Here we have the long awaited pic of rue harmala citrates crashed from butyl acetate! (Summer happened and the test ideas got greatly simplified.)
Beaker on the left has relatively light fluffy stuff, yellow in suspension and orange-brown in bulk when still moist with solvent. On the right, a denser, olive-brown, clumpy material. Both display a similar fluorescence as seen in Loveall's photo.
This material was prepared by drip-leaching rue bases (precipitated from rue tea using ammonia) with butyl acetate through a cotton wool filter plug in a glass pipette. Black, insoluble material remained trapped in the filter. A differential solubility was observed (although whether this was noted down is another matter entirely... [EDIT:
here they are!]) and this is what gave rise to the two fractions as seen in the photograph. One of them dissolved first, it doesn't entirely matter which, but it could at least be observed by the relative colour of the material in the extraction tube.
To the two resulting batches of orange-yellow solution was added a saturated solution of citric acid in moistened butyl acetate ('CASBA').
Moist butyl acetate was prepared by repeatedly shaking 100mL butyl acetate, fresh from the tin, in a stoppered measuring cylinder with ca. 2mL of distilled water several times for about ten seconds each time, followed by a short pause to allow droplets to settle. After this became too boring and it looked like no more water was being absorbed, a saturated citric acid solution was prepared by dripping the moist butyl acetate through another glass filter column with a cotton wool filter plug, this time filled with citric acid. The packet claimed this was anhydrous citric acid but that seems a tad spurious; it may well have been the monohydrate. Its hydration level was not assessed.
It is possible to be reasonably confident about the solution being saturated because the unused CASBA deposited crystals of citric acid quite readily owing to some evaporation of the solvent during storage, as well as the preparation method being a reasonable guarantee of producing a saturated solution.
The material in the photo is what remains after allowing the precipitates to settle and removing the supernatant.
Rinsing with fresh butyl acetate should remove any excess citric acid from solvent residues and evaporation thereof. If the solubility of citric acid is insufficient for this cleanup, a rinse with anhydrous acetone will be attempted, where there is a better solubility, but the solubility of harmala citrates in acetone is yet to be determined (as far as I'm aware).
More data to follow. Time for a pull from the seeds with BA, and I ought to get that chroma sorted too. Little (tiny) column is ready and waiting to be packed.