Table 14: Linear regression analysis of the determination of Fe(II) and Co(II) in mixture by second derivative spectrophotometry.

Metal ion determined Wave length (nm)Other metal present (μg mL−1) Slope Intercept Correlation coefficient
Fe(II)Co(II)

Fe(II)436 0.9994
0.589 0.9995
Co(II)426 0.9999
0.33 0.9998