Add time:08/18/2019         Source:sciencedirect.com

An improved method is proposed for the spectrophotometric determination of nitrate with 2,4-xylenol. The sample in aqueous (1.7 + 1 ) sulfuric acid is treated with 2,4-xylenol to produce 6-nitro-2,4-xylenol which is distilled into an ammoniacal water—isopropanol mixture. The intense yellow color of the ammonium salt of 6-nitro-2,4-xylenol is measured at 455 nm. The distillation is done in a Parnas—Wagner Kjeldahl Semimicro distillation apparatus. The isopropanol keeps the excess of 2,4-xylenol in solution. Two procedures are described. In the first (applicable to samples containing alkali nitrates but no chloride, alkaline earth, or ammonium salts), the solution is evaporated to dryness, and (1.7 + 1) sulfuric acid and 2,4-xylenol in acetone are added. In the second (applicable to samples containing chloride, alkaline earth, or ammonium salts), concentrated sulfuric acid is added dropwise to a cooled aliquot and the 2,4-xylenol reagent is then added; if chloride is present, it must be removed by prior precipitation with silver sulfate. Nitrite shows a slight interference which depends on the amount of nitrate and nitrite present.

We also recommend Trading Suppliers and Manufacturers of 2,4-Xylenol (cas 105-67-9). Pls Click Website Link as below: cas 105-67-9 suppliers