Fig. 1.

Schematic representation of run order within batch for the HAPO Metabolomics study. Data include 1200 analytical samples (400 maternal fasting, 400 maternal 1-hour, 400 newborn cord serum) of interest and 300 QCs (150 maternal, 150 newborn) processed in 50 batches of 30 samples each. Maternal samples placed at the beginning, middle and end of each batch are labeled M1, M2 and M3, respectively. Newborn (or baby) samples placed at the beginning, middle and end of each batch are labeled B1, B2 and B3, respectively. In a batch of total size 30, maternal QCs were placed at run order 1, 15 and 29 and newborn QCs were placed at run order 2, 16 and 30. Maternal / newborn sample triples were run in sequence with 8 sets of triples included in each batch