Determination of Retention Factors of s-Triazines Homologous Series in Water Using a Numerical Method Basing on Ościk's Equation

Liquid Chromatography in Studying Lipophylicity and Bioactivity of Pesticides

“…In the method the values of log k org, log k and x org are known (experimentally evaluated) and log k w parameter is determined by numerical fitting to equation 14 to obtain the linearity between the left term denoted as G and x org . We tested numerical method for different groups of substances, using various mobile and stationary phases by thin-layer, overpressured-layer and column reversed-phase chromatography techniques [Janicka, 2003;Janicka et al, 2006;Janicka, 2007) and numerical log k w parameters proved to be very good lipophylicity descriptors linear correlated to experimental and calculated log P values and moreover, in contrary to extrapolated, almost independent of the range of organic modifier concentration in the effluent.…”

Some problems of the optimization of the separation process in liquid chromatography

“…One of them is linear extrapolation of the relationship between log k and composition of the aqueous mobile phase -volume fraction of the organic modifier in aqueous mobile phase (logk=f(x 1 )). This method is not precise, because the linear relationship between log k values and volume fraction of the organic modifier exist only in limited range (for small concentration of organic modifier the relationships do not exist) [27,28]. Janicka and Kwietniewski show that the Ościk's equation can be used for determination log k w values successfully [27][28][29][30][31].…”

“…This method is not precise, because the linear relationship between log k values and volume fraction of the organic modifier exist only in limited range (for small concentration of organic modifier the relationships do not exist) [27,28]. Janicka and Kwietniewski show that the Ościk's equation can be used for determination log k w values successfully [27][28][29][30][31]. Because in literature in QSAR studies log k w are used, the equation 9a can be described as follows: On the basis of the equation 9b and described procedure, log k w values were determined for many groups of the solutes and compared with logP values.…”

Application of various methods to determine the lipophilicity parameters of the selected urea pesticides as predictors of their bioaccumulation

“…[1,2] Numerous research papers that have been published during the last years confirmed that the lipophilicity has significant impact on toxicity of organic compounds including pesticides and also on their bioaccumulation. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The relationship between bioaccumulation coefficient (K d ) of these compounds and partition coefficient (designated, e.g., as K ow or logP) determined by the use of proper method (theoretical or experimental) shows that described lipophilicity may correlate with bioaccumulation profile of pesticides according to Eq. (1):…”