Boric Acid Could Improve Portable Cannabis Testing

Testing cannabis outside a conventional laboratory sounds simple until scientists have to distinguish cannabinoids that look remarkably similar from an electrochemical perspective. That challenge becomes especially important when testing needs to happen quickly, whether in a field, processing facility, cultivation operation, or regulatory inspection. Now, researchers have identified a surprisingly simple chemical interaction that could give portable cannabis sensors a new way to tell some of these compounds apart, the key ingredient being boric acid.

Research¹ in the Microchemical Journal reports that boric acid can selectively interact with the acidic cannabinoids THCA and CBDA, producing distinctive analytical signals that are not seen with their neutral counterparts. The finding could provide a new foundation for developing faster, lower-cost electrochemical tools for cannabis screening. Let’s dive into the research and what the future of cannabis testing may look like.

Why Cannabis Testing Needs Better Sensors

Cannabis testing traditionally relies on sophisticated laboratory techniques, including chromatography and mass spectrometry. These methods can provide highly detailed cannabinoid profiles, but they generally require specialized equipment, trained personnel, controlled laboratory environments, and sample preparation. This creates a practical limitation when testing needs to happen somewhere other than a laboratory. For instance, cultivators may want to evaluate plants before harvest, while processors may need to assess incoming material, and regulators may need preliminary information at the point of inspection. In each situation, a portable screening technology could provide valuable information before a sample is sent for comprehensive laboratory analysis.

Electrochemical sensors are attractive for this purpose because they can potentially be made smaller, faster and less expensive than traditional laboratory instrumentation. There is a problem, however, as structurally similar cannabinoids can produce overlapping electrochemical responses, making distinguishing individual cannabinoids difficult. A sensor may detect that cannabinoid-related compounds are present without being able to confidently determine exactly which compounds are responsible for the signal. The emerging research addresses that problem in an unexpected way.

How Boric Acid Interacts With THCA

The researchers found that boric acid selectively binds with the acidic cannabinoids THCA and CBDA. The interaction involves the cannabinoids’ carboxylate group and phenolic oxygen, allowing boron to form a stabilized tetrahedral complex with the molecule. In simpler terms, boric acid essentially gives the sensor a new chemical feature to recognize.

This matters because THC and CBD do not undergo the same complexation under the conditions examined in the study. As a result, the acidic cannabinoids generate analytical characteristics that distinguish them from their neutral counterparts.

The researchers supported the proposed interaction using multiple analytical techniques, including differential pulse voltammetry, fluorescence measurements, and ^11B nuclear magnetic resonance spectroscopy. This combination moves the finding beyond simply observing that boric acid changes a signal to providing evidence for why the signal changes at the molecular level.

A New Way to Distinguish Cannabis Cannabinoids

The most interesting aspect of the research may not be that boric acid reacts with THCA and CBDA. It is that the reaction creates a new analytical signature. When the acidic cannabinoids form the borate complex, the researchers observed the emergence of a distinctive high-potential oxidation peak using differential pulse voltammetry. The neutral cannabinoids THC and CBD did not display this same feature because they did not form the corresponding complex, and that distinction could be extremely useful for sensor development. Instead of relying solely on the natural electrochemical behavior of cannabinoids, which can overlap, future sensors could potentially use boric acid complexation as a selective chemical recognition mechanism.

This is a fundamentally different approach to the problem.The sensor would not simply show whether a sample produces a cannabinoid signal, but whether that signal corresponds to an acidic cannabinoid capable of forming the complex. That additional layer of chemical selectivity could make portable cannabinoid testing considerably more informative.

What This Means for Hemp and THC Testing

One potential application is distinguishing high THCA cannabis from low THC hemp. This has been particularly challenging within current laboratory testing because THCA is the acidic precursor to THC. As cannabis plants mature and are processed, the relationship between the acidic and neutral forms becomes important when determining the chemical profile of the material. A portable method capable of selectively recognizing THCA could provide an additional screening tool for cultivators, regulators, and laboratories.

While the study provides a mechanistic foundation for sensor development, it does not establish that a commercially available handheld device can replace validated laboratory testing just yet. Instead, the significance lies in opening a pathway toward that possibility.

Portable Testing Before Harvest and Processing

Portable cannabinoid sensors could also have practical value throughout the cannabis supply chain. Before harvest, growers could potentially use field-based screening to gather rapid information about cannabinoid development. While in processing, producers could use portable measurements to screen incoming plant material or monitor changes in cannabinoid composition. That could make testing significantly more responsive. Rather than collecting a sample, transporting it to a laboratory and waiting for results before making every decision, producers could potentially use portable screening to identify samples that require closer examination.

The technology could also complement laboratory analysis. A rapid field test could serve as an initial screen, while detailed chromatographic testing could provide the definitive cannabinoid profile when greater accuracy is required.

Regulatory and Forensic Cannabis Testing

The same principle could have applications in regulatory and forensic settings. Inspectors may encounter cannabis plants, extracts, or other materials that require rapid preliminary characterization. A portable electrochemical sensor could eventually provide an inexpensive first-line screening method before samples undergo comprehensive laboratory testing. Forensic applications could similarly benefit from tools capable of rapidly distinguishing acidic and neutral cannabinoids.

Why THCA and CBDA Matter During Testing

There is another reason preserving information about acidic cannabinoids matters: decarboxylation. THCA can convert to THC when exposed to heat, while CBDA can similarly convert to CBD. That means the chemical profile of cannabis can change during drying, heating, extraction, and other processing steps.

If testing focuses only on the neutral cannabinoids after decarboxylation has occurred, some information about the original acidic cannabinoid profile may be lost. A method that can selectively detect THCA and CBDA before they are converted could therefore provide a more complete picture of the material being tested. That could be particularly valuable when analyzing fresh or minimally processed cannabis, where acidic cannabinoids represent an important part of the plant’s cannabinoid profile.

The Future of Portable Cannabis Testing

The broader significance of this research is not that boric acid suddenly becomes a cannabis-testing solution by itself. It is that researchers have identified a relatively straightforward chemical recognition mechanism that could help solve one of electrochemical cannabis testing’s biggest problems of distinguishing compounds with similar structures and overlapping electrochemical behavior.

The study’s evidence suggests that boric acid complexation gives THCA and CBDA a different analytical identity from THC and CBD. The resulting electrochemical, fluorescence, and NMR signatures help explain the molecular basis of that selectivity. That knowledge gives sensor developers a mechanism they can potentially build upon. Future research will need to determine how well this chemistry performs in real-world cannabis samples, how selective and sensitive portable devices can become, and whether the approach can withstand the complexity of commercial cannabis products and environmental conditions.

But the concept is compelling. If researchers can translate the chemistry into reliable portable devices, cannabis testing could eventually become faster, more accessible, and more capable of preserving the chemical information that conventional field screening can miss. For portable cannabis testing, the breakthrough may not be a more complicated sensor. It may be finding the right chemical interaction to make a difficult cannabinoid distinction easier to see.

References:

^{1. Filippo Lugli, Alessandro Monari, Monica Caselli, Erika Ferrari, Davide Vanossi, Iuri Camilli, Martina Campi, Laura Pigani, Analytical determination of cannabinoids in Cannabis Sativa L.: the key role of boric acid complexation, Microchemical Journal, Volume 229, 2026, 119269, ISSN 0026-265X, https://doi.org/10.1016/j.microc.2026.119269}