ジチゾン

解説ジチゾン,ジフェニルチオカルバゾンともいう．フェニルヒドラジンと二硫化炭素から得られる．青黒色の結晶性粉末．融点167 ℃(分解)．水に不溶，四塩化炭素，クロロホルムに可溶．ケト形とエノール形の互変異性体が存在し，金属キレート錯体も両者が存在するが，一般にケト形が安定で，有機溶媒に易溶．多数の金属イオンと反応し，特有のキレート錯塩をつくるので，微量の金属の分離，定性，定量に用いられる．

用途金属の比色分析、溶媒抽出試薬。

用途カドミウム、銀、水銀、銅、亜鉛、鉛などの重金属イオンと反応して、水に溶けにくいキレート錯体の着色沈殿（黄褐色、赤色、紫色など）をつくるので、重金属イオンの検出、分離に用いられる。また沈殿はクロロホルムに溶けるので、比色定量に利用することができる。この種の試薬のうち、もっともよく研究されている。

使用Dithizone is an organosulfur compound that acts as a chelating agent and forms complexes with metals such as lead and mercury. Dithizone is used to assess the purity of human pancreatic islet preparations used for transplantation into patients with type 1 diabetes.

一般的な説明Dithizone (Diphenylthiocarbazone) is used as chelating agent for zinc. It is widely used for the liquid-liquid and solid phase extraction of various metals since it forms stable complexes with the metals.

純化方法The crude dithizone is dissolved in CCl4 to give a concentrated solution. This is filtered through a sintered glass funnel and shaken with 0.8M aqueous ammonia to extract dithizonate ion. The aqueous layer is washed with several portions of CCl4 to remove undesirable materials. The aqueous layer is acidified with dilute H2SO4 to precipitate pure dithizone. This is dried in a vacuum. When only small amounts of dithizone are required, purification by paper chromatography is convenient. [Cooper & Hibbits J Am Chem Soc 75 5084 1933.] Instead of CCl4, CHCl3 can be used, and the final extract, after washing with water, can be evaporated in air at 40-50o and dried in a desiccator. It complexes with Cd, Hg, Ni and Zn. [Beilstein 16 H 26, 16 IV 18.]