Showing papers by "Purnendu K. Dasgupta published in 1978"
12 citations
TL;DR: In this article, a ring oven method for the determination of sulfate at ng levels is described, where sulfate is bound as 2-perimidinyl ammonium sulfate by spotting the sample solution on a glass fiber filter impregnated with 2-Perimidyl ammonium bromide.
Abstract: A ring oven method for the determination of sulfate at ng levels is described. Sulfate is bound as 2-perimidinyl ammonium sulfate by spotting the sample solution on a glass fiber filter impregnated with 2-perimidinyl ammonium bromide. The excess reagent is removed by frontal elution chromatography with methanol and the sample spot cut out and then exposed to nitric acid vapor where upon the organic amine, bound as sulfate, is converted to the highly colored 2-amino 4,6,9-trinitro perimidine. The excess acid is neutralized by exposure to ammonia vapor. The sample spot is finally placed on a filter paper positioned on a ring oven and the color is eluted to the ring zone by successive aliquots of acetone. The sensitivity of the method is 5 ng sulfate and the working range is 20 ng to 1 μg. The method is free of significant interferences.
2 citations