Abstract
1. Silica'e: Diénert-Wandenbulcke's method has been studied. The presence of chloride up to about 20% Cl- causes no error where the tint becomes slightly yellowish, this is however easily Eeglected with a pale yellow glass filter. The small content of phosphate (0.1mg P3O5/l) and iron (1mg Fe/l) a so gives no influence for this analysis.
2. Nitrite: Griess-Romijin's powder reagent (α-naphtylamine lgr., sulphanilic acid 10gr. and tartaric acid 89 gr.) is especially well adapted to the analysis of the nitrite in water. NH4C1, NaCl, KNO3, Na2CO3, CaCl2, Na2NO4, Na2SiF6, KH2PO4, MgCl2 and small quantity of Fe+++ and Fe++ do not interfere with the analysis.
