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Determination of selected terpenoids by HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with the determination of carvacrol, thymol, and eugenol by HPLC with electrochemical detection. Carbon paste electrode and boron doped diamond film electrode were used as the working electrodes. For the comparison, UV spectrophotometric detection at 275 nm was used besides the electrochemical detection. The separation was performed on LiChroCART 125-4, RP-18e (5 µm) column. Optimum separation conditions were found: mobile phase consisting of acetonitrile and acetate buffer in ratio 50:50, the optimum buffer pH was pH 5. The optimum potential of working electrode during electrochemical detection was +0,8 V and +1,2 V for carbon paste electrode and boron doped diamond film electrode, respectively. For both electrodes, repeatability of the measurement was examined; the surface of both electrodes had to be renewed between the measurements. Under the obtained optimum conditions, calibration dependences were measured. The studied substances were determined in real samples, in Thymus vulgaris L. and Achillea millefolium L. and in thyme-containing tea and syrup.
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Determination of carvacrol using HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with determination of a mixture of carvacrol with thymol and eugenol by HPLC with electrochemical detection. Carbon paste electrode was used as the working electrode. The separation was performed on Kromasil-C18, 250x4,6 mm column. For the comparison, UV spectrophotometric detection at 275 nm was used besides electrochemical detection. Optimal separation conditions were found: mobile phase consisting of acetonitrile and phosphate buffer in ratio 60:40, the optimal buffer pH was pH 4. As the optimum potential of working electrode during electrochemical detection, potential +1.1 V was found. Under the obtained optimal conditions, calibration dependences were measured. Limit of quantification for carvacrol was found to be 9,6·10-7 mol dm-3 using UV spectrophotometric detection and 4,0·10-8 mol dm-3 using electrochemical detection.
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Determination of selected terpenoids by HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with the determination of carvacrol, thymol, and eugenol by HPLC with electrochemical detection. Carbon paste electrode and boron doped diamond film electrode were used as the working electrodes. For the comparison, UV spectrophotometric detection at 275 nm was used besides the electrochemical detection. The separation was performed on LiChroCART 125-4, RP-18e (5 µm) column. Optimum separation conditions were found: mobile phase consisting of acetonitrile and acetate buffer in ratio 50:50, the optimum buffer pH was pH 5. The optimum potential of working electrode during electrochemical detection was +0,8 V and +1,2 V for carbon paste electrode and boron doped diamond film electrode, respectively. For both electrodes, repeatability of the measurement was examined; the surface of both electrodes had to be renewed between the measurements. Under the obtained optimum conditions, calibration dependences were measured. The studied substances were determined in real samples, in Thymus vulgaris L. and Achillea millefolium L. and in thyme-containing tea and syrup.
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Determination of carvacrol using HPLC with electrochemical detection
Mužíková, Jana ; Schwarzová, Karolina (referee) ; Dejmková, Hana (advisor)
This thesis deals with determination of a mixture of carvacrol with thymol and eugenol by HPLC with electrochemical detection. Carbon paste electrode was used as the working electrode. The separation was performed on Kromasil-C18, 250x4,6 mm column. For the comparison, UV spectrophotometric detection at 275 nm was used besides electrochemical detection. Optimal separation conditions were found: mobile phase consisting of acetonitrile and phosphate buffer in ratio 60:40, the optimal buffer pH was pH 4. As the optimum potential of working electrode during electrochemical detection, potential +1.1 V was found. Under the obtained optimal conditions, calibration dependences were measured. Limit of quantification for carvacrol was found to be 9,6·10-7 mol dm-3 using UV spectrophotometric detection and 4,0·10-8 mol dm-3 using electrochemical detection.
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Hydrogenace thymolu ve zkrápěném reaktoru
Dudas, J. ; Hanika, Jiří ; Lepuru, J. ; Barhuysen, M.
the main objective of the investigation was to collect experimental data for scale up for the hydrogenation of thymol in a trickle bed reactor. Based on bench scale data and process simulation using physico-chemical parameters and measured reaction kinetics, a pilot scale reactor has been designed during this study. One major focus of the work was the determination of the limetife of a commercially available nickel catalyst.
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