Multivariate classification techniques and mass spectrometry as a tool in the screening of patients with fibromyalgia

Fibromyalgia is a rheumatological disorder that causes chronic pain and other symptomatic conditions such as depression and anxiety. Despite its relevance, the disease still presents a complex diagnosis where the doctor needs to have a correct clinical interpretation of the symptoms. In this context, it is valid to study tools that assist in the screening of this disease, using chemical work techniques such as mass spectroscopy. In this study, an analytical method is proposed to detect individuals with fibromyalgia (n = 20, 10 control samples and 10 samples with fibromyalgia) from blood plasma samples analyzed by mass spectrometry with paper spray ionization and subsequent multivariate classification of the spectral data (unsupervised and supervised), in addition to the treatment of selected variables with possible associations with metabolomics. Exploratory analysis with principal component analysis (PCA) and supervised analysis with successive projections algorithm with linear discriminant analysis (SPA-LDA) showed satisfactory results with 100% accuracy for sample prediction in both groups. This demonstrates that this combination of techniques can be used as a simple, reliable and fast tool in the development of clinical diagnosis of Fibromyalgia.

Mass spectrometry with paper spray ionization in analysis of the Arrabidaea chica leaf tea

The species Arrabidaea chica (Humb. & Bonpl.) B. Verl. (Bignoniaceae) is a plant native to tropical forests, popularly known as pariri or crajiru, and it is widely used in folk medicine to treat inflammatory diseases, anemias, skin diseases and to assist in the treatment of leukemia. Because of the widespread use of the plant, concern with its quality and effectiveness is fundamental. This study demonstrates the application of mass spectrometry with ionization by paper spray (PS-MS) as a chemical characterization method to evaluate the presence of the active principles in teas prepared by infusion from commercial samples of the medicinal plant Arrabidaea chica by infusion. The analyses of the samples were performed in two periods: 24 hours and 15 days after the preparation of the teas. Compounds referring to the class of substances 3-deoxythocyanidins were detected without any pre-treatment of the sample or chromatographic separation to provide valuable information for the evaluation and quality control of this product. Significant changes in the m/z signals of greater intensity, referring to the class of 3-deoxythocyanidins, were observed in the mass spectra, and multivariate analysis corroborated the degradation of this class of substances with time, resulting in a probable loss of the quality and effectiveness of the tea.