Our drug checking service has some limitations that you need to know about
Please be aware that FTIR spectroscopy has some limitations. The FTIR Spectrometer shines an infrared laser at the sample to create a unique light spectrum. Our technicians use reference databases with over 15,000 substances to match what your sample is.
If multiple substances are detected, the software we use can also estimate the approximate amount (%) of each. These percentages are estimates and may not accurately indicate the potency/strength of your substance which can also vary per individual.
While this form of technology is ideal for high volume drug checking, it has a limited ability to test certain types of samples, and also only provides an estimate of the amount of each substance present.
The FTIR has a detection limit of 5%. That means that we cannot detect anything present under 5%. This could include unexpected or dangerous substances!
Test strips also have some limitations. They do not indicate what analog is present, the test strips do not tell you the amount of the substance being detected, and there is sometimes a chance for false or invalid results.
If you are interested in the different drug checking technologies out there, please consult the BCCSU’s drug checking evidence report.
FTIR Limitations
Must be in library database
Our technicians can only identify substances which are already listed in our reference libraries. These libraries do include over 15,000 substances and are regularly updated, but some novel drugs and organic substances will not be listed. If a sample has no possible matches, we list it as no library match.
5% detection threshold
The FTIR has an estimated detection limit of about 5%. This is only an estimate and the limit of detection could vary slightly per sample and per technician. Any substance present at concentrations below this detection limit may not be detected. These could be toxic, they could change the potency of your drugs and cause unexpected effects.
We can use test strips to determine the presence of fentanyl and some other substances which are potent at extremely low doses.
The 5% detection limit effects our ability to test potent samples with low doses, like some pills or drugs on blotters. These samples usually have active ingredients below our detection limit. It also limits our ability to test liquid samples, as the active ingredient is usually less than 5% of the solution. This means we may not be able to test most liquid samples or accurately identify their contents.
The detection limit also means we cannot test complex mixtures like organic material or drugs in food. Organic matter like cannabis and salvia are mixtures of hundreds of compounds and they only appear as uncertain carbohydrates and oils on the machine.
If we detect a substance at levels close to our detection limit we may not be able to identify it, we will list these as “uncertain match”. In cases where we cannot match substances, we will use our experience to try and provide as much information as possible on what it may be, but cannot guarantee its validity.
Percentage estimate limitations
We sometimes provide a percentage range for various substances in a sample. These are estimates based on software and technician experience. The FTIR does not separate and measure each individual substance, therefore percentage estimates given may not be accurate or consistent. These estimates can vary between technicians and between samples. Potency may vary between samples with similar test results. Be aware of these limitations and use these figures as a general guideline only.
We do not include percentages if only one substance is detected. Values listed as N/A are substances we were unable to assign a percentage to.
Sample mixing and variability
Poor mixing and inconsistent production can mean that a small sample does not represent the entire substance. (Testing a small portion of a pill does not guarantee that the rest of the pill is exactly the same.) The results and percentage estimates we provide cannot account for the entire substance the sample was taken from. If samples have been stored in the same bag or in direct contact with each other this can also produce inconsistent results.
Test Strip Limitations
We use test strips to detect the presence of three substances which are potent at extremely low doses. Those are fentanyl, benzodiazapene and lysergamide (LSD).
These test strips are originally designed to detect substances and their metabolites in urine, they aren’t specifically designed for drug checking. As a result there are limitations of which you should be aware.
Do not indicate what analog is present
We rely on test strip results to confirm if potent substances are present below our 5% detection limit. The test strips are specific for certain substances and ones that share similar structures (analogs). We cannot confirm what specific analog was detected, only if it is present or not. These structurally similar analogs could be less potent or even stronger then what the test strip is meant to detect. (For example, the fentanyl test strips will show positive for both fentanyl or carfentanil – a substance which is 100-200 times stronger than fentanyl.)
Do not tell you the amount of the substance being detected
When there is a positive result, it simply means that the substance or an analog is present. If it did not appear on our FTIR then we know it is below our 5% detection limit. Fentanyl strips can show positive to around 0.001%. Due to this broad detection range, test strip results do not indicate anything about the concentration of the substance in question.
The 3 test strips we use and their detection thresholds
Fentanyl: 20ng/mL
Lysergamide: 50ng/mL
Benzodiazepine: 300ng/mL
Risk of false or invalid results
The strips may malfunction and provide false positives – a positive results when the drug is not actually present. A test strip can appear positive when a substance that has a similar structure to the drug that is being detected is present. This is called cross reactivity.
Our technicians are trained to be aware of this. We use our experience, repeat tests and use our knowledge of cross reactive compounds to perform these tests as accurately as possible.
There is also the possibility of false negatives – negative results when the drug being detected is actually present. These can happen when the drug is present at trace quantities in the sample or when dealing with analogs that the test strip is less sensitive for and does not detect as easily. (For example, the test strips are less sensitive for 3-methyl fentanyl or carfentanil, compared to fentanyl.)
We do our best to keep our testing solution in an ideal concentration window and as thoroughly mixed as possible to help mitigate this. Sometimes, the test strip is too difficult to interpret or the test strip does not function with certain substances. We log these results as invalid.
Other considerations
Your experience with a drug has many influencing factors. Therefore, if your results do not align with what you experienced, this could be due to something else. We often refer to the 3S’s in harm reduction:
Setting
This is where, how and with who you are using. Are you taking the drug with friends? alone? are you comfortable? are you stressed? are you upset? – All of these can cause different experiences when taking the same substance again at the same dosage.
Substances
Dosage? You’ve used multiple times this week? Are you consuming multiple substances? Is the substance cut with anything? Different route of consumption? – Differences in your substances, how much you take, how you take it and how often you’ve been taking a substance can cause different experiences, even when in the same setting.
Set
This is what you are bringing to the experience, your current physical state and mindset. What is your knowledge and experience with a drug? Your age? Last meal? Hydration? Alertness? Current mental and physical health? – This will always change and depending on where your body is at, your drugs could create a different experience despite the same setting and the exact same substance.