Published online by Cambridge University Press: 10 July 2009
A DDT sol, prepared in glass dishes in the manner described, has a reproducible zeta potential of −25 mv. Electrophoretic measurements showed that DDT conditioned in cardboard cartons has a zeta potential of zero.
The zeta potential of the suspension behaves in a predictable and measurable manner in the presence of mono-, di-, tri-, and tetravalent ions.
Spectrographic analyses showed that there are two identifiable sources of ions: (1) the DDT, and (2) the cardboard container. A third source of ions was indicated as being, singly or together, the distilled water and/or the DDT solvent.
Spectrographic data showed that ions were associated with the conditioned DDT.
In glass containers, a poor source of ions, kill of larvae of Anopheles quadrimaculatus Say was higher than in paper containers, a good source of ions. These data are correlated with the zeta potential and flocculation behaviour of DDT suspensions.