以多巴胺为配体示差脉冲伏安法间接测定生物体液中的铝(英文)

Differential Pulse Voltammetric Indirect Measurement of Aluminum in Biological Fluids Using Dopamine as Sequestering Agent

建立了用神经递质多巴胺作电活性配体示差脉冲伏安法间接测定生物体液中的铝的方法 .多巴胺在玻碳电极上的氧化峰电流随铝浓度的增加而线性下降 .在最佳测定条件 (pH 7.0 ,2 .4× 1 0 -4 mol/L多巴胺 ,0 .0 8mol/LNH4Ac缓冲溶液 )下 ,铝的检测下限、相对标准偏差 (4× 1 0 -6mol/LAl(III) ,n =8)、线性范围分别为 1 .7× 1 0 -7mol/L、3 .4%、4 .0× 1 0 -7～ 42×1 0 -7mol/LAl(III) .对许多生物体液中可能存在的物质进行了干扰试验 .采用标准加入法将所建立的方法应用于实际样品如人全血、脑病患者的脑脊液、糖尿病患者的尿、肺癌患者的腹水、合成肾透析液及合成脑脊液等样品中铝测定 ,结果表明回收率在 95 %～1 0 8%之间 ,所测得的样品中铝含量与文献值和ICP法值吻合 .通过紫外光谱、拉曼光谱及 1 3 C核磁共振谱探讨了测定方法的原理 .加入铝后多巴胺氧化峰电流的下降原因是铝与多巴胺的邻羟基配位 。

Neurotransmitter dopamine(3,4_dihydroxyphenylethylamine,DA)has been adopted as an electroactive sequestering agent of aluminum(Al)for indirect determination of Al in biological fluids.It was observed that the decrease of the differential pulse voltammetric(DPV)anodic peak current of DA was linear with the increase of Al in the pH range from6.0to7.6.Under optimum experimental conditions(pH7.0,2.4×10 -4 mol/L DA,and0.08mol/L NH 4 Ac buffer solution),the detection limit of Al in the linear range from4.0×10 -7 to42×10 -7 mol/L is1.7×10 -7 mol/L and the relative standard deviation for4.0×10 -6 mol/L Al Ⅲ is3.4%(n=8).Many foreign species possibly existing in biological fluids have been tested for interference.Recoveries between95%～108%have been achieved in the application of the method to measurements of Al in biological samples such as synthetic renal dialysate,Ringer’s solution,human blood,cerebrospinal fluid of patients,and urine of diabetic patients.The methodological principle that Al is complexed with DA on the electroactive site resulting in the depression of electroactive DA has been verified from the electrochemical evidences and the responses of UV_vis,Raman,and 13 C NMR of DA both in the presence and absence of Al.This principle is applicable to both the chelants with the same electroactive functional groups as DA and similar cases such as monitoring electrochemical inactive species by electroactive ligands through complexation reactions.