A Certificate of Analysis (COA) is the primary document consumers rely on for transparency and safety in the CBD industry. This report provides the results of third-party laboratory testing, confirming cannabinoid content and checking for potential contaminants. Understanding technical jargon like the Limit of Quantitation (LOQ) is central to interpreting these results, as the LOQ is a specific analytical threshold that determines the reliability of the measurements listed.
The Definition of LOQ
The Limit of Quantitation (LOQ) represents the lowest concentration of a substance that a testing method can measure accurately and with acceptable precision. This threshold is established during testing validation to ensure the reported number is reliable. Below the LOQ, measurement uncertainty is too high for the laboratory to confidently state the exact amount present.
Think of the LOQ like a highly calibrated scale used for measuring ingredients. If the scale is designed to measure items 1 gram or more, it can accurately report 1.5 grams. If you place an object weighing only 0.05 grams on the scale, the result will be imprecise, and the lab cannot quantify it reliably.
For CBD products, the LOQ applies to various substances, including cannabinoids (CBD and THC) and contaminants (heavy metals or residual solvents). A result above the LOQ is considered a verified concentration, providing a numerical value that meets predefined goals for bias and imprecision. This standard ensures that any reported figure on the COA is scientifically sound.
The Difference Between LOQ and LOD
The LOQ is often confused with the related analytical term, the Limit of Detection (LOD). The key difference lies in the level of certainty and precision required. The LOD is the lowest concentration of a substance that can be reliably distinguished from a blank sample or background noise, meaning the lab is only confirming the presence of the substance.
The LOD is always a lower concentration than the LOQ because detecting a substance requires less analytical rigor than accurately measuring its exact quantity. If you were trying to identify a faint sound, the LOD is the point where you first hear the noise, confirming it exists. The LOQ, by contrast, is the point where the sound is loud enough to accurately measure its decibel level with a meter.
If a substance is present between the LOD and the LOQ, the lab knows it is there but cannot report an exact numerical value with confidence. For example, the instrument may confirm the existence of a trace amount of a pesticide, but the concentration is too low to quantify precisely. The LOQ provides the necessary stricter threshold for producing meaningful quantitative data in the COA.
What LOQ Means for CBD Product Quality
When reviewing a COA, the LOQ translates the technical capabilities of the lab into practical consumer information. A result listed as “