Abstract: A method and device for vaporization injection in which there is at least one constriction between the end of the sample injection needle or tube and the interior of the heated vaporization chamber. The terminal part of the needle or tube can be heated to improve nebulisation of the sample and therefore its vaporization speed.

Abstract: The invention concerns a method for the realignment of peaks in gas chromatographic analyses after the replacement of the used capillary column with a nominally equal one, wherein a K coefficient characteristic of the column is preventively calculated by flowing carrier gas in the column under stabilized conditions of pressure and flow rate and of the column temperature, said K coefficient being stored in a memory of the gas chromatographic system. Said K coefficient is used to correlate at least two of the above mentioned parameters in subsequent analyses, obtaining an automatic realignment of peaks. The invention also concerns the analytical equipment to perform the method, and the capillary gas chromatographic column characterized as reported above.

Abstract: There is provided a method and apparatus for controlling the carrier gas flow through a gas chromatographic apparatus with capillary column subjected to variations in temperature, through control of feeding pressure achieved following computerized processing of the equation of the carrier flow rate as a function of inlet pressure, column temperature and system structural parameters, including preliminary determination of the system parameters through detection of pressure, temperature and flow rate values in stabilized conditions of carrier passage through apparatus and calculation of a constant representing said parameters on the basis of values detected and in application of the aforesaid equation; storage of aforesaid constant; utilization of constant in the mentioned equation for controlling carrier flow rate through calculation and control of its feeding pressure during utilization of the gas chromatographic apparatus.

Abstract: A device and method are described for the gas chromatographic separation of a sample, aimed in particular at the analysis of large volume samples. Provision is made for the use of calculating and memorizing a plurality of reference values corresponding to the evaporation rates of solvents combined with a carrier gas for a corresponding plurality of discrete values representing the conditions of pressure, temperature, injected sample volume and sample injection rate. The effective solvent evaporation rate is then calculated in correspondence to the effective conditions in which the process is carried out to determine the volumetric fraction of the sample which is transferred through the capillary column in relation to its characteristics and geometrical dimensions.

Abstract: The invention concerns a method and an equipment for the simulated distillation, by means of gas chromatography, of petroleum products, capable of characterizing also high boiling products, exceeding C55, over 600.degree. C. TBP. A chromatograph is used with a capillary column having a length less than or equal to 10 m, containing an immobilized non polar polydimethylsilicon gum stationary phase with a film thickness less than or equal to 0.2 .mu.m. The sample is introduced through a non vaporizing direct cold on-column injection and the eluted sample is detected by means of a FID detector. The column oven is operated in temperature programming conditions up to temperatures exceeding 400.degree. (up to 430.degree.-450.degree. C.).

Abstract: This invention concerns a chamber for chromatographic analyses, in which capillary columns, in particular columns of fused silica, are thermally conditioned. The chamber comprises a thermally insulated space which can be perfectly sealed towards the outside and which houses means for heating the air and at least a fan for air circulation inside said space. In order to make the air flow going to the column(s) within the chamber as homogeneous and stable as possible from the thermal viewpoint the heating means are positioned on the suction side of the fan or of each fan, so to cause a perfect mixing of cold and hot fluid flow threads or lines in correspondence with the fan itself, and thereby obtain a uniform and stable air current from the fan towards the column.

Abstract: A device for heating sample containing vials, in a gas-chromatographic apparatus provided with an automatic sampler, which includes a shroud in which a depression is made by a fan which sucks external air and conveys it under pressure into a Venturi tube shaped duct. This depression causes more external air to be sucked through separate openings of the shroud and to follow a different path along the resistors, the sampler, the tray and the vials and to be eventually exhausted through the vent together with air coming from the fan duct.

Abstract: The invention concerns a method and an equipment for the simulated distillation, by means of gas chromatography, of petroleum products, capable of characterizing also high boiling products, exceeding C55, over 600 C TBP. A chromatograph is used with a capillary column having a length less than or equal to 10 m, containing an immobilized non polar polydimethylsilicon gum stationary phase with a film thickness less than or equal to 0.2 .mu.m. The sample is introduced through a non vaporizing direct cold on-column injection and the eluted sample is detected by means of a FID detector. The column oven is operated in temperature programming conditions up to temperatures exceeding 400 (up to 430-450 C.).

Abstract: The invention relates to a method and device for direct non-vaporizing on column-injection of samples containing high boiling point and/or medium volatile compounds, in gas chromatographic analysis on capillary column. For reasons of economy, the oven containing the column is maintained at a temperature very mcuh higher than the boiling point of the solvent, while the initial part of the column (at least 10 cm) is cooled during the injection. The quantity of sample and solvent injected is related to the length of the cooled section of the column.

Abstract: The present invention relates to an automatic sampling apparatus for sample injection into a gas chromatographic column. In order to allow automatic injection with a non-vaporizing direct on-column injector, the apparatus includes a switch valve, an on-column injector, and a pre-column each having a passage with a diameter greater than 0.5 mm for receiving the injection syringe. The present invention also relates to a device provided with a series of small arms for driving the needle during injection, a switch valve constructed and arranged in a manner to prevent any contamination of the injector by the sample during the injection step, as well as an injection method which can be used with the apparatus and switch valve.

Abstract: The invention relates to a direct on column non-vaporizing injector for gas chromatographic analyses and comprising an accessory device capable of allowing injection with sample vaporization and possible splitting. The accessory device is formed by a tubular element which, at one end, can be fixed to the injector body coaxially to the passage for the injection syringe needle, while its opposite end is closed by an insert provided with an axial hole in which the gas chromatographic capillary column head is pneumatically inserted, said insert being provided with at least one other hole for splitting the vaporized sample. The tubular element houses a vaporization tube which under conditions of thermal exchange with heating means, is pneumatically connected to said passage for the injection syringe needle and to said insert holes and receives the upper end of the gas chromatogaphic column.

Abstract: A method and apparatus for controllably and reproducibly introducing small amounts of a liquid sample into chromatographic systems, especially high resolution gas chromatographic systems and thin-layer chromatographic systems, order to obtain sampling extremely reduced in volume and presenting maximum reliability and reproducibility, uses a sample container having a pipette-like or nozzle-like outlet neck of very small diameter. The liquid placed in the container is submitted to at least one pressure pulse which is controlled in time and/or amplitude in order to determine emission of a corresponding and controlled quantity of liquid from the outlet neck. The pressure pulse can be a pneumatic pulse directly applied to the liquid sample in the container, or a mechanical pulse applied to the liquid sample through a device acting by magnetostriction or by a piezoelectric system.

Abstract: An apparatus for controlling the injection passage of on-column injector is disclosed. The apparatus includes a valve having at least one channel inside it and leading to the injection passage for the injection syringe needle. The channel is connected outside the injector to a source for carrier gas introduction, when the valve is open, or to the atmosphere, when the valve is closed, so as to allow a quick-type injection without the drawbacks of this injection type, as well as to have a solvent exhaust after injection.

Abstract: This invention relates to a method and a device for vaporization injection of a liquid sample in a gas chromatographic column housed in an oven comprising a direct on column injector suitable for injecting a liquid sample into the initial zone of a capillary column and capable of pneumatically sealing the injection port at the end of injection. Between the injector and the gas chromatographic column itself an uncoated capillary column length is provided in which vaporization of the injected sample occurs using heat from an oven housing said capillary column length, said oven being the same or separate from the oven containing said gas chromatographic column.

Abstract: A device is disclosed for coordinating the position of an injection syringe needle in a gas chromatographic apparatus with at least one other operation of the gas chromatographic apparatus downstream of the device. The device comprises a first channel for introducing the injection syringe. The first channel is substantially aligned with the injection channel of a gas chromatographic injector.

Abstract: An apparatus for feeding carrier gas at a constant rate to on-column injectors for capillary and micropacked gas-chromatographic columns. The apparatus includes a constant pressure gas delivering device in operation during the sample injection, and a constant rate gas delivering device in operation during the sample processing stage inside the column. The two devices are connected in parallel and a switch controls the alternative operation of the same.

Abstract: A method and device for sample injections into a gas chromatographic column, wherein, in order to achieve sample trapping and solvent effects, the injection zone and an initial portion of the column are kept at a low temperature and then a quick temperature change is performed at the end of said initial portion. The cooling action is preferably performed by a cooling fluid acting outside the injector and column, while said temperature change is obtained by a suitable thermoregulation of the oven wherein said gas chromatographic column is housed.