title: Estimation of the toxicity of sulfadiazine to Daphnia magna using negligible depletion hollow-fiber liquid-phase microextraction independent of ambient pH.
abstract: The toxicity of ionizable organic compounds to organisms depends on the pH, which therefore affects risk assessments of these compounds. However, there is not a direct chemical method to predict the toxicity of ionizable organic compounds. To determine whether hollow-fiber liquid-phase microextraction (HF-LPME) is applicable for this purpose, a three-phase HF-LPME was used to measure sulfadiazine and estimate its toxicity to Daphnia magna in solutions of different pH. The result indicated that the sulfadiazine concentrations measured by HF-LPME decreased with increasing pH, which is consistent with the decreased toxicity. The concentration immobilize 50% of the daphnids (EC50) in 48 h calculated from nominal concentrations increased from 11.93 to 273.5 mg L-1as the pH increased from 6.0 to 8.5, and the coefficient of variation (CV) of the EC50 values reached 104.6%. When calculated from the concentrations measured by HF-LPME (pH 12 acceptor phase), the EC50 ranged from 223.4 to 394.6 mg L-1, and the CV decreased to 27.60%, suggesting that the concentrations measured by HF-LPME can be used to estimate the toxicity of sulfadiazine irrespective of the solution pH.
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.|Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, PR China.|Collaborative Innovation Center of Farmland Weeds Control, Loudi, Hunan province, PR China.
authors.forename: Kailin
authors.initials: K
authors.lastname: Liu
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.
authors.forename: Shiji
authors.initials: S
authors.lastname: Xu
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.
authors.forename: Minghuan
authors.initials: M
authors.lastname: Zhang
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.
authors.forename: Yahong
authors.initials: Y
authors.lastname: Kou
authors.affiliation: Biotechnology Research Center, Hunan Academy of Agricultural Sciences, Changsha 410125, PR China.|Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, PR China.|Collaborative Innovation Center of Farmland Weeds Control, Loudi, Hunan province, PR China.
authors.forename: Xiaomao
authors.initials: X
authors.lastname: Zhou
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.|Collaborative Innovation Center of Farmland Weeds Control, Loudi, Hunan province, PR China.
authors.forename: Kun
authors.initials: K
authors.lastname: Luo
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.|Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, PR China.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Hu
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.|Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, PR China.
authors.forename: Xiangying
authors.initials: X
authors.lastname: Liu
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.|Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, PR China.|Biotechnology Research Center, Hunan Academy of Agricultural Sciences, Changsha 410125, PR China.|Collaborative Innovation Center of Farmland Weeds Control, Loudi, Hunan province, PR China.
authors.forename: Lianyang
authors.initials: L
authors.lastname: Bai
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D003621:Daphnia; D006863:Hydrogen-Ion Concentration; D013411:Sulfadiazine / Q000032:analysis* / Q000633:toxicity*
chemical_list: D013411:Sulfadiazine