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An antimony‐silver/silver chloride electrode system for measuring pH in insect gut contents
Author(s) -
Biggs David R.,
Greenway Robert M.,
McGregor Peter G.
Publication year - 1994
Publication title -
entomologia experimentalis et applicata
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 83
eISSN - 1570-7458
pISSN - 0013-8703
DOI - 10.1111/j.1570-7458.1994.tb01836.x
Subject(s) - electrode , silver chloride , antimony , reference electrode , glass electrode , chloride , ph meter , standard hydrogen electrode , materials science , analytical chemistry (journal) , inorganic chemistry , chemistry , electrochemistry , chromatography , metallurgy
An electrode system consisting of a cast antimony rod with a silver chloride‐coated wire as a reference electrode has been developed to measure pH in insect gut contents. The electrode works well with buffer volumes down to 0.1 μl. Response to pH is linear between pH 4 and 11 and equates to a change of 52.3 mV per pH unit at 18–20 °C. Electrical resistance is low (0.25 MΩ), so the electrode can be used with low‐impedance meters and does not require shielding from induced currents. Its useful range lies between redox potentials −330 mV (pH 7) and +297 mV to 350 mV, corresponding to a pe + pH range of 1.4 to about 10.8. This covers reported gut pH values for most insects so far examined. Consequently the electrode is suitable for measuring pH of gut contents from many insects that are too small to be analysed with current commercial electrodes.