<sod >As much as 100 grams of nerve agent may have been used in the poisoning of former Russian spy Sergei Skripal and his daughter Yulia.< eod>< sod > The international chemical weapons watchdog has backtracked on a suggestion as much as 100 grams of nerve agent may have been used in the poisoning of former Russian spy Sergei Skripal and his daughter Yulia.< eod>