Method and device for the direct on-column injection of samples containing high boiling point and/or medium volatile compounds
AssigneeCarlo Erba Strumentazione S.p.A.
InventorsSorin Trestianu, Fausto Munari, Giovanni Ostan, Carlo Saravalle
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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.
Claims21
A method for the direct non-vaporizing on-column injection of samples containing high boiling point and/or medium volatile components dissolved in volatile solvents, by means of an apparatus for gas chromatographic analysis comprising an oven which houses a gas chromatography column whose upstream end is fitted directly, or by a precolumn, to a non-vaporizing direct on-column injector, the method characterized in that:
- (a) the oven temperature is maintained at least 50.degree. C. above the solvent boiling point;
- (b) the sample and solvent are injected at a point along a tract of the column, or precolumn, within the oven while being cooled by a cooling system in operation during injection wherein the cooling system maintains the tract of the column or precolumn at a temperature sufficiently low to maintain therein the high boiling point and/or medium volatile compounds to be analyzed, and wherein the tract of the column or precolumn is cooled for at least 10 cm along the length thereof.
A method of injecting directly non-vaporizing samples dissolved in a solvent into a gas chromatography column by utilizing an on-column injector on the chromographic column and housing the column in an oven, the method comprising the steps of:
- (a) maintaining the oven temperature at least 50.degree. C. above the boiling point of the solvent;
- (b) cooling the sample and solvent while the sample and solvent are being injected by cooling the column along a cooling portion of the length thereof wherein the temperature is maintained during the cooling step so as to maintain the solvent and samples in the cooling portion of the column, and the length of the cooling portion is at least 10 cm;
- (c) selecting the quantity of the sample and solvent in accordance with the uncooled length of the precolumn;
- and
- (d) stopping the cooling step after the solvent and sample have passed through the cooled portion of the column.
The method according to 19 wherein the column includes a precolumn portion along which the cooling portion extends.
Dependencies are inferred from the claim text.