A method of controlling a sample separation apparatus, for separating a fluidic sample using a mobile phase provided from at least one mobile phase container, includes determining a weight and volume reduction behavior according to which weight and volume of mobile phase in a mobile phase container are reduced during conveying mobile phase from the mobile phase container in the sample separation apparatus, and determining a tare weight of the mobile phase container based on a gross weight information, a volume information, and the determined weight and volume reduction behavior. The gross weight information is indicative of an initial gross weight of the mobile phase container including its mobile phase, and the volume information is indicative of an initial mobile phase volume in the mobile phase container.