A system, device, and a method for determining a compound content in transformer oil are provided. The method includes positioning a syringe filled with transformer oil in the device to transfer the oil to a vial using the device. The device includes a stand, a threaded rod, a handle, a disc, and a syringe holder. The threaded rod is movable in a vertical direction by rotation of the handle and is configured to apply pressure via the disc on a plunger of the syringe positioned in the syringe holder to maintain an airtight connection between the vial and the device. The compound content is determined using a gas chromatograph by analyzing an aliquot extracted from a headspace gas of the vial.