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: This invention concerns a method and apparatus for vaporization injection of large volumes of liquid sample (substance to be analysed + solvent) introduced by means of the needle of a syringe onto a heated vaporization chamber which is part of an injector applied to a device for gas chromatographic analysis, the sample being sent in form of a liquid band travelling through said vaporization chamber at high speed until reaching stopping and vaporization means positioned adjacent to the inlet of a capillary to collect the vapours.

Abstract: This invention relates to a modulator for use in gas chromatographic analysis, adapted 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 C02 via a related valve, and means for alternatively opening said valve(s) for a predetermined time, to cause a jet of liquid C02 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.

Abstract: The invention concerns a device for vaporizing injections of samples into a gas chromatography analysis device, comprising a vaporization chamber elongated lengthways and heated, as well as a syringe equipped with a needle, the device being of the type in which the introduction of the sample is carried out without prior vaporization of the sample within the needle, and also foresees at least one stop and vaporization means for the liquid inside the vaporization chamber. To improve the conditions of vaporization and the transfer of the sample, the distance between the free end of the needle and the stated stop and vaporization means for the liquid is greater than 55 mm (FIG. 1).

Abstract: A vaporization injector for gas chromatography analysis instruments, of the type including a vaporization chamber, heated or which may be heated, with a longitudinally elongated shape, a device for hermetically inserting the needle of a syringe containing the sample (substance to be analysed and solvent) into the chamber, a connection for feeding a carrier gas into the chamber and a gas chromatography capillary column with an upstream end open inside the vaporization chamber. In order to allow the vaporization of large sample volumes, the upstream end of the gas-chromatography column and the injection point of the sample into the vaporization chamber are both arranged adjacent to one of the longitudinal ends of the vaporization chamber and the feed connection for the carrier gas is located adjacent to the other end.

Abstract: A method and an apparatus for chromatography are described, wherein at least one element in electrically conductive material is provided to heat the capillary column in a direct way and wherein the control of the temperature is carried out according to a mathematical model having a component of predictive type, or Feed Forward type, that describes the thermodynamic behavior of the assembly comprising the electrically conductive element and the column at least as a function of the thermal resistance and the thermal capacity of the assembly thus constituted in order to regulate the supply of electrical power supplied to the conductive element.