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: This invention concerns an automatic sampler (AS) associable with two or more chromatographic analysis instruments (GC1, GC2, GCn), such as gas chromatographs for example, which can be interfaced with two or more separate data systems (DS1, DS2, DSn), each operating in an independent manner.

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 invention relates to a device for positioning and holding one or more chromatographic column lengths being subjected to one or more jets of fluid to change the temperature, especially in a modulator for GC×GC. The device comprises one or more V-shaped seats in which the column is housed, and pushed within the groove.

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 present invention relates to a device for washing samples that are intended to be introduced in an analysis apparatus, particularly for elemental analysis, which has a chamber sized such as to house only one sample at a time, means for feeding the samples, from a condition in contact with the ambient atmosphere, one at a time to said chamber, means for closing said sample-containing chamber relative to the environment, means for feeding and releasing a washing gas to and from said chamber, and means for opening this chamber to the analysis apparatus in sealed conditions relative to the atmosphere.

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: The invention relates to a device for positioning and holding one or more chromatographic column lengths being subjected to one or more jets of fluid to change the temperature, especially in a modulator for GC×GC. The device comprises one or more V-shaped seats in which the column is housed, and pushed within the groove.

Abstract: A method for detecting substances or mixtures of substances within a sample in an apparatus for comprehensive two-dimensional gas-chromatographic analysis according to the present invention, comprising the steps of: subjecting the sample to a first separation within a first capillary column; modulating in time the effluents from the first column by means of the subdivision into adjacent fractions of the effluents from the first column and subsequently sending each fraction into a second capillary column, the modulation of the effluents being periodic with a first modulation frequency f1 of the sample; separating each of the fractions in the aforesaid second capillary column; and detecting, at the end of the second capillary column, the effluents by means of periodic sampling by discrete time points at a second frequency f2.

Abstract: This invention concerns a method and apparatus for vaporization injection of large volumes of liquid sample (substance to be analysed+solvent) introduced by a syringe needle into a heated vaporization chamber which is part of an injector coupled operatively to a device for gas chromatographic analysis. The sample is sent in the form of a liquid band traveling through the vaporization chamber at high speed until it reaches a stopping and vaporization device positioned adjacent to the inlet of a capillary to collect the vapors. In order to inject large volumes without modifying the vaporization chamber and without partial losses of the samples, the sample vapors, in splitless mode, are drawn up from the vaporization chamber into the capillary by virtue of the local action of volume contraction caused by recondensation of at least the solvent vapors in the capillary.

Abstract: This invention relates to a modulator for use in gas chromatographic analyses, in particular for comprehensive two-dimensional gas chromatography, adapted to alternatively trap and release fractions of solutes in a length of a capillary column within a chromatographic oven, of the type comprising one nozzle placed to spray one jet in one corresponding capillary column section along said capillary column length, said nozzle being connected to a source of liquid CO2 and means for alternatively causing a jet of gaseous CO2 to impinge during a predetermined time on said capillary column section and to leave the oven atmosphere to heal said capillary column section after said predetermined time. By controlling said capillary column section cooling time by the single jet and said column section heating time by the oven atmosphere in each modulation cycle comprising a heating time and a cooling time a perfect modulation of the sample fractions can be ontained.

Abstract: This invention relates to a modulator for use in gas chromatographic analysis, adopted for alternatively trapping and releasing fractions of solutes in a length of a capillary column within a chromatographic oven, characterized in that it comprises at least one nozzle placed to spray at least one jet in at least one corresponding place along said capillary column length, said nozzle(s) being connected each to a source of liquid CO2 via a related valve, and means for alternatively opening said valve(s) for a predetermined time, to cause a jet of liquid CO2 to impinge for said predetermined time on said column place and to leave the oven atmosphere to heat said column place after said predetermined time. The modulator can be used in a conventional GC system or in a two dimensional GC system, for modulating the analytes fed to the second capillary column.