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 photoionization detector for a gaschromatographic apparatus includes an ionization chamber provided with a polarizing electrode and a collector electrode. The electrodes are mounted on and heated by a base portion of the detector. A lamp with a window spaced from the chamber and mounted on the base portion through supporting means having low thermal conductivity is provided. A gas curtain of a gas that is transparent to the said lamp radiation is provided at least between the window and the ionization chamber and comprises a first portion of substantially still gas acting as thermal insulant and a second portion of flowing gas also acting as sweep gas for the lamp window.

Abstract: This invention provides a process for determining the nitrogen content of a sample involving (a) combusting the sample in a combustion reactor in the presence of oxygen, which oxygen is introduced into the combustion reactor in pulse form; (b) reducing the resulting combustion gases by flowing them in a flow of helium or other noble carrier gas through a Cu-containing reduction reactor; (c) performing the steps of (i) making anhydrous in a water trap the reduced gases, (ii) flowing the reduced gases through a gas-chromatographic column in order to carry out a gas-chromatographic separation of N.sub.2 from CH.sub.4 possibly present within the reduced gases, and (iii) removing CO.sub.2 from the reduced gases using a CO.sub.2 trap, with the proviso that step (i) immediately precedes step (ii); and (d) analyzing the resulting gases by detecting thermal conductivity.

Abstract: A device for automatically feeding samples to an elemental analysis combustion apparatus. The device has a housing for the sample and is rotatable from an external sample receiving position to a sample feeding position. The housing is insulated from the atmosphere and is connected to the combustion apparatus. The moving body is a truncated cone which is rotatable about its axis within a seat.

Abstract: The determination of the halogen content in a substance is carried out by oxidative combustion of the sample under a continuous flow of gas, in the presence of oxygen, the gases coming out of the combustion reactor being then carried by gas flow to analysis equipment.

Abstract: An anlytical equipment and method for the selective detection of individual oxygenated compounds in complex organic mixtures, in particular fuels, comprising, downstream an equipment of chromatographic separation, a cracking reactor, a catalytic hydrogenation microreactor and a FID detector. The cracking reactor is provided with a catalyst under the form of metal elements, made of palladium, inserted inside the capillary tube though which flows the gas under test. Thanks to the present equipment, the analytical process, based on the specific response of oxygenates to the method of flame ionization detection (O-FID), foresees that the cracking reaction takes place at temperatures below 1000 degrees C. and, consequently allows to keep the cracking reactor at stand-by temperatures below 700 degrees C.

Abstract: The invention concerns a process and a device for splitless vaporizing injection of samples into equipments of gas chromatographic analysis.The technique is applied specially when liquid samples generate volumes of vapors which cannot be housed inside the vaporizing chamber.Inside the vaporisation chamber, kept at high temperature, evaporation of the sample solvent forms a cool zone where the solutes are retained while the solvent vapors expand out of the vaporizing chamber and leave the injector. The sample liquid is kept in place within the vaporization chamber by suitable obstacles or by a packing material. At the end of solvent evaporation, i.e. when cooling ceases, the injection zone returns to the regulated injector temperature and the compounds to be analysed are transferred to the column by the carrier gas.