Abstract
Benzalkonium compounds are widely used and found in environmental samples. Due to their amphiphilic nature, it is important to know sorption coefficients to account their bioavailability. However, currently available models describing their partitioning were developed using low molecular weight homologues and it cannot be ascertained whether they are applicable to their higher molecular weight homologues. Reasons for the scarcity of data on highly sorptive compounds include the lack of reliable quantification techniques for analyzing these chemicals at environmentally relevant levels. This study, therefore, reports on an algal growth inhibition assay-based method for the determination of kaolinite/water distribution coefficients for benzalkonium compounds at their environmentally relevant concentration range. Sorption to clay was computed using the difference between median effective concentration determined in a culture with kaolinite and that derived from a culture grown in standard medium. A kinetic model was used to account for uptake into algal cells and to calculate free concentrations. Due to the sensitivity of the algal species, Pseudokirchneriella subcapitata, it was possible to determine distribution coefficients below micromole per liter concentrations. The computed distribution coefficients showed a linear increase with number of carbon atoms in the alkyl chain up to 14. The proposed bioassay-based method should be applicable to determine distribution coefficients for highly hydrophobic chemicals and ionic liquids at a concentration range lower than typical analytical limits.
| Original language | English |
|---|---|
| Pages (from-to) | 491-497 |
| Number of pages | 7 |
| Journal | Ecotoxicology and Environmental Safety |
| Volume | 174 |
| DOIs | |
| Publication status | Published - 2019 Jun 15 |
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Keywords
- Algal growth inhibition
- Bioavailability
- Kaolinite
- Organic cation
- Sorption coefficient
ASJC Scopus subject areas
- Pollution
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis
Cite this
Application of an algal growth inhibition assay to determine distribution coefficients of benzalkonium ions between kaolinite and water. / Ndabambi, Mlamuli; Kwon, Jung-Hwan.
In: Ecotoxicology and Environmental Safety, Vol. 174, 15.06.2019, p. 491-497.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Application of an algal growth inhibition assay to determine distribution coefficients of benzalkonium ions between kaolinite and water
AU - Ndabambi, Mlamuli
AU - Kwon, Jung-Hwan
PY - 2019/6/15
Y1 - 2019/6/15
N2 - Benzalkonium compounds are widely used and found in environmental samples. Due to their amphiphilic nature, it is important to know sorption coefficients to account their bioavailability. However, currently available models describing their partitioning were developed using low molecular weight homologues and it cannot be ascertained whether they are applicable to their higher molecular weight homologues. Reasons for the scarcity of data on highly sorptive compounds include the lack of reliable quantification techniques for analyzing these chemicals at environmentally relevant levels. This study, therefore, reports on an algal growth inhibition assay-based method for the determination of kaolinite/water distribution coefficients for benzalkonium compounds at their environmentally relevant concentration range. Sorption to clay was computed using the difference between median effective concentration determined in a culture with kaolinite and that derived from a culture grown in standard medium. A kinetic model was used to account for uptake into algal cells and to calculate free concentrations. Due to the sensitivity of the algal species, Pseudokirchneriella subcapitata, it was possible to determine distribution coefficients below micromole per liter concentrations. The computed distribution coefficients showed a linear increase with number of carbon atoms in the alkyl chain up to 14. The proposed bioassay-based method should be applicable to determine distribution coefficients for highly hydrophobic chemicals and ionic liquids at a concentration range lower than typical analytical limits.
AB - Benzalkonium compounds are widely used and found in environmental samples. Due to their amphiphilic nature, it is important to know sorption coefficients to account their bioavailability. However, currently available models describing their partitioning were developed using low molecular weight homologues and it cannot be ascertained whether they are applicable to their higher molecular weight homologues. Reasons for the scarcity of data on highly sorptive compounds include the lack of reliable quantification techniques for analyzing these chemicals at environmentally relevant levels. This study, therefore, reports on an algal growth inhibition assay-based method for the determination of kaolinite/water distribution coefficients for benzalkonium compounds at their environmentally relevant concentration range. Sorption to clay was computed using the difference between median effective concentration determined in a culture with kaolinite and that derived from a culture grown in standard medium. A kinetic model was used to account for uptake into algal cells and to calculate free concentrations. Due to the sensitivity of the algal species, Pseudokirchneriella subcapitata, it was possible to determine distribution coefficients below micromole per liter concentrations. The computed distribution coefficients showed a linear increase with number of carbon atoms in the alkyl chain up to 14. The proposed bioassay-based method should be applicable to determine distribution coefficients for highly hydrophobic chemicals and ionic liquids at a concentration range lower than typical analytical limits.
KW - Algal growth inhibition
KW - Bioavailability
KW - Kaolinite
KW - Organic cation
KW - Sorption coefficient
UR - http://www.scopus.com/inward/record.url?scp=85062565868&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85062565868&partnerID=8YFLogxK
U2 - 10.1016/j.ecoenv.2019.03.011
DO - 10.1016/j.ecoenv.2019.03.011
M3 - Article
VL - 174
SP - 491
EP - 497
JO - Ecotoxicology and Environmental Safety
JF - Ecotoxicology and Environmental Safety
SN - 0147-6513
ER -