Abstract
A Plackett-Burman design was carried out in order to find the significant experimental parameters affecting Cd, Co, Cr, Cu, Mn, Pb, and Zn extraction by microwave energy in paper samples. Eight variables were studied and optimized by means of a factorial design. The design showed that HCl and HNO3 concentrations were the significant parameters in the microwave extraction procedure. The trace elements were determined by FAAS and ETAAS under optimum conditions. The levels of metals present in commercial samples, representing different types of paper and board and manufacturers are lower than those provided by the legislation.
Notes
a Injection volume, 20 µL; measurement mode, peak area; pyrolitic graphite coated graphite tubes and Ĺvov platforms.
b DABC = Deuterium arc background correction.
a Repeatability for all analytical methods (n = 10). b mg L−1. c n = 4.
a Expressed as for N = 11 and t (95.%) = 2.26.
a Repeatability for all analytical method (n = 10). b n = 4.
a Expressed as for N = 11 and t (95.%) = 2.26.