硫化物标准配制与测定方法可靠性研究

STUDY ON RELIABILITY OF SULFIDE STANDARD PREPARATION AND ITS DETERMINATION METHOD

采用４０ｇ／ＬＮａＯＨ吸收气态Ｈ２Ｓ后的溶液或用不含结晶水的固体硫化钠配制硫化物标准．标准液中硫量基本是以Ｓ２－形式存在的量．用三种方法对不同种类含硫物质进行了测定比较：碘量法直接滴定水中硫化物，其结果一般偏高；对氨基二甲基苯胺比色法直接测定水中硫化物，其结果一般偏低；Ｓ－ＸＹＸ气化光度法直接测定水中硫化物时，其测定结果与水样中硫（Ｓ２－）化物含量基本一致，不受其他价态硫化物存在的影响．

A sulfide standard is prepared by using 40g/L NaOH solution which has absorbed gaseous hydrogen sulfide or the solid Na2S without crystal water.The sulfur content in the standard solution is basically that in the form of S2-.Three different methods are compared through the determination of different kinds of S-containing substances. Normally when a sulfide in water is directly titrated by iodimetry,the result is normally on the high side;when it is directly determined by the photometric method of p-aminodimethylaniline,the result is on the low side; when it is directly determined by S-XYX gaseous photometric method,the result is basically conformable to the sulfide content(S2-) in the water sample without the affection of other co-existing valence sulfides.