SampleAliquot aliquot = workflowExecutor.createAliquotFromParent(sample); aliquot.setVolume(((VolumeStep) aliquotHandlingSteps.get(3 * i + 1)).getVolume()); aliquot.setConcentration(((ConcentrationStep) aliquotHandlingSteps.get(3 * i + 2)).getConcentration());