The Manufacturing And Properties Of Medical Glass Micro Electrode

pH glass electrodes widely apply to industry, agriculture, environmental protection,medicine field and so on. The pH value of mortal stomach juice is a very importantparameter in medicine field. With the rapid rhythm of society, people increasingly de-mand the safety, rapidity, and accuracy of diagnostic results. In this paper, the microglass electrodes with reversible solid contact are developed in order to satisfy the forenamed requirements about gastropathy diacrisis. This kind of electrode with the-diameter of 2mm and length of 5mm has such a small size that it is easy to get di-rectly into mortal stomach.Some properties of Li₂O36.5%La₂O₃2.5%ZrO₂1.5%SiO₂59.5% (in mol) glass areresearched, such as the water-resistance tested by powder method and the acid-resis-tance tested by surface method are 3rd classe. DTA method shows that this kind ofglass will occur crystal within 700～800℃temperature. The X-ray diffraction spectrumof such glass heated at 780℃shows that the crystalline phases are Li₂SiO₃ andLa₂SiO₇.This kind of glass with suitable chemical stability is used for sensitive films ofelectrodes. The Li-Pb. alloy melted down and deposited on the internal surface of elec-trodes sensitive films in vacuum has low melting point. The manufacturing technologyof micro glass electrodes is explicated. And we also develop Ag-AgC1 reference elec-trodes and formulize the manufacturing method.The properties of trial-produced glass micro electrodes are detected all-sidedly Theresults show that a better Nernst response, stability, and reproducibility of the glasselectrodes exist in the range of pH=1～9. This kind of electrode has a short response time(about 20s) and the drift mobility of the potential difference with time is about 1.5mV/h. ThepH value surveyed for stomach juice of 25 pieces of white rats by such electrodes is within2～5. As compared with the measurement of pH values by PB-20 Sartorius AG acidimeter,the statistical figures show that the average deviation of such electrodes is slight, approximate ±0.2.The pH rang of mortal stomach juice is pH=2～3 at normal status. It can be concludedfrom this result that it is possible to utilize for the detection of mortal stomach juice by thiskind of electrodes.The properties of trial-produced reference electrodes detected show that "the referenceelectrodes have good stabilities, the drift mobility of the potential difference with time isabout 0.04mV/min.