Both in the field of veterinary drug residue analysis and sport doping the continuous development of new techniques is necessary in order to follow the rapid changes in illegal use of drugs. In the Netherlands 4 years ago a large project was started to reduce the illegal use of growth promoting drugs. The basic concept behind this project was to develop new screening and confirmation technology with the highest possible chance to trace new illegal drugs. In order to improve the methods used at that time worldwide we have developed in addition to the immunoassay based-systems also analytical systems based on receptor technology which allow screening based on biological activity and not on structure. As an example the ß-agonists and oestrogenic steroid screening system will be discussed, showing the very broad range of screening enabling new compounds to be traced. In addition the existing confirmation systems are based on a combination of EI and CI low resolution GC/MS and EI high resolution GC-MS developed to trace compounds above 0.2 ppb. An important improvement would be to change the confirmation system into an LC-MS/MS procedure because this will be more flexible, faster and cheaper. Currently the criteria are being developed to achieve the acceptation of this approach in the EEC. Examples and the overall strategy will be discussed.