http://www.sciencedirect.com/science/article/pii/0304423885900093 napisał:
Abstract
Silver thiosulfate (STS) complex stability and degradation during formulation and storage were monitored indirectly by determining the effectiveness of treatment solutions in retarding flower petal abscission in geraniums (Pelargonium hortorum Baily). Freshly prepared solutions composed of Ag+:S2O32− ratios from 1:1 to 1:16 at constant silver concentration were all equally effective. There were no differences in effectiveness when a Ag+:S2O32− solution of ratio 1:4 was formulated at 5, 25 or 50°C, when prepared at pH 4.01, 7.0 or 10.0, or when prepared in the presence of 10 mM KCl, Na2CO3, Ca(NO3)2 or MgSO4. The ability of solutions to retard abscission was reduced when Ag+ was substantially in excess of S2O32−. Rapid mixing of AgNO3 and Na2S2O3 solutions yielded effective solutions, independent of mixing order. Complete loss of activity was observed when solutions were stored in contact with either tin or galvanized metal for 5 days, whereas there was no loss in activity after 3 months' storage in plastic or glass at 2°C. These results indicate that currently recommended formulation procedures are unnecessarily stringent, and that long-term cold storage of prepared STS solutions is feasible.
Keywords
degradation; formulation procedures; silver thiosulfate; stability
Copyright 1985 Published by Elsevier B.V.