The electronics industry needs ultra-high purity gases in order to manufacture products. In some cases, impurities cannot exceed 1 ppb. High-purity N-2 is the main product (in terms of volume) used in this area (for example to ensure an inert environment for the manufacture of chips). Such a pure gas requires particular attention during its production, storage and distribution. Typically, this ultra-pure nitrogen is produced by a plant installed on the customer's site, which may involve cryogenic distillation plus purification techniques for achieving the purities required. In the case of unit failure or a peak in consumption, ultra-pure nitrogen can be provided by a back-up storage located near the plant. In some cases, cryogenic plants produce only ultra-pure gaseous N-2. The back-up storage then has to be fed from trucks with standard liquid N-2 produced by a non-electronic unit. Typically, this standard liquid N-2 (LIN) contains impurities such as CO and O-2, because ppb cryogenic distillation is not achieved by non-electronic units. Since it is more convenient for the customer to have a high-purity back-up, Air Liquide has developed a dedicated solution to purify standard liquid nitrogen withdrawn from trucks: CO and O-2 are removed by adsorption through a cryogenic ultra-purifier, specially designed far electronics requirements. Ultra-pure liquid nitrogen is then fed to the storage unit. This cryogenic technique involves a simple operation: purification of the LIN during withdrawal from the truck to the back-up, in a manual mode, carried out by the truck driver. The efficiency of our cryogenic ultra-purifier has been checked by APIMS measurements in order to validate purification at the ppb level. The paper presents the technical and economical aspects of this new solution, and compares it to already existing techniques. (C) 1997 Elsevier Science B.V.