Three-dimensional liquid chromatography with parallel second dimensions and quadruple parallel mass spectrometry for adult/infant formula analysis

•First report of 3D-LC, LC × 2LC, with quadruple parallel mass spectrometry, LC3MS4.•First report of dual parallel second dimensions with mass spectrometry in each.•Multi-cycle (aka “constructive wraparound”) chromatography demonstrated.•Transferred eluent dilution used to sharpen peaks.