title: Evaluation of the effect of reactive sulfide on the acute toxicity of silver (I) to Daphnia magna. Part 1: description of the chemical system.
abstract: Experiments were designed to assess the potential protective effect of the presence of sulfide against the acute (48-h) toxicity of silver(I) to Daphnia magna. Tests were conducted in borosilicate glass beakers (250 ml) in moderately hard synthetic water. Toxicity solutions were replaced after 24 h by static renewal method. This paper describes the chemical system, and the acute toxicity results are presented in a companion paper. Sulfide was below detection limit (<5 nM) in controls with no sulfide added. Sulfide, added as zinc sulfide clusters at approximately 35- or approximately 350-nM concentration, dropped in concentration to approximately 25 and 250 nM, respectively, over the 24-h period of measurements. Silver also decreased in concentration during the experiment (up to 59%), and the rate of loss was greater in the absence of sulfide compared with the presence of sulfide. A filtration experiment indicated a 1:1 binding ratio of silver to sulfide and a conditional stability constant for the Ag(I)-zinc sulfide complex of log K' = 8.9. The losses of sulfide and silver during the experiments highlighted the need for regular monitoring of the important chemical components of the system, even during short (48-h) toxicity tests.
authors.affiliation: School of Geography and Geology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Karl C
authors.initials: KC
authors.lastname: Bowles
authors.forename: Adalto
authors.initials: A
authors.lastname: Bianchini
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Brauner
authors.forename: James R
authors.initials: JR
authors.lastname: Kramer
authors.forename: Chris M
authors.initials: CM
authors.lastname: Wood
mesh_terms: D000818:Animals; D001682:Biological Availability; D003621:Daphnia; D004347:Drug Interactions; D007928:Lethal Dose 50; D008024:Ligands; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry / Q000633:toxicity*; D013440:Sulfides / Q000737:chemistry* / Q000494:pharmacology*; D014873:Water Pollutants / Q000633:toxicity*
chemical_list: D008024:Ligands; D013440:Sulfides; D014873:Water Pollutants; D012834:Silver