Liquid chromatography/tandem mass spectrometry for analysis of 1,2‐dibromo‐4‐(1,2‐dibromoethyl)cyclohexane (TBECH) and 1,2,5,6‐tetrabromocyclooctane (TBCO)

Although the two flame retardants 1,2‐dibromo‐4‐(1,2‐dibromoethyl)cyclohexane (TBECH) and 1,2,5,6‐tetrabromocyclooctane (TBCO) have been widely used, a selective instrumental method of analysis for these compounds has not been developed to date. In this study, we demonstrate the feasibility to utilize liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the separation and analysis of α‐ and β‐TBCO and α‐, β‐, γ‐, and δ‐TBECH. Acetone was initially used in a tetrahedron solvent system for LC optimization. A simple isocratic elution allowed near‐baseline separation of these compounds. Different ionization approaches and mechanisms were investigated. The mass spectrometric transition of [M + O 2 ] – => Br – (459.8 => 78.9) was a selective detection method for the target analytes. Good instrument detection limits (5 pg for γ‐/δ‐TBECH, 125 pg for α‐/β‐TBECH, and 30 pg for α‐/β‐TBCO with 2.0 µL injection) were obtained. Excellent linearity up to 50 ng/µL ( R 2 >0.999) was also achieved. This method has been applied to environmental samples (surface water) for screening purposes with recoveries ranging from 76–92% (CV%: 5–8%). This method shows significant improvement over previous methods. Copyright © 2011 John Wiley & Sons, Ltd.