Intensity-Independent Noise Filtering in FT MS and FT MS/MS Spectra for Shotgun Lipidomics

5 years ago

Intensity-Independent Noise Filtering in FT MS and FT MS/MS Spectra for Shotgun Lipidomics

Yury O. Tsybin, Jacobo Miranda Ackerman, Henrik Thomas, Kai Schuhmann, Andrej Shevchenko, Konstantin O. Nagornov

Shotgun lipidomics relies on the direct infusion of total lipid extracts into a high resolution tandem mass spectrometer. A single shotgun analysis produces several hundred of densely populated FT MS and FT MS/MS spectra, each of which might comprise thousands of peaks although a very small percentage of those belong to lipids. Eliminating noise by adjusting a minimal peak intensity threshold is biased and inefficient since lipid species and classes vary in their natural abundance and ionization capacity. We developed a method of peak intensity–independent noise filtering in shotgun FT MS and FT MS/MS spectra that capitalizes on a stable composition of the infused analyte leading to consistent time-independent detection of its bona fide components. Repetition rate filtering relies on a single quantitative measure of peaks detection reproducibility irrespectively of their absolute intensities, masses, or assumed elemental compositions. In comparative experiments, it removed more than 95% of signals detectable in shotgun spectra without compromising the accuracy and scope of lipid identification and quantification. It also accelerated spectra processing by 15-fold and increased the number of simultaneously processed spectra by ∼500-fold hence eliminating the major bottleneck in high-throughput bottom-up shotgun lipidomics.

Publisher URL: http://dx.doi.org/10.1021/acs.analchem.7b00794

DOI: 10.1021/acs.analchem.7b00794