# US 8,785,209 B2 · Thin-film photochemical vapour generation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,209 B2 - Document ID: US8785209B2 - Status: Granted - Kind: B2 - Application number: 12/930,992 - Filed: 2011-01-20 - Published: 2011-08-11 - Granted: 2014-07-22 - Earliest claimed: 2010-01-21 - Assignees: National Research Council of Canada - Applicants: Ralph Sturgeon; Chengbin Zheng - Inventors: Ralph Sturgeon; Chengbin Zheng - Web page: https://patentgrep.com/patent/US8785209B2 ## CPC - B01D 3/346: {the gas being used for removing vapours, e.g. transport gas} - B01D 1/065: {by film evaporating} - Y10T 436/25875: Gaseous sample or with change of physical state - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A photochemical vapor generator is disclosed having a reaction chamber with a liquid sample inlet, a carrier gas inlet and a carrier gas outlet. A liquid sample support surface for supporting a film of a liquid sample is in the reaction chamber. A source of ultraviolet radiation is positioned in radiative contact with the liquid sample support surface. Also described is a process for detecting and/or quantifying an analyte by providing a liquid film of a sample containing an organic acid or a salt thereof and a precursor compound of the analyte, exposing the liquid film to ultraviolet radiation to generate a volatile species of the analyte, separating the volatile species from the liquid film to form a vapor containing the volatile species, and directing the vapor to a detector to detect and/or quantify the analyte in the vapor. Amalgamation of photochemical reactions with thin film generation and gas-liquid phase separation achieves the benefits of all of these principles in a single unit, providing a simple and effective way of enhancing generation of an expanded suite of elements. ## Claims ### Claim 1 A photochemical vapour generator comprising: a reaction chamber having a liquid sample inlet, a carrier gas inlet and a carrier gas outlet; a liquid sample support surface for supporting a film of a liquid sample in the reaction chamber; and a source of ultraviolet radiation positioned in radiative contact with the liquid sample support surface, the ultraviolet source comprising an ultraviolet lamp or an ultraviolet LED, and the ultraviolet source further comprising: a coil that surrounds the reaction chamber and the liquid sample support surface, or straight discharge tubes configured around the reaction chamber and the liquid sample support surface and running up and down a length of the reaction chamber. ### Claim 2 (depends on 1) The generator according to claim 1, wherein the liquid sample support surface comprises one or more topographical features to increase residence time of the liquid sample in the reaction chamber. ### Claim 3 (depends on 2) The generator according to claim 2, wherein the one or more topographical features comprise one or more features to increase surface area of the liquid sample support surface, one or more features to direct flow of the liquid sample in a specific path, or a combination thereof. ### Claim 4 (depends on 2) The generator according to claim 2, wherein the topographical features comprise one or more of a threaded screw, a pattern of bumps, a pattern of depressions, a series of cups or rings that provide a cascade of flowing liquid, a tube, a channel, or a combination thereof. ### Claim 5 (depends on 2) The generator according to claim 2, wherein the topographical features comprise a threaded screw. ### Claim 6 (depends on 2) The generator according to claim 2, wherein the topographical features comprise a channel. ### Claim 7 (depends on 1) The generator according to claim 1, wherein the liquid sample support surface is a surface of a liquid sample support element separate from and housed within the reaction chamber. ### Claim 8 (depends on 7) The generator according to claim 7, wherein the liquid sample support element comprises a quartz rod. ### Claim 9 (depends on 7) The generator according to claim 7, wherein the liquid sample support element comprises a quartz channel. ### Claim 10 (depends on 1) The generator according to claim 1, wherein the reaction chamber further comprises a liquid waste outlet. ### Claim 11 (depends on 1) The generator according to claim 1, wherein the reaction chamber comprises a quartz tube. ### Claim 12 (depends on 1) The generator according to claim 1, wherein the reaction chamber comprises one or more caps and the one or more caps comprise the inlets and outlets. ### Claim 13 (depends on 1) The generator according to claim 1, wherein: (a) the reaction chamber comprises a vertically-oriented quartz tube, a first cap at a first end of the tube comprising the liquid sample inlet and carrier gas outlet, a second cap at a second end of the tube comprising the carrier gas inlet and a liquid waste outlet; (b) the liquid sample support surface is a surface of a quartz rod positioned concentrically in the quartz tube to permit the liquid sample to flow along the rod under influence of gravity from the first end to the second end; and, (c) the source of ultraviolet radiation comprises an ultraviolet coil lamp surrounding the quartz tube and quartz rod. ### Claim 14 (depends on 13) The generator according to claim 13, wherein the liquid sample support surface comprises a screw thread to increase surface area thereby increasing residence time of the film of liquid sample on the liquid sample support surface. ### Claim 15 (depends on 1) The generator according to claim 1, wherein: (a) the reaction chamber comprises a horizontally-oriented quartz tube, a first cap at a first end of the tube comprising the liquid sample inlet and carrier gas outlet, a second cap at a second end of the tube comprising the carrier gas inlet and a liquid waste outlet; (b) the liquid sample support surface is an inner surface of a quartz channel positioned in the quartz tube to permit the liquid sample to flow in the channel from the first end to the second end under control of an active flow regulator; and, (c) the source of ultraviolet radiation comprises an ultraviolet coil lamp surrounding the quartz tube and quartz channel or an ultraviolet lamp comprising straight discharge tubes configured around the quartz tube and quartz channel and running up and down a length of the quartz tube. ### Claim 16 A process for detecting and/or quantifying an analyte comprising: providing a liquid film of a sample containing an organic acid or a salt thereof and a precursor compound of the analyte at a liquid sample support surface of a reaction chamber that has a liquid sample inlet, a carrier gas inlet, and carrier gas outlet; exposing the liquid film to ultraviolet radiation to generate a volatile species of the analyte by providing an ultraviolet source comprising an ultraviolet lamp or an ultraviolet LED, and the ultraviolet source further comprising either a coil that surrounds the reaction chamber and the liquid sample support surface, or straight discharge tubes configured around the reaction chamber and the liquid sample support surface and extending a length of the reaction chamber; separating the volatile species from the liquid film to form a vapour containing the volatile species; and, directing the vapour to a detector to detect and/or quantify the analyte in the vapour. ### Claim 17 (depends on 16) The process according to claim 16, wherein the organic acid comprises formic acid, acetic acid, propionic acid or a mixture thereof, and the salt comprises a sodium salt, potassium salt or a mixture thereof. ### Claim 18 (depends on 16) The process according to claim 16, wherein separating the volatile species from the liquid film comprises stripping the volatile species from the liquid film with aid of a carrier gas. ### Claim 19 (depends on 16) The process according to claim 16, wherein the liquid film is provided without nebulization or aerosolization of the sample. ### Claim 20 A photochemical vapour generator comprising: a reaction chamber having a liquid sample inlet, a carrier gas inlet and a carrier gas outlet; a liquid sample support surface for supporting a film of a liquid sample in the reaction chamber wherein the liquid sample support surface is a surface of a quartz rod that is separate from, and housed within, the reaction chamber; and, a source of ultraviolet radiation positioned in radiative contact with the liquid sample support surface. ### Claim 21 (depends on 20) The generator according to claim 20, wherein the liquid sample support surface comprises one or more topographical features to increase residence time of the liquid sample in the reaction chamber. ### Claim 22 (depends on 21) The generator according to claim 21, wherein the one or more topographical features comprise one or more features to increase surface area of the liquid sample support surface, one or more features to direct flow of the liquid sample in a specific path, or a combination thereof. ### Claim 23 (depends on 21) The generator according to claim 21, wherein the topographical features comprise one or more of a threaded screw, a pattern of bumps, a pattern of depressions, a series of cups or rings that provide a cascade of flowing liquid, a tube, a channel, or a combination thereof. ### Claim 24 (depends on 21) The generator according to claim 21, wherein the topographical features comprise a threaded screw.