Virtual instruments for flow-based and discrete analytical methodsKuljanin, Aleksandra (Avtor) Gros, Nataša (Mentor) Lotrič, Uroš (Komentor) LabVIEWvirtual instrumentsmultifunctional analytical platformsmultipoint detectionconductivitysequential injection analysisIn the field of analytical chemistry, the use of virtual instruments is still mostly limited to signal acquisition and instrument control. The developed platforms are focused on a specific analytical method or determination. By utilizing the multichannel capabilities of the LabVIEW environment, platforms of wider functionality can be created, and there are many possibilities for further development and improvements. The starting point was an already developed, virtually-supported LabVIEW platform for flow-based and discrete analytical methods. The work within this thesis was focused on additional extension and upgrading of the platform. Through software modifications, hardware components for multipoint conductometric detection were integrated into the virtually-supported sequential injection analysis system. Furthermore, a new virtual instrument was developed to process peak signals and calculate key zone penetration parameters. The spectrometric microchamber, part of the virtually-supported microtitrator, was redesigned for conductometric monitoring. The number of physical and chemical factors affecting the SIA-gram peak profile is large, and the behavior of the plug within the liquid conduits cannot be accurately predicted. Developed virtual instrument for peak processing and calculation of most important zone penetration parameters in combination with multipoint conductivity monitoring enabled prompt and accurate insight into the behavior of the plugs of different chemical composition. The influences of flow rate, plug volume and coil length on peak profiles and peak overlapping, for plugs of different chemical composition, were studied by using multivariate analysis. Under studied set of conditions, it was shown that the total overlapping area parameter highly correlate with experimental peak absorbance maxima values (R2 > 0.99) for the reactions that employ the same plug medium. This was confirmed on the example of two reactions with different kinetics, the reaction of iron(II) with ferrozine and the reaction of copper(II) with EDTA. By applying the established correlation, absorbance peak maxima can be calculated for the conditions which were not tested experimentally, which significantly reduces the total number of experiments and chemical consumption in later optimization phases. It was also shown that detailed studies of the total overlapping area and the overlapping fraction of the reagent peak can be useful for defining the parameters’ range for high reagent utilization and adequate method sensitivity. The operating capabilities of the redesigned microchamber were confirmed for monitoring urea decomposition catalysed by Jack bean urease. In this way, the platform gained additional functionality as another detection method was integrated into the virtually-supported microtitrator. The virtually-supported multipoint conductometric detection is a starting point for the introduction of other electroanalytical methods and further extension of the platform. The spectrometric microchamber can be remodeled into a dual-detection microchamber, to simultaneously monitor changes in absorbance and conductivity.20232023-04-17 15:15:02Doktorsko delo/naloga145324VisID: 7641COBISS_ID: 149992707sl