A microfluidic chip formed with multiple fluid channels terminating at a tapered electrospray ionization tip for mass spectrometric analysis. The fluid channels may be formed onto a channel plate that are in fluid communication with corresponding reservoirs. The electrospray tip can be formed along a defined distal portion of the channel plate that can include a single or multiple tapered surfaces. The fluid channels may terminate at an open-tip region of the electrospray tip. A covering plate m...

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 a...

A microfluidic chip formed with multiple fluid channels terminating at a common electrospray ionization tip for mass spectrometric analysis. The fluid channels may be formed within a substrate plate that are in fluid communication with corresponding reservoirs. The electrospray tip can be formed along a defined portion of the substrate plate, wherein the electrospray tip includes an open-tip region at which the fluid channels converge. A top laminate plate may substantially enclose most portions...

A mass spectrometer and associated methods analyze an ion beam by accumulating ions for a sequence of time periods, and driving the accumulated ions in pulses. Differing quantities of ions can be accumulated in the sequential pulses according to a psuedo-random sequence, and the slower ions are overtaken by the faster ions of a subsequent pulse. A mass spectrum may be reconstructed from an overlapping ion detector signal using an inverse of a weighted simplex matrix or inverse Hadamard transform...

Microfluidic devices provide substances to a mass spectrometer. The microfluidic devices include first and second surfaces, at least one microchannel formed by the surfaces, and an outlet at an edge of the surfaces which is recessed back from an adjacent portion of the edge. Hydrophilic surfaces and/or hydrophobic surfaces guide substances out of the outlet. A source of electrical potential can help move substances through the microchannel, separate substances and/or provide electrospray ionizat...