pH-elektrode

摘要

PCT No. PCT/GB92/00049 Sec. 371 Date Oct. 13, 1992 Sec. 102(e) Date Oct. 13, 1992 PCT Filed Jan. 2, 1992 PCT Pub. No. WO91/18549 PCT Pub. Date Dec. 12, 1991.A pH electrode suitable for in vivo use is provided in a cannula 10, and comprises a reference electrode 14 consisting of a chloridized silver wire surrounded by a solid unbuffered internal reference material 16 comprising potassium chloride, silver chloride, citric acid and sorbitol as a hygroscopic agent. The material 16 is surrounded by a PVC sleeve 12. The tip of the cannula 10 has a pH sensitive polymer-based membrane 20 across its end. The reference material has a pH when hydrated of about 2 which is below the range of pH response of the membrane 20.