Multi-channel microfluidic chip for electrospray ionization

A microfluidic chip for electrospray ionization comprising:

• a bottom polymer plate formed with at least two non-intersecting fluid channels that are each in fluid communication with corresponding fluid reservoirs included within the polymer plate;
• an electrospray tip positioned within a recessed portion formed in the bottom polymer plate, wherein the electrospray tip includes an open-tip region at which each of the non-intersecting fluid channels converge;
• and
• a top polymer plate that substantially encloses the non-intersecting fluid channels formed in the bottom polymer plate except for the open-tip region of the electrospray tip.

A method for conducting mass spectrometric analysis of multiple samples in a sequential manner comprising the following steps of:

• selecting a microfluidic chip formed with a electrospray tip, wherein the microfluidic chip includes a plurality of fluid channels that converge at an open-end distal portion of the electrospray tip;
• positioning the electrospray tip relative to a mass spectrometer for analysis of multiple samples;
• introducing a first sample through a first fluid channel within the microfluidic chip that directs an electrospray of the first sample emanating from the open-end distal portion of the electrospray tip into the mass spectrometer;
• conducting a mass spectrometric analysis of the first sample;
• introducing a second sample through a second fluid channel within the microfluidic chip that directs an electrospray of the second sample emanating from the open-end distal portion of the electrospray tip into the mass spectrometer;
• conducting a mass spectrometric analysis of the second sample, wherein the mass spectrometric analysis of the first sample and the second sample are conducted sequentially from the same electrospray tip formed on the microfluidic chip.