Here is what might be a good procedure:
1) pulverize the straw as much as possible. submerge in water brought to a pH between 2.5 and 3. let stand for several hours (overnight, but not days).
2) filter through a stainless mesh to get the big chunks
**) IDEALLY you would filter it through a second, smaller mesh filter, like those sometimes used in coffee makers (not a paper coffee filter, but more of a plastic, small mesh filter) like this:
http://www.amazon.com/Cuisinart-GTF-Gold-Tone-Filter/dp/B0001IRRLG/ref=sr_1_2?ie=UTF8&s=kitchen&qid=1231326450&sr=1-2
3) filter throught an actual coffee filter (paper). make sure that the coffee filter you are using does not have small holes. these ones typically DO NOT have holes, but are so thin that several must be used:
http://www.amazon.com/BUNN-BCF250-Commercial-Coffee-Filters/dp/B0006VNO7Y/ref=sr_1_24?ie=UTF8&s=kitchen&qid=1231326450&sr=1-24
the type pictured here (the one on the top of the pile) typically DO have holes:
http://www.dkimages.com/discover/previews/774/172387.JPG.
the holes are there so that a small amount of the small-grain ground coffee beans actually go into the pot. this is NOT desirable for the process described here.
4) you now have (most likely) a TON, probably a liter or 2, of an acidic, filtered, poppy pod extract.
you want to concentrate it.
bring the pH up to about 8 (near the pH range where the morphine is not soluble in the water). why this pH? the double bond in the morphine is NOT sensitive to base (hydroxide). nor is any other part of the molecule. at a pH of 8 (or, really, even 9) there is no acid left, and the pH is not high enough to "deprotonate" any of the weakly acidic carbon acids on morphine (all of which have pka values above 20, so it doesnt matter anyway).
realistically, you could probably bring the pH even higher than that without being concerned (again, because morphine is pretty inert to base), but considering the small quantity that you will likely end up with, it is probably better to be paranoid and stick to a safe pH.
if you follow my advice here, you can nearly boil the solution. yes. i wouldnt recommend it, but it is done ALL THE TIME. again, the solution (at the pH I mentioned) is pretty inert to morphine.
it would probably be best (safest) to do this at a lower temp, somewhere near 70 C or maybe even a bit higher. concentrate it WAY down.
how much should you have in the end?
if 100 grams of straw was used, and (for the sake of simplicity) the morphine content was 1%, there will be 1 gram of morphine in the solution. the solubility of morphine HCl is about 20 mg/mL (it is actually a little bit more) at room temp (higher at higher temps)
that means, you will want no less than 50 mL of solution. so, basicallly, concentrate the HELL out of it.
continued in next post