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Carbohydrazide Test Kits

Carbohydrazide Test Kits

Click on a catalog number in the tables below for more information or to purchase a test kit.

Visual Kits

Range MDL Method Kit Catalog No. Refill Catalog No.
0-0.50 0.05 ppm PDTS K-1805 R-1805


Carbohydrazide is added to boiler system water as an oxygen scavenger to control corrosion. It is a safer alternative to hydrazine, which is toxic. Carbohydrazide reacts with oxygen at low temperatures and pressures. The products of the reaction are volatile and do not contribute dissolved solids to the boiler water. Like hydrazine, carbohydrazide will also passivate metal surfaces.

The PDTS Method

Reference: G. Frederick Smith Chemical Co., The Iron Reagents, 3rd ed., p. 47 (1980).
The test kits employ the PDTS chemistry. Carbohydrazide reduces ferric iron to the ferrous state, and the ferrous iron reacts with PDTS (3-(2-pyridyl)-5,6-bis (4-phenylsulfonic acid)-1,2,4-triazine disodium salt) to form a peach-pink colored complex in direct proportion to the carbohydrazide concentration. Test results are expressed as ppm (mg/L) carbohydrazide.