Zn2+ Cr3+ Conditions 320 298 Wavelength, nm 10 10 Lamp current, mA 1.3 1.3 Slit width 80-120 80-120 Heating program Drying temp., °C 30 30 Time/sec 400 300 Ashing temp., °C 30 30 Time/sec 2100 1700 Atomization temp., °C 7 7 Time/sec 3000 2600 Cleaning temp., °C 30 30 Time/sec

Table 1: Operational conditions for AAS measurement.