A spearman correlation matrix was created to showcase the power of our approach for deriving possible impacts of exogenous exposures on the endogenous metabolite, that are of high interest for further thorough mechanistical studies. Various significant correlations between xenobiotics but also xenobiotics and metabolites were demonstrated (Figure ). Mainly analytes detected in many samples, e.g., mono butyl phthalate, ethylparaben, MEHP, benzophenone and enterolactone, yielded significant correlations, probably due to the higher statistical power. High correlation coefficients were observed for monobutyl phthalate and MEHP (0.72), ethylparaben and p-hydroxybenzoic The human biomonitoring (HBM) guidance value was added in red. C) Extracted ion chromatograms (XICs) of selected analytes, including corresponding MS2 spectra of experimental samples and authentic reference standards. Variation of analyte concentration in six individuals for selected xenobiotics demonstrate severe exposure dynamics and the need for longitudinal sampling design acid (0.64), benzophenone-1 and enterolactone (0.74), and propylparaben and methylparaben (0.59). MEHP and monobutyl phthalate are both urinary biomarkers of phthalate exposure with estrogenic potential . The preservatives ethylparaben and p-hydroxybenzoic acid were likely to be an ingredient in the same type of personal care products and also methylparaben and ethylparaben may be present in similar products. Enterolactone, a biotransformation product of plant lignans originating from, e.g. flaxseeds and sesame , and the urinary biotransformation product of benzophenone-3, benzophenone-1, a UV-filter used in cosmetics , clearly have different sources. However, both are hormonally active and have a shared mechanism concerning obesity antagonism. This was demonstrated to be associated with late onset of puberty in girls .