Microanalytical Determination of Carbon and Hydrogen

Abstract

and elsewhere. A simplified method for the microdetermination of carbon and hydrogen is described below, incorporating numerous improve-

The teaching of quantitative organic microanalysis

“…The changes have been most pronounced in the carbon and hydrogen determination. One apparatus is set up precisely as described by Niederl and Roth (20), having only one combustion gas line, a preheater, and electrically heated combustion tube with side-inlet, filled according to Pregl. The other apparatus is identical, with the exception that it contains silver wool instead of the lead superoxide, thus eliminating the objectionable features of this reagent (5,12,29), but also limiting the use of this second apparatus to compounds not containing nitrogen.…”

Determination of Carbon and Hydrogen by Combustion

“…Dehydrite and Ascarite were chosen for use in this procedure. They offer the advantages of being solids; as Niederi and Roth (11) reported, Dehydrite absorbs up to 30% of its weight and Ascarite absorbs 10 times as much carbon dioxide as does soda lime.…”

Handling and Weighing Absorbtion Tubes in Microdeterminations of Carbon and Hydrogen

“…The glass panel was entirely covered by a dull black opaque paper, except for a slit 2 mm. wide by 12 by an upturned hood of black paper so that light was thrown up on the tube while the source was hidden from the eye. This box was fastened on the wall, with the light opening in a horizontal direction.…”

“…The original absorption agents, calcium chloride and soda lime, have been almost entirely replaced now by magnesium perchlorate (8,10,12) and ascarite. The anhydrous granular magnesium perchlorate has almost double the moistureabsorbing capacity of the trihydrate salt and is the preferable form to use.…”