Charged particle source with droplet control for mass spectrometry

An ion source for preparing gas phase ions from a liquid sample, containing chemical species in a solvent, carrier liquid or both, wherein the ions generated have a momentum substantially directed along an ion production axis, said source comprising:

• a) an electrically charged droplet source for generating primary electrically charged droplets of the liquid sample in a flow of bath gas, wherein said primary electrically charged droplets have a selected droplet exit time and a momentum directed along a droplet production axis;
• b) an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, in fluid communication with the electrically charged droplet source and positioned at a selected distance downstream from the electrically charged droplet source with respect to the flow of bath gas, for receiving the flow of bath gas and the primary electrically charged droplets, wherein the optical axis of the lens system is coaxial with the ion production axis, wherein the primary electrically charged droplets enter the internal end and at least partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplets in the aerodynamic ion lens system generates at least one gas phase ion;
• secondary electrically charged droplets or both wherein the flow of bath gas through the lens system focuses the spatial distribution of the primary electrically charged droplets, secondary electrically charged droplets, gas phase ions or any combinations of these about the ion production axis, wherein the secondary electrically charged droplets, gas phase ions or both exit said external end of the aerodynamic ion lens system having a momentum substantially directed along the ion production axis, and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplets and said gas phase ions;
• and
• c) at least one flow inlet, in fluid communication with said charged droplet source for introducing the flow of bath gas, wherein said flow of bath gas conducts said primary electrically charged droplets, secondary electrically charged droplets and gas phase ions through said aerodynamic ion lens system.

A device for determining the identity, concentration or both of chemical species in a liquid sample containing the chemical species in a solvent, carrier liquid or both, said device comprising:

• a) an electrically charged droplet source for generating primary electrically charged droplets of the liquid sample in a flow of bath gas, wherein said primary electrically charged droplets have a selected droplet exit time and a momentum directed along a droplet production axis;
• b) an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, in fluid communication with the electrically charged droplet source and positioned at a selected distance downstream from the electrically charged droplet source with respect to the flow of bath gas, for receiving the flow of bath gas and the primary electrically charged droplets, wherein the optical axis of the lens system is coaxial with the ion production axis, wherein the primary electrically charged droplets enter the internal end and at least partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplets in the aerodynamic ion lens system generates gas phase ions, secondary electrically charged droplets or both wherein the flow of bath gas through the lens system focuses the spatial distribution of the primary electrically charged droplets, secondary electrically charged droplets, gas phase ions or any combinations of these about the ion production axis, wherein the secondary electrically charged droplets, gas phase ions or both exit said external end of the aerodynamic ion lens system having a momentum substantially directed along the ion production axis, and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplets and said gas phase ions;
• c) at least one flow inlet, in fluid communication with said charged droplet source for introducing the flow of bath gas, wherein said flow of bath gas conducts said primary electrically charged droplets, secondary electrically charged droplets and gas phase ions through said aerodynamic ion lens system;
• and
• d) a charged particle analyzer operationally connected to said aerodynamic ion lens system, for analyzing said gas phase ions.

A device for determining the identity, concentration or both of chemical species in a liquid sample containing the chemical species in a solvent, carrier liquid or both, said device comprising:

• a) an electrically charged droplet source for generating a primary electrically charged droplet of the liquid sample in a flow of bath gas, wherein said primary electrically charged droplet has a selected droplet exit time and a momentum substantially directed along a droplet production axis;
• b) a charged droplet trap in fluid communication with the electrically charged droplet source and positioned along said droplet production axis at a selected distance downstream from said electrically charged droplet source, with respect to the flow of bath gas, for receiving the flow of bath gas and primary electrically charged droplet;
• wherein the primary electrically charged droplet remains in the charged droplet trap for a selected residence time sufficient to provide partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplet generating at least one secondary electrically charged droplet having said selected size or a combination of at least one gas phase ion and at least one secondary electrically charged droplet having said a selected size;
• wherein the secondary electrically charged droplets having said selected size exit the trap along an ion production axis at a selected release time;
• and
• c) at least one flow inlet in fluid communication with said charged droplet source for introducing a flow of bath gas;
• and
• d) charge particle analyzer operationally connected to said charged droplet trap, for analyzing said gas phase ions generated from the secondary electrically charged droplets having a selected size.

A device for determining the identity, concentration or both of chemical species in a liquid sample containing the chemical species in a solvent, carrier liquid or both, said device comprising:

• a) an electrically charged droplet source for generating a primary electrically charged droplet of the liquid sample in a flow of bath gas, wherein said primary electrically charged droplet has a selected droplet exit time and a momentum substantially directed along a droplet production axis;
• b) a charged droplet trap in fluid communication with the electrically charged droplet source and positioned along said droplet production axis at a selected distance downstream from said electrically charged droplet source, with respect to the flow of bath gas, for receiving the flow of bath gas and primary electrically charged droplet;
• wherein the primary electrically charged droplet remains in the charged droplet trap for a selected residence time sufficient to provide partial evaporation of solvent, carrier liquid or both from the electrically charged droplet generating at least one secondary electrically charged droplet having a selected size;
• wherein the secondary electrically charged droplets having said selected size exit the trap along an ion production axis at a selected release time;
• c) an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, in fluid communication with the electrically charged droplet source and positioned at a selected distance downstream from the droplet trap, with respect to the flow of bath gas, for receiving the flow of bath gas and secondary electrically charged droplets having said selected size, wherein the optical axis of the lens system is coaxial with the ion production axis, wherein the secondary electrically charged droplets having said selected size, enter the internal end and at least partial evaporation of solvent, carrier liquid or both from the secondary electrically charged droplets having said selected size in the aerodynamic ion lens system generates gas phase ions, wherein the flow of bath gas through the lens system focuses the spatial distribution of the secondary electrically charged droplets having said selected size, gas phase ions or both about the ion production axis, wherein the secondary electrically charged droplets, gas phase ions or both exit said external end of the aerodynamic ion lens system along said ion production axis, and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplets and said gas phase ions;
• d) at least one flow inlet, in fluid communication with said charged droplet source for introducing the flow of bath gas;
• and
• e) a charge particle analyzer operationally connected to said aerodynamic ion lens system, for analyzing said gas phase ions.

A method of generating charged particles from a liquid sample, containing chemical species in a solvent, carrier liquid or both, said method comprising the steps of:

• a) providing a flow of bath gas;
• b) generating a primary electrically charged droplet of the liquid sample in said flow of bath gas, wherein said primary electrically charged droplet exits a charged particle source at a selected droplet exit time having a momentum substantially directed along a droplet production axis:
• c) directing said primary electrically charged droplet into a charged droplet trap in fluid communication with the electrically charged droplet source and positioned along said droplet production axis at a selected distance downstream from said electrically charged droplet source with respect to the flow of bath gas;
• d) confining the primary electrically charged droplet in the charged droplet trap for a selected residence time sufficient to provide partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplet thereby generating at least one secondary electrically charged droplet having a selected size;
• d) releasing said secondary electrically charged droplet having said selected size, wherein said secondary electrically charged droplets exit the trap along an ion production axis at a selected release time.

A method of generating gas phase ions from a liquid sample, containing chemical species in a solvent, carrier liquid or both said, method comprising the steps of:

• a) providing a flow of bath gas;
• b) generating a primary electrically charged droplet of the liquid sample in said flow of bath gas, wherein said primary electrically charged droplet exits a charged particle source at a selected droplet exit time having a momentum substantially directed along a droplet production axis;
• c) directing said primary electrically charged droplet into a charged droplet trap in fluid communication with the electrically charged droplet source, wherein said charged droplet trap is positioned along said droplet production axis at a selected distance downstream from said electrically charged droplet source with respect to the flow of bath gas;
• d) confining the primary electrically charged droplet in the charged droplet trap for a selected residence time sufficient to provide partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplet thereby generating at least one secondary electrically charged droplet having a selected size;
• d) releasing said secondary electrically charged droplet having said selected size, wherein said secondary electrically charged droplets exits the trap along an ion production axis at a selected release time;
• e) directing said secondary electrically charged droplet and said flow of bath gas through an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, wherein the optical axis of the lens system is coaxial with the ion production axis, wherein the secondary electrically charged droplet enters the internal end and at least partial evaporation of solvent, carrier liquid or both from the secondary electrically charged droplet in the aerodynamic ion lens system generates at least one gas phase ion, wherein the flow of bath gas through the lens system focuses the spatial distribution of the secondary electrically charged droplet, gas phase ion or both about the ion production axis, wherein the gas phase ion exit said external end of the aerodynamic ion lens system along said ion production axis and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplets and said gas phase ion.

A method of generating gas phase ions from a liquid sample, containing chemical species in a solvent, carrier liquid or both, said method comprising the steps of:

• a) providing a flow of bath gas;
• b) generating a primary electrically charged droplet of the liquid sample in said flow of bath gas, wherein said primary electrically charged droplet exits a charged particle source at a selected droplet exit time having a momentum substantially directed along a droplet production axis;
• and
• c) directing said primary electrically charged droplet and said flow of bath gas through an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, wherein the ion optical axis of the lens system is coaxial with a ion production axis, wherein the primary electrically charged droplet enters the internal end and at least partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplets in the aerodynamic ion lens system generates at least one gas phase ion, wherein the flow of bath gas through the lens system focuses the spatial distribution of the primary electrically charged droplet, gas phase ion or both about the ion production axis, wherein said gas phase ion exits said external end of the aerodynamic ion lens system having a momentum substantially directed along the ion production axis, and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplet and said gas phase ions.

A method of determining the identity and concentration of chemical species in a liquid sample containing chemical species in a solvent, carrier liquid or both, said method comprising the steps of:

• a) providing a flow of bath gas;
• b) generating a primary electrically charged droplet of the liquid sample in said flow of bath gas, wherein said primary electrically charged droplet exits a charged particle source at a selected droplet exit time having a momentum substantially directed along a droplet production axis;
• c) directing said primary electrically charged droplet and said flow of bath gas through an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, wherein the ion optical axis of the lens system is coaxial with a ion production axis, wherein the primary electrically charged droplet enters the internal end and at least partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplets in the aerodynamic ion lens system generates at least one gas phase ion, wherein the flow of bath gas through the lens system focuses, the spatial distribution of the primary electrically charged droplet gas phase ion or both about the ion production axis wherein said gas phase ion exits said external end of the aerodynamic ion lens system having a momentum substantially directed along the ion production axis, and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplet and said gas phase ions;
• and
• analyzing said gas phase ion with a charged particle analyzer positioned along said ion production axis, thereby determining the identity and concentration of said chemical species.

A method of determining the identity and concentration of chemical species in a liquid sample containing chemical species in a solvent, carrier liquid or both, said method comprising the steps of:

• a) providing a flow of bath gas;
• b) generating a primary electrically charged droplet of the liquid sample in said flow of bath gas, wherein said primary electrically charged droplet exits a charged particle source at a selected droplet exit time having a momentum substantially directed along a droplet production axis;
• c) directing said primary electrically charged droplet into a charged droplet trap in fluid communication with the electrically charged droplet source and positioned along said droplet production axis at a selected distance downstream from said electrically charged droplet source with respect to the flow of bath gas;
• d) confining the primary electrically charged droplet in the charged droplet trap for a selected residence time sufficient to provide partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplet thereby generating at least one secondary electrically charged droplet having a selected size;
• d) releasing said secondary electrically charged droplet having said selected size, wherein said secondary electrically charged droplets exit the trap along an ion production axis at a selected release time;
• e) at least partially evaporating said secondary electrically charged droplet having said selected size, thereby generating at least one gas phase ion;
• analyzing said gas phase ion with a charged particle analyzer positioned along said ion production axis, thereby determining the identity and concentration of said chemical species.

A method of determining the identity and concentration of chemical species in a liquid sample containing chemical species in a solvent, carrier liquid or both, said method comprising the steps of:

• a) providing a flow of bath gas;
• b) generating a primary electrically charged droplet of the liquid sample in said flow of bath gas, wherein said primary electrically charged droplet exits a charged particle source at a selected droplet exit time having a momentum substantially directed along a droplet production axis;
• c) directing said primary electrically charged droplet into a charged droplet trap in fluid communication with the electrically charged droplet source, wherein said charged droplet trap is positioned along said droplet production axis at a selected distance downstream from said electrically charged droplet source with respect to the flow of bath gas;
• d) confining the primary electrically charged droplet in the charged droplet trap for a selected residence time sufficient to provide partial evaporation of solvent, carrier liquid or both from the primary electrically charged droplet thereby generating at least one secondary electrically charged droplet having a selected size;
• d) releasing said secondary electrically charged droplet having said selected size, wherein said secondary electrically charged droplets exits the trap along an ion production axis at a selected release time;
• e) directing said secondary electrically charged droplet and said flow of bath gas through an aerodynamic ion lens system of selected length having an ion optical axis, an internal end and an external end, wherein the optical axis of the lens system is coaxial with the ion production axis, wherein the secondary electrically charged droplet enters the internal end and at least partial evaporation of solvent, carrier liquid or both from the secondary electrically charged droplet in the aerodynamic ion lens system generates at least one gas phase ion, wherein the flow of bath gas through the lens system focuses the spatial distribution of the secondary electrically charged droplet, gas phase ion or both about the ion production axis, wherein the gas phase ion exit said external end of the aerodynamic ion lens system along said ion production axis and wherein said aerodynamic lens system is substantially free of electric fields generated from sources other than said electrically charged droplets and said gas phase ion;
• and
• analyzing said gas phase ion with a charged particle analyzer positioned along said ion production axis, thereby determining the identity and concentration of said chemical species.