Hydrazine Test Kit Colorimetric Procedure
Colorimetric Procedure
The objective is to maintain a hydrazine residual between 0.05-0.2 ppm depending on operating pressure and boiler designe. Actual consumption is determined under operating conditions. A normal dosage is approximately 1 ltr. per day, depending of system layout.
Hydrazine is a convenient reductant because the by-products are typically nitrogen gas and water. Thus, it is used as an ANTIOXIDANT, an oxygen scavenger, and a corrosion inhibitor in water boilers and heating systems.
Hydrazine is mainly used as a foaming agent in preparing polymer foams.
No oxygen is entering the boiler with the feed water when hydrazine is present in the water.
Directions for use : Based on Colorimetric Procedure
1. Take 5 ml of sample to be tested in the Test jar ( Before testing, samples must be cooled to 25oC by passing them through a cooler.). if necessary. Turbid samples are to be filtered with a filter paper.
2. Add 40 drop (2ml) of Reagent TK-16. Mix wel
3. Add 2 micro spoon full of Reagent TK-17. Mix well upto provider dissolves Completely. Wait for 10 minutes.
4. Now rinse the empty comparator tube with above solution and will upto the half level of the comparator tube.
5. Insert this tube in sample slot of comparator.
6. Compare the developed colour with standard comparator colours. Slide the comparator until the colors match. Check the mea- surement reading in the recess on the comparator reed. Mid values can be estimated
7. Note down the ppm level of Hydrazine as N2H4
8.After use, rinse out both measuring glasses thoroughly and seal them.
Note 1 ::: Studies showed that hydrazine was not stable on the sampling device, therefore, immediate extraction of samples after collection was recommended.
Note 2 ::: color is stable for 1 hours.
Sample of Hydrazine is Harmful. Handle with due care.
All open chemicals should be used only in a fume hood.
Avoid any skin contact with all chemicals. Immediately flush contaminated areas with copious amounts of water.
Wear safety glasses at all times.
Hydazine Dose Level
|
Low Pressure Boiler ( 0 to 40 bar ) |
0.10 to 0.2 ppm level |
|
Medium Pressure Boiler ( 41 to 60 bar ) |
0.1 to 0.15 ppm level |
|
High Pressure Boiler ( more then 60 bar) |
0.05 to 0.10 ppm level |
|
Interfering Substance |
Interference Level |
|
Ammonia |
No interference up to 10 mg/L. May cause a positive interference of up to 20% at 20 mg/L. |
|
Highly colored or turbid samples |
Prepare a 1:1 mixture of deionized water and household bleach. Add one drop of this mixture to 25 mL of sample in a graduated mixing cylinder and invert to mix. This will destroy any hydrazine in the sample. Use this solution, instead of deionized water, to prepare the blank in the test procedure.
|
| Morpholine | No interference up to 10 mg/L. |
Accuracy Test :
Standard solution method
Use the standard solution method to validate the test procedure, the reagents and the instrument. Items to collect:
1. Hydrazine sulfate, reagent grade
2. 1-L volumetric flask, Class A (2)
3. 10-mL volumetric pipet, Class A and pipet filler
4. Deionized water, oxygen-free
Preparation Method :
Prepare a 25-mg/L hydrazine stock solution as follows:
Add 0.1016 g of hydrazine sulfate into a 1-L volumetric flask. Dilute to the mark with oxygen-free deionized water (heat water to boiling and cool). Mix well. Prepare the stock solution each day.
Prepare a 0.25-mg/L (250-μg/L) hydrazine standard solution as follows:
Use a pipet to add 10.00 mL of the 25-mg/L hydrazine stock solution into a 1-L volumetric flask.
Dilute to the mark with oxygen-free deionized water. Mix well. Prepare the standard solution immediately before use.
Use the test procedure to measure the concentration of the prepared standard solution.
Compare the expected result to the actual result.
Note: The factory calibration can be adjusted slightly with the standard adjust option so that the instrument shows the expected value of the standard solution. The adjusted calibration is then used for all test results. This adjustment can increase the test accuracy when there are slight variations in the reagents or instruments.
PRINCIPLE of Hydrazine TEST for Boiler water and Water:::
Under acidic conditions, hydrazine combines with Hydrazine Test Reagent TK - 17 to form a yellow- colored complex. Color development follows and is stable after maximum color is developed in 10 to 15 minutes.
Where Hydrazine Test Kit used ?
HYDRAZINE TEST KIT is used for the determination of Hydrazine content in the Boiler’s Water. The test must be performed when in the vessel’s Boiler Water Treatment used hydrazine ingredient to control rust and corrosion RXSOL-50-5022-025 / RXSOL-50-5007-025 / RXSOL-19-1541-025. This is an activated hydrazine solution (Hydrazine with a catalyst for faster reaction with Dissolved Oxygen,) and applied for marine and industrial Boilers in low, medium and high pressures.
Benefit of Hydrazine Test Kit ?
Following the procedure above, the concentration in ppm of Hydrazine in the Boiler Water will be obtained. According to the Boiler’s working conditions, and the results obtained the dosage of Oxygen Scavenger / Hydrazine must be adjusted considering the dose chart. For effective boiler water treatment with Hydrazine and in order to avoid any problem of Oxygen corrosion, the test at the initial period of use of RXSOL Oxygen Scavenger must be performed every day. Once a small concentration of Hydrazine obtained in the Boiler water then the test could be repeated every 2–3 days.
Limitation of Hydrazine Dose ?
Control of Hydarazine level in Boiler water is very important. As proper level maintenance protect metal machinery parts from corrosion, However, precautions must be taken to prevent excess dose of hydrazine chemical as excess hydrazine will begin to decompose at temperature above 200oC to form Ammonia.
Hydrazine is one of popular an alternative Oxygen Scavenger. It is very important to protect boiler components from feed boiler water corrosion.
Precaution : Strictly observe the temperature and reaction time since they strongly affect the color intensity. The measurement must be taken in 5 min and not before or later, and preferably at the temperature of 20oC - 25oC.
Before Sampling all PRECAUTION should be taken :::
Toxic effects of Hydrazine ( which is collected in sample ) is a severe skin and mucous membrane irritant in humans; in animals.In humans, the vapor is immediately irritating to the nose and throat and causes dizziness and nausea; itching, burning, and swelling of the eyes develop over a period of several hours. Severe exposures of the eyes to the vapors causes temporary blindness lasting for about 24 hours. Recurrent exposure to hydrazine hydrate has been reported to cause contact dermatitis of the hands without systemic intoxication. In humans, hydrazine is absorbed through the skin, by inhalation, and orally; systemic effects include weight loss, weakness, vomiting, excited behavior, and convulsions; the chief histologic findings are fatty degeneration of the liver and nephritis.
