Twenty-four urine samples collected from Nigerian women were analyzed with the same high-and low-resolution LC-MS configurations as the reference standards (Table , Table ). Typically, approximately ten different analytes were detected in each sample with high-resolution mass spectrometry, whereas about 17 analytes were observed on the more sensitive QQQ instrument in each sample (Figure ). On average, each analyte was present in eight (HRMS) and ten samples (QQQ). In total, 40 different compounds were identified in the tailored, targeted approach. Ten compounds were exclusively detected with the lowresolution instrument, thus 30 individual contaminants were also identified by the HRMS assay. Excluding matairesinol (present in 7 samples), these analytes were usually only observed in a few samples (maximum 3). Nearly half of the analytes (40%) that were solely detected in the low-resolution measurements were from the category of endogenous estrogens. Other analytes not present in the HRMS analyses included the mycotoxins aflatoxin B1 and aflatoxicol, the plasticizer BPA, the plastic component tetrabromobisphenol A, isobutylparaben, and matairesinol. For all the urine samples analyzed with the low-resolution assay, the targeted analytes were observed 415 times. Conversely, in the high-resolution analyses approximately 60% of the analytes were not detected (n=240) (Figure ). A quantitative result was achieved for approximately 60% and 75% of all detected analytes in high-and low-resolution mass spectrometry, respectively. Thus, the discrepancy between the number of analytes detected by highand low-resolution mass spectrometry widened with approximately 55% less quantitative information obtained from the HRMS experiments. For the analytes detected in a sample with both methods, at a concentration within the calibration range and a confidence level of 95% (p > 0.05), the concentrations in the high-resolution data were not significantly different from the low-resolution results (Figure ). When the QQQ values (x-axis) were plotted against the high-resolution results (y-axis), the correlation between both data sets was excellent with an R2 of 0.98. However, a slope of 0.81 indicates an underestimation of the concentration in HRMS compared to QQQ. A similar trend was observed by and a higher likelihood of isobaric interferences in QQQ and the higher LOQs in HRMS were suggested as possible causes. A plot of the quantitative concentration in the low-resolution measurement against the area determined in the high-resolution measurement revealed a good correlation with a R 2 of 0.91 (Figure ). Nevertheless, the area, which is often applied in the evaluation of high-resolution data, is in good agreement with the concentrations derived from the primarily quantitatively used lowresolution approach. To highlight the versatility of high-resolution measurements in additional toxicants beyond the pre-determined target list, additionally, a preliminary suspect screening was performed. Only features detected in at least 6 of the 24 urine samples (25%) were considered. The search resulted in 57 and 418 features that matched 59 and 589 suspects in positive-and negative-ion mode, respectively (Table , Table ). The number of candidates was higher than the number of features as several isomers with identical m/z values were included in the suspect list; thus, for one feature multiple candidates might be possible.