Spectrophotometric determination of sulphur dioxide by reduction of iron(III) and simultaneous chelation of the iron(II) with 2,4,6-tri(2-pyridyl)1,3,5-triazine

Determination of sulfur dioxide in stack gases by ultraviolet absorption spectrometry

“…Several instrumental finishes have been developed for the analysis of SO2 after an air sample has been scrubbed through an appropriate solution to form sulfite or sulfate. These include the polarographic (1, 2), conductometric (3, 4), coulometric (3,5), and colorimetric (6)(7)(8)(9) finishes. In the West and Gaeke method, which is endorsed by the Environmental Protection Agency as the reference method for determination of SO2 in ambient air (6,(10)(11)(12), SO2 is removed by bubbling air through a tetrachloromercurate solution, adding acidified pararosaniline dye and measuring absorbance at 548 nm.…”

Super‐Absorbent Polymer Valves and Colorimetric Chemistries for Time‐Sequenced Discrete Sampling and Chloride Analysis of Sweat via Skin‐Mounted Soft Microfluidics

“…The approach incorporated here exploits a well‐known colorimetric assay commonly used for the determination of chloride ion concentration in applications involving wastewater and biofluid media. This assay relies on competitive chelation between mercury‐(II), Hg 2+ , and ferrous‐(II), Fe 2+ , using 2,4,6‐tris(2‐pyridyl)‐s‐triazine (TPTZ) as a chelating agent . In a solution containing TPTZ (chelator), Hg 2+ and Fe 2+ , stoichiometric complexation between Hg 2+ and TPTZ is favored, resulting in the formation of colorless Hg [TPTZ] 2 (Figure S5, Supporting Information).…”

“…This assay relies on competitive chelation between mercury-(II), Hg 2+ , and ferrous-(II), Fe 2+ , using 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ) as a chelating agent. [38][39][40] In a solution containing TPTZ (chelator), Hg 2+ and Fe 2+ , stoichiometric complexation between Hg 2+ and TPTZ is favored, resulting in the formation of colorless Hg [TPTZ] 2 ( Figure S5, Supporting Information). Upon introduction of chloride, a reaction with Hg 2+ yields mercuric chloride, HgCl 2 .…”

Properties and application of aryl-substituted azines (review)

“…This is probably due both to its synthetic availability and to the stability of the color of the complexes [79]. It is necessary to mention the use of this reagent in the determination of sulfur dioxide in the outgoing gases of various processes, based on the reduction of Fe(III) to Fe(II) and the formation of a violet chelate complex by the latter [80]. The same principle of complexation and subsequent spectrometry is used in analyses for iron, chlorine, and ascorbic and uric acids in such biological substrates as blood serum and plasma, urine, and protein-containing fluids and also in the determination of cholesterol in blood, adrenaline, and noradrenaline and similar compounds in medicinal preparations [81][82][83][84][85][86].…”