Fast gas chromatography using vacuum outlet conditions

Abstract

In this study the possibility of operating a wide‐bore column with an inner diameter of 530 μm at vacuum conditions was investigated as a route towards fast gas chromatography. High analysis speeds can be obtained as a result of the sub‐ambient pressure conditions present in the column, and the consequently high diffusion coefficient of the solute in the mobile phase. The advantage of using a wide‐bore column is the high sample capacity. To enable vacuum operation through coupling a wide‐bore column to a mass spectrometer, three types of restricting the column flow were investigated. The first method uses a narrow bore pre‐column (60 cm length×100 μm i.d.), the second method relies on the use of a tapered on column supercritical fluid chromatography restrictor (SFC‐restriction), whereas the third method makes use of a micro‐injection valve. It was concluded that the best performance was obtained using the narrow‐bore column restriction and the SFC‐type restriction. Analysis examples in the seconds‐ and minutes‐range are shown, with peak‐widths ranging from 0.1 to 2 seconds at half height. It was concluded that with a film‐thickness above 1.5 μm, the advantage of the increase in analysis‐speed due to low pressures is nullified due to retention time increase on a thick film column. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 613–622, 2000

Fast analysis of decabrominated diphenyl ether using low-pressure gas chromatography–electron-capture negative ionization mass spectrometry

“…0.53 mm internal diameter (ID)) to a narrow and short restriction capillary (e.g. 0.1 mm ID) that is positioned at the injector [Mastovska, 2001;de Zeeuw et al, 2000;van Deursen et al, 2000]. On the other hand, the use of MS detectors, which also require low pressure for analysis, can provide the vacuum for LP-GC, avoiding additional instrumentation.…”

Characterization of supercritical fluid extracts from raw wool by TLC‐FID and GC‐MS

“…GC-MS permitted characterization at a molecular level, whereas TLC-FID enabled characterization in accordance with chemical classes, thereby providing complementary information. Subambient pressure GC coupled with MS (19,20) was chosen as an identification technique because it was the most suitable method to analyze the complex high-molecular-mass mixture of wool wax at lower elution temperatures compared with conventional GC (19,20). Prior to the MS analysis, SFE extracts were prefractionated by gel permeation chromatography (GPC) to obtain two fractions in accordance with their M.W.…”

Rapid analysis of food products by means of high speed gas chromatography

“…In this respect, there has been an ever-present interest within the chromatographic community for the introduction of faster GC techniques. Over the past decades several approaches have been theorized and developed with various outcomes: multicapillary columns [2,3], microparticle packed capillary columns [4,5], low pressure (LP) outlet conditions (LP-GC) [6], turbulent flow [7], helically coiled columns [8], shorter conventional column lengths (previously mentioned) [9], resistive heating [10,11], reduced column id and stationary phase thickness (narrow-bore capillaries) [12,13]. Several reviews have been reported describing the most important existing high-speed GC methods [14][15][16][17].…”