Pneumatically assisted electrospray device with alternating pressure gradients for mass spectrometry

The method of forming a spray of charged particles from a sample carrying liquid, comprising the steps of

• a) transporting said sample carrying liquid generally along a central axis to a selected point on said control axis,
• b) transporting a nebulizing gas independently along a plurality of paths spaced from said central axis, and
• allowing said nebulizing gas from each said plurality of paths to expand at substantially the same axial coordinate whereby gas pressure is exerted radially and azimuthally on said sample carrying liquid whereby said radially directed pressure varies around said sample carrying liquid in the plane transverse to said central axis in the neighborhood of said axial coordinate,
• c) directing each of said plurality of paths to intersect said central axis at a selected point along said central axis.

The method of forming a spray of charged particles from a sample carrying liquid, comprising the steps of

• a) transporting said sample carrying liquid at a first flow rate generally along a central axis to a selected point on said central axis,
• b) transporting a nebulizing gas independently at a second flow rate along a plurality of paths spaced from said central axis, and
• allowing said nebulizing gas from each said plurality of paths to expand at substantially the same axial coordinate whereby gas pressure is exerted radially and azimuthally on said sample carrying liquid whereby said radially directed pressure varies around said sample carrying liquid in the plane transverse to said central axis in the neighborhood of said axial coordinate,
• c) adjusting said selected point on said central axis with respect to said same axial coordinate to optimize said selected point for said flow rates.