However, some of these substances can be found in a routine analysis without being the result of poisoning. Substances such as acetone and 2-propanol, among others, can be endogenous in origin. Several papers [15–17] have been published dealing with the detection of these two substances in post-mortem cases. 2-propanol appears in blood in the case of diabetes, starvation, dehydration, chronic use of ethanol, or ketosis by acetone metabolization [16], and so its identification may be important to diagnose the cause of death. In many cases acetone is detected as a metabolic product resulting from the oxidation of 2-propanol by hepatic alcohol dehydrogenase [17]. Acetaldehyde may appear in the routine analysis because it is the main metabolite of ethanol. It is also forensically interesting because it can be used as a marker of sample putrefaction [18,19].