Determination of Dodecanol and Short-Chained Ethoxylated Dodecanols by LC-MS/MS (with Electrospray Ionization) After Their Derivatization (with Phenyl Isocyanate).

Abstract: This report describes the application of LC-MS/MS for the separation of dodecanol (C12 OH) and homogenous fatty alcohols ethoxylated (AE) containing a dodecyl moiety and 1-9 ethoxy groups. These ethoxylates and free alcohol were derivatized for LC-MS/MS analysis with phenyl isocyanate (PIC). The derivatives of analytes with PIC were separated using a C18 column. Gradient elution with a mixture of ethyl acetate and acetonitrile (5 mM) was employed. The described determination method is characterized by low detection limits (range from 0.005 µg L-1 for: C12 OH, C12 EO2-7 to 1 µg L-1 for C12 EO1 ) and quantification limits (range from 0.01 µg L-1 for: C12 EO5-7 to 2 µg L-1 for C12 EO1 ). The developed and validated method was used in combination with liquid-liquid extraction (using ethyl acetate) in order to identify and quantitatively determine the C12 OH and C12 EO1-9 present in environmental samples collected from Warta river water in Poznan.