Plackett–Burman designs in the pretreatment of macroalgae for Pb, Cr and Al determination by GF-AAS

In this paper, a screening approach, involving the use of the Plackett–Burman experimental design, permitted the evaluation of the effects of 25 parameters from the sample pretreatment stage (furnace heating temperature, furnace heating duration, cooling, filtration, addition of HCl…) on the Pb, Cr and Al determination in macroalgae by graphite furnace atomic absorption spectrometry (GF-AAS). According to the found results, the influences of the different factors depend on the selected metal. Nevertheless, addition of the concentrated acids HF and HCl enhanced the analytical signals of all the metals. The effects of some parameters, such as filtration or cooling of samples, were negligible. These factors could be eliminated from the pretreatment stage to gain cost and time. The obtained results allowed the proposition of a method for the pretreatment of algae. This method was validated against BCR-CRM 279 sea lettuce ( Ulva lactuca ).