Toxicity of five phenolic compounds to brine shrimp Artemia sinica (Crustacea: Artemiidae)

Abstract

The acute toxicity of five phenolic compounds each to 15 d old Artemia sinica was determined in this study. The brine shrimp A. sinica was hatched from the encysted dry eggs (Bohai Bay Brand) produced by Dongying Ocean Artemia Co., Ltd., China at 27°C ± 1°C in pre-filtered (through pores of 0.45 μm in diameter) and autoclaved seawater (salinity 31, pH 7.5–8.0) in a cilindroconical glass beaker (2000 mL in volume) under continuous illumination (provided by a side set 20 W fluorescent lamp) with slight aeration. Ten Artemia individuals from the same batch of the hatched were cultured in 10 mL toxicant solution prepared with seawater (salinity 31, pH 7.5–8.0) at room temperature (about 20°C) to determine 24 h, 48 h and 72 h medium lethal concentration (LC50) of 5 phenolic compounds each. It was found that the toxicity of n-heptylphenol was the highest followed by nonylphenol, t-butylphenol, 2,4-dichlorophenol and bisphenol A in order. The LC50 values of the 5 compounds were calculated with regression analysis. The real concentration (in μg L−1) of 5 phenolic compounds each in toxicant solutions was measured with GC/MS analysis. Significant loss of phenolic compounds caused by either adsorption or desorption was not found. The significant difference of LC50 values was found among the five compounds 3 exposure times each. The range between the highest no-observed-effect concentration (NOEC) and 100% death causing concentration of five phenolic compounds each was determined. The toxicity in term of 24 h LC50 value of n-HP was 9.10 times higher than that of BPA, 1.71 times higher than t-BP, 1.53 times higher than 2,4-DCP and 1.36 times higher than NP, respectively.