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Mwankuna CJ, Kiros F, Mariki EE, Mabiki FP, Malebo HM, Mdegela RH, Styrishave B. Optimization of HPLC-MS/MS method for determination of antimalarial adulterants in herbal products. ANAL SCI 2023; 39:407-416. [PMID: 36633808 DOI: 10.1007/s44211-022-00255-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/19/2022] [Indexed: 01/13/2023]
Abstract
The use of herbal products is booming all over the world because of being believed as safer than conventional drugs and free of side effects. However, there are untrustworthy manufacturers who adulterate herbal products by adding conventional drugs which might eventually lead to microbial resistance and herb-to-drug interactions. There is a need to develop methods for detecting adulterants in herbal products. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for simultaneous identification and determination of conventional antimalarials (chloroquine, quinine, sulfadoxine, pyrimethamine, mefloquine, lumefantrine, amodiaquine, artemisinin, dihydroartemisinin, artesunate and artemether) in herbal products was developed. Stable isotopically labelled compounds (artemether-d3, quindine-d3, and sulfadoxine-d3) were used as internal standards (ISs) for quantitative analysis. Extraction of analytes was performed using methanol: water: formic acid (90:10:0.1, v/v) and chromatographic separation was done in a gradient mode using mobile phase A: Ultrapure water containing 0.1% formic acid and 1 mM ammonium formate and mobile phase B: Acetonitrile/methanol (50:50) containing 0.1% formic acid and 1 mM ammonium formate. The calibration curves were linear (r2 ≥ 0.991) over the range of 0.001-0.3 µg mL-1 for all compounds. The limit of detection (LOD) ranged from 0.002 to 0.02 μg mL-1 while the limit of quantification (LOQ) ranged from 0.006 to 0.08 μg mL-1. Accuracy, expressed as recovery of spiked herbal products ranged from 52 to 128%. The precision, expressed as percent relative standard deviation (%RSD) at two concentration levels, ranged from 1.0 to 13.8%. The matrix effect expressed as the matrix factor (MF) ranged from 0.77 to 0.97. The developed method was used to identify and quantify conventional antimalarials in herbal product samples from Tanzania. Ten out of 50 herbal products were found to contain amodiaquine, sulfadoxine, pyrimethamine, mefloquine, dihydroartemisinin, artemether and lumefantrine. The developed method is considered a valuable tool for getting a better understanding of the adulteration of conventional antimalarials in herbal products.
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Affiliation(s)
- Christopher J Mwankuna
- Department of Chemistry and Physics, College of Natural and Applied Sciences, Sokoine University of Agriculture, P.O. Box 3038, Morogoro, Tanzania.
| | - Feven Kiros
- Toxicology Laboratory, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Eliapenda E Mariki
- Department of Chemistry and Physics, College of Natural and Applied Sciences, Sokoine University of Agriculture, P.O. Box 3038, Morogoro, Tanzania
| | - Faith P Mabiki
- Department of Chemistry and Physics, College of Natural and Applied Sciences, Sokoine University of Agriculture, P.O. Box 3038, Morogoro, Tanzania
| | - Hamisi M Malebo
- UNESCO National Commission of the United Republic of Tanzania, 7 Magogoni Street, P.O. Box 20384, Dar Es Salaam, Tanzania
| | - Robinson H Mdegela
- Department of Veterinary Medicine and Public Health, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, P.O. Box 3015, Morogoro, Tanzania
| | - Bjarne Styrishave
- Toxicology Laboratory, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark Universitetsparken 2, DK-2100, Copenhagen, Denmark
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Aurell J, Gullett B, Holder A, Kiros F, Mitchell W, Watts A, Ottmar R. Wildland Fire Emission Sampling at Fishlake National Forest, Utah Using an Unmanned Aircraft System. Atmos Environ (1994) 2021; 247:118193. [PMID: 34335074 PMCID: PMC8318188 DOI: 10.1016/j.atmosenv.2021.118193] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Emissions from a stand replacement prescribed burn were sampled using an unmanned aircraft system (UAS, or "drone") in Fishlake National Forest, Utah, U.S.A. Sixteen flights over three days in June 2019 provided emission factors for a broad range of compounds including carbon monoxide (CO), carbon dioxide (CO2), nitric oxide (NO), nitrogen oxide (NO2), particulate matter < 2.5 microns in diameter (PM2.5), volatile organic compounds (VOCs) including carbonyls, black carbon, and elemental/organic carbon. To our knowledge, this is the first UAS-based emission sampling for a fire of this magnitude, including both slash pile and crown fires resulting in wildfire-like conditions. The burns consisted of drip torch ignitions as well as ground-mobile and aerial helicopter ignitions of large stands comprising over 1,000 ha, allowing for comparison of same-species emission factors burned under different conditions. The use of a UAS for emission sampling minimizes risk to personnel and equipment, allowing flexibility in sampling location and ensuring capture of representative, fresh smoke constituents. PM2.5 emission factors varied 5-fold and, like most pollutants, varied inversely with combustion efficiency resulting in lower emission factors from the slash piles than the crown fires.
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Affiliation(s)
- J. Aurell
- University of Dayton Research Institute, 300 College Park, Dayton, OH 45469, USA
| | - B. Gullett
- U.S. Environmental Protection Agency, Office of Research and Development, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
- Corresponding author : phone (+1-919) 541-1534; fax (+1-919) 541-0554
| | - A. Holder
- U.S. Environmental Protection Agency, Office of Research and Development, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - F. Kiros
- University of Dayton Research Institute, 300 College Park, Dayton, OH 45469, USA
| | - W. Mitchell
- U.S. Environmental Protection Agency, Office of Research and Development, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - A. Watts
- Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA
| | - R. Ottmar
- U.S. Forest Service, Pacific Wildland Forest Service Laboratory, 400 North 34 Street, Seattle, WA 98103, USA
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Gupta P, Doraiswamy P, Levy R, Pikelnaya O, Maibach J, Feenstra B, Polidori A, Kiros F, Mills KC. Impact of California Fires on Local and Regional Air Quality: The Role of a Low-Cost Sensor Network and Satellite Observations. Geohealth 2018; 2:172-181. [PMID: 31157310 PMCID: PMC6544158 DOI: 10.1029/2018gh000136] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 05/20/2023]
Abstract
PM2.5, or fine particulate matter, is a category of air pollutant consisting of particles with effective aerodynamic diameter equal to or less than 2.5 μm. These particles have been linked to human health impacts as well as regional haze, visibility, and climate change issues. Due to cost and space restrictions, the U.S. Environmental Protection Agency monitoring network remains spatially sparse. To increase the spatial resolution of monitoring, previous studies have used satellite data to estimate ground-level PM concentrations, despite these estimates being associated with moderate to large uncertainties when relating a column measure of aerosol (aerosol optical depth) with surface measurements. To this end, we discuss a low-cost air quality monitor (LCAQM) network deployed in California. In this study, we present an application of LCAQM and satellite data for quantifying the impact of wildfires in California during October 2017. The impacts of fires on PM2.5 concentration at varying temporal (hourly, daily, and weekly) and spatial (local to regional) scales have been evaluated. Comparison between low-cost air quality sensors and reference-grade air quality instruments shows expected performance with moderate to high uncertainties. The LCAQM measurements, in the absence of federal equivalent method data, were also found to be very useful in developing statistical models to convert aerosol optical depth into PM2.5 with performance of satellite-derived PM2.5, similar to that obtained using the federal equivalent method data. This paper also highlights challenges associated with both LCAQM and satellite-based PM2.5 measurements, which require further investigation and research.
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Affiliation(s)
- P. Gupta
- GESTAR‐Universities Space Research AssociationsColumbiaMDUSA
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | | | - R. Levy
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - O. Pikelnaya
- South Coast Air Quality Management DistrictDiamond BarCAUSA
| | - J. Maibach
- GESTAR‐Universities Space Research AssociationsColumbiaMDUSA
| | - B. Feenstra
- South Coast Air Quality Management DistrictDiamond BarCAUSA
| | | | - F. Kiros
- RTI InternationalResearch Triangle ParkNCUSA
| | - K. C. Mills
- RTI InternationalResearch Triangle ParkNCUSA
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