提高硫化物标准溶液稳定性的研究

Research on the Improvement of Stability of Sulphide Standard Solution

用ｐＨ＝９．２的硼砂缓冲液（内含一定量的Ｚｎ（Ａｃ）２－ＮａＡｃ）作硫化物的保存剂，配制５．０μｇ／ｍｌ的标准溶液．此种标液均匀性好，稳定性强，置冰箱保存一年，浓度基本不变，标准曲线斜率年内变化率＜４％．

Borax buffer solution (containing a certain amount of Zn(Ac)2-NaAc),of which pH value is 9.2, is used as the preservative substance of sulphide to mix a kind of standard solution of which the concentration is 5.0 μg/mL. The homogeneity and stability of this kind of standard solution are good. Its concentration after being preserved in refrigerator for one year is almost the same. The change rate of slope of standard curve within a year is less than 4%.