A Two Step method in cleaning up Gummy candies or Chocolates based Food Items for the isolation of CBD/THC compound(s) in GC-MS

Typically, crime laboratories are starting to receive commercially packaged food products which resembled candies or baked goods of various types. These include chocolate bars, pieces and colorful fruit chewy candies. Chocolates are generally easier than those sticky gummy candies. The use of methanol makes this the best choice for extracting samples for CBD/THC since it works very well for e-cigarette cartridges. So the first choice should be the use of methanol as your extraction solvent. Unfortunately, there is a lot of interfering substances sometimes in the data which makes it hard to isolate a suspect CBD/THC compound

I. Cleaning up Chocolate based food items for the Analysis of CBD/THC by Gas   Chromatography-Mass Spectrometry (GC-MS)

The first part is that chocolate based candies and bars are typically easier to deal with during extractions. The CBD/THC appears to dissolve readily into the batter of chocolate based cakes or candy bars.

To set up extraction for chocolates based samples, take about 1-2 cm x 1-2 cm square and place it into a weight boat or use a 13 x 100 mm test tube (the only reason I don’t suggest the test tube is that everyone wants to centrifuge the sample). Liberally wash the sample with mass spectroscopy grade methanol. Try to keep the methanol at a minimum, but just let it soak for about 5 minutes. If it appears to dry out or be absorbed by the chocolate add a little more methanol. If you let it sit too long or vortex your sample too long, it will become cloudy since it will pick up some of the fats or other excipients. Decant off the methanol into a test tube or if you have a lot, transfer methanol into an aluminum pan so that you can gently heat it over a hot plate. At this point you can take some sample and dry it into a spot plate and perform a chemical Duquenois test to test for cannabis. Dry down enough so that you can fill two insert/liners about ? way up (300-400 uL) for the GC-MS 2 mL vials. This will give you two separate samples for running on two different instruments. Amazingly, you will get a very decent separation. If you don’t like the excipients that are present you can go to my final clean-up protocol, otherwise this should be sufficient for chocolate based samples. 

II.  Cleaning up gummy candies including the sugar coated varieties for analysis by GC-MS

 Most of the gummy candies I believe are probably coated rather than mixed in the matrix of the candy so by gently mixing or rinsing the surface or cuttings, the potential presences of CBD/THC should readily be extracted out using methanol. It does not make any sense to manufacture gummy candies when the base candies are available. So it would seem  rather complicated by trying to emulsify the candies to extract out the CBD/THC oil.

1. Cut out a 2 cm x 2 cm or if you have a rope type candy cut two pieces of 2 cm long.
2. Place theses into a weight boat or test tube and soak with a small amount of methanol.
3. To visualize this in a test tube cover the sample with methanol, but don’t overload.
4. Gently mix and add more methanol if it appears to dry out, but don’t let this sample sit too long, no more than 5-10 minutes.
5. If you let it sit too long, the food color dyes will come out.  This should not be a problem if you plan on the clean-up protocol in the next section.
6. At this point, take a sample for a quick color test to determine if you have cannabis or concentrate down you sample in an aluminum pan over a hot plate at low heat to about 1 mL or enough to place into a 2 mL insert/liner and place into a GC-MS vial. Run the analysis on the GC-MS.    

III. Cleaning up your sample for your CBD/THC from your Extracted gummy candies or chocolates. 

1. To proceed with this step, take your samples from either step I or II where the sample has been soaking in the methanol. Decant or transfer the methanol extract to either an aluminum pan or a 10 x 75 mm test tube and dry this down to completeness either on a hot plate at low heat for the aluminum pan or in an oven (90o C) for the test tube. Do not let it sit too long on the hot plate or you will caramelize the residue.
2. Prepare you extraction solution by labeling a new 10 x 75 mm test tube and add about 1 mL of CH2Cl2, dichloromethane or chloroform.
3. Add about ? mL or 20 drops of fresh concentrated NH4OH (ammonium hydroxide) to above tube (#2). You should have a nice two layer solution with the dichloromethane on the bottom layer. This is your ANOR reagent (Alternate Non-Organic Ratio) extraction procedure. Vortex this for about 30 seconds.
4. Remove the top layer of your ANOR and dispose the ammonium hydroxide. Save this tube and set aside.
5. Take your dried test tube or pan and add the content of step III-4 ANOR reagent to it. Swirl it gently in the pan or vortex the tube gently.
6. Transfer the content by pouring it or pipetting it to a new clean aluminum pan.
7. Heat this over the hot plate to dryness. There should be no or little residue.
8. Take off hot plate and add a minimum amount of methanol and swirl this.
9. Transfer the methanol to a GC-MS insert/liner to about ? way up. If you have too much left over gently heat to evaporate off the excess. Place it inside a 2 mL GC-MS vial and analyze for the presence of CBD/THC.  Inject 2 uL in the GC-MS.