1. Differential-Pulse Polarography was used to determine ascorbic acid in fruit-juices and lemonades.

2. Applicability of polarography for the continuous determination of dissolved oxygen in sewage and activated sludge was investigated.

3. The method of polarography used for measuring half-wave potential of the cyanine dye is one of the important ways in studying the spectral sensitization property of dye.

4. 1-Methyladenine, deoxyadenosine (deoxy-A), deoxyadenosine-5′-monophosphate (deoxy-5′-AMP), adenylyl-(3′→5′)-adenosine (APA) and adenylyl-(3′→5′)-guanosine (APG) were studied at various pH-values by differential pulse polarography at the dropping mercury electrode.