Help SN method. Very strange behaviour of aquarium strips!

[Red Desert]

Hi! Yesterday, I attempted to verify the purity of my sodium nitrite (SN) using aquarium test strips.
I carefully followed all the steps outlined in @Vizzy's SN Bible.


Materials used:

• Technical sodium nitrite (NaNO₂, 99%)
• Two 0.5L plastic cups
• Industrial distilled water
• A 1 ml Pasteur pipette
• Aquarium test strips (25 pieces for $3.50)

Results:
1. Just distilled water. LOOKS OK!




2. Water with SN at 5 g/L. The nitrite stained the strip an obscure ivory color. WTH?!




3. Water with SN at 10 mg/L. LOOKS OK!




4. Water with a huge amount of SN at 40-50 g/L. I immersed 6 strips simultaneously, assuming the strip from case 2 was defective. The color remains unclear. WTH?!



MAIN QUESTION:
Why did I observe an ivory color rather than a deep pink-red in cases 2 and 4? Is my SN pure, given that the result in case 3 was successful?

 

[nir]

That's really weird. Is this SN from DMC, or a different source?

 

[sevennn]

dunno but gonna bump the thread

 

[Plato'sCaveDweller]

if there was no user error in your testing, then I suppose this may be yet more proof that testing strips are unreliable indicators of purity.

Bumping, in case someone knows anything.

 

[sevennn]

в русском треде посмотри. там какой то юзер знает как тестировать сн помимо этих методов (кажется)

 

[Red Desert]

That's really weird. Is this SN from DMC, or a different source?

SN from a popular Russian marketplace. It's easy to obtain in Russia. The substance is manufactured by a large chemical company named Uralchem («Уралхим»).

 

[sevennn]

SN from a popular Russian marketplace. It's easy to obtain in Russia. The substance is manufactured by a large chemical company named Uralchem («Уралхим»).

я тоже хотела у них купить, не купила пока еще

 

[Red Desert]

я тоже хотела у них купить, не купила пока еще

Даа, но больше склоняюсь, что эти полоски — некачественная дешёвка.

 

[sevennn]

Даа, но больше склоняюсь, что эти полоски — некачественная дешёвка.

тоже вариант

 

[Red Desert]

An error that I made in my experiment has been found. I kept the strips in the water for 2 minutes instead of the specified two seconds.

I apologize for my oversight. I will check again, and if necessary, I will reply in this same thread.

Stay tuned!

 

[sevennn]

An error that I made in my experiment has been found. I kept the strips in the water for 2 minutes instead of the specified two seconds.

I apologize for my oversight. I will check again, and if necessary, I will reply in this same thread.

Stay tuned!

ok!! i'll watch the thread

 

[Plato'sCaveDweller]

An error that I made in my experiment has been found. I kept the strips in the water for 2 minutes instead of the specified two seconds.

I apologize for my oversight. I will check again, and if necessary, I will reply in this same thread.

Stay tuned!

did you retest?

 

[Red Desert]

did you retest?

Nah, I'm waiting for a convenient moment when no one will be around.