Development of high-resolution chromatographic techniques based on mass spectrometry and infrared spectroscopy hyphenation

The present research thesis was focused on the development and application of liquid (LC) and gas-chromatographic (GC) techniques hyphenated to high-resolution tandem mass spectrometry (MS/MS) and solid-state infrared spectroscopy (sd-FTIR) for the characterization of complex matrices. Two fields of research have been followed in parallel, which implied the use of the two types of detectors. The first part of the thesis describes the retrieval and characterization of biologically active peptides obtained from fish protein hydrolysates (FPHs), which exert well-known biological activities in the organism, by LC-MS/MS. Among the numerous biological activities of FPHs, short-length peptides have shown promising antimicrobial activities, high stability and low toxicity toward human cells. According to the principle of green and blue economy, a possible reuse of FPHs as source of active peptides would further benefit from easier manufacturing and cheaper production of short-length peptides, compared to the long-chain ones. Part of this research work has been carried out in the laboratory of Biochemistry, Technology and Innovation of Meat and Meat Products under the supervision of Professor Fidel Toldrá and Doctor Leticia Mora (Institute of Agrochemistry and Food technology of Valencia, Spain). A second research topic has consisted in the development of prototype systems based on the hyphenation of LC and GC to a novel FTIR detector. The coupling of high-resolution, front-end separation to the unique identification capability of FTIR fingerprinting was aimed at achieving identification power for unknown components in complex mixtures, including regioisomers which often represent a challenging task in MS routine measurements. The results achieved during the PhD course have been the subject of various research papers, as well as oral and poster communications listed at the end of this document.