Determination of isopropanol (isopropyl alcohol)

Isopropanol (C ₃ H ₇ OH, isopropyl alcohol) is used in industry and clinical laboratory diagnostics as a solvent. It is less toxic than methanol and ethylene glycol.

Isopropanol poisoning is observed in clinical practice not often. Upon ingestion, isopropanol is rapidly absorbed and metabolized by alcohol dehydrogenase to form acetone, CO _2, and water. The half-life of isopropanol is approximately 3 hours, a lethal dose of 250 ml is considered. The clinical picture of poisoning is manifested by dizziness, greased speech, headache, nausea, vomiting, abdominal pain, hemorrhagic gastritis, diarrhea, ataxia, arterial hypotension, stupor and coma. Later, bradycardia, rhabdomyolysis and hemolysis develop. The concentration of isopropanol in the blood above 40 mg% is regarded as severe intoxication, at a concentration above 100 mg% coma develop, a lethal concentration above 350 mg%. Severe metabolic acidosis and a high anion interval often accompany poisoning with isopropanol, but are not specific. Lactatacidosis and high concentration of acetone in blood and urine are characteristic. The presence of acetone in blood and urine, especially in high concentrations, in patients in a coma suggests poisoning with isopropanol.

Methanol, ethylene glycol and isopropanol are metabolized similarly to ethanol and also cause metabolic acidosis, although the true metabolic products of these alcohols are different.

Characteristic of the toxic effect of various alcohols

Alcohol	Metabolites	Acidosis	Ketosis	Clinical manifestations
Ethanol Ethylene glycol Methanol Isopropanol	Acetaldehyde Glycolic aldehyde Glyoxal Formaldehyde Formiat Acetone	+++ ++ -	+ - - ++	Alcoholic ketoacidosis Renal insufficiency Blindness Hemorrhagic tracheobronchitis, gastritis

[1], [2], [3], [4]