抄録
The amount adsorbed and the mode of adsorption onto cellulose products of benzalkonium chloride (BC) were determined in an effort to estimate a possible reduction by adsorption of the concentration of this disinfectant in solutions in actual use.
BC in aqueous solution was quickly adsorbed onto cellulose products, a quasi-equilibrium being attained in a matter of 10 minutes of contact.
Under these conditions the adsorption of BC was shown to take place according to the Langmuir's adsorption isothermal line. The maximum quantity of BC adsorbed as estimated from the Langmuir's formula was 6.4 mg/g of absorbent cotton, 4.5 mg/g of cotton balls and 3.1 mg/g of gauze.
When 5 g of cellulose products are immersed in 100 ml of 0.025% BC solution, the final concentration of BC as calculated from the Langmuir's formula is reduced to 0.0073% with absorbent cotton, 0.0133% with cotton balls, and 0.0188% with gauze. In order to secure a final BC concentration of 0.01%, respective initial BC concentrations of 0.030%, 0.020% and 0.014% are required for absorbent cotton, cotton balls and gauze. By the same token, in order to secure a final BC concentration of 0.025%, respective initial BC concentrations of 0.051%, 0.040% and 0.032% are required.
These results clearly indicate that BC, having a remarkable liability to be adsorbed onto cellulose products, it is necessary to pay due regard to this property of the disinfectant in determining its concentration in the solution to be used.
