Disposable Pipette Extraction Followed by Direct MS/MS Analysis of Beta Amyloid Peptides (Aβ38, Aβ40, and Aβ42) in Cerebrospinal Fluid Samples

• Published in: Journal of the Brazilian Chemical Society Vol. 36; no. 1
• Main Authors: Grecco, Caroline, Crevelin, Eduardo José, Tumas, Vitor, Hallak, Jaime Eduardo, Queiroz, Maria Eugênia
• Format: Journal Article
• Language: English; Portuguese
• Published: Sociedade Brasileira de Química 2025
• Subjects: CHEMISTRY, MULTIDISCIPLINARY; Alzheimer’s disease; amyloid beta peptides; MS-MS analysis; disposable pipette extraction
• ISSN: 0103-5053; 1678-4790; 1678-4790
• DOI: 10.21577/0103-5053.20240084

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by extracellular accumulation of amyloid-β (Aβ) peptides in the brain. This study demonstrates the direct association of the disposable pipette extraction (DPX) with tandem mass spectrometry (MS/MS) for the analysis of Aβ peptides in cerebrospinal fluid (CSF) samples. Different parameters were optimized in order to improve detectability in the MS/MS including mobile phase percentage of ammonium hydroxide, mobile phase flow rate and acquisition mode. Also, this method used an electrospray ionization (ESI) low-flow probe and direct infusion of an organic solution in the MS/MS. The DPX-MS/MS method showed adequate linearity for determining Aβ peptides in CSF-linearity ranged from 0.1 to 1.5 ng mL-1. The coefficients of determination were higher than 0.99; the precision coefficient of variation (CV) ranged from 0.3 to 12.7%; and the accuracy relative standard deviation (RSD) ranged from -13.6 to 13.2%.