Al, Cu @ 5µg/mL Mg @ 10µg/mL Zn @ 20µg/mL Fe, Pb @ 25µg/mL Ca @ 50µg/mL B @ 250µg/mL P @ 1000µg/mL K @ 2500µg/mL Na @ 5000µg/mL in 3% HNO3 (v/v), 500mL 500ml