Thin-layer chromatographic image analysis for the determination of sulfide ions using pyrylium cations

A derivatization approach using pyrylium salts for the sensitive and simple determination of sulfide in spring water by high performance liquid chromatography

“…The following parameters were optimized for the chromatographic determination of sulfide ions in water samples: reaction mixture pH, a concentration of each component, and derivatization time. The derivatization procedure for LN1 was modified basing on [26]. The similar procedure was applied for derivatization process for L1.…”

“…The reactions between sulfide and LN1 or L1 pyrilium cations described in previous reports were carried out in an alkaline solution [25][26][27]. In order to find the optimum pH of the reaction mixture, TRIS buffer and phosphoric buffer solutions (0.1 mol L −1 ) in the 7.0-12.0 pH range were prepared.…”

“…The addition of acetonitrile into the derivatization mixture is necessary due to the poor solubility of L1 and LN1 in pure water [25][26][27] and the volume of this organic solvent has a clear effect in the yield of the derivatization reaction. In order to optimize the volume of acetonitrile in the derivatization mixture, different volumes of this organic solvent in the range of 0-6 mL were tested.…”

“…The impact of hydrochloric acid on the cyclization of the reaction intermediate and the derivatization procedure was described previously [26,27]. In order to estimate its optimum volume, different amounts of hydrochloric acid (36%) in the range of 0-600 L were transferred into the 10 mL flasks where the reaction took place.…”

“…The procedure proposed in this paper is based on a prechromatographic reaction of sulfides with pyrylium salts (4-[p-(N,Ndimethylamino)phenyl]-2,6-diphenylpyrylium perchlorate (LN1) or 2,4,6-triphenylpyrylium tetrafluoroborate (L1), and the conversion of the derivatization reagent into the corresponding LN3 and L3 thiopyrylium cations [25][26][27] (Fig. 1).…”