New Instrumental Approach in Phase-Selective Second Harmonic Alternating Current Polarography

The development of a simple and inexpensive ($10-$20) approach to obtaining the second harmonic response is described using electronic multiplication of the ac reference signal to the phase-selective detector. The principle can be understood by consideration of trigonometric identities of the type [formula omitted] The performance of the circuitry is assessed on a commercially available instrument and the theoretical response obtained in both aqueous and nonaqueous solvents. Phaseselective detection is employed and the use of this readout form in analytical work is discussed.