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

The use of high-performance liquid chromatography with diode array detector for the determination of sulfide ions in human urine samples using pyrylium salts

“…The use of L1 and LN1 in determination of sulfide ion content has been shown previously in spring water [37]. The goal of this study was to extend the above derivatization scheme for the determination of sulfide ions in urine samples.…”

“…Conversion of the derivatization reagents into the corresponding 2,4,6-triphenylthiopyrylium (L3) and 4-[p-(N,Ndimethylamino)phenyl]-2,6-diphenylthiopyrylium (LN3) cations was T described in other works (Fig. 1) [36,37]. For instance, for LN1 such transformation involves a blue-shift of the absorption band from 540 nm for the pyrylium derivative to 580 nm for LN3 [36].…”

“…Chromatographic conditions were initially set according to previously developed method in our research group [37]. To maximize the performance of the assay, the following chromatographic parameters were optimized for both methods (L3 and LN3): percentage of acetonitrile in the mobile phase, flow rate of the mobile phase, pH of the phosphate buffer solution, concentration of the phosphate buffer solution and wavelength detection.…”

“…The reaction of sulfide ions with L1 or LN1 takes place in two steps [36,37] leading to the conversion of the derivatization reagents into thiopyrylium cations. There are different experimental variables that may affect each step of the derivatization reaction efficiency.…”

“…Reactions between sulfide and pyrylium cations described in previous reports were carried out in an alkaline solution [36,37]. Due to the poor solubility of L1 and LN1 in water, acetonitrile must be added into the derivatization mixture [37] and the volume of this organic solvent has a clear effect in the yield of the derivatization reaction.…”