TY  - JOUR
AU  - Babay, P. A.
AU  - Gettar, R. T.
AU  - Magallanes, J.F.
AU  - Becquart, E.T.
AU  - Thiele, B.
AU  - Batistoni, D. A.
TI  - Column temperature as an active variable in the isocratic, normal-phase high-performance liquid chromatography separation of lipophilic metabolites of nonylphenol ethoxylates
JO  - Journal of chromatography / A
VL  - 1157
SN  - 0021-9673
CY  - New York, NY [u.a.]
PB  - Science Direct
M1  - PreJuSER-57080
SP  - 227 - 236
PY  - 2007
N1  - Record converted from VDB: 12.11.2012
AB  - 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.
KW  - Chromatography, High Pressure Liquid: instrumentation
KW  - Ethylene Glycols: isolation & purification
KW  - Ethylene Glycols: metabolism
KW  - Sensitivity and Specificity
KW  - Spectrophotometry, Ultraviolet
KW  - Temperature
KW  - Ethylene Glycols (NLM Chemicals)
KW  - terics (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:17540387
UR  - <Go to ISI:>//WOS:000248107200028
DO  - DOI:10.1016/j.chroma.2007.05.038
UR  - https://juser.fz-juelich.de/record/57080
ER  -