The following software was used for creating figures and performing statistics. Figures were created with ggplot2 (version 3.3.2) and the statistical tests of the linear regression model were carried out in RStudio (1.4.1717) using R (version 4.1.1). OriginPro 2021 was used to create correlation plots and to perform an ANOVA analysis to control if there was a significant difference between both measurements (confidence level = 95%). For the ANOVA analysis, only samples were considered where the analyte was present in both analyses within the calibration range above the LOQ. Moreover, the R package patron ) was utilized for suspect screening. Conversion to mzML files was performed using ProteoWizard ) and the files were split according to instrument polarity. Process blanks were selected as blank measurements and all 24 urine samples were used as samples. The "openms" algorithm was applied for peak picking and grouping. The parameters were as follows: noise threshold = 8E3, chromFWHM = 3, minFWHM = 1, maxFWHM = 30, chromSNR = 5, mzPPM = 3. In a subsequent filtering step, features with an intensity < 3E5 or a minimum feature intensity above blank <5 that were present in <25% of all samples were omitted. The candidate list was derived from the EPA's ToxCast library with >4000 analytes used in the ENTACT trial ). An m/z window of 0.001 was defined for the suspect screening. The protonated molecule [M+H] + and the deprotonated molecule [M-H] -, and the elements C, H, N, O, P, S, Cl, and Br were utilized to generate molecular formulas in genform,. The algorithm metfrag ) was used to generate compounds. Using annotateSuspects, the suspect screening output was complemented with the generated peak list, formula, and compound data. Depending on the rank and scores (isoScore, individualMoNAScore) of the formula and compound candidates, an identification level based on was suggested. No MS2 data was acquired, therefore, the highest assigned confidence level was 4b (good formula isotopic pattern match). This confidence level is assigned to a feature if it is: the top ranked formula candidate, the isoScore is >0.9, and the score is at least 0.2 higher than the next best-ranked candidate. The confidence level 5 was attributed to all other features as these did not match any criteria. The main focus of this study was to compare sensitivity in a targeted manner using reference standards and not to annotate analytes in a non-targeted fashion, therefore acquisition of fragmentation data was not performed.