Potatoes, carrot and peas (1.0 g) were digested with 8 mL of
concentrated HNO3, 2 mL H2O2 (30%) in microwave digestion system
and diluted to 50 mL with deionized water. NCS ZC85006 Tomato
(0.5 g) was digested with 5 mL of concentrated HNO3 and
2 mL concentrated H2O2 in microwave digestion system and diluted
up to 50 mL with deionized water. The pH of solution was adjusted
using diluted NaOH and buffer solutions. A blank digest was
carried out in the same way. The sample was prepared using the
co-precipitation procedure. The levels of heavy metals in the samples
were determined by ICP-OES and F-AAS.