DEHA Test Kits
What is DEHA?
N,N-Diethylhydroxylamine (C2H5)2NOH, or DEHA, is a volatile amine commonly used for oxygen scavenging and passivating the steam condensate system in various boilers and heat recovery steam generators. DEHA is often used in boilers because of its low toxicity and ability to enter the steam phase in mid and high-pressure boilers. It is frequently used to control dissolved oxygen in boilers during wet lay-up. DEHA also helps control pH within the boiler by degrading into neutralizing amines.
Why Test for DEHA?
As an oxygen scavenger, DEHA is a critical component of controlling dissolved oxygen in a boiler, which in turn helps control corrosion. DEHA tests ensure the dosing of systems with sufficient chemical to protect metal from corrosion but not so much that treatment chemicals are wasted. Regular boiler feedwater testing therefore ensures maximum efficiency of the system.
About Our Test Kits
CHEMetrics offers three different boiler water test kits with two different chemistries for measuring DEHA concentration.
For visual colorimetric analysis, the CHEMets® test kit employs the PDTS chemistry and can be used to measure DEHA in the 0-400 & 400-3000 ppb range. K-3925 utilizes CHEMetrics’ Titrets® titration cells with ceric sulfate titrant and ferroin indicator to measure a higher range of 25-250 ppm during lay-up.
For instrumental analysis, the Vacu-vials® colorimetric test kit K-3903 requires the use of a CHEMetrics direct-readout photometer or spectrophotometer capable of accepting a 13-mm diameter round cell. It measures between 0-2.00 ppm DEHA using the PDTS chemistry.
Click on a catalog number in the tables below for more information or to purchase a DEHA test kit.
Visual Kits
| Range | MDL | Method | Kit Catalog No. | Refill Catalog No. |
|---|---|---|---|---|
| 0-400 & 400-3000 ppb | 15 ppb | PDTS | K-3902 | R-3902 |
| 25-250 ppm | 25 ppm | Ceric Sulfate Titrant with Ferroin Indicator | K-3925 |
Instrumental Kits
| Range | Method | Kit Catalog No. |
|---|---|---|
| 0-2.00 ppm | PDTS | K-3903 |
Methods
Reference: G. Frederick Smith Chemical Co., The Iron Reagents, 3rd ed., p. 47 (1980). The boiler water test kits employ the PDTS chemistry, in which DEHA reduces iron III (ferric state) to iron II (ferrous state), which readily reacts with PDTS (3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine disodium salt) to form a pink-purple colored complex in direct proportion to the DEHA concentration. Test results are expressed in ppb (ug/L) or ppm (mg/L) DEHA.
Reference: Developed by CHEMetrics, LLC CHEMetrics developed a titrimetric method that employs a ceric sulfate titrant and ferroin end point indicator. DEHA reduces ferric iron to the ferrous state, and the resulting ferrous iron is titrated with the ceric sulfate titrant. Test results are expressed in ppm (mg/L) DEHA.