A-priori biomarker knowledge based mass filtering for enhanced biomarker detection

Abstract

Methods and apparatus for mass filtering based on a-priori biomarker knowledge and elution time intervals for selected ion species from a separation device. A sample may be screened for biomarker patterns based on distinct elutions times for selected ions or peptides. A mass spectrum for species of interest can be tailored by filtering out undesired ions by measuring corresponding elution times and determining a priori selected elution time intervals for desired ion species only. The invention assists in the identification of biomarkers having known mass spectral peaks corresponding to known proteins or ions of interest that are known to elute from a separation device within a pre-defined elution time window.

Description

CROSS-REFERENCE [0001] This application is a continuation application of Ser. No. 10 / 810,332, filed Mar. 25, 2004, which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION [0002] The invention relates to methods and apparatus for increasing the dynamic range and sensitivity of mass spectrometers. More specifically, the invention relates to improved performance of mass spectrometers with selective ion filtering and accumulation of desired ions that provide selected biomarker patterns based on a priori elution time intervals. BACKGROUND OF THE INVENTION [0003] A mass spectrometer is an analytical tool for determining the mass of sample ions based on its mass to charge ratio (m / z). A sample solution may be ionized by inducing either the loss or gain of a charge before introducing the resulting ions into a mass analyzer. The formed ions are separated afterwards according to their relative mass to charge ratios followed by detection to provide a resulting mass spe...

AI Technical Summary

Problems solved by technology

The sensitivity and performance of trapping mass analyzers is known to diminish when there is a large abundance of undesired ion species within a mixture which can be referred to as background ions.

When interfaced with CE separation techniques in particular, the total number of ion species eluted and the complexity of the overall mixture itself can be significant while the relative abundance of components of interest is extremely limited.

The elution of highly abundant peptides can restrict the detection of less abundant peptides eluting at or near the same time since the dynamic range of mass spectrometers can be relatively limited.

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