Lower potency tinctures not testing right

Hey hey!
I have been having an issue with lower potency tinctures. My analytics department seems to struggle with anything that is below 25mg/g. Has anyone else had this problem? This is the case with all kinds of batch sizes. At first I thought we were potentially degrading CBD through our side of the process but everything else typically tests out fine- which indicates otherwise. Let’s discuss!

In house?

If the problem is with the analytics then we need the one doing the analysis here.

Unless you can tell us exactly what they are doing…

My guess is they are simply not injecting enough material/are diluting too far before injection.

GC? hPLC? TLC?

See?!?

If for instance your analysis dept is using a GC & following @srihugh1’s protocol, and are taking a 100ul sample of your “strong” tincture, they need 2or3x that for your weaker ones.

Yes, in house. HPLC, not sure of their methods. I can discuss and get back with you

Trained chemist?

Or just someone following a recipe?

If it’s a trained chemist, they should be able to solve this. Either way, playing telephone is not the efficient route to a solution. Getting them on here directly is my suggestion.

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When do you become a chef :slightly_smiling_face:

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They are trained. I understand that’s not an ideal form of communication… Apparently they prep the samples the exact same way as higher potency tinctures. They are going to try and play around with increasing the amounts as you suggested. In my opinion, they should have solved this issue a very long time ago- which is why I’m fed up with it and jumping on here now.

Can I ask how much you’re paying them then?

Because a trained chemist that has been told repeatedly that there is an issue with detection and hasn’t resized the injection/changed the dilution factor needs to find a new job imo.

(So you’re right, sending them here might get them beat up).

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Hire me instead…

Edit: understand that holding my tongue is not one of my greatest skills :shushing_face:

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Cutthroat!! Haha yeah these are definitely concerns I have thrown out there.

I’ll keep that in mind.

Yeah, I figured someone on here would be honest about it. It’s hard, they definitely have tenor here but I have butted heads with this person a lot. I run the product R&D dept and always have issues with this person testing my stuff. My background in chemistry may not be in analytics but it’s strong enough in that area to be able to help problem solve. Of course they get defensive about it… So it’s nice to hear some ideas that aren’t coming from me directly. Hopefully they will be taken better.

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If they haven’t already covered these things…

Check their limit of detection and limit of quant - especially if they only have a single set dilution. They are probably below either of those so things come out wonky.

I agree with @cyclopath if your “chemist” can’t manage to look at the dilution process, LOQ/LOD and then change the dilution or extraction process to fix this, they need to go. This is basic method development - the method should even be specific for lowest and highest concentrations that can be tested and what dilutions need to happen to have things fit within the calibration curve.

25mg/g it totally doable - that’s 25000ppm!! Most HPLC can detect down to 5ppm, if not lower. So its just a prep issue, IMO.

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Just an update! The increase in sample size totally worked. Thank you! On the other hand…I’m assuming that if you have a super high potency tincture then you should use a smaller sample size? Their high potency tincture tests are coming back high.

You should use the SAME sample size for the higher potency - but do a dilution. That way your sample prep stays consistent. And you only need to do the dilution if your peak saturation is above 150% of your highest calibrator.

Feel free to ping me if you have more questions. These are just best practices for analytical chemistry - so its not a secret or anything. :slight_smile:

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Right on!! Thank you!