Abstract: A method to measure the concentration of a constituent element in a gas sample contained in an analyzer. A sample cell of a detector has an inlet and an outlet. The outlet of the sample cell is sealed. A predetermined mass of a gas sample is received through the inlet into the sample cell over a predetermined pressurization period until substantially the entire mass of the gas sample contained in the analyzer is contained within the sample cell. The gas sample is pressurized to a predetermined pressure over the pressurization period. A concentration of a constituent element in the pressurized gas sample is determined.

Abstract: A purge and trap concentrator has a sample processing system that includes a network of fluid passageways and fluid control devices. A flow controller couples to a purge gas inlet provides an electrically adjustable purge gas flow rate as a function of an electrical input. A digital controller provides the system cycle and provides the electrical input. The electrical input varies as a function of the system cycle to increase the rate of flow of purge gas during a bake step relative to the rate of flow of purge gas during a purge step in the system cycle.

Abstract: A purge and trap concentrator and a method for drying a stream of sample gas in a gas analysis instrument. A dryer tube has an inlet that receives a stream of sample gas during a drying interval and receives a stream of dry gas during a regeneration interval. The dryer tube also has an outlet and an interior passageway between the inlet and an outlet. Support material comprising polymer sorbent is placed in the interior passageway and provides a support surface area for a hygroscopic coating comprising lithium chloride. A controller controls a heater to increase the temperature of the dryer tube to between 100 and 300 degrees centigrade during the regeneration interval and controls the heater to decrease the temperature of the dryer tube to below 100 degrees centigrade during the drying interval.

Abstract: A vial autosampler includes a vial cup adapted to contain a vial with a stir member inside. The vial autosampler includes a vial mixing system for agitating the contents of the vial. The mixing system has an actuator, such as a motor, and a mixing hub that is coupled to the actuator. The mixing hub includes at least one magnetic field source disposed to rotate a magnetic field about the vial cup.

Abstract: A purge and trap concentrator and a method for drying a stream of sample gas in a gas analysis instrument. A dryer tube has an inlet that receives a stream of sample gas during a drying interval and receives a stream of dry gas during a regeneration interval. The dryer tube also has an outlet and an interior passageway between the inlet and an outlet. Support material comprising polymer sorbent is placed in the interior passageway and provides a support surface area for a hygroscopic coating comprising lithium chloride. A controller controls a heater to increase the temperature of the dryer tube to between 100 and 300 degrees centigrade during the regeneration interval and controls the heater to decrease the temperature of the dryer tube to below 100 degrees centigrade during the drying interval.

Abstract: A three stage needle for use with a sampling station of an autosampler to facilitate gas and liquid extractions and injections. The needle includes a bottom stage, a middle stage, and a top stage. Each of the stages of the needle includes at least one aperture used to extract gas or liquid from a specimen or perform an injection. In addition, each of the stages can be placed in fluidic communication with the sampling station to facilitate the desired extraction or injection.

Abstract: A system for concentrating a volatile organic compound (VOC) sample uses in one embodiment a bypass line and a valve coupled thereto to regulate an amount of carrier gas flowing through a carrier gas line. A flow splitter fluidly couples the bypass line to the carrier gas line, and connects to the output of a cryofocuser. The valve opens at the onset of transferring the VOC sample from a concentrator trap such as a sorbent trap to the cryofocuser, thereby resulting in an increased amount of carrier gas flow between the concentrator trap and the cryofocuser for more efficient desorbing of the concentrator trap. The valve is closed when the focused VOC sample is flushed out of the cryofocuser for delivery to a gas chromatograph, preferably delivering the entire VOC sample to the GC.