Appts. for coating substrates with film polymer of para:xylylene|using vapour phase chemical oxidn. process

A method of depositing conducting polymer onto a tube comprises performing the deposition using a vapour phase chemical oxidn. process.Also claimed is a chromatograph comprising a tube coated with at least one conducting polymer.USE - The tube contg. deposited conducting polymer is useful as chromatographic column for performing gas-solid chromatography for sepn. of components in samples and/or its purification.ADVANTAGE - The use of the active chromatographic supports permits rapid sepn. through the use of shorter columns than previously possible. Because the surfaces of the polymers are charged, non-polar analytes are retained for much less time than polar analytes. By applying electric field the local charge on the polymer surface may be modulated to stimulate active release of adsorbed analytes selectively.