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| Hauptseite > Publikationsdatenbank > Column temperature as an active variable in the isocratic, normal-phase high-performance liquid chromatography separation of lipophilic metabolites of nonylphenol ethoxylates |
| Hauptseite > Publikationsdatenbank > Column temperature as an active variable in the isocratic, normal-phase high-performance liquid chromatography separation of lipophilic metabolites of nonylphenol ethoxylates |
| Journal Article | PreJuSER-57080 |
; ; ; ; ;
2007
Science Direct
New York, NY [u.a.]
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Please use a persistent id in citations: doi:10.1016/j.chroma.2007.05.038
Abstract: Normal-phase separation of technical grade nonylphenol (t-NP, about 90% 4-nonylphenol), 4-nonylphenol mono-ethoxylate (4-NP1EO) and 4-nonylphenol di-ethoxylate (4-NP2EO) was assessed, with the inclusion of column temperature as an active variable. The compound 2,4,6-trimethylphenol was evaluated for use as internal standard. Isocratic elution with 2-propanol/hexanes mixtures from an amino-silica column and spectrometric UV detection at 277 nm were employed. Technical nonylphenol presented a significant contribution from unknown substances that eluted with retention times similar to that of 4-NP1EO. GC-MS analysis of the unknowns allowed to identify them as isomers of 2-NP. The response of the system to joint variations in flow rate, eluent composition and column temperature was investigated by means of Doehlert statistical experimental design. A model for retention of the analytes as a function of the experimental variables was proposed, and separation selectivity was studied. Selection of the optimal working zone was made through desirability function (D) calculations. Potential co-elution of 2-NP isomers with 4-NP1EO was considered when optimizing the separation. The occurrence of a restricted region of the experimental space where baseline resolution of analytes, associated impurities and internal standard results feasible (D not equal to 0) is apparent.
Keyword(s): Chromatography, High Pressure Liquid: instrumentation (MeSH) ; Ethylene Glycols: isolation & purification (MeSH) ; Ethylene Glycols: metabolism (MeSH) ; Sensitivity and Specificity (MeSH) ; Spectrophotometry, Ultraviolet (MeSH) ; Temperature (MeSH) ; Ethylene Glycols ; terics ; J ; nonylphenol ethoxylates (auto) ; lipophilic metabolites (auto) ; normal-phase HPLC (auto) ; column temperature (auto) ; separation selectivity (auto)
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