Optimization of conditions for high temprature capillarary gas chromatography using a split-mode programmable temprature vaporizing injection system

Abstract. A reliable method of sample introduction is presented for online gas chromatography with a special application to in situ field portable atmospheric sampling instruments. A traditional multi-port valve is replaced with a valveless sample introduction interface that offers the advantage of long-term reliability and stable sample transfer efficiency. An engineering design model is presented and tested that allows customizing this pressure-switching-based device for other applications. Flow model accuracy is within measurement accuracy (1%) when parameters are tuned for an ambient-pressure detector and 15% accurate when applied to a vacuum-based detector. Laboratory comparisons made between the two methods of sample introduction using a thermal desorption aerosol gas chromatograph (TAG) show that the new interface has approximately 3 times greater reproducibility maintained over the equivalent of a week of continuous sampling. Field performance results for two versions of the valveless interface used in the in situ instrument demonstrate typically less than 2% week−1 response trending and a zero failure rate during field deployments ranging up to 4 weeks of continuous sampling. Extension of the valveless interface to dual collection cells is presented with less than 3% cell-to-cell carryover.

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Determination of residual solvents in pharmaceutical products by gas chromatography coupled to a head-space injection system and using an external standard

Journal of Chromatography A ◽

10.1016/s0021-9673(00)96345-3 ◽

1987 ◽

Vol 403 ◽

pp. 109-121 ◽

Cited By ~ 18

Author(s):

J.P. Guimbard ◽

M. Person ◽

J.P. Vergnaud

Keyword(s):

Gas Chromatography ◽

Pharmaceutical Products ◽

Injection System ◽

Residual Solvents ◽

Head Space ◽

External Standard

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Note on Gas Chromatographic Determination of Antihistamines Employing a Dual Column Direct Injection System

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/53.3.609 ◽

1970 ◽

Vol 53 (3) ◽

pp. 609-611

Author(s):

Thomas J Reiss

Keyword(s):

Gas Chromatography ◽

Direct Injection ◽

Extraction Procedure ◽

Direct Analysis ◽

Chromatographic Determination ◽

Injection System ◽

Column System ◽

The Common ◽

Dual Column

Abstract A GLC method is presented for the rapid direct analysis of antihistamines in pharmaceuticals in which the common interfering components are separated by gas chromatography. In previous papers the interferences are first separated by extraction before injection on the column. A dual column system makes it possible to separate each of the antihista mine peaks from each of the 7 most common accompanying component peaks. A simple 1-step extraction procedure is given for the separation of flavoring materials in sirups. Since only 1 or 2 antihistamines are present in any given sample, peak overlapping does not usually present a problem. Deviations from linearity on each column tested were minimal.

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