Sensitive and selective quantification of glyphosate and aminomethylphosphonic acid (AMPA) in urine of the general population by gas chromatography-tandem mass spectrometry.

Glyphosate is the highest volume herbicide used worldwide, and its main biodegradation product is aminomethylphosphonic acid (AMPA), both are listed as priority substances in the Human Biomonitoring for Europe (HBM4EU) initiative which aims at improving policy by filling knowledge gaps by targeted research. The objective of the current study was to advance the sensitivity of an existing gas chromatography-tandem mass spectrometry analytical method to measure environmental population exposures. A 50% lower limit of quantification of 0.05 µg/L was achieved for both analytes by slight modifications in sample work-up, and use of another isotope labelled internal standard. In a pilot study, 41 urine samples from the general German population were analysed, of which glyphosate and AMPA could be quantified in 66% and 90% of the samples respectively, which is sufficient to reliably describe distributions of urinary concentrations in the non-occupationally exposed population.