Stability of Main Components in Rainwaters

Abstract

Stabilities of pH, electric conductivity and main components of rainwater were investigated under various conditions by using rainwaters collected in Kobe area, to find a suitable sampling and preservation method.
When the rainwater was stored in a polyethylene bottle in the dark at 4°C, concentrations of most components were kept constant for more than five years, but the concentration of NO₃^-was slightly increased due to the unknown cause.
The concentrations of the main components in the rainwater stored in a glass vessel were stable on standing in a room for 10-30 days, but on longer standing in a room (about one year), pH value of the rainwater was increased gradually.
Some rainwaters were exceptional and exhibited the changes in both pH value and ammonium concentration, irrespectively of the storage condition.