钠离子选择性双管微电极及在生物医学中的适用性

钠离子选择性电极可用来测量体液及体表面钠离子进行疾病的诊断及监测,钠玻璃微电极巳用于研究心肌及神经细胞内钠离子的生理、病理作用^1-4]。液膜型钠离子选择性微电极制作方便,内阻较小,亦有报导^5]。本工作采用N,N′-双二苄基-3,6-二氧杂辛二酰胺为活性物质,癸二酸二丁酯为增塑剂研制了一种PVC膜钠离子选择性双管复合型微电极。探讨了该微电极在生物医学测量中的适用性。该微电极性能良好,对K⁺的选择性同文献报道的同类电极^6]相近,而抗Ca²⁺、Mg²⁺等离子的干扰能力有较大的提高。

DOUBLE-BARRELED SODIUM ION-SELECTIVE MICROELECTRODE FOR BIOMEDICAL MEASUREMENTS

A double-barreled sodium ion-selective microelectrode based on N, N'-bis(dibenzyl)-3,6-dioxaoctyl diamide, with tip diameter of 2.5μm, has been constructed. The microelectrode shows a linear relationship in the range of 10^-3～5×10^-1mol·dm^-3(25℃)in NaCl solution.The selectivity coefficients with respect to K⁺, Mg²⁺, and Ca²⁺ are 0.053, 6.2×10^-4, and 5.8×10^-3, respectively. The response characteristics of the microelectrode for Na⁺ in body fluids was measured. The Na⁺ concentrations in some clinical microsamples were determined using this microelectrode.