Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples

Figure 10

Ratio spectra (a) and first derivative ratio spectra (b) of chlorothalonil (0.5, 1, 1.5, 2, 3, 4, 5, 6, and 7 μg·mL⁻¹) when 15 μg·mL⁻¹ of pyriproxyfen was used as divisor in methanol (∆λ = 4 nm).

(a)

(b)