Inductively coupled plasma-based (ICP) methods were employed to determine 22 inorganic constituents (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Sb, Se, Sr, V and Zn) in children's modelling clay samples.  The limits of quantification (LoQ) obtained were between 0.003 mg kg-1 (Cd, Co and Sb) and 0.54 g kg-1(Ca) employing ICP-based methods.  The ICP-based methods presented an efficient routine application in the analysis of modelling clay.
ICP
Analysis of children modelling clay (toy) using inductively coupled plasma-based methods.This work proposes the application of a Doehlert design to optimize dilute HNO3 and H2O2 concentrations employed for the digestion of samples of modelling clay for children (used as toy). 
Doehlert design