What kind of ethanol are you using? 190 or 200 proof? Have you compared a 3 hour soak to a sample thats been soaked for 1 hour three times? 1 hour sonication three times to extract a tiny sample seems like overkill to me. Adding a little chloroform to your extraction solvent can also increase extraction speeds.
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thats a given! always clean your stuff in general. liquinox is a life saver
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I think you’re trying to hard here. Sonication for over 30 minutes seems excessive IMO. Not to mention that noise can drive a person crazy after a while.
In our lab we take a representative sample, break it up into a weigh boat by hand, weigh out 500 mg, dilute that in 9:1 MeOH Chloroform, sonicate for 15 minutes, vortex, filter, then dilute into a sample vial. MeOH and Chloroform are really good at extracting what you want in this time frame but if you let them soak longer it will begin to draw out more undesirables and could possibly even degrade your analytes.
Doing anything more labor intensive than this seems like a waster of money, time and energy. If this is just for in house analytics during pheno hunting a relative number is all you will really need. If you’re unhappy with your results then just retest with a new sample or 3! You said these results are going to be confirmed with third party? I really don’t see the need to get OVERLY scientific with your grinding process if that’s the case.
@CannabinoidChemist
Second this. 15 minutes with MeOH at room temperature is enough. Even sonicating is excessive and rather causes problems - it breaks up cells causing more waxes being disolved; they plug the HPLC column and streak peaks at the beginning of the run; unnecessary strain on your pump and guard column.
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My HPLC is reading everything high it seems like. I have tested RSO over 90% and I have had 3rd party come back with 70’s is it possible for higher potencys to be off even when they are on the cal curve and the r values are .999? Its really blowing my brain when the products on the lower portion of the cal curve are fairly accurate. Maybe changing the concentration of high potency products will adjust results? If anyone has experienced this and can advise it would be greatly appreciated.
How are your standards checks? Are they off too? It should be really easy to tell. 1mg/mL standards will be way above your calibration curve, so you will be able to confirm high levels (create dilutions towards the high end of your curve and check) - if commercial standard is off, then it is your calibration curve or standard dilution. If the standard is within 1-2% of what it should be, then your calibration curve is fine and it is something else. You can buy a standard for ca. $60. It would be my first thing to check. It is entirely possible that your calibration curve is wrong. You can have R2 0.999 and the curve may still be comletely wrong. For instance, if you bought a standard initially from a bad company, or the standard wasnt kept in freezer and used right away for calibration curve. These standards are not very stable and also the solvent evaporates way too quickly at room temperature. If that happened and you built a curve based on such standard, then it was say 1mg in 0.95ml (50uL evaporated) then all your readings would be minimum 5% lower, and vice versa if THC in your standard decomposed because of wrong storage, youd get higher readings even though building a 0.999 curve.