Fig. 9

The first derivative of ratio spectra of (a1) ternary mixture of SLD, TRI, and TYL,2 µg/mL each, using double divisor mixture (1 µg/mL TYL + 1 µg/mL SLD), (a2) DD1 of 2 µg/mL pure TRI using the same double divisor, showing coincidence point at 236.5 nm