The assay measured matrix effects separately from extraction recovery. A suppressed instrument response and loss during sample preparation are different problems, even when both can influence the final cannabinoid signal.
The authors used distinct comparisons
In meconium, reported matrix-effect values included 78% for THC and 79% for CBD, where 100% represented no matrix effect. Cord values for the validated analytes were closer to that reference, ranging from 91% to 94%. Extraction recoveries were reported separately and differed by analyte.
These percentages concern laboratory response under tested conditions. They are not percentages of maternal dose transferred to the fetus or retained in either neonatal specimen.
Do not combine unlike percentages
A matrix-effect percentage describes how co-extracted material changes ionization response relative to the comparison used. Recovery concerns how much analyte survives a preparation step. Multiplying or averaging the two without the method’s definitions does not reconstruct a clinical concentration or biological transfer fraction.
Interpret the validated result
Calibration, internal-standard behavior and accuracy checks determine whether the complete workflow reports concentrations acceptably. A raw response effect alone does not prove that every final result is biased by the same amount. The study supports matrix-specific analytical interpretation while leaving individual exposure timing and clinical outcomes unresolved.
Related reading: interpreting cannabinoid assay validation.
Research cited
Jensen and colleagues (2019). Detection of in utero Exposure to Cannabis in Paired Umbilical Cord Tissue and Meconium by Liquid Chromatography-Tandem Mass Spectrometry. DOI: 10.1016/j.clinms.2019.01.002.
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