Analyte λ (nm) Dynamic linear range (mg L-1) Regression equation R2 LOD (mg L-1) AM             238 1.7-20 S=0.019CAM -0.0125 0.981 0.074   268 1.7-20 S=-0.0229CAM +0.0187 0.967 0.011   269 1.7-20 S=-0.0228CAM +0.0183 0.968 0.010   270 1.7-20 S=-0.0224CAM +0.02 0.965 0.010 AT             235 3.6-35 S=-0.019CAT -0.0283 0.991 0.079   256 2.2-35 S=0.012CAT -0.0184 0.986 0.037   309 2.2-35 S=-0.0167CAT +0.0098 0.991 0.013   310 2.2-35 S=-0.018CAT +0.008 0.993 0.010

Table 4: Statistical results of calibration curves at zero-cross points for AM and AT.