The Ghost Trap DS-HP column has an activated charcoal packing to trap impurities and contaminants from HPLC system parts and solvents, and can significantly reduce the appearance of ghost peaks. It is most effective when installed after the mixer, and lasts for 500 or more gradient runs. Working pH 2-12, maximum pressure 100 MPa (14,500 psi). Dead volume of approx. 60 uL.