Optimized SPE for Highly Organic Samples

A typical setup as seen in our previous application note employs three pumps – one for loading the sample out of the autosampler’s sample loop, one for diluting the sample’s organic solvent with water for trapping, and one for the analytical gradient, eluting the concentrated analytes off the trapping column onto an analytical column for separation.

We optimized this design a little, replacing the loading and dilution pumps by a single pump. See how it works in our new animation (turn on sound and/or subtitles):

Application Note: Quantification of Amyloid Beta Peptides in Human Cerebrospinal Fluid using Micro HPLC-HRMS

Amyloid peptides (Abeta; Aβ) result from cleavage of amyloid precursor protein (APP) by beta and gamma secretase.The 42-amino acid variant, amyloid β peptide 1–42 is a widely accepted key biomarker for Alzheimer’s disease (AD) together with the total tau (T-tau) and phosphorylated tau (P-tau) protein. Diagnostic accuracy of the Aβ 1–42 /Aβ 1–40 ratio in cerebrospinal fluid (CSF)
compared to the concentration of Aβ 1–42 alone was found to be even more significant.

Currently these peptides are analyzed routinely in CSF by immunoassays, but in recent years, liquid chromatography tandem mass spectrometry (LC-MS/MS) has been investigated for the quantification of Aβ1-38, Aβ1-40, and Aβ1–42.

[Blennow 2010, Lewczuk 2015, Lame 2011]

Amyloid-beta-42_1IYT
Figure 1: Solution structure of the Alzheimer’s disease amyloid beta-peptide (1-42)

Continue reading Application Note: Quantification of Amyloid Beta Peptides in Human Cerebrospinal Fluid using Micro HPLC-HRMS