Comparando o desempenho de dois analisadores de massas (FT-ICR MS & LTQ MS): uma aula experimental sobre análise de compostos orgânicos

COMPARING THE PERFORMANCE OF TWO MASS ANALYZERS (FT-ICR MS & LTQ MS): AN EXPERIMENTAL CLASS ON ANALYSIS OF ORGANIC COMPOUNDS

Mass spectrometry (MS) is a high-performance analytical technique that allows a measurement of the mass/charge (m/z) ratio of compounds present in a sample. MS is able to separate two m/z ions with determined values (mass resolution), being an important characteristic, especially in the analysis of biochemical components and complex mixtures. Mass analyzers define the resolving power and accuracy of different types of mass spectrometers. Herein, the performance of two mass analyzers (Fourier Transform Ion Cyclotronic Resonance (FT-ICR) and quadrupole ion trap (LTQ)) was tested on low (M_w = 165-679 Da) and high (M_w = 783-8.58 kDa) molecular weight molecules (Phenacetin, Procaine, Benzocaine, Caffeine anhydrous, Lidocaine, two metal porphyrin standards, the first cobalt and the second vanadium, and two protein standards, Ubiquitin and Beauvericin), and finally, for an oil sample. LTQ-MS and FT-ICR-MS had similar performance and high reproducibility. However, the mass accuracy and resolution power of the FT-ICR (error lower than 5 ppm and RP higher than 400,000) was higher, being therefore, it was more suitable for the analysis of proteins and oil, for instance. On the other hand, the CID analysis via LTQ demonstrated its applicability in fragmentation experiments, being able to determinate the chemical connectivity of organic compounds in non-complex mixtures.

Keywords:
mass spectrometry; FT-ICR; quadrupole-linear ion trap; ultra-high resolution; electrospray