The gas-liquid mass transfer coefficient k(L)a for gas-liquid countercurrent flow in a packed column with a novel internal was measured using the absorption of oxygen. A correlation formula for predicting k(L)a that shows a satisfactory agreement with experimental results is presented. The mass transfer coefficient is directly proportional to the liquid hold-up, which depends on the structural parameters of the internal, the superficial liquid flow velocity and the porosity of the packing bed. A suitable internal should be made of many springs of small diameter. (C) 2004 Elsevier B.V. All rights reserved.