6 MAINTENANCE
9070
Note:
Waltron L.L.C. offers Hydrazine Standard 1000 ppm in a 1 liter
size part number H1234-060
Dissolve 4.058(
±
0.001)g of analytical reagent grade Hydrazine Sulfate
(N
2
H
4
H
2
SO
4
) in approximately 800ml high purity water. Transfer this
solution to a one-liter volumetric flask and make up to the 1-liter mark
with more high purity water to give a stock solution of 1000ppm
Hydrazine. Store in a plastic container. Hydrazine Sulfate at this
concentration is stable for one year.
Prepare a 100ppb Hydrazine Standard as follows:
Note
. A two-step dilution is usually more accurate than a single dilution.
The following dilution method produces more accurate results than those
obtained by calorimetric laboratory analysis of the final diluted standard.
9
Pipette 10ml of the 1000ppm stock solution to a one-liter volumetric
flask. Make up to the 1-liter mark with high purity water to give an
intermediate solution of 10ppm Hydrazine Sulfate.
9
Pipette 20ml of the 10ppm intermediate stock solution to a 2-liter
volumetric flask. Dilute with high purity water to give a final
standard concentration of 100ppb.
Note
. Do not prepare hydrazine solutions of less than 20ppb because low
concentration solutions rapidly become contaminated and change in
concentration.
Note
. High purity water is water containing less than no Hydrazine and a
specific conductivity of less than approximately 0.2µS/cm.
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