作者研究了有少量鈣、錳、銅和鈷存在下,硫酸和磷酸溶液中少量鉄的容量测定的可能性。当硫酸及磷酸的量在一定的限度内,鉄(Ⅱ)可被重鉻酸鉀法用二苯胺对磺酸或邻二氮菲作指示剂来測定。用∝、∝′联吡啶为指示剂时,錳的存在会使测定結果偏高;而N-苯基邻 The authors investigated the possibility of measuring the volumetric capacity of small amounts of sulfuric acid and phosphoric acid in the presence of small amounts of calcium, manganese, copper and cobalt. When the amount of sulfuric acid and phosphoric acid within a certain limit, 鉄 (Ⅱ) can be potassium dichromate method with diphenylamine sulfonic acid or phenanthroline as an indicator to determine. When α, α ’bipyridine is used as an indicator, the presence of manganese will make the determination result higher; and N-phenyl ortho