Use of fractional factorial design for optimization of digestion procedures followed by multi-element determination of essential and non-essential elements in nuts using ICP-OES technique

摘要: Two digestion procedures have been tested on nut samples for application in the determination of essential (Cr, Cu, Fe, Mg, Mn, Zn) and non-essential (Al, Ba, Cd, Pb) elements by inductively coupled plasma-optical emission spectrometry (ICP-OES). These included wet digestions with HNO(3)/H(2)SO(4) HNO(3)/H(2)SO(4)/H(2)O(2). The later one is recommended better analytes recoveries (relative error<11%). calibrations (aqueous standard addition) were studied proved that addition was preferable all analytes. Experimental designs seven factors (HNO(3), H(2)SO(4) H(2)O(2) volumes, time, pre-digestion temperature hot plate sample weight) used optimization procedures. For this purpose Plackett-Burman fractional factorial design, which involve eight experiments adopted. HNO(3) volume, time found to be most important parameters. instrumental conditions also optimized (using peanut matrix rather than aqueous solutions) considering radio-frequency (rf) incident power, nebulizer argon gas flow rate uptake rate. analytical performance, such as limits detection (LOD<0.74mugg(-1)), precision overall deviation between 2.0 8.2%) accuracy errors 0.4 11%) assessed statistically evaluate developed good agreement measured certified values error <11%) respect IAEA-331 (spinach leaves) IAEA-359 (cabbage) indicates method well suited further studies fate major nuts possibly similar matrices.