Table 2 lists the linear and nonlinear calibration curves that were automatically generated using the Aspect CS software (Aspect CS1.5.6, Analytic Jena AG, Jena, Germany). Obviously, the R2 values of the nonlinear curves are higher than those of the linear curves. Therefore, nonlinear calibration curves (see Fig. 2) with R2 > 0.998 were selected for quantifying the Pb, Cd, Cr, Cu, and Ni in tea.