Matrix Effects of Urine Marker Substances in LC-MS/MS Analysis of Drug of Abuse.
Therapeutic drug monitoring February 1, 2024 Bernd Huppertz, Silke Möller-Friedrich, Klaus Baum 10 citations
Polyethylene glycol (PEG) molecules with 6 to 12 repeating units, used in the Ruma urine marker system, can suppress the signal of certain drugs during LC-MS/MS analysis, depending on their retention times. At a PEG concentration of 20 mcg/mL, the matrix effect fell below 60% for all drugs except nortilidine, and all drugs remained detectable. Quantification error was under 15% for drugs with deuterated internal standards and under 32% for those without. Sample preparation methods did not clearly reduce the effect, likely due to similar solubilities of PEGs and analytes.