摘要:
基于酚和吡啶可以分别与Cu2+和水杨酸生成稳定的三元络合物,酚或吡啶的存在会抑制铜离子在玻炭电极上还原富集,使铜的微分溶出峰电流ip′减小,根据溶出峰电流的减水值Δip,可以间接测定酚和吡啶。工作电极为玻炭电极,预电解电位为-0.9V(vs.SCE),铜的微分溶出峰值电位为-0.25V(vs.SCE)。本文对测定条件,干扰及其消除方法进行了研究。测得酚的下限为4×1012mol/L,而吡啶的下限为1×10-11mol/L,提出了一个灵敏,准确、简便的测定地面水和空气中痕量酚和吡啶的方法。
Abstract:
A sensitive method for indirect determination of trace pyridine (Py) and phenol (Ph) is developed. Electrodeposition was established on the surface of glass carbon electrode at - 0.9v(vs.SCE) in a base solution containing Cu2+, HgCl2, and salicylic acid (H2Sal). A stripping peak current of copper Cip')was shown by potantial scanning reversely.Then, the glass carbon electrode was moved into the.base solution containing pyridine and phenol. Since a ternary complex Cu2+- Py-Sal and Cu2+ -Ph-Sal was formed, the stripping peak current of copper decreased (ip') and varied linearly with the concentration of pyridine or phenol. The limits of detection were found to be 1 � 10-11 mol/L for pyridinc and 4 � 10-2mol/l for phenol.
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