Optimization of comprehensive two dimensional gas chromatography-flame ionization detection–quadrupole mass spectrometry for the separation of octyl- and nonylphenol isomers

In the present work, the separation of complex nonylphenol technical mixtures has been optimized using comprehensive two-dimensional gas chromatography coupled with a flame ionization detector and quadrupole mass spectrometer (GC × GC–qMS), using valve-based modulator. The optimization of GC × GC–qMS has been carried out using experimental designs and the optimal separation was obtained at the following conditions: 1st column flow: 1 mL/min; 2nd column flow: 17.75 mL/min, oven temperature ramp: 1 °C/min, modulation period: 1.5 s and discharge time: 0.12 s. These values have been used to determinate the previously synthesized 22OP, 33OP, 363NP and 22NP isomers in two different nonylphenol technical mixtures. Percentages obtained were as follows: 4.86% and 0.59% for 22OP, 4.91% and 2.82% for 33OP, 11.79% and 7.71% for 363NP and 2.28% and 1.98% for 22NP, in Fluka and Aldrich mixtures, respectively. The values obtained for NP isomers are in good agreement with the literature.