Electrothermal atomic absorption spectrometric determination of cobalt in biological samples and natural waters using a flow injection system with on-line preconcentration by ion-pair adsorption in a knotted reactor

摘要: An on-line flow injection preconcentration-ETAAS method is developed for trace determination of cobalt in biological materials and natural samples by ion-pair sorption on the inner walls a PTFE knotted reactor. The formed between negatively charged cobalt-nitroso-R-salt complex tetrabutylammonium counter-ion. enhancement factor 15, sampling frequency 17 concentration efficiency 4 are obtained preconcentration time 60 s sample loading rate 5 mL min–1. detection limit (3σ) ng L–1. relative standard deviation at 0.2 μg L–1 level 2.3%. analytical results reference good agreement with certified or indicated values satisfactory recoveries spiked tap water obtained.