Abstract: A differential mobility analyzer (DMA) for separating charged particles or ions suspended in a gas and a method of using the DMA for separating such particles. The invention includes various means for increasing the resolution of the DMA by stabilizing the laminar flow within the DMA and by allowing unusually large flow velocities.

Abstract: The present invention concerns the formation of a stable electrospray of a volatile liquid at reduced pressures by limiting its tendency to evaporate. In a first approach, multi-component capillary jets are produced, comprising a thin layer of low volatility liquid, which is not necessarily a good conductor, surrounding a core of volatile and conducting liquid such as water, so as to minimize direct exposure of the volatile liquid to the region of low pressure. In a second approach, the diameter of the meniscus of a Taylor cone is reduced to a critical diameter, below which no evaporative freezing occurs.

Abstract: A differential mobility analyzer (DMA) for separating charged particles or ions suspended in a gas and a method of using the DMA for separating such particles. The invention includes various means for increasing the resolution of the DMA by stabilizing the laminar flow within the DMA and by allowing unusually large flow velocities.

Abstract: A differential mobility analyzer (DMA) for separating charged particles or ions suspended in a gas and a method of using the DMA for separating such particles. The invention includes various means for increasing the resolution of the DMA by stabilizing the laminar flow within the DMA and by allowing unusually large flow velocities.

Abstract: The present invention concerns the formation of a stable electrospray of a volatile liquid at reduced pressures by limiting its tendency to evaporate. In a first approach, multi-component capillary jets are produced, comprising a thin layer of low volatility liquid, which is not necessarily a good conductor, surrounding a core of volatile and conducting liquid such as water, so as to minimize direct exposure of the volatile liquid to the region of low pressure. In a second approach, the diameter of the meniscus of a Taylor cone is reduced to a critical diameter, below which no evaporative freezing occurs.

Abstract: An analytical apparatus provides for the separation and analysis of a subset of ions from a mixture of ions in a gas. The apparatus includes an ion supply, such as an electrospray, which provides a population of variously charged ions. An analyzing chamber is coupled to the ion supply and includes a first wall with an inlet orifice for receiving the flow of variously charged ions, and a second wall opposed to the first wall. A laminar gas flow is established within the analyzing chamber along a flow axis. The second wall is provided with an outlet orifice that is displaced by a determined distance along the gas flow axis from the inlet orifice. A potential difference is applied between the first and second walls which causes the flow of ions, introduced via the inlet orifice, to migrate towards the outlet orifice.

Abstract: An electrospray apparatus incorporating the invention includes a capillary with an exit for ejecting a fluid, and an electrode positioned downstream from the exit. A gas source is used to establish a region of gas, at least immediately about the exit. A voltage supply creates a potential difference between the capillary exit and the electrode, the potential difference being sufficient to both establish a cone jet mode of operation at the exit of the capillary, to ionize the region of gas about the exit and create a current flow between the exit and the electrode. The current flow exhibits an increased value upon the gas becoming ionized, thus enabling detection of the establishment of a corona. This action creates a corona-assisted cone jet mode of electrospray operation which enables the fluid to disperse into highly uniform sized particles. The preferred gas is carbon dioxide.

Abstract: An analytical apparatus provides for the separation and analysis of a subset of ions from a mixture of ions in a gas. The apparatus includes an ion supply, such as an electrospray, which provides a population of variously charged ions. An analyzing chamber is coupled to the ion supply and includes a first wall with an inlet orifice for receiving the flow of variously charged ions, and a second wall opposed to the first wall. A laminar gas flow is established within the analyzing chamber along a flow axis. The second wall is provided with an outlet orifice that is displaced by a determined distance along the gas flow axis from the inlet orifice. A potential difference is applied between the first and second walls which causes the flow of ions, introduced via the inlet orifice, to migrate towards the outlet orifice.