Determination of toxaphene specific congeners in fish liver oil and feedingstuff using gas chromatography coupled to high resolution mass spectrometry

A new method for the determination of nine toxaphene specific congeners in fish liver oil and feedingstuff has been developed. The samples were extracted using pressurized liquid extraction followed by a purification on silica and florisil columns. Identification and quantification were conducted using GC–(EI)-HRMS, and comparison with MS/MS detection was performed, using electron ionization and negative chemical ionization. Limits of detection were ranged from 0.01 to 0.22 μg kg−1 (12% moisture) as required for feed samples. The calibration curves showed a good linearity for all congeners (R2 > 0.99). Repeatability was below 9% for all the congeners and recoveries were in-between 73 and 86%. This analytical method was applied to the quantification of thirteen real samples collected within national monitoring plans for further risk assessment.