A simplified method for simultaneous quantitation of alkylphenols and alkylphenol ethoxylates in meat and fish using high-performance liquid chromatography with fluorescence detection

Nonylphenol (NP), octylphenol (OP), nonylphenol monoethoxylate (NP 1 EO) and nonylphenol diethoxylate (NP 2 EO) are products of the biodegradation of alkylphenol polyethoxylates (AP n EO) which are used worldwide as detergents and surfactants. NP and OP are categorized as definitely endocrine disruptors. 2,4-Tert-butylphenol (BP) is extensively used for anti-oxidant of rubber and plastics. This work proposed a simple and stable method for simultaneously determining the concentration of NP, OP, BP, n -NP 1 EO and n -NP 2 EO in meat and fish, without requiring the complex pretreatments of current methods. This study used liquid extraction with acetonitrile and hexane and solid extraction using Florisil, in that order to pretreat samples. The sample solutions were analyzed to identify NP, OP, BP, n -NP 1 EO and n -NP 2 EO by HPLC with fluorescence detection. The mean recoveries were 85.3 ± 3.32% for OP, 87.5 ± 6.01% for BP, 90.9 ± 4.72% for NP, 86.4 ± 4.81% for n -NP 2 EO and 90.9 ± 4.84% for n -NP 1 EO. The average coefficients of variation were about 6%. The method's detection limits were 5.4 ng g -1 for OP, 5.2 ng g -1 for BP, 8.9 ng g -1 for NP, 8.7 ng g -1 for n -NP 2 EO and 8.1 ng g -1 for n -NP 1 EO. This work analyzed 5 kinds of usual foodstuffs of meat and fish that are frequently consumed by residents of Taiwan. All of these samples contained NP, but not detectable levels n -NP 1 EO. Only salmon was contaminated with n -NP 2 EO. The NP level was highest in cod (198.41 ± 129.34 ng g -1 , wet weight). The fried chicken had the highest BP level (48.0 ± 41.3 ng g -1 , wet weight), and the uncooked chicken had the highest OP level (66.6 ± 53.0 ng g -1 , wet weight).