The primary method for assessing cannabis and hemp potency is by High-Performance Liquid Chromatography (HPLC). Most ISO 17025 certified labs will use an HPLC for cannabis analysis. Does this mean cannabis and hemp professionals should take the accuracy of HPLC results for granted?

First, let us set the record straight. An HPLC yields analysis results based on estimations. Just like other analytical chemistry methods it is also prone to errors. The accuracy of an HPLC depends on multiple factors, such as the skills of the individual operating it, the analytical protocol being applied, and the state of the hardware itself. Did the laboratory technician prepare the samples properly? When was the last time the HPLC was calibrated? Has the protocol been validated? Were the results interpreted correctly?

Even when samples are carefully chopped up and homogenized, variations in potency measurements of about 20% are not uncommon. A European study involving 40 labs found that around one third of results were either more than 29% greater or more than 29% lower than the mean value. Even worse precision could be expected if the measurement error, caused by the sampling and extraction process, were to be included.

Another study published in the United States showed that infrared spectroscopy can yield results with an accuracy of 1.5X to 2X greater than HPLC. This may be since infrared spectroscopy avoids the complex sample preparation necessary for HPLC analysis which is subject to human error. The GemmaCert device, based on spectroscopy, does not require any sample preparation for potency analysis. The risk of human error is removed and there is also $0 sample waste.

Cannabis and hemp professionals must be wary of misleading results even when the analysis was conducted by an HPLC in a certified lab. To be on the safe side, businesses should adopt in-house testing practices to support decisions. Reducing the dependency on laboratories will also save time and money.

Spectroscopy may be the smarter choice for in-house quality monitoring, regulatory risk mitigation, product refinement and process measurements. Laboratories will also benefit from a boost in credibility and reputation if they adopt spectroscopy to monitor the quality of their results. The industry will gain most when consumers can be assured of product quality and label accuracy. For this to happen, and the sooner the better, the dependency on a single primary method for cannabis and hemp analysis must be reduced across the supply chain from seed to sale.