Preliminary study of quantitative analysis of ammonium ions in a raindrop following Liesegang ring formation.

NH(4)(+) concentration in an individual droplet was determined by forming a Liesegang ring on a gelatin film containing NaB(C(6)H(5))(4). The NH(4)(+) concentration (mol L(-1) abbreviated to M) was calculated from the NH(4)(+) amount (mol) ascertained in a droplet using pixel count measurements. The droplet volume (L) was calculated by measurement of the diameter of a droplet print on the gelatin film. For rainwater, the NH(4)(+) concentration estimated using this method corresponded with results obtained using ion chromatography.