MALDI-MSI: a fast and reliable method for direct melatonin quantification in biological fluids

Author(s)

Ferreira, Monica Siqueira ^[1] ; de Oliveira, Diogo Noin ^[1] ; Mesquita, Caroline Costa ^[2] ; de Lima Barbosa, Ana Paula ^[2] ; Anhe, Gabriel Forato ^[2] ; Catharino, Rodrigo Ramos ^[1]

Affiliation

^[1] Univ Estadual Campinas, Sch Pharmaceut Sci, INNOVARE Biomarkers Lab, Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Coll Med Sci, Diabet Mellitus Pharmacol Lab, Campinas, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF ANALYTICAL SCIENCE AND TECHNOLOGY; v. 7, 2016.
• Web of Science Citations: 0

Abstract

Background: This work reports, for the first time, a validated methodology for qualitative and quantitative melatonin analyses directly from a complex matrix, namely rat milk, using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), in a useful strategy for fast assessment of this molecular species. Methods: This novel approach uses the imaging feature of a MALDI instrument to create bidimensional images of a selected area. Results for sample concentration are expressed as a function of pixel-by-pixel intensity in grayscale, which are quantified according to pixel intensity through ImageJ open source software. For the extent of this work, two conditions were monitored: light-and dark-obtained milk. Results: Quantification was performed using the selected reaction monitoring (SRM) transitions m/z 233. 174 for melatonin. Limit of detection and limit of quantification have presented lower values (picomolar) when compared to other melatonin quantification strategies, indicating that this method presents high sensitivity. Furthermore, this method has a total analysis time of less than 1 min. Conclusions: Melatonin concentrations are significantly higher in samples obtained from dark conditions, consistent with previous results, and thus proving that MALDI-MSI is a suitable, simple, and highly sensitive methodology for direct melatonin analysis from complex biological samples. (AU)

• FAPESP's process: 14/00084-2 - Identification of adulterations and simultaneous determination of nutrients and contaminants in food using direct analysis mass spectrometry and imaging
• Grantee: Diogo Noin de Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/50400-0 - Mitochondrial energy metabolism, redox state and functionality in cell death and cardiometabolic and neurodegenerative disorders
• Grantee: Aníbal Eugênio Vercesi
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/06809-1 - Determination of chemical markers in various bovine products using mass spectrometry
• Grantee: Rodrigo Ramos Catharino
• Support Opportunities: Regular Research Grants