For the optimization of the eluent/column combination, a solvent standard and a matrix-matched standard at a medium concentration range (Level 6; Table ) were used. SRM1950 (Metabolites in Frozen Human Plasma) and SRM3672 (Organic Contaminants in Smoker's Urine) were purchased from the National Institute of Standards & Technology (NIST, Gaithersburg, USA). In addition, 24 h urine samples from a food intervention study performed in 2021 with four individuals (two female and two male) collected at three different time points (three different days) were tested. For details, kindly refer to . Furthermore, urine samples from Nigerian women sampled in 2016 were investigated. This longitudinal sample set was already analyzed before on biomarkers of mycotoxin exposure . Therefore not all samples from the original study were available due to limited sample volumes. The sample set included 77 spot urine specimens from four time points (morning and evening over two days) of 23 mothers. All samples were stored at -80°C until analysis. The Nigerian study was approved by the Ethics committee of Babcock University in Nigeria (BUHREC294/16) and the Austrian samples were collected following approval by the University of Vienna ethics committee under the authorization number #00650.