Figure 4From: Novel catalytic fluorescence method for speciative determination of chromium in environmental samples Fixed time, variable time, and fluorescence-quenching behaviour studies for HPTU-Cr(III). (a) A fixed time study of HPTU-Cr(III) reaction system (at t = 25 min). (b) A variable time study of HPTU-Cr(III) reaction system. (c) Study of HPTU-Cr(III) reaction system using tangents' method. (d) Study of fluorescence-quenching behaviour using Stern-Volmer plots.Back to article page