Table 10. Linearity and recovery test of heavy metals analyzed

Element Correlation coefficient (R2) Concentration (μg/kg) Recovery ± RSD (%)
Pb 0.9966 0.5 100.8 ± 10.3
2.0 104.8 ± 1.2
Cd 0.9999 0.5 97.0 ± 7.2
2.0 106.1 ± 0.3
Correlation coefficients were over 0.9966 at five concentration levels (0.0–2.0 μg/kg).