Hossein Tavallali - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۴۶۹۷, Tehran, Iran
Gohar Deilamy-Rad - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۴۶۹۷, Tehran, Iran
Mohammad Ali Karimi - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۴۶۹۷, Tehran, Iran
Elaheh Sharifi - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۴۶۹۷, Tehran, Iran
Zahra Tavallali - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۴۶۹۷, Tehran, Iran
Arshida Najafi-Nejad - Department of Chemistry, Payame Noor University, P.O. Box ۱۹۳۹۵-۴۶۹۷, Tehran, Iran

Bromopyrogallol Red (BPR) dye (Dibromopyrogallolsulfonphthalein), was evaluated as a highly selective colorimetric chemosensor for tin and citrate ion. BPR displayed rapid response, high specificity, visual determination and good selectivity toward tin and citrate ion over other competing cations and anions in DMSO/H۲O (۱:۱ v/v) media. The sensing mechanism was discussed by UV–Vis, titration, and a comparison study. Over a wide range from ۰.۴ µmol L-۱ to ۱۵۳.۸ µmol L-۱ and ۰.۰۲ µmol L-۱ to ۱.۰۸ µmol L-۱, a good linear relationship between the absorbance and the concentration of tin and citrate ion was found respectively and the detection limit was estimated to be as low as ۰.۰۶ and ۰.۰۰۳ µmol L-۱ (S/N = ۳) for tin and citrate ion. This proposed chemosensor has also been successfully applied for the determination of citrate in real samples which demonstrates its value of practical applications in food and biological systems. 

Colorimetric Chemosensor, Bomopyrogallol Red dye, Tin(II) ion, Citrate ion