Chemistry |
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2007, No. 2
A.P. Bobrov, S.V. Tsaplin, P.P. Purygin
Techniques of clearing of metal details from lubricants are developed by solutions of surfactants and quality assurance of degreasing, their detergent power is investigated and analysed. Factors of interfacial tension of water from the additive of sintamid-5, volgonat, OP-10, DS-10 sintanol solutions are experimentally determined. On a basis a spline interpolation of experimental results parabolic dependence of factor of interfacial tension on concentration of additives is determined. Interfacial tension of a solution DS-10 sintanol is investigated by introduction in a solution of various salts of sodium. Critical concentration of micelle formation and their superficial activity have been calculated for various surfactants. The degree of clearing of various details is determined by solutions of surfactants and high efficient detergent power of these details is found out by solution OP-10.
R.V. Shafigulin, A.V. Bulanova
PLC OF SEMI-FERMENTATED GRADES OF TEA
An reverse-phase HPLC method with gradient elution for the quantification of catechins in semi-fermentated grades of tea is developed.