Organoarsenical (3-nitro-4-hydroxyphenylarsonic acid, 3-NHPAA) used as s feed additive for broiler chickens in order to control coccidial intestinal parasites, thereby improving feeding efficiency.![](../../../../../Public/Data/sp/Image/Roxarsone_structure.gif) Keywords: Pharmaceutical materials , Trace elements, Organometallics, Speciation analysis, Arsenic speciation |