PRECONCENTRATION OF TRACE COPPER IN WATER SAMPLES WITH FI-SOLVENT EXTRACTION AND AAS

A technique of on-line chelation, extraction, and preconcentration of copper in water samples with flow injection and subsequent determinati on with atomic absorption spectrometry is described. A chelate of copp er with 5,7-dibromo-8-hydroxyquinoline was generated and extracted wit h xylene. Various parameters affecting the intensity of the copper sig nal such as pH of the solution, flow rate of the carrier streams, flow rate of aqueous/organic ratio, extraction coil length and configurati on, loading time, reagent concentration, and the effect of ultrasonic agitation were investigated. A preconcentration factor of 11 and sampl ing frequency (sample injection) of 80/h was achieved in the present w ork. The method was applied to the determination of copper in rain wat er and over-night tap water samples (water left standing in the pipe o ver-night. The copper in the tap water sample was also determined by t he standard addition method using this system and was then compared wi th ICP-AES results,