Tiosulfato

Tiosulfato is an inorganic compound with the chemical formula S2O32-. It is a polyatomic anion consisting of two sulfur atoms, three oxygen atoms, and two sulfur-oxygen bonds. Tiosulfato is a reducing agent, meaning it can donate electrons to other compounds, and it is commonly used in analytical chemistry for titrations and as a preservative in the food industry.

The tiosulfato ion is formed when hydrogen sulfide (H2S) reacts with sodium thiosulfate (Na2S2O3), a process that occurs naturally in some environments. It is also produced industrially by the reaction of sodium sulfide with oxygen. Tiosulfato is a weak acid, with a pKa value of approximately 1.8, which means it partially dissociates in water to form bisulfite (HSO3-) and hydrosulfite (HS-) ions.

In the food industry, tiosulfato is used as a preservative to inhibit the growth of bacteria and mold. It is particularly effective against Clostridium botulinum, the bacterium responsible for botulism. Tiosulfato is approved for use as a food additive in many countries, including the United States and the European Union, under the designation E221.

Tiosulfato is also used in analytical chemistry for titrations. It reacts with iodine to form triiodide (I3-), which can be titrated to determine the concentration of iodine in a solution. This reaction is the basis for the iodine titration method, which is used to determine the concentration of various substances, such as starch and glucose.

Tiosulfato is generally considered safe for human consumption when used as a food additive, but like any chemical, it should be handled with care. It can cause irritation to the skin, eyes, and respiratory system, and it may be harmful if ingested in large amounts. It is also a strong reducing agent, which means it can react with other chemicals to form potentially harmful compounds.