T H E J O U R N A L OF IiVDUSTRIAL A N D EJVGINEERING C H E M I S T R Y
Oct., 1914
A NEW METHOD FOR THE DETERMINATION OF ZINC IN TREATED WOOD B y hl. HUMEBEDFORD A K D R . PFAKSTIEL Received July 20, 19 I4
Several methods have been proposed for t h e determination of zinc in wood treated with zinc chloride. Each of these methods is based upon t h e manner in which t h e organic m a t t e r is destroyed. I n t h e case of hard woods, particularly red oak, i t was found t h a t certain organic compounds were not destroyed b y some of t h e ordinary processes, a n d called for a modified a n d prolonged operation. For this reason this investigation h a s been confined t o treated red oak. Francis C. Frary' a n d M. Gordon SIastin use a nickel crucible a n d fuse the wood shavings with potassium hydroxide a n d a small q u a n t i t y of potassium nitrate, added t o complete t h e oxidation of t h e organic m a t t e r . I n t h e above article, mention is made of a method b y L. A. Stenger, i n which t h e sawdust is digested with dilute sodium hydroxide solution. T h e zinc is t h e n determined b y electrolysis. E r n s t Batem a n 2 describes a modified Kjeldahl digestion for destroying t h e organic m a t t e r . I n this method t h e wood shavings are heated with a mixture of nitric acid a n d potassium chlorate a n d finally sulfuric acid is added a n d t h e excess of nitric acid is evaporated off. I n t h e method here proposed t h e wood is burned in a n iron b o m b with sodium peroxide. The accompanying figure shows t h e design of t h e bomb. T h e bowl is about 4 I j 2 in. internal diameter a n d 5 in. deep, h - h b c % t oj
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