In a cannabis extract, the major cannabinoids can be present at concentrations far above the minor compounds. One dilution can bring an abundant analyte into the instrument’s calibration range while pushing a minor analyte below the level the method can quantify.
McRae and Melanson coupled LC–MS/MS with a broad calibration range and multiple dilutions of plant extracts. They reported a quantifiable range of 0.002 to 200 mg/g in plant material for the method. They also evaluated performance in a candidate cannabis reference material and measured precision across seven cannabis samples.
Ask which dilution supplied the reported result for each analyte and whether its instrument response fell within calibration. A minor compound that falls below the quantification limit in a highly diluted extract may still be quantifiable at a lower dilution. The method’s coverage depends on both the calibration and the dilution used.
McRae and Melanson, Analytical and Bioanalytical Chemistry · PubMed record