Sample Logistics
All samples were received over a period
of 1 year in five batches. Each batch was measured shortly after reception
of the samples. Before the start of the measurement, the samples were
stored at −80 °C. The number of samples per batch were
respectively 152, 100, 125, 200, and 125 for batches 1–5. A
workflow summarizing the sample and data analysis is presented in Overview of the sample
preparation and data analysis strategy for
serum samples. Abbreviations: DHS-VTT-GC-MS, dynamic headspace vacuum
transfer in-trap gas chromatography coupled with mass spectrometry;
FDR, false discovery rate; nparLD, nonparametric analysis of longitudinal
data; SPE, solid phase extraction.