Precautions in ashing techniques for lead determination in food

In determining lead in food, the matrix must be destroyed before quantitation by atomic absorption spectrophotometry. Wet or dry ashing techniques are generally used. Dry ashing assisted by ultrapure H2SO4 or K2SO4 has the advantages of safety, low reagent blanks, rapidity, and good recoveries of added lead. These techniques are also less labor-intensive than wet ashing.