ND, "not detected", means that the lab's method saw no signal for that compound at or above its limit of detection. It is a statement about the method's sensitivity as much as about the sample. A lab with an LOD of 0.1 µg/g and another with 0.005 µg/g can both report ND honestly on samples that contain very different trace levels.
In practice
When a COA shows ND for a pesticide, look for the LOD or LOQ printed beside it and the action limit that applies. "ND (LOD 0.01 µg/g)" is informative; a bare "ND" on a page with no limits or methods is not. In potency results, ND for a minor cannabinoid such as THCV usually just means it's below the panel's limit. It doesn't prove the plant can't make any.
Don't confuse with
- <LOQ: detected, but too low to put a reliable number on.
- Pass: a result below the regulatory action limit; a detected value can still pass.
- 0.00%: some reports print zero for ND; it still means "below LOD".
The LOD (limit of detection) is the lowest amount of a compound a method can reliably tell apart from zero, but not necessarily measure accurately.A COA (certificate of analysis) is a lab's signed report of what it measured in a specific sample, such as cannabinoids, terpenes, moisture and contaminants, with methods and limits.The LOQ (limit of quantitation) is the lowest concentration a method can measure with acceptable accuracy and precision; below it a result is reported as <LOQ.A cannabinoid is any compound that binds the body's cannabinoid receptors or shares the typical cannabis terpenophenolic structure; the plant-made ones are phytocannabinoids such as THCA and CBDA.THCV (tetrahydrocannabivarin) is the propyl-chain (C3) analogue of THC, formed by decarboxylating THCVA; it is a minor cannabinoid in most cultivars but notable in some African-derived lines.A pesticide panel screens a cannabis sample for a defined list of pesticide residues, typically by LC-MS/MS and GC-MS/MS, reporting each against its action limit.Measurement uncertainty is the quantified range around a lab result within which the true value is expected to lie, typically stated as ± a value at about 95% confidence.
