%0 Journal Article
%A Babay, P. A.
%A Gettar, R. T.
%A Magallanes, J.F.
%A Becquart, E.T.
%A Thiele, B.
%A Batistoni, D. A.
%T Column temperature as an active variable in the isocratic, normal-phase high-performance liquid chromatography separation of lipophilic metabolites of nonylphenol ethoxylates
%J Journal of chromatography / A
%V 1157
%@ 0021-9673
%C New York, NY [u.a.]
%I Science Direct
%M PreJuSER-57080
%P 227 - 236
%D 2007
%Z Record converted from VDB: 12.11.2012
%X 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.
%K Chromatography, High Pressure Liquid: instrumentation
%K Ethylene Glycols: isolation & purification
%K Ethylene Glycols: metabolism
%K Sensitivity and Specificity
%K Spectrophotometry, Ultraviolet
%K Temperature
%K Ethylene Glycols (NLM Chemicals)
%K terics (NLM Chemicals)
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:17540387
%U <Go to ISI:>//WOS:000248107200028
%R 10.1016/j.chroma.2007.05.038
%U https://juser.fz-juelich.de/record/57080