Flow Injection Analysis of Aziprotryne Using an Electrochemical Sensor Based on Cobalt Phthalocyanine Modified Carbon Paste Electrode

✍ Scribed by Manuel Chicharro; Antonio Zapardiel; Esperanza Bermejo; Elena Madrid; Cristina Rodríguez

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 543 KB
• Volume: 14
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/1521-4109(200207)14:13<892::aid-elan892>3.0.co;2-#

✦ Synopsis

The detection and determination of aziprotryne in flow injection analysis with an amperometric method based on a carbon paste electrode modified with phthalocyanine is described. The concentrations of herbicide in acidic solutions were determined using the electrocatalytic reduction signal corresponding to herbicide reduction at this kind of electrode. A detection limit of 9 ng/mL (0.9 ng aziprotryne) was obtained for a sample loop of 100 mL at a fixed potential of À 130 mV (vs. Ag/AgCl) in 0.1 M perchloric acid and a flow rate of 4.0 mL/min. The developed method was applied to determine aziprotryne in environmental and tap water samples; using a prior solid-phase extraction step, aziprotryne concentrations lower than 0.2 ng/mL could be measured. Furthermore the modified carbon paste electrodes offered reproducible responses in such system, and the relative standard deviation was 3.1% using the same surface and 4.6% for different surface. The response of the electrodes was stable, with more than 98% of the initial retained activity in the first 35 minutes of continuous use.