Capacity factors, liquid chromatography

Solvent optimization in reversed-phase liquid chromatography is commenced by selecting a binary mobile phase of the correct solvent strength to elute the seuaple with an acceptable range of capacity. factor values (1 < k <10 in general or 1 < k < 20 when a larger separation capacity is required). Transfer rules (section 4.6.1) are then used to calculate the composition of other isoeluotropic binary solvents with complementary selectivity. In practice, methanol, acetonitrile and tetrahydrofuran are chosen as the selectivity adjusting solvents blended in different... 

Sherblom, P.M., Eganhouse, R.P. (1988) Correlations between octanol-water partition coefficients and reversed-phase high-performance liquid chromatography capacity factors. J. Chromtogr. 454, 37-50. 

Hamisch, M., Mockel, H.J., Schule, G. (1983) Relationship between log Pow shake-flask values and capacity factors derived from reversed-phase high-performance liquid chromatography for n-alkylbenzenes and some OECD reference substances. J. Chromatogr. 282, 315-332. 

Vowles and Mantoura [38] determined sediment-water partition coefficients and the high-performance liquid chromatography capacity factors for 14 alkylbenzene and polyaromatic hydrocarbons. The partition coefficients correlated well with the alkyl-cyano capacity factors, and it was concluded that this phase gave a better indication of sorption on sediment than either the octanol or octadecylsilane phases. 

Relationships such as Eqs. (45) and (46) have been utilized extensively in correlating solubility properties (such as gas/liquid and liquid/liquid partition coefficients), retention volumes in gas/solid chromatography, capacity factors in high-pressure liquid chromatography, etc.199 200 For instance, gas/liquid partition coefficients for each of 35 different liquid stationary phases were represented with R > 0.985.205 Other applications have been in biochemical and pharmacological areas,199 200 e.g., enzyme inhibition and pollutant effects. 

DK Lloyd, A Ahmed, F Pastore. A quantitative relationship between capacity factor and selector concentration in capillary electrophoresis and high-performance liquid chromatography evidence from the enantioselective resolution of benzoin using human serum albumin as chiral selector. Electrophoresis 18 958-964, 1997. 

S.A. Ahmed, C.A. Lau-Cam and S.M. Bolton, Factorial design in the study of the effects of selected liquid chromatographic conditions on resolution and capacity factors. Journal of Liquid Chromatography, 13(3) (1990) 525-541. 

Self-Test M4.1B Inorganic cations can be separated by liquid chromatography according to their ability to form complexes with chloride ions. For the separation, the stationary phase is saturated with water and the carrier solvent is a solution of HC1 in acetone. The relative solubilities of the following chlorides in concentrated hydrochloric acid are CuCl2 > CoCI2 > NiCl2. Predict the relative values of the capacity factor k for the three salts. 

Correlations with Capacity Factors Obtained from High Performance Liquid Chromatography (RP-HPLC)... 

Experimental retention times or capacity factors generated by reverse phase high performance liquid chromatography (RP-HPLC) (Vowles and Mantoura, 1987 Hodson and Williams, 1988 Pussemier et al., 1990 Szabo et al., 1990a,b Hong et al., 1996) also have been correlated with Koc. 

Experimentally determined retention times or capacity factors (k) generated by reverse phase, usually octadecylsilane (ODS), high performance liquid chromatography (RP-HPLC) have been used widely to estimate Kow values (McDuffie, 1981 Haky and Young, 1984 Sarna, 1984 Doucette and Andren, 1988). More recently, this approach has been used to directly estimate Koc (Vowles and Mantoura, 1987 Hodson and Williams, 1988 Szabo et al., 1990 Kordel et al., 1993 Kordel et al., 1995 Hong et al., 1996). This is not strictly an estimation method because it relies on the acquisition of experimental retention times. 

Chromatographic system (see Chromatography, in the general procedure (621)) The liquid chromatography is equipped with a 280-nm detector and a 4.6 mm x 15-cm column that contains 5-/im packing L7. The flow-rate is about 0.8 ml/min. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure the capacity factor, k , is not less than 6 the column efficiency is not less than 3000 theoretical plates the tailing factor is not more than 1.5 and the relative standard deviation (RSD) for replicate injections is not more than 1%. 

Yamagami, C., Takao, N. (1992) Hydrophobicity parameters determined by reversed-phase liquid chromatography. V. Relationship between capacity factor and the octanol-water partition coefficient for simple heteroaromatic compounds and their ester derivatives. Chem. Pharm. Bull. 40(4), 925-929. 

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