A new, sensitive, and low cost solid-phase extraction method using pyridine-functionalized MCM-48
mesoporous silica for the extraction, pre-concentration, and electrothermal atomic absorption spectrometric
determination of nickel and lead in food samples at ng mL1 levels is described herein. The levels
of nickel and lead in different types of vegetables grow in Shiraz–Iran and Rafsanjan–Iran were determined
by electrothermal atomic absorption spectrometry. The use of two standard reference materials
and also comparing the results to a standard reference procedure ensured the accuracy of this method.
Factors, such as flow rate of extraction, and the type, pH, concentration, and volume of eluent, were
appraised. The effect of various ions on recovery was also investigated. Detection limits of 0.11 and
0.14 ng mL1 were obtained for lead and nickel, respectively.
2011