Suitability of the pH buffers 3-[N-N-bis(hydroxethyl)amino]-2-hydroxypropanesulfonic acid and N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid for in vitro copper toxicity studies

• Type: Article in International Scientific Journal
• Date: 1996

Authors

lage, om (Author) FCUP; vasconcelos, mtsd (Author) Other; soares, hmvm (Author) FEUP; osswald, jm (Author) Other; sansonetty, f (Author) Other; parente, am (Author) Other; salema, r (Author) Other

Journal

Title: Archives of Environmental Contamination and Toxicology

Vol. 31

Pages: 199-205

ISSN: 0090-4341

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 16 Citations

Scopus - 19 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-001-DWA

DOI: 10.1007/bf00212366

Abstract (EN): The influence of the zwitterionic (ampholytic) pH buffers, 3-[N-N-bis(hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO, 10 mM) and N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES, 25 mM), on the toxicity of copper(II) to the marine dinoflagellate, Amphidinium carterae, was investigated. For this purpose, DIPSO or HEPES buffered complete ESAW (enrichment solution artificial seawater) growth media as well as simplified (enrichment solution deficient) buffered media were assayed in the toxicity tests, at pH 8.0. Similar assays were performed in unbuffered ESAW medium. Toxicity evaluation was based on growth changes, EC(50) (effective concentration of labile copper that reduces growth rate by 50%) and esterase activity. In addition to biological parameters, electrochemical behavior of the buffers in the presence of copper(II) was used to interpret the results. Neither of the buffers were toxic to A. carterae. HEPES increased copper toxicity (synergistic effect) while DIPSO diminished it (strong antagonistic effect). HEPES does not significantly complex copper(II) and this effect was possibly due to change in kinetics of metal binding to the organisms due to its surfactant properties at 25 mM. DIPSO is a strong copper(II) complexing agent (average conditional stability constant, log K = 7.3, pH 8.0, 25 degrees C). These results suggest that DIPSO may substitute EDTA in culture media with the advantage of simultaneously buffering changes in pH and metallic cations.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7