Kava (Piper methysticum) is a perennial shrub native to the Pacific Islands.Traditionally kava was used for medicinal and cultural purposes but gained popularity as a medication for anxiety in other countries.The lifting of the kava importation ban in Australia will increase the substance's availability in the country.Kava is a depressant with similar effects to those of alcohol and its prolonged misuse could result in undesirable health effects.Therefore, it is important to have a tool to measure kava uptake at a population scale for public health purposes.This research presents a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the detection of dihydrokavain, dihydromethysticin, desmethoxyyangonin, kavain, yangonin, and potentially methysticin, as well as the human urinary metabolites p-hydroxy kavain and p-hydroxy-7,8dihydrokavain in wastewater.Influent wastewater samples were extracted with ethyl acetate using the liquid-liquid extraction (LLE) technique.The method validation criteria assessed were linearity, precision, accuracy, matrix effect, recovery, stability, and filtration loss.The correlation coefficient (r) values recorded for all the analytes were above 0.995.The intra-day and inter-day precision values had coefficients of variation of less than 15%.Accuracy was generally also within the acceptable range, including at 20% for the nominal limit of quantification (LOQ) values.The addition of preservatives to wastewater samples prolonged the stability of the analytes.Application of the method to influent wastewater collected in South Australia resulted in the detection of all targets analytes with daily excreted loads ranging between 0.1 and 28.1 mg/d/ 1000 people.
Makanye et al. (2026) studied this question.