Piperacillin EP Impurity T;(2R,4S)-2-(carboxy((R)-2-(4-ethyl-2,3-dioxopiperazine-1-carboxamido)-2-phenylacetamido)methyl)-3-((2S,5R,6R)-6-((R)-2-(4-ethyl-2,3-dioxopiperazine-1-carboxamido)-2-phenylacetamido)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carbonyl)-5,5-dimethylthiazolidine-4-carboxylic acid;