Capillary column switching in gas chromatography/mass spectrometry

Abstract

Installation of a Commercially available capillary-to-capillary column switching system in an otherwise unmodified gas chromatographhass spectrometer instrument is described. The first column is monitored via the jet separator, the second being connected directly to the ion source. This arrangement obviates the need for an auxiliary detector. A single gas chromatographic oven is adequate for many purposes.

Day–night rhythm of 5-methoxytryptamine biosynthesis in the pineal gland of the golden hamster (Mesocricetus auratus)

“…The GC oven Model 5710 (Hewlett-Packard, Les Ulis, France) was fitted with a capillary column switching facility (Scientific Glass Engineering (SGE), Villeneuve-Saint-George, France). The first column was 12-5 m 0-32 mm methyl silicone (SGE ref. 12QC3/BP1-0.5) and the second column was 25 m 0-32 mm 5% phenylmethyl silicone (SGE ref. 25QC3/BP5-0-5) ; the second column was led directly into the ion source, and the first column was moni¬ tored when necessary through the jet separator (Lee & Esnaud, 1987). The injector was at 250°C and the interfaces at 260°C.…”

“…The 5-methoxytryp¬ tamine derivative eluted from the first column as a broad peak, retention time 2-9 min (chromatogram not shown). Heartcutting was performed from 2-5-3-5 min, during which time the compound was focussed at the start of the second column by means of a liquid C02 cold trap (Lee & Esnaud, 1987). The 5-methoxytrypta¬ mine derivative eluted from the second column as a sharp peak, at a total retention time of 5-8 min.…”