Iranian researchers measured very tiny amounts of some of toxic heavy metals in water and foodstuff by using SBA-15 nanoporous compound functionalized with guanidin groups as perfect sorbent for metals.
In the first stage of the research, SBA-15 nanoporous compound functionalized with guanidin was prepared and its structural properties were investigated. In the next stage, the compound was used for the extraction and preconcentration of some of heavy metals that are classified among toxic and hazardous elements for the living creatures and environment, and as a result, it made possible the measurement of very small amounts of the elements. Finally, the concentration of lead, copper, cadmium, and zinc ions were measured in various water and food samples, and promising results were obtained.
Nanopores in the structure of SBA-15 increase the interface of sorbent with the solution, and therefore, ion sorption capacity increases on this compound. Besides, the high regularity and homogeneity of the nanopores result in excellent repeatability of the extraction process.
Nanoporous SBA-15 functionalized with guanidin was used as a new extraction agent to concurrently extract lead, copper, cadmium, and zinc ions. The extraction was carried out in 25ml of solution containing 2 mg/l of each ion in 10 minutes and with very small amount of sorbent (10 mg).
Results of the research have been published in details in Food Chemistry, vol. 141, issue 3, December 2013, pp. 1916-1922.