ヒドロキシメタンスルフィン酸ナトリウム二水和物

解説スルホキシル酸ホルムアルデヒド塩の商品名．通常はロンガリットCとよばれるナトリウム塩NaHSO2・HCHO・2H2Oで，Na(H2CHO)SO3・2H2Oが少し混合している．無色結晶．還元剤として染色工業で用いられる．ロンガリットZとよばれるものはZnSO2・HCHO・H2Oで，水に難溶の無色粉末．強力な還元剤で，絹，羊毛，化学繊維などの抜染漂白に用いられる．

用途還元剤、捺染剤。

使用Pharmaceutic aid (preservative).

Sodium formaldehyde sulfoxylate is manufactured from sodium dithionate and formaldehyde in water.

純化方法It crystallises from H2O as the dihydrate and decomposes at higher temperatures. Store it in a closed container in a cool place. It is insoluble in EtOH and Et2O and is a good reducing agent. [X-ray structure: Tuter J Chem Soc 3064 1955.] Note that this compound {HOCH2SO2Na} should not be confused with formaldehyde sodium bisulfite adduct {HOCH2SO3Na} from which it is prepared by reduction with Zn. [Beilstein 1 IV 3052.]