Determination of Copper and Zinc Ions by Flame-AAS After Preconcentraction Using Sodium Dodecyl Sulfate Coated Alumina Modified with 3-((1H-Indol-3-yl)-3,4,5-trimethyl)-1H-indole

A sensitive and simple method for the simultaneous preconcentration of trace amount Cu²⁺ and Zn²⁺ ions in some real samples has been established, which is based on the sorption of Cu²⁺ and Zn²⁺ on 3‐((1H‐indol‐3‐yl)‐3,4,5‐trimethyl)‐1H‐indole (ITMI) loaded on sodium dodecyl sulfate (SDS) coated alumina. The metal absorbed on the complexes was eluted using 3 mol/L nitric acid. The influences of the analytical parameters including pH and sample volume were investigated. The effects of matrix ions on the retentions of the analytes were also examined. The recoveries of analytes were generally higher than 95% with a low RSD. The method has been successfully applied to content evaluation of these metals in real samples.     

Highly Selective Perchlorate Membrane Electrode Based on Cobalt(III) Schiff Base as a Neutral Carrier

A highly selective poly(vinyl chloride) (PVC) membrane electrode based on Co(III)-Schiff base [Co(5-NO2- Salen)(PBu3)]ClO4•H2O (where 5-NO2-SalenH＝bis(5-nitrosalycilaldehyde)ethylenediamine) as a new carrier for construction of perchlorate-selective electrode by incorporating the membrane ingredients on the surface of a graphite electrodes has been reported. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0×10－6 to 5.0×10－1 mol•L－1 with a slope of (59.4±0.9) mV per decade of perchlorate concentration with a low detection limit of 5.0×10－7 mol•L－1 and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (＜5 s) and a wide pH independent range (3.0—12.0) in comparison with recent reported electrodes and can be used for at least 2 months without any considerable divergence in their potential response. This electrode was used for the determination of perchlorate in river water, drinking water, sludgy water and human urine with satisfactory results without complicated and time consuming pretreatment.