Evaporative electrical detector

A process for determining non-volatile residue concentrations, including:

• generating an aerosol stream composed of liquid droplets containing non-volatile material;
• drying the droplets, whereby the aerosol stream at a point downstream of aerosol stream generation is composed of residue particles of the non-volatile material;
• generating multiple ions, and providing a gas flow past the ions to entrain at least a portion of the ions in the gas flow to provide an ion stream;
• after drying the droplets, directing the ion stream and the aerosol stream towards one another and into a turbulent merger to promote a mixing of the ions and the residue particles to apply a size-dependent electrical charge to each of the residue particles;
• generating an electrical signal having a level proportional to an aggregate electrical charge of a selected sequence of the electrically charged residue particles in the aerosol stream;
• and
• using the electrical signal to indicate a concentration of the at least one non-volatile material in the liquid sample over a region thereof corresponding to the selected sequence of the charged residue particles.

A system for analyzing liquid samples containing non-volatile analytes, including:

• an analyte separator adapted to separate different non-volatile analytes in a liquid sample by concentrating the different non-volatile analytes primarily into different regions within the liquid sample;
• a nebulizer disposed to receive the liquid sample from the separator, and adapted to nebulize at least a portion of the liquid sample to generate an aerosol stream composed of droplets of the liquid sample suspended in a carrier gas and containing the at least one analyte, the droplets tending to evaporate whereby the aerosol stream at a selected location downstream of the nebulizer is composed of residue particles of the at least one analyte;
• an electrical charger disposed to receive the aerosol stream near the selected location and adapted to apply a size-dependent electrical charge to each of the residue particles;
• and
• a charge-responsive device disposed to receive the electrically charged residue particles and adapted to generate an electrical signal in proportion to an aggregate charge of the received residue particles and thereby indicate a concentration of the at least one analyte in the liquid over a range determined by the received residue particles.

A detector for determining concentrations of non-volatile analytes in liquid solutions, including:

• a nebulizer disposed to receive a liquid incorporating non-volatile material, and adapted to nebulize at least a portion of the liquid to generate an aerosol stream composed of droplets of the liquid suspended in a carrier gas, the droplets tending to evaporate whereby the aerosol stream at a selected location downstream of the nebulizer is composed of residual particles of the non-volatile material suspended in the carrier gas;
• an ion generator disposed near the selected location;
• a source of compressed gas for providing a gas flow, and a fluid conduit adapted to guide the gas flow past the ion generator to entrain at least a portion of the ions and carry the entrained ions into a confluence with the aerosol stream, to apply a size-dependent electrical charge to each of the residue particles;
• and
• a charge-responsive device disposed to receive the charged residue particles and adapted to generate an electrical signal having a level proportional to an aggregate charge of the received residue particles, thereby to indicate a concentration of the non-volatile material in the liquid.

A non-volatile analyte concentration detection device including:

• an enclosure defining a chamber;
• a first fluid passage disposed to receive an aerosol stream composed of liquid droplets containing non-volatile material and suspended in a carrier gas, said first fluid passage being adapted to guide the aerosol stream toward the chamber as the liquid droplets substantially evaporate whereby the aerosol stream as it enters the chamber is composed of residue particles of the non-volatile material;
• an ion generator disposed near the chamber and adapted to generate multiple ions;
• a second fluid passage for guiding a gas flow toward the chamber and past the ion generator, to entrain at least a portion of the ions and carry the entrained ions into the chamber to merge with the aerosol stream, thus to apply a size-dependent electrical charge to each of the residue particles;
• and
• a charge-responsive device disposed downstream of an exit of the chamber to receive at least a portion of the charged residue particles and adapted to generate an electrical signal having a level proportional to an aggregate charge of the received residue particles, thereby to indicate a concentration of the non-volatile material.