Using Mini Canna Lab with alcohol or glycerin based tinctures takes a bit more effort but it can still yield useful results. The main issue is the test fluid is also alcohol based, so it does not mix, there are a few work arounds.
The best solution is to prepare the sample as usual, weigh 100 mg (.1g) and then keep the lid open, allowing the alcohol to evaporate overnight. When the alcohol has evaporated completely, then add the test fluid and use the chart as normal. If you do not see any residue in the bottom of the test tube after evaporation, you can assume the test will be less than 1% and not waste the test.
The main problem with testing and an alcohol or glycerin tincture, or even an oil infusion, is the final product is often less than 1%. The test will not quantify under 1% . Many infusions are between 1% and 4%. Very rarely are they over 5% unless they have been double infused. If you know the product is under 1% and you just want to see the profile of cannabinoids, you can double or triple the sample, (200 to 300 mg) allow the alcohol to evaporate. Check for residue and then add testing fluid and continue as normal. This reading will give you a profile but not an accurate reading of percentage.
A second method of testing an alcohol-based tincture, is to add a pinch of lecithin granules to the test tube with the sample and test fluid. Shake it vigorously and pull the pipette immediately. This will also give an accurate reading, but again, the samples are often under 1%. This method of testing is the only way to test a glycerin sample.