GDX-502树脂吸附分离富集-微分电位溶出测定水样中痕量酚

Indirect Determination of Trace Phenol in Water Samples by Differential Potentiometric Stripping Analysis

研究了酚（ｐｈｅｎ）－Ｃｕ－水杨酸（Ｈ２ｓａｌ）和四乙基碘化铵（Ｅｔ４ＮＩ）的四元体系中微分电位溶出分析法（ＤＰＳＡ）测定痕量酚。在ｐＨ为７．０的介质中，ｐｈｅｎ－Ｃｕ－Ｈ２ｓａｌ的配合物抑制了Ｃｕ在玻炭电极上的还原富集，降低Ｃｕ的微分电位溶出峰（Δｄｔ／ｄＥ），且０．４～２００μｇ／Ｌ的酚与Δｄｔ／ｄＥ呈线性关系。加入Ｅｔ４ＮＩ使检测灵敏度提高２．７５倍。天然水样经ＧＤＸ－５０２树脂吸附分离富集后，除去了吡啶、苯胺等物质的干扰。ＮａＯＨ洗脱，预电解富集３ｍｉｎ，酚的检出限为０．２μｇ／Ｌ；实验测定２０μｇ／Ｌ的酚，相对标准偏差为２．７％（ｎ＝１１）；标准加入回收率为８８．１０％～１１３．２０％。方法用于天然水中痕量酚的测定，结果与４－氨基安替比林分光光度法结果符合。

A sensitive and accurate method for indirect determination of trace phenol by DPSA is described in this paper. In the base solution containing phenol, copper(Ⅱ), mercuric chloride, salicylic acid and tetraethylammonium iodide (Et 4NI), electrodeposition of copper(Ⅱ) on the surface of filmed mercury glass carbon electrode is suppressed and the reduction of differential potentiometric stripping peak (Δd t /d E )of Cu(Ⅱ) is linear with phenol concentration in a range of 0.4～200 μg/L. The sensitivity for phenol is improved by a factor of 2.75 when Et 4NI is added. Phenol in natural and industrial waste water samples were separated from co existent interference components (e.g pyridine,aniline etc.) by chromatography with GDX 502 adsorption resin. After eluting with NaOH and pre concentration by electrolysis for 3 mins, phenol was determined by the mentioned method. The detection limit for phenol is 0.2 μg/L. The recovery from standard addition of 20 μg/L of phenol is 88.10%～113.20%. The method has been applied to the determination of trace phenol in natural water samples and the results are in good agreement with those provided by spectrophotometry.