Due to some PM requests, Swim wants to post where he is now with this procedure for this given OTC product.
Recall that Swim was obtaining roughly 190mL of GBL per 500mL of remover, however GHB resulting from this was an odd paste like consistency, off colour, and funny tasting.
Swim observed that the tan colour in his product was forming only with the addition of 10M NaOH to the remover. It seemed as though the NaOH was hydrolysing another compound in the remover, which in turn was moving into the aqueous layer with the GBL, and ending up in the final product.
To summarize the remainder of the post for those beez who only have a slight interest, and don't want full experimental details:
a) Swim was able to simply use dh2o washes to remove GBL from the remover, and leave behind a huge chunk impurity was reacting with NaOH and showing up in the final NaGHB product. Technique results in 50mL loss of GBL being recovered (per 500mL)
b) Swim was able to further tweak his washing to obtain a highly pure product subjectively identical to one made with pure GBL. Technique results in an additional 30mL loss of GBL per 500mL (ie 110ishmL being recovered instead of 190).
Technique 1:
1) 500mL of product placed into a seperatory funny, and washed 3 times with distilled water (250mL, 250mL, 125mL). Water layer stays on top, garbage stays on the bottom.
2) The three washes are collected, and reacted with 10M NaOH to pH 7 and excess water boiled off to collect NaGHB (s) according to standard procedure
It's as simple as that!
Observations: The product is whiter, a much harder consistency, and no longer has an odd aftertaste, so obviously the impurity is not pulled into the water washes, and the water washes can be safely reacted with NaOH. Yield calculations show roughly 140-145mL of GBL being obtained per 500mL of product (so around a 50mL loss of GBL). However, product _still_ has a touch of yellow colouration when a quantity of it (50-100g) is dissolved in distilled water (!)
Swim however has observed that the first 250mL water wash is cloudly, while the second and third washes are clear. So swim decided to try the following:
- Washing 500mL of remover with 3x250mL of distilled water. As per usual, first wash is cloudy, while 2nd and 3rd are clear. The first wash is put aside while the second/third washes are combined and reacted with NaOH.
- Results: Product is the picture of perfection, however calculations show that only 110mL of GBL now being recovered. Obviously, a) some GBL is in the first wash, and b) none or trace impurity is in the 2nd/3rd washes.
Swim has now been trying to stepwise determine the minimum amount of dh2o needed in the 1st wash to prevent any impurities from showing up in the second/third washes. So far swim has tried using 125mL and 150mL for the first wash. In both cases, yield of GBL only goes down by around 5mL, (ie 130-135mL recovered) while bulk impurity is removed. Impurity still shows up in the final product, so Swim (when time permits) will try and gradually increase the water used in the first washes, to try and establish the amount of water to use to maximize impurity removal while minimizing GBL loss.
Hope that helps those out there who have been PMing Swim. If anyone out there has any suggestions for how to optimize the H2O washings, please post your suggestions!