Reference solutions for Ammonia and Nitrite?

[Whitebeam]

I use and regularly recommend the test kit calibration solutions from Left C's sticky in this section. I've just been asked in another place if there are instructions to make up similar test kit calibration solutions for Ammonia and Nitrite. I could easily busk an answer for Ammonia if I assume that the concentration shown in my bottle of domestic Ammonia is accurate, but haven't a clue where to start for Nitrite - its not something we usually have to hand. Is it? Any suggestions please?

Peter

 

[Biollante]

Somewhere Over The Rainbow...

Hi Peter,

I have one for Nitrite around here somewhere.

You are correct I have found household ammonia sufficient, though obviously you can purchase very pure ammonia from a variety of chemical supply houses.

I think I recall that NH4 is tricky, or I just not smart enough , though I have found the household ammonia gets us remarkably close.

For NH3 simply cut plain household ammonia, reasonably pure (no detergent) to 2, 4 and 8-ppm along with distilled water will be quite accurate.

Biollante

 

[Biollante]

Speed Cure

Hi Peter,

Somewhere I know I have a little more elegant do-it-yourself Nitrite (NO2) reference solution, so since I do not have any smart folk with me, I will have to fake it.

For real accuracy order Nitrite solution from Hach.

Easiest, cheapest source of Nitrite for average folk would be home meat curing product such as Speed Cure, InstaCure, or Quick Cure. I just happen to have Witts Speed Cure on hand.

Witts Speed Cure contains as the active ingredient 6.25 % sodium Nitrite (NaNO2) that yields around 4.2% Nitrite (NO2).

Since I am by myself today and do not have any talented folks around, I did not do any high precision measuring, the scale I used is +/- 0.01 gram the volumetric measures are +/- 2.5%.

The way I did it was:
add 1 gram Witts Speed Cure to 1 liter distilled water (results in about 40-ppm NO2, actual is closer 42-ppm)

• 100ml of 40-ppm solution into 500ml of distilled water (results in about 8-ppm NO2)
• 100ml of 8-ppm solution into 100ml of distilled water (results in about 4-ppm NO2)
• 100ml of 8-ppm solution into 300ml of distilled water (results in about 2-ppm NO2)

You should now have about:

• 900ml of 40-ppm NO2 reference solution (way to high for our purposes.)
• 300ml of 8-ppm NO2 reference solution (extreme end of hobbyist scale)
• 200ml of 4-ppm NO2 reference solution
• 400ml of 2-ppm NO2 reference solution

The reference solutions, I would think can be kept refrigerated (4 C) for at least 6 months, maybe a year...

Biollante

 

[Whitebeam]

Easiest, cheapest source of Nitrite for average folk would be home meat curing product such as Speed Cure, InstaCure, or Quick Cure.

Supurb, my only problem is that I've never heards of those products over this side of the pond - I'll have to keep my eyes open for similar and check ingredients.

When I had to busk the Ammonia instructions, this is what I came up with (borrowing a few words from Left C at the end ;-) My only issue is that I'm now not 100% certain whether the quantity of water in step 2 should be 475ml or 470ml (the 5 coming from the Household Ammonia) - I suspect 470, but the concentration difference is pretty much irrelevant anyway).

1) Go to Homebase (other sources of Ammonia are available) and buy some 9.5% 'Household Ammonia' solution (make sure whatever you buy doesn't have scent or detergent in it). This is the same stuff you can use to 'fishless cycle' a tank.
2) Measure out 475ml of distilled or deionised water (from Halfords or a hardware store or LFS RO water) using a measuring cylinder (you can get one from a home brew shop). A rougher way of doing this is to put a bowl onto an accurate kitchen scale, zero the reading and then pour in 475g of your water.
3) Using a children's medicine dosing syringe (any good pharmacist) measure out precisely 5ml of the household Ammonia and add this to the water. This gives you a 1000ppm stock solution.
4) Add 1 ml of the 1000 ppm solution to 9 ml of distilled water. This makes 10 ml of a 100 ppm solution.
5) Add 2 ml of the 100 ppm solution to 18 ml of distilled water. This makes 20 ml of a 10 ppm solution.

Then, as needed:

6) Add 1 ml of the 10 ppm solution to 99 ml of distilled water. This makes 100 ml of a 0.1 ppm solution.
7) Add 1 ml of the 10 ppm solution to 49 ml of distilled water. This makes 50 ml of a 0.2 ppm solution.
8) Add 1 ml of the 10 ppm solution to 19 ml of distilled water. This makes 20 ml of a 0.5 ppm solution.
9) Add 1 ml of the 10 ppm solution to 9 ml of distilled water. This makes 10 ml of a 1.0 ppm solution.
10) Add 2 ml of the 10 ppm solution to 8 ml of distilled water. This makes 10 ml of a 2.0 ppm solution.
11) Add 3 ml of the 10 ppm solution to 7 ml of distilled water. This makes 10 ml of a 3.0 ppm solution.
12) Add 4 ml of the 10 ppm solution to 6 ml of distilled water. This makes 10 ml of a 4.0 ppm solution.
13) Add 5 ml of the 10 ppm solution to 5 ml of distilled water. This makes 10 ml of a 5.0 ppm solution.

Peter

 

[Biollante]

470ml of Distilled Water

Hi Peter,

Step 2 is indeed 470ml of distilled water adding 5ml of 9.5% ammonia, in a perfect world yields 1000-ppm.475ml of distilled water would yield 989.5-ppm, in a perfect world.

• 475ml of distilled water would yield 989.5-ppm, in a perfect world.

I do not know that detergent or scent added to household ammonia would change the accuracy of the reference solution.

Also, I believe that the ammonia loses potency quickly after opening, so realize if this is household cleaner you have been using regularly and have had around for while your solutions will be somewhat weaker, perhaps even substantially.

As to measuring, actually weighing for most of us is more accurate than volumetric. Granted pure ammonia is about 83% the weight of water, given that it is 9.5% in this case, I still think weighing is likely to be more accurate.

Also for most cheap scales or volumetric measure, larger quantities are easier to gain accuracy than smaller, in this test were I to write it I would start with 940ml of distilled water and 10ml of 9.5% household ammonia and work my way down.

Biollante

 

[Biollante]

Prague Powder #1

Hi Peter,

Prague Powder #1 is an equivalent to Speed Cure, available in the UK.

Biollante