, V/V) was selected as the optimum medium. In this medium, concentration dependences were measured; calculated triclosan detection limit were 0,49 µmol dm-3 for carbon polystyrene composite electrode and 0,25 µmol dm-3 for carbon polycarbonate composite electrode, respectively. The possibility of further increasing the sensitivity of the determination by the accumulation step was studied. Accumulation of triclosan on carbon polystyrene composite electrode was observed, but the increase in response was connected with the loss of repeatability. Accumulation of triclosan on carbon polycarbonate composite electrode was...

Voltammetric methods for the determination of diazepam (DZ) and nordiazepam (NDZ) were developed. Techniques differential pulse voltammetry (DPV) and DC voltammetry were used for determination of DZ and NDZ at meniscus modified silver solid amalgam electrode (m-AgSAE). The effect of pHa on the intensity of signal was observed in the mixture of Britton-Robinson buffer and methanol (9:1), and in the mixture of 0.1 mol.l−1 NaOH and methanol (9:1). The stability of the signal during repeated measurements in the mixture of 0.1 mol.l−1 NaOH and methanol (9:1), and in the mixture of BR buffer and methanol (9:1) was monitored. Optimal pHa 13.2 of medium of 0.1 mol.l−1 NaOH and methanol (9:1) was used for determination of DZ with DPV and DCV techniques. Optimal pHa 10.1 of medium of BR buffer and methanol (9:1) was used for determination of NDZ with DPV and DCV techniques. Under these conditions linear dependencies calibration were measured. Concentration range of DZ was measured with DCV in range of 10x10−5 - 6x10−6 mol.l−1 and with DPV technique in range of 10x10−5 - 2x10−6 mol.l−1 . Concentration range of NDZ was measured with DCV technique in range of 10x10−5 - 4x10−6 mol.l−1 and with DPV technique in range of 10x10−5 - 2x10−6 mol.l−1 . The limit of detection for DZ was calculated 6.6x10−6 mol.l−1 with DCV and...