Introduction: Surfactants can be classified into cationic, anionic and nonionic ones. Benzalkonium chlorides are cationic surfectants and being widely used as a disinfectant and germicide using their strong protein-denaturing action. Especially in hospitals, 10 % solution of benzalkonium chloride mixture is being usually used; it is diluted to – % solution to be used for various types of disinfection. The drugs are contained in gargles and preservative solutions for contact lenses. Fatal benzalkonium chloride poisoning cases, in which the 10 % solution had been ingested, were reported [1, 2]; it can be regarded as one of the most important poisons. | Benzalkonium chlorides by Kazuhiro Koyama and Yoko Shimazu Introduction Surfactants can be classified into cationic anionic and nonionic ones. Benzalkonium chlorides are cationic surfectants and being widely used as a disinfectant and germicide using their strong protein-denaturing action. Especially in hospitals 10 solution of benzalkonium chloride mixture is being usually used it is diluted to solution to be used for various types of disinfection. The drugs are contained in gargles and preservative solutions for contact lenses. Fatal benzalkonium chloride poisoning cases in which the 10 solution had been ingested were reported 1 2 it can be regarded as one of the most important poisons in daily necessities. As poisoning symptoms a pungent sense of the oral mucous membranes sore throat cyanosis convulsion and coma can be mentioned 3 4 . Benzalkonium chlorides are the mixture of multiple analogous compounds. To measure the concentration it is necessary to combine concentrations of each component. The quaternary ammonium salt benzalkonium chlorides can be expressed as C6H5CH2N CH3 2R Cl where R is the mixture of C8H17-C18H37. In most cases the major R s are C12H25 C12 C14H29 C14 and C16H33 C16 especially according to the National Formulary XVI C12 C14 and C12 C14 count more than 40 20 and 70 respectively 5 . Therefore upon analysis of benzalkonium chlorides it seems necessary to measure at least the C12 and C14 compounds Figure . O Figure CH3 ch2-n - ch2 h-ch3 cr CTh benzyldimethyldodecylammonium C12 CH3 ch2-n - ch2 i3-ch3 cr ch3 benzyldimethyltetradecylammonium C14 CH3 ch2-n - ch2 15-ch3 cr ch3 benzyldimethylhexadecylammonium Cie Structures of main components of benzalkonium chlorides. Benzalkonium chlorides are a mixture of quaternary ammonium salts showing the structures of C6H5CH2N CH3 2R Cl where R is a mixture of C8H17-C18H37. However main structures of R are C12H25 C12 C14H29 C14 and C16H33 C16 C12 S 40 C14 S 20 and C12 plus C14 S
