Odd results from GCMS and HPLC test on NPP sample

[Luka.Halotestin]

These are two test, GCMS and HPLC, ran on the same NPP sample.

As you can see GCMS showed only NPP. @Sampei told me it was wrong.

HPLC later showed NPP slightly below 80%.

Can someone with more knowledge about lab testing elaborate on this? Is GCMS just wrong or is there something more to it?

 

[Luka.Halotestin]

Tests

 

[readalot]

GCMS cant detect impurities that dont volatilize at 300/350 deg C. So if your NPP is cut with fine sand or something other non volatile shit (sand is dumb example I know since that gets filtered out prior to hitting column but you get the idea), the GCMS test wont pick it up. GCMS meant to elegantly identify organics that vaporize similar to the AAS API.

Cool example where HPLC wins.

HPLC purity with jano is mg of API divided by mg of sample.

GCMS still very fucking useful tool.

Your supplier is cutting your raw with filler.

 

[readalot]

Post in thread 'Source QC and C of A (do you have one?)'

Jan 25, 2024

In your experience what is the typical bias range (purity by area count minus purity by mass ratio)? 1.5 to 3% lower by latter accurate method?

Oh no no, nothing like that. It can easily range up to 95%. Normalisation used incorrectly can yield 100% pure result with something that has an API content of 5% and the rest is flour.

• janoshik

• 

Or flour. Lol.

 

[Luka.Halotestin]

Thanks man!

 

[readalot]

Thanks man!

Thank you. Particularly damning results since the impurity isn't AAS precursor and GCMS didn't pick it up. So good probability the vendor is adulterating their raws to save money assuming we take test results at face value. You busted them. They ain't just being sloppy on the conversion and cleanup steps.

 

[Luka.Halotestin]

Yess! Busted them and threw away over $2000 for 1.5 kg of my NPP raw.

I am not buying anything until this crackdown situation settles. They would sell dog shit right now because some desperate brewer will buy it.

 

[readalot]

Yess! Busted them and threw away over $2000 for 1.5 kg of my NPP raw.

I am not buying anything until this crackdown situation settles. They would sell dog shit right now because some desperate brewer will buy it.

Horrible joke I know, but makes you wonder if they are selling to brewers or bakers.

Get a 20% refund at least. Problem is you have no idea what the other 20% is.

Thanks for sharing the results.

 

[Luka.Halotestin]

It usually ends up like this:

"Dear, I check with the lab."

"Dear, the lab say it is ok."

"Dear, the lab say they test it 99%."

"Dear, the lab refuse to give refund."

 

[readalot]

Could use solvent recrystallization to clean up and then confirm HPLC purity. Send vendor your clean up bill. If it is flour/sawdust etc would be easy to cleanup. But as you say, unacceptable.

 

[readalot]

Relevant thread.

M

Post in thread 'Save your unusable raws Guaranteed.'

Oct 30, 2025

Ethyl Acetate/n-heptane batch with test e is done. Yield was great, only about a 2% loss. Started with 10g and ended with 9.8g. After hot filtering, solvents had to be reduced down quite a bit before it would drop out in freezer. Caution, ethyl acetate stinks to high heavens and lingers.... smells just like a nail salon. But at least it was all done using all class 3 solvents

• mongo5165

• 
• 

 

[Sampei]

These are two test, GCMS and HPLC, ran on the same NPP sample.

As you can see GCMS showed only NPP. @Sampei told me it was wrong.

HPLC later showed NPP slightly below 80%.

Can someone with more knowledge about lab testing elaborate on this? Is GCMS just wrong or is there something more to it?

@readalot explained perfectly, to be honest I knew it was wrong but I worded it badly. I didn't mean Jano was wrong I meant it wasn't the real picture of your raw, because in a time like this no one has something that purr and I believe not even before when raws where flowing left and right, you were going to find raws that were 100℅ perfectly pure. 98% with small trace of contamination? Sure.

100℅ pure? Naaaaa

 

[readalot]

@readalot explained perfectly, to be honest I knew it was wrong but I worded it badly. I didn't mean Jano was wrong I meant it wasn't the real picture of your raw, because in a time like this no one has something that purr and I believe not even before when raws where flowing left and right, you were going to find raws that were 100℅ perfectly pure. 98% with small trace of contamination? Sure.

100℅ pure? Naaaaa

Really cool example of GCMS telling you something even when "purity" is "100%" when compared to HPLC result.