Flow Injection Method for Preconcentration and Polarographic Determination of Copper in Water

✍ Scribed by Pablo Richter; M. Inés Toral; Pablo Jaque

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 81 KB
• Volume: 12
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/(sici)1521-4109(20000301)12:5<390::aid-elan390>3.0.co;2-6

✦ Synopsis

The analytical application of a simple polarographic ¯ow through cell, which was previously designed for the continuous polarographic analysis of organic compounds in pharmaceuticals and urine, is proposed in this work for the determination of copper in diluted water samples. The cell contains a conventional dropping mercury electrode (DME), a mercury pool and a platinum wire as the working, reference and counter electrodes, respectively. Enrichment of the analyte, previous to the polarographic continuous determination, was necessary and was achieved by using a microcolumn containing Chelex-100, located in the loop of the injection valve. The ¯ow through detector can be used either amperometrically, under continuous ¯ow operation, or voltammetrically in quiet solution, under continuous ¯ow-stopped ¯ow mode. Under continuous ¯ow operation of the cell, after a preconcentration time of 3 min, the preconcentration factor was calculated to be 90, with a limit of detection of 9.5 ngamL and a sampling rate of 15 h 71 . The repeatability of the analytical signals, expressed as RSD, was always lower than 2.1%. Validation of the method was carried out by analysis of certi®ed reference materials, and the recovery was 101.96 + 1.38%.