Simplified Enrichment Method Using NeedlEx

Introduction

Ambient odor analysis typically requires enrichment of analytes because odor thresholds are usually very low. Normally, a specialized device is required for enrichment and desorption during introduction into the GC; specialized devices often involve complex operation. The NeedlEx introduced here can be used to selectively enrich volatile organic compounds in ambient air by desorbing them into the enrichment medium packed inside the injection needle. This technique provides simplified operation, and no special devices are required for either desorption of the enriched compounds or extraction using solvent. The NeedlEx, containing about 1 mL of aspirated nitrogen gas, is attached to the Luer-lock type gas tight syringe, and the needle is simply inserted into the GC sample injection port as in a typical gas sample injection operation. The compounds are thermally desorbed and then injected with the nitrogen gas into the GC column.

June 2, 2009 GMT