Kava Science Using Acetone for Measuring Extraction Efficiency

[HeadHodge]

I've been studying for shits and giggles the use of spectrometers to measure the results of acetone tests for the detection of the mystical orange color indicating the presence of tudei.

I've also been goofing around with different extraction techniques, like the use of hot water, sonic excitation, blenders, double washes, etc.

But the problem I'm having is how can I tell which extraction method is pulling the most lactones from the root?

I've read that even though people are using acetone for tudei detection, it also appears to be an efficient way to extract lactones in general from the kava root. If you use acetone to extract kava the results are lactones suspended in the acetone which gives the acetone a yellowish or golden color.

Since yellow is in the visible spectrum of light it would be easy to use a cheap spectrometer to measure not only the wavelength of the yellowish color but also the magnitude (saturation) as well.

So my theory or actually just wondering out loud... If I used my multiple extraction methods using the same batch of kava, I wonder if I could then apply some acetone to the resulting grog to extract the lactones in the grog and then subsequently measure the color of the acetone with my spectrometer to measure the relative effectiveness of my extraction techniques?

Any thoughts from the chemists out there would be appreciated.

 

[verticity]

Quantitive measurement of total kavalactones would be hard to do, because what you see in the visible spectrum is a little bit of kavalactone absorbance, obscured by flavokavain absorbance, which absorb better in the visible, although their concentrantion is much lower. A UV spectrum might give you a better idea, since that's where the majority of the KL absorbance is. Again, the FKs also absorb in the UV, but their concentration is much smaller than KLs.

As a rough relative estimate, you could just dissolve kava in acetone, centrifuge, remove the acetone, allow the acetone to evaporate, and weigh the crud that is left (the extract).
Now a single step extraction will contain other stuff besides KLs, so this would only be a relative measurement.
To get more accurate, you would have to add one or more purification steps.
For one step, you could just wash the extract with water to remove stuff that is water soluble (which KLs are mostly not). Let it dry.
For a second step, to remove FKs and other things that are less polar than KLs, you could dissolve the extract in methanol, place it in a separation funnel, also place some n-hexane in the funnel, shake it, shake it, shake it, and allow the methanol to drip out leaving the hexane which will have removed a lot of the FKs. (Ethanol wont work because it is miscible with hexane, weirdly). Let it dry again. Weigh it. The weight will be lower because you have removed some stuff that is not KLs. Or, at this point you could dissolve in acetone, and measure the UV spectrum, also. The UV spectrum after these 2 steps would just be determined by the KLs, since most of the FKs would be gone.

Separation Funnel:
https://en.wikipedia.org/wiki/Separatory_funnel
https://en.wikibooks.org/wiki/Struc...Chemistry/Methods_of_Separation_and_Isolation

 

[verticity]

Here is a nice summary of organic purification methods:

 

[HeadHodge]

@verticity don't you really mean IR instead of UV?

 

[verticity]

@verticity don't you really mean IR instead of UV?

No, for this use case (quantifying total KLs, not trying to figure out KL profile), I mean UV.

 

[HeadHodge]

No, for this use case (quantifying total KLs, not trying to figure out KL profile), I mean UV.

any idea of the required spectrum ranges?

 

[verticity]

any idea of the required spectrum ranges?

300-400 nm? there are UV spectra in one of Lebot's papers... (the one that 'validates' the acetone test)
But, really, if you can get it pure enough, it is easier just to weigh it.

 

[verticity]

If you measure US absorbance, even integrated absorbance over the whole range of UV, your result might be dependent on the KL profile, since different KLs have different absorbances. So you would have to do both IR reflectance to determine KL profile, and UV absorption for the total. Weighing is best.

 

[HeadHodge]

If you measure US absorbance, even integrated absorbance over the whole range of UV, your result might be dependent on the KL profile, since different KLs have different absorbances. So you would have to do both IR reflectance to determine KL profile, and UV absorption for the total. Weighing is best.

So what does the visible yellow color in the acetone represent?

 

[verticity]

So what does the visible yellow color in the acetone represent?

Flavokavians and 2 of the kavalactones that are visible in a visible spectrum (I can't recall which ones at this time--yangonin maybe? I know kavain is not visible)