Endocrine-disrupting nonylphenols - ultra-trace analysis and time-dependent trend in mussels from the German bight

A very sensitive and efficient analytical procedure is presented for the de termination of 4-nonylphenols (NP) in blue mussels by use of off-line coupl ing of highperformance liquid chromatography (HPLC) and gas chromatography with mass spectrometric detection (GCMS). Combined steam distillation and s olvent extraction were used to extract the analytes from the mussel samples . Before quantification by GC-MS the raw extracts were purified by normal-p hase HPLC. 4-n-Nonylphenol was used as internal standard. The detection lim it was 15 ng NP absolute, calculated from the blank value. The method was a pplied to the determination of NP in blue mussel samples from the German No rth Sea sampled over a period of 10 years. Collection, homogenization, and storage of the mussels were performed according to the Standard Operating P rocedures of the German Environmental Specimen Bank since 1985. The total N P concentrations in the mussels decreased significantly from 1985 (4 mug kg (-1)) to 1995 (1.1 mug kg(-1)).