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Reddy K, Renuka N, Kumari S, Ratha SK, Moodley B, Pillay K, Bux F. Assessing the potential for nevirapine removal and its ecotoxicological effects on Coelastrella tenuitheca and Tetradesmus obliquus in aqueous environment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 317:120736. [PMID: 36460185 DOI: 10.1016/j.envpol.2022.120736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/07/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Remediation of the antiretroviral (ARV) drug, nevirapine (NVP) has attracted considerable scientific attention in recent years due to its frequent detection and persistence in aquatic environments and potential hazards to living organisms. Algae-based technologies have been emerging as an environmentally friendly option for the removal of pharmaceutical compounds, but their ARV drug removal potential has not been fully explored yet. This study aimed to explore the ecotoxicity and removal potential of NVP by two microalgal species, Coelastrella tenuitheca and Tetradesmus obliquus. Lower environmental concentrations (up to 200 ng L-1) of NVP enhanced the microalgal growth, and the highest dry cell weight of 941.27 mg L-1 was obtained in T. obliquus at 50 ng L-1 NVP concentration. Both microalgae showed varying removal efficiencies (19.53-74.56%) when exposed to NVP concentration levels of up to 4000 ng L-1. At the late log phase (day 8), T. obliquus removed the highest percentage of NVP (74.56%), while C. tenuitheca removed 48% at an initial NVP concentration of 50 ng L-1. Photosynthetic efficiency (Fv/Fm and rETR) of the two microalgal species, however, was not affected by environmental concentrations of NVP (up to 4000 ng L-1) at the mid log phase of growth. SEM analysis demonstrated that both algal species produced distinct ridges on their cell surfaces after NVP uptake. In the ecotoxicity study, the calculated IC50 values of NVP (0-100 mg L-1) after 96 h of exposure were 23.45 mg L-1 (C. tenuitheca) and 18.20 mg L-1 (T. obliquus). The findings of the present study may contribute to a better understanding of the environmental hazards associated with NVP and the efficacy of microalgae in removing this pharmaceutical from aquatic environments.
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Affiliation(s)
- Karen Reddy
- Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban, 4000, South Africa
| | - Nirmal Renuka
- Algal Biotechnology Laboratory, Department of Botany, Central University of Punjab, Bathinda, 151401, India
| | - Sheena Kumari
- Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban, 4000, South Africa
| | - Sachitra Kumar Ratha
- Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban, 4000, South Africa; Phycology Laboratory, CSIR-National Botanical Research Institute, Lucknow, 226001, India
| | - Brenda Moodley
- School of Chemistry and Physics, College of Agriculture, Engineering and Sciences, University of KwaZulu-Natal, Private Bag X54001, Westville, Durban, 4000, South Africa
| | - Kriveshin Pillay
- Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban, 4000, South Africa
| | - Faizal Bux
- Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban, 4000, South Africa.
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Venter P, van Onselen R. Evaluating the "wrong-way-round" electrospray ionization of antiretroviral drugs for improved detection sensitivity. Anal Bioanal Chem 2023; 415:1187-1193. [PMID: 36637494 PMCID: PMC9899738 DOI: 10.1007/s00216-022-04499-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 01/14/2023]
Abstract
The presence of antiretroviral drugs (ARVDs) in the aquatic environment poses a significant health risk to the ecosystem. The dilution of these compounds during wastewater treatment processes, followed by discharge into the environment, results in extremely low concentrations in the range of ng/L. Therefore, to enable detection of these low concentrations, it is important to determine the most efficient electrospray ionization (ESI) mode using the right mobile phase modifier and to establish a selective extraction procedure. In this study, we compared the ESI intensity in the positive and negative mode using both formic acid (FA) and ammonium hydroxide (NH4OH) as mobile phase modifiers. The results revealed a phenomenon known as the "wrong-way-round" (WWR) ESI in which high intensity [M + H]+ ions were detected under basic conditions using NH4OH as modifier and, similarly, high intensity [M-H]- ions were detected under acidic conditions using FA as modifier. Furthermore, mixed-mode strong cation (MCX) and mixed-mode strong anion (MAX) exchange sorbents were evaluated for extraction recoveries, which yielded extraction recoveries between 60 and 100%. Finally, the recoveries obtained using mixed-mode ion exchange sorbents compared to ion production during the ESI process provide evidence that ions produced in solution do not necessarily reflect the ions that are produced during the ESI process. Based on the results of this study, it is recommended to evaluate the optimal ionization mode under basic and acidic conditions, instead of defaulting to the use of acidic modifiers with positive ion detection.
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Affiliation(s)
- Pieter Venter
- grid.415021.30000 0000 9155 0024Biomedical Research and Innovation Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg, 7505 South Africa
| | - Rianita van Onselen
- grid.415021.30000 0000 9155 0024Biomedical Research and Innovation Platform, South African Medical Research Council, P.O. Box 19070, Tygerberg, 7505 South Africa
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