General procedure
In order to perform the calibration curve, an estipulate volume of CF
standard solution containing 1.1 to 9.7 · 10−3 g L−1 was placed in a volumetric
flask and 200 μL of BSA 1 · 10−5 mol L−1was added. Thewhole
mixture was made up to 10 mL with ultrapure water.
Standard/samples were injected into a flowing buffer stream
conformed by phosphate 5 · 10−3 mol L−1 pH 6.8. The continuous
flow diagram is shown in Fig 1. In the “loading” position, the carrier
was impulse by the first peristaltic pump (PP) to the fluorescence detector
generating the baseline at λem=338nm(λex=280);while the second
peristaltic pump aspirate the sample charging the sample loop
(L) in the injection valve located among 1 and 4 positions. The loading
was carried out for 30 s, enough time to fill L with sample/standard. In
the “injection position” carrier flowed through the L and carried the analyte
to the detector. The second PP is turned off.
3. Results