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 dried blood spot update: still an important bioanalytical technique? This article discusses the benefits of dried blood spot sampling and the recent issues that have emerged when this technique is used in the regulated quantitative bioanalytical environment. The author explores what the way forward might be for this important technique and what some of the unexpected benefits of this change in sampling methodologies have been.
{"Chemical": []}