The analysis of samples taken by UN inspectors in Syria probing alleged use of chemical weapons could take \"up to three weeks,\" the Organisation for the Prohibition of Chemical Weapons (OPCW) said Saturday. \"The evidence collected by the team will now undergo laboratory analysis and technical evaluation,\" said the group based in The Hague where the team arrived Saturday. \"These procedures may take up to three weeks for completion in a systematic, orderly and objective manner.\"