You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

A practical quantification method for Heinz bodies in birds applicable to rapid response field scenarios. Oil-induced oxidative injury to red blood cells results in Heinz body hemolytic anemia. Here, we evaluated three Heinz body staining techniques in brown pelican (Pelecanus occidentalis) blood. Using a range of in vitro acetylphenylhydrazine incubations, we validated a field-adapted technique against laboratory wet-mounts and verified the stability of this technique for one month following preparation. Employing this technique during petrochemical spill responses allows for delays between sample collection and analysis.
{"Chemical": ["acetylphenylhydrazine"]}