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Michael Markelov

Yuri Kazakevich

A headspace sampling apparatus ( ) operates to provide a sample of a vapor phase of a substance being analyzed under conditions of thermodynamic equilibrium. The substance is held in a vial ( ). The vapor phase of the substance ( ) is moved through a sample loop ( ) between a first variable volume chamber ( ) and a second variable volume chamber ( ). A constant volume and temperature is maintained within the variable volume chambers, the sample loop and the headspace of the vial. An aliquot of the equilibrated vapor in the sample loop is passed to an analytical instrument ( ) for analysis. The sample is obtained under conditions in which the sampling process does not affect the makeup of the sample because thermodynamic equilibrium is maintained.

Headspace sampling apparatus and method

A headspace sampling apparatus collects headspace vapor from a container holding a vapor phase and a non-vapor phase of a substance which is to be analyzed. The apparatus includes a dual needle apparatus ( ). The dual needle apparatus is extended through a septum into a headspace portion ( ) of a vial ( ) holding the substance for analysis. A purge gas is supplied to a first fluid passage ( ) in the dual needle. The purge gas sweeps the material in the headspace and passes the sample through a send fluid passage ( ) in the needle. The extracted sample is selectively directed through a six port valve ( ). In a first condition of the valve the sample is directed to a trap ( ) for collection therein. After sample collection the condition of the six port valve is changed. Material is desorbed from the trap and directed through the valve into an analytical instrument ( ). The ratios of the volumes occupied by liquid or solid phase of the substance and the vapor phase in the headspace of the vial is adjusted to selectively maximize sensitivity.

A headspace instrument ( ) operates to equilibrate a vapor phase of a headspace sample in a sample loop ( ). The sample is equilibrated by flow through the headspace between variable volume chambers ( ). The volume of the variable volume chambers are changed in coordinated relation so that a constant total volume is always maintained. An aliquot of the equilibrated sample in the sample loop is delivered to an analytical instrument. The headspace instrument enables delivering a vapor sample from a headspace under conditions which do not disturb the thermodynamic equilibrium between the vapor phase and the non-vapor phase of the sample and avoids having the sampling process impact the results of the analysis. Alternative forms of the headspace instrument enable the conduct of concentration dependent processes and absorption and desorption experiments.

Headspace instrument

A system for analysis of materials includes a sensor loop (,). The sensor loop includes sensors (,) therein. The sensor loop includes traps (,). Sample material is desorbed from a first trap, moved past the sensors and collected in the second trap. The material is then desorbed from the second trap, moved past the sensors and again collected in the first trap. The amount and rate of flow of the sample material past the sensors is controlled, and the repeated exposure of the sensors to the sample material enhances sensitivity.

Recirculation analysis apparatus and method

A headspace autosampling apparatus (92) for generating and delivering gaseous samples to a gas chromatograph or other instrument. The vials are delivered one at a time through a vial delivery mechanism (160) to a heated zone (146) wherein the substances (94, 96) to be analyzed reach equilibrium with the headspace (100, 102) above the samples in the vials. The vials are generally cylindrical and extend horizontally to facilitate attainment of equilibrium rapidly upon heating. The vials are also preferably rotated about their longitudinal axis prior to sampling so as to achieve a film effect on the interior walls of the vials which further aids in attainment of equilibrium. The apparatus is operative to first pressurize the headspace in the vial with an inert gas, and then to place said headspace in fluid communication with the inlet of a gas chromatograph wherein analyses in the headspace volume are analyzed to determine the composition thereof. One form of vial (260) operates to minimize changes in amounts of materials in the sample due to changes in equilibrium during sampling.

Headspace vial apparatus and method

A headspace autosampling apparatus (92) for generating and delivering gaseous samples to a gas chromatograph or other instrument includes a plurality of vials (98) in a carousel (150). The vials are delivered one at a time from the carousel through a vial delivery mechanism (160) to a heated zone (146) wherein the substances (94, 96) to be analyzed reach equilibrium with the headspace (100, 102) above the samples in the vials, preferably using the full evaporation technique (FET). The vials are generally cylindrical and extend horizontally to facilitate attainment of equilibrium rapidly upon heating. The vials are also preferably rotated about their longitudinal axis prior to sampling so as to achieve a film effect on the interior walls of the vials which further aids in attainment of equilibrium. The apparatus is operative to first pressurize the headspace in the vial with an inert gas, and then to place said headspace in fluid communication with the inlet of a gas chromatograph wherein analytes in the headspace volume are analyzed to determine the composition thereof.

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Chesterland, OH, United States of America

Michael Markelov