Ketoacidosis is an extreme and uncontrolled form of ketosis, which is a normal response to prolonged fasting. Embodiments of this in vention test the ketone level of a patient by measuring the ketone bodies in breath condensation. Some embodiments include a device for medical testing comprising a hollow container, comprising powder mixture of sodium nitroferricyanide, ammonium sulfate and silica and a liquid including an ammonium hydroxide solution.