2.5. Pyrene fluorescence probe
An ethanol solution of pyrene was prepared with 0.01 g pyrene
and 100 mL ethanol in a beaker. The test suspensions were then
prepared by using 0.1 mL ethanol solution of pyrene, 2.0 g minerals
(38 lm), the test concentration of the pure collector, and 30 mL
water. The suspensions were then oscillated for 24 h using a constant
temperature oscillator at room temperature (25 C).
The pyrene fluorescence spectra of the samples were obtained
using a PerkinElmer LS55 fluorescence spectrophotometer. The
excitation wave length of pyrene was 334 nm, and the width of
excitation and emission slits were 10 and 4 nm, respectively.