Detection of hydrazine, methylhydrazine and isoniazid by capillary electrophoresis with a 4-pyridyl hydroquinone self-assembled microdisk platinum electrode

Capillary electrophoresis (CE)/electrochemical detection (EC) for the simul taneous detection of hydrazine, methylhydrazine, and isoniazid has been dev eloped with a 4-pyridyl hydroquinone self-assembled microdisk platinum elec trode. Such an electrode has very high catalytic ability for hydrazines and they could be detected even at 0.0 V. The responses for hydrazine, methylh ydrazine, and isoniazid are linear over 3 orders of detected concentration and of magnitude of 0.2-400 mu M, 0.2-400 mu M, 0.5 mu M-2 mM, with correla tion coefficients of 0.9998, 0.9991, and 0.9982, respectively. And they cou ld be detected to levels of 0.1, 0.1 and 0.2 mu M, respectively. This modif ied electrode was found to be very stable and reproducible when continuousl y used as detector for capillary electrophoresis for period of at least 4 w eeks with no apparent loss of response. (C) 1999 Elsevier Science B.V. All rights reserved.