D1385-07 – Standard Test Method Technical Guide

This standard under the designation D1385 –07 (Reapproved 2018) covers the colorimetric determination of hydrazine in water. The method is applicable to treated waters such as boiler feed and condensates.

📌 Scope and Application

This test method covers the colorimetric determination of hydrazine in boiler feed waters, condensates, natural, and well waters that have been treated with hydrazine (N₂H₄). This test method is usable in the range from 5.0 to 200 µg/L (ppb) hydrazine. The range is for photometric measurements made at 458 nm in 50 mm cell. Higher concentrations of hydrazine can also be determined by taking a more diluted sample. It is the users’ responsibility to ensure the validity of this test method for untested types of waters. The values stated in SI units are to be regarded as standard.

🔬 Principle of the Test Method

When a solution of p-dimethylaminobenzaldehyde in methyl alcohol and hydrochloric acid is