Scanometric method has been attended for the study and determination of different analytes. This method coupled with preconcentration methods for improvement the detection limit and applied for the determination of Nile blue and Rhodamine B in binary systems.
In this work cloud point extraction-scanometry (CPE-SC) method was used for preconcentration, simultaneous separation and determination of trace amounts of the rhodamine B (RhB) and Nile blue A (NBA) in aqueous solutions. Some of the advantages of this method are simplicity, cheapness, novelty, rapidity, sensitivity, and safety. Analysis of images obtained from the solution scanning after cloud point extraction of the cited dyes and dilution with proper solvent is done using the RGB program in Visual Basic 6 (VB 6) media. Using three red, green, and blue factors, the RhB and NBA contents were investigated in the aqueous solution. Detection limits of the determination of these dyes were acceptable, and their values were 0.002 and 0.008 µg/mL for NBA and RhB, respectively. The linear ranges of the mentioned method for determining Nile blue A and rhodamine B are 0.01–1.33 µg/mL and 0.01–1.00 µg/mL, respectively.