On-line preconcentration cold vapour atomic absorption spectrometry for the determination of trace mercury in edible seaweeds†
Abstract
Possibilities for the use of an inexpensive sulfydryl cotton fiber (SCF) adsorbent to separate and preconcentrate traces of mercury from acid digests from edible seaweed have been evaluated. Commercial empty cartridges were filled with around 0.75 g of laboratory-made adsorbent and they were incorporated in the 5-way valve of an automatic flow injection analysis system. Traces of mercury in acid digests were pumped through the cartridges for 45 s (flow rate of 8.8 ml min−1) and then eluted from cartridges with 0.5 M