A potency test needs to separate the compounds of interest from other ingredients in the product. Analakkattillam and colleagues developed a reversed-phase liquid chromatography method to measure CBD and THC in hemp oil products. They used a C18 column for separation and an ultraviolet detector operating at 214 nm.
The authors assessed specificity, accuracy, precision, linearity, range and robustness. Those checks address different potential sources of error. Precision describes how closely repeated measurements agree. Specificity addresses whether the method can measure the target in the presence of other components. The authors applied the assay to products including oils, tablets and soft gels.
When reviewing a result, identify the matrix the laboratory validated and the range over which it demonstrated acceptable performance. This study evaluated a product assay. A measurement in blood or oral fluid would require a method evaluated for that specimen and its expected concentrations.