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NO. 8,
JULY 1978
1073
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RECEIVED for review January 26,1978. Accepted March 27, 1978. Work supported in part by the National Science Foundation, Grant No. CHE76-07378.
Rapid Drop Time On-Line Fast Fourier Transform Faradaic Admittance Measurements Roger J. O'Halloran, Jerome C. Schaar, and Donald E. Smith* Department of Chemistry, Northwestern University, Evanston, Illinois 6020 7
A recently-described computerized Fast Fourier Transform faradaic admittance measurement protocol is shown to be applicable to rapid, mechanically-controlled mercury drop time (C1 s) measurements. Data defining the 4-dlmenslonal profiles of in-phase and quadrature faradaic admittance magnitudes vs. dc potential and frequency are obtainable using very short measurement times, on the order of several seconds. Typical experlmental results are presented for aqueous and nonaqueous systems which illustrate that data quality obtained with the rapidly dropping mercury electrode is comparable to that achleved wlth normal mercury drop lives ( 2 1 s). Thus, previously demonstrated advantages of rapid drop tlme polarographic measurements can be coupled readily to the powerful FFT faradaic admittance measurement procedure, enhancing the benefits of both measurement techniques.
The use of rapid mercury drop time (
