On-line reversed phase LC-GC by using the new TOTAD (Through Oven Transfer Adsorption Desorption) interface: Application to parathion residue analysis

Abstract

A new interface named TOTAD (Through Oven Transfer Adsorption Desorption) for on-line coupling reversed phase liquid chromatography to gas chromatography (RPLG-GC) is presented. TOTAD interface is a great modification of a programmable temperature injector (PTV). Changes affect pneumatics, sample introduction, solvent elimination, and operation mode. The volume of the LC fraction that can be transferred (with a very strong eluent flow during the transfer step) is very high. Manufacturing this system is not difficult, operation mode is easy and automatization is possible. Analysis of parathion residues in water samples has been carried out in order to illustrate the applicability of the system. The analysis of pesticide residue is performed by off-line SPE and on-line RPLC-GC using the new interface presented. The extract (50 μL) is injected in the LC system. Eluent fraction containing parathion is sent to the TOTAD interface at the same LC column flow. Analytes are retained by a sorbent placed in the insert of the interface and thermally desorbed to the capillary column. A nitrogen-phosphorus detector (NPD) is used. ©1999 John Wiley & Sons, Inc. J Micro Sep 11: 582–589, 1999