Towards universal detection and quantification of dissolved organic matter with charged aerosol detector

Može, Martina (author), Kočar, Drago (mentor)

The charged aerosol detector (CAD) works on the principle of detecting non-volatile analytes in a mobile phase comprised of volatile components. It is usually implemented in the chromatographic workflow instead of usual ultraviolet absorption (UV) detector when analytes lack chromophores. Its response, which is independent of chemical structure, derives from a formation of solid particles from non-volatile analytes under consistent flow. The detector has already been used to also detect and quantify compounds with unknown structures, mostly in pharmaceutical analysis. Here, CAD was implemented to investigate samples of dissolved organic matter (DOM) after isocratic size-exclusion chromatography. Initially, individual compounds in different mobile phases were tested on CAD to better understand its response. The response of different compound groups was compared to the response of reference material of fulvic acids that has been isolated from rivers. The main objective was to create a universal calibration curve that would fit a variety of chemical compounds usually found in the environment. Fractions of the reference material were also captured after separation and tested by a total organic carbon detector to test CAD’s universality. CAD’s response was also compared to commonly used UV and electrospray ionisation with detection by mass spectrometry. These two detectors were shown to cover different DOM pools of fulvic acids which were separated under the chromatographic conditions. Additionally, fractions from UV active and ionisable pools were collected and measured on proton NMR instrument to get information about structural composition of both fractions.

• Language: English
• Keywords: Dissolved organic matter, charged aerosol detector, size-exclusion chromatography, UV and ESI-MS detectors, SRFA
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-122381
• COBISS.SI-ID: 43985667
• Publication date in RUL: 07.12.2020

Secondary language

• Language: Slovenian
• Title: Detekcija in kvantifikacija raztopljene organske snovi z detektorjem nabitih aerosolov

Abstract

Magistrsko delo se osredotoča na implementacijo detektorja nabitih aerosolov za analizo raztopljene organske snovi. Obravnava njegov univerzalen odziv ter kvantifikacijo kompleksnih okoljskih vzorcev.

• Keywords: Raztopljena organska snov, detektor nabitih aerosolov, velikostno izključitvena kromatografija, UV-Vis detektor in ESI-MS detektor, SRFA