Figure 4: IC-ICPMS traces and calibration curve for phosphite. A: Chromatogram of a blank and of phosphite-bearing solutions with concentrations from 0.1 to 10 ppb (0.003 to 0.32 µmol/L). Red lines are smoothened curves obtained by FFT filtering with a points of window value of 15. The 0.003 µmol/L (0.1 ppb) solution has a detectable phosphite peak as compared to the blank. B: Phosphite calibration curve with the peak integral data.