Abstract: The invention concerns a method for preparing a sample to be introduced in a chromatographic analysis system from the headspace of a vial, by introducing a pressurized inert gas in said headspace, controlling the pressure or flow, and subsequently by discharging said pressure from the headspace through a loop having constant volume and through a discharge duct provided with a valve, the discharge duct branching with respect to the feed duct. To eliminate the drawbacks of the known methods, during the step of discharging the pressure, the feed duct is kept open and the pressure in said loop is controlled by detecting the feed and/or discharge pressure.

Abstract: The invention concerns a method for preparing a sample to be introduced in a chromatographic analysis system from the headspace of a vial, by introducing a pressurized inert gas in said headspace, controlling the pressure or flow, and subsequently by discharging said pressure from the headspace through a loop having constant volume and through a discharge duct provided with a valve, the discharge duct branching with respect to the feed duct. To eliminate the drawbacks of the known methods, during the step of discharging the pressure, the feed duct is kept open and the pressure in said loop is controlled by detecting the feed and/or discharge pressure.

Abstract: An injection port for a gas chromatograph (GC) is operated such that, during an injection sequence, an inert gas is used for sample transfer to the analytical column while hydrogen is subsequently utilized for the majority of the analytical separation. This allows for a high degree of chromatographic efficiency, while also reducing unwanted chemical reactions involving hydrogen and/or reactive solvents in a hot injection port. Certain embodiments also provide an increased margin of safety when using hydrogen, since the total flow may be limited such that the concentration of hydrogen in the GC oven never exceeds a safety limit, such as the lower explosive limit.

Abstract: An injection port for a gas chromatograph (GC) is operated such that, during an injection sequence, an inert gas is used for sample transfer to the analytical column while hydrogen is subsequently utilized for the majority of the analytical separation. This allows for a high degree of chromatographic efficiency, while also reducing unwanted chemical reactions involving hydrogen and/or reactive solvents in a hot injection port. Certain embodiments also provide an increased margin of safety when using hydrogen, since the total flow may be limited such that the concentration of hydrogen in the GC oven never exceeds a safety limit, such as the lower explosive limit.

Abstract: The invention relates to a vaporization injector for a gas chromatograph, said injector comprising a structure (11) mounted in a detachable manner on the gas chromatograph body and including the sample introduction means, the vaporization chamber and pneumatic connections for feeding the carrier gas to the vaporization chamber and to the septum purge means, as well as pneumatic connections for evacuating the splitted sample and carrier gases.

Abstract: This invention is related to a gas chromatograph wherein more substitutable modules are foreseen, in particular injector modules and/or detector modules, as well as one embodiment in an oven module. Each module is insertable in a seat of the gas chromatograph mainframe with fast connections of its electronic and pneumatic means to corresponding outlets on said mainframe. Each module has its own heating element.

Abstract: A device for conserving helium gas in a gas chromatograph system is characterized in that during the majority of an analytical separation, helium is used as the carrier gas while an auxiliary non-helium gas is used to pressurize the inlet and provide for septum purge and split vent flow. Prior an injection period, a coaxial helium flow is established at the column entrance wherein the coaxial helium flow is less than the column flow. Following the injection and sample transfer period, a coaxial helium flow is established wherein the flow is greater than the column flow.

Abstract: A device for conserving helium gas in a gas chromatograph system is characterized in that during the majority of an analytical separation, helium is used as the carrier gas while an auxiliary non-helium gas is used to pressurize the inlet and provide for septum purge and split vent flow. Prior an injection period, a coaxial helium flow is established at the column entrance wherein the coaxial helium flow is less than the column flow. Following the injection and sample transfer period, a coaxial helium flow is established wherein the flow is greater than the column flow.

Abstract: The invention relates to a vaporization injector for a gas chromatograph, said injector comprising a structure (11) mounted in a detachable manner on the gas chromatograph body and including the sample introduction means, the vaporization chamber and pneumatic connections for feeding the carrier gas to the vaporization chamber and to the septum purge means, as well as pneumatic connections for evacuating the splitted sample and carrier gases.

Abstract: A device for conserving helium gas in a gas chromatograph system is characterized in that during the majority of an analytical separation, helium is used as the carrier gas while an auxiliary non-helium gas is used to pressurize the inlet and provide for septum purge and split vent flow. Prior an injection period, a coaxial helium flow is established at the column entrance wherein the coaxial helium flow is less than the column flow. Following the injection and sample transfer period, a coaxial helium flow is established wherein the flow is greater than the column flow.

Abstract: This invention is related to a gas chromatograph wherein more substitutable modules are foreseen, in particular injector modules and/or detector modules, as well as one embodiment in an oven module. Each module is insertable in a seat of the gas chromatograph mainframe with fast connections of its electronic and pneumatic means to corresponding outlets on said mainframe. Each module has its own heating element.

Abstract: This invention concerns a method and a gas chromatographic instrument in which a gas feeding low pressure condition, for instance from a cylinder, is monitored by controlling an electric parameter operating on a proportional solenoid valve placed along the gas line, and wherein an alarm to the operator is foreseen when said parameter reaches a pre-set value, so to allow a cylinder substitution before the pressure falling to zero.

Abstract: The present invention relates to a method for injecting a sample (i.e. a material to be analyzed that may be dissolved in a solvent) in a vaporization chamber or in a pre-column or a gas chromatograper, this method implying separately injecting a co-solvent, with the co-solvent being injected in advance of the sample and/or in a point in the vaporization chamber other than the sample injection point.

Abstract: The invention relates to a CO2-absorption device within an elemental analysis instrument, comprising at least one combustion reactor and one detector, connected by a pneumatic line for the gasses undergoing analysis emerging from the combustion reactor, along which said CO2-absorption device is arranged downstream of the combustion reactor and upstream of the detector. In order to accelerate the operational cycle and improve efficiency without excessive bulk, two regenerable CO2 filters, valve means for feeding the gasses undergoing analysis to one of said filters, alternating between one another for each analysis, and for supplying a regenerating flow of wash gas to the second filter, in the opposite direction with respect to the direction of flow of the gas undergoing analysis in the same filter are envisaged, as well as means for temporarily heating the filter during the regeneration stage.

Abstract: The invention concerns a device for washing the injector in a liquid chromatography equipment, comprising a sealed passage for the injection needle and, upstream, a mobile valve for alternatively connecting said passage with the outside for introduction of the needle, or with at least one source of washing fluid.

Abstract: The present invention relates to a method for injecting a sample (i.e. a material to be analyzed that may be dissolved in a solvent) in a vaporization chamber or in a pre-column or a gas chromatograper, this method implying separately injecting a co-solvent, with the co-solvent being injected in advance of the sample and/or in a point in the vaporization chamber other than the sample injection point.

Abstract: A method for obtaining reproducibility of the retention times of the components of a mixture to be analysed in an apparatus for gaschromatographic analysis provided with a capillary column, when there occurs one of the following variations: variation in the length of the column, or alternatively its replacement with a column having identical real specifications with the exception of the length, and/or variation in the pressure of the carrier gas at output from said column. The method envisages that the pneumatic resistance of the column is known and preferably measured before and after the aforesaid variations, and that a new input pressure or a new mass flow of the carrier gas will be entered into said apparatus for gaschromatographic analysis in relation to said values of pneumatic resistance.

Abstract: Chromatography column assembly of the direct heating type, comprising at least a capillary column, at least a tubular structure which envelops the capillary column and is coaxial with it, means to directly heat the column, means to detect the temperature of the column and one or more electrically insulating covering elements, wherein the tubular structure comprises a plurality of tubular meshes each formed of a plurality of filaments woven together (FIG. 3).

Abstract: A direct-heating column assembly for chromatography, includes at least one capillary column and at least one element made of electrically conductive material in contact with the capillary column. The element includes a plurality of filaments woven together to form a tubular mesh that uniformly envelops the outer surface of the capillary column both in radial and longitudinal directions.

Abstract: A method for obtaining reproducibility of the retention times of the components of a mixture to be analysed in an apparatus for gaschromatographic analysis provided with a capillary column, when there occurs one of the following variations: variation in the length of the column, or alternatively its replacement with a column having identical real specifications with the exception of the length, and/or variation in the pressure of the carrier gas at output from said column. The method envisages that the pneumatic resistance of the column is known and preferably measured before and after the aforesaid variations, and that a new input pressure or a new mass flow of the carrier gas will be entered into said apparatus for gaschromatographic analysis in relation to said values of pneumatic resistance.