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Optimized QuEChERS (quick, easy, cheap, effective, rugged and safe) method of sample preparation was employed for five selected pharmaceutical compounds on its advantage of simplicity, less extraction solvent and extraction time. Different parameters affecting the extraction efficiency of the target analyte was optimized. Since QuEChERS was developed for pesticides, uses of the method for pharmaceuticals need modification and evaluation of different parameters. Clean-up sorbents were evaluated for their matrix effect removal after extraction and a combination of d-SPE sorbent, MgSO4, PSA, C18 and diatomaceous earth found to be selective clean-up sorbent for the targeted compounds. The addition and amount of diatomaceous earth and EDTA during the clean-up and extraction steps, respectively, were also examined and the amount was optimized. Solvent type and composition, salt type and extraction time were also optimized and methanol, MgSO4 with NaCl salt and 5 min extraction time was obtained. The method was successfully applied to different vegetable samples collected from Addis Ababa, Ethiopia and Johannesburg, South Africa (carrot, cabbage and lettuce) and none of the target analytes were found in the sample investigated. The matrix effect study on vegetable samples collected was found very high that suppresses the signal during analysis. [ABSTRACT FROM AUTHOR]

The present work was aimed to determine the contents of ascorbic acid and the antioxidant activity of eight types of common fruits commercially available in Addis Ababa, Ethiopia using iodometric titration and UV-Vis spectrophotometric methods, respectively. The contents of ascorbic acid were found in the range 15.41 mg/100 g in grapes to 78.01 mg/100 g in papaya. The antioxidant activity was found highest in papaya (89.41) and lowest in water melon (31.28) in mg of ascorbic acid equivalent per 100 g of the edible part of fruit juice. The calibration curve of ascorbic acid was in the range 50 - 3.125 mg/L with R² = 0.9994. The results also revealed the strong correlation (r = 0.863) between ascorbic acid contents in fruits and their antioxidant activity. Using the optimized conditions, UV-Vis spectrophotometric method with the 2,2-diphenyl-1-picrylhydrazil assay allows determination of antioxidant activity of fruits with limit of detection 0.32 mg/L and limit of quantification 0.96 mg/L. The precision was in the acceptable range (relative standard deviation, RSD < 20%) for determination of ascorbic acid and < 10% for antioxidant activity determination. The recovery of ascorbic acid was between 85% and 113% for selected fruits showing good accuracy of the results. [ABSTRACT FROM AUTHOR]

Nowadays, particulate matter and total volatile organic compounds in the air are the primary environmental concern of the world due to their health impact. Therefore, the present work was focused on the assessment of short-term exposure to particulate matter (PMs) in the air samples of different particle size (PM1, PM2.5, PM4, PM7, PM10) and total suspended particles (TSP), total volatile organic compounds (TVOCs) and trace elements in PM10 in the living room (a place where inhabitants spent more of their indoor time). PMs and TVOCs were measured by simple and portable sensors, respectively. The elemental composition of PM10 was analysed by using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The geometric mean (GOM) of PMs in the living room ranged from 5.68 to 99.0 µg m−3, whereas the TVOCs were found to be 289 µg m−3. The health risk due to exposure to PM2.5, PM10, and TSP was performed according to the United States Environmental Protection Agency prescription using hazard quotient calculation (HQ) and hazard index calculation (HI). The results showed that HI and HQ for PM2.5, PM10 and TSP were less than one indicating that the non-carcinogenic effect is not significant. The levels of trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu, and Zn) in PM10 were found in the range: 0.001–0.026 µg m−3. The carcinogenic and non-carcinogenic risks due to elements in PM10 exposure were also not significant. [ABSTRACT FROM AUTHOR]

Traditional toothbrushes are used by the vast majority of people who cannot afford to buy the commercial toothbrush and toothpaste. The traditional toothbrushes are generally obtained from any slim woody part of a toothbrush tree. The main purpose of this study was to determine selected metals (Ca, Fe, Mg, Al, Cu, Cr, Ni, Zn, Mn, Pb, and Cd) in traditional toothbrushes obtained from three plants including Ligustrum vulgare L., Phoenix reclinata and Olea africana, which are extensively used in Addis Ababa, Ethiopia, by using microwave plasma-atomic emission spectroscopy (MP-AES) after wet digestion. Recoveries of the metals in spiked samples varied from 90.4-107%. The overall mean concentrations determined (mg/kg, dry weight) were in the ranges of Ca (4267-36514) > Fe (131-318) > Al (81.6-224) > Mg (45.6-122) > Zn (27.2-175) > Mn (20.1-29) > Cu (6.6-20.3) > Cr (6.7-8.9) > Ni (2.6-7.9). Analysis of variance at 95% indicated significant differences in the metals' contents of three toothbrushes. The results indicated that the selected traditional toothbrushes are good sources of essential metals and free from Pb and Cd. Therefore, the investigated Ethiopian traditional toothbrushes are found to be safe for human use. [ABSTRACT FROM AUTHOR]

Pharmaceutical consumption is increasing worldwide as it is essential to treat and prevent health issues but they end up in the environment. However, in many African countries like Ethiopia, the status of these compounds in various environmental samples is not very well known. In this study, a simple method for the extraction and determination of thirteen pharmaceutical compounds of different therapeutic classes in water samples using solid-phase extraction and HPLC-DAD was developed. Different parameters affecting extraction were optimised and obtained as hydrophilic-lipophilic balance (HLB) extraction cartridge, water sample pH of 5, elution solvent of 2% formic acid in water with methanol (20:80%, v/v), a sample volume of 150 mL and addition of 0.5% w/v EDTA in the sample. The limits of detection and quantification of the optimised method were in the range of 0.1–0.8 µg/L and 0.2–2.6 µg/L, respectively. The relative recovery in the spiked environmental water sample was in the range of 70–117% except for amoxicillin and acetylsalicylic acid in influent wastewater. The precision for all ranged from 0.3 to 11%. The proposed method was successfully tested for the detection and quantification of different environmental water samples collected from Addis Ababa, Ethiopia. Trimethoprim, caffeine and albendazole concentrations of 7.8 (1.1), 3.2 (0.4) and 2.1 (0.1) µg/L were quantified in hospital wastewater, respectively. The concentration of norfloxacin was found to be below the limit of quantification in the same water. Trimethoprim and ciprofloxacin were also found in the sewage treatment plant influent sample at a concentration of 0.5 (0.02) and 0.3 (0.01) µg/L, respectively. [ABSTRACT FROM AUTHOR]

This study was undertaken to assess indoor air pollution and potential exposure to particulate matters (PMs—PM1, PM2.5, PM4, PM7, PM10), and total suspended particles [TSP] and total volatile organic compounds [TVOCs] during baking of Ethiopian traditional staple food, Injera using different types of stoves at Addis Ababa, Ethiopia. The geometric mean (GOM) of PMs pollutant using clean, improved, and traditional stoves were ranged 10.8–235, 23.6–462, and 36.4–591 µg/m3, respectively. The GOM of TVOCs in the wet and dry season using the clean, improved, and traditional stoves were 1,553, 2,234, 4,421, and 845, 1,214, and 2,662 µg/m3, respectively. The health risk of an exposed person to PM2.5, PM10, and TSP during baking of Injera was characterized and the results showed only baking of Injera using any of the stove types does not cause health problems to the baker. However, the percent contribution to the total chronic intake is high up to 38%. [ABSTRACT FROM AUTHOR]

The consumption of bottled drinking water has been increasing in the world. But, the quality of bottled water used for human consumption is not subjected to any stringent quality control measure in Ethiopia. The present study was carried out to determine the physicochemical quality parameters of twenty brands of bottled drinking water available in Addis Ababa and to compare with drinking water guidelines set by World Health Organization (WHO) and Compulsory Ethiopia Standards (CES). The samples were collected by random sampling technique. The physicochemical parameters such as pH; TDS and EC; total alkalinity, total hardness, HCO3-, Cl-; SO42-, NO3-, NO2-, F-) and common cations (Ca2+, Mg2+, Na+, and K+) were determined by pH meter, conductivity meter, titration, UV-Visible spectrometry, fluoride ion selective electrode and microwave plasmaatomic emission spectrometry, respectively. The mean physicochemical concentration of TDS, total alkalinity, total hardness, HCO3-, SO42-, NO3-, NO2-, F-, Cl-, Ca2+, Mg2+, Na+, K+, pH and EC in bottled water samples were found in the range (4.67-139), (12-165), (4-97), (16.3-202), (0.05-3.84), (0.02-0.84), (0.08-0.28), (0.03-1.26), (4.28-20.8), (0.19-8.9), (0.02-2.5), (1.8-24.5), (0.14-8.08 mg/L), (6.43-7.69) and (9.8-289 µs/cm), respectively. The drinking water quality index (WQI) was calculated based on 15 important quality parameters and the results were found in the range 3.85-49.2. The mean concentrations of physicochemical parameters in almost all the bottled drinking water were below the permissible limit set by WHO and CES. Hence, all the tested bottled water samples are safe for drinking purpose. [ABSTRACT FROM AUTHOR]

Abstract: Samples of vegetables, water and soil were collected from four vegetable farms in Addis Ababa to evaluate the extent and trend of metal accumulation in these systems and health risk concerns to consumers. Vegetable samples were digested in HNO3 and HClO4, soil samples in Aqua Regia and water samples were pre-concentrated with methyl isobutyl ketone (MIBK) using the chelating agent ammonium pyrrolidine dithiocarbamate (APDC). All the samples were analyzed for Co, Cr, Cu, Mn, Ni, Zn, Cd and Pb with flame atomic absorption spectrophotometer. The concentrations of Cd (0.12–1.13mgkg−1) and Pb (0.11–0.89mgkg−1) in the vegetables surpassed the maximum recommended levels. The total metal concentrations in soils were (mgkg−1): Cr, 9.9–22.8; Co, 28.0–47.3; Cu, 25.1–51.4, Mn, 1000–1054; Ni, 16.4–55.8; Zn, 146–149; Cd, 1.4–1.8 and Pb, 22.0–50.7. The trace metals Cd, Co, Cu, Mn and Ni in most of the water samples collected from Goffa, Kera and Akaki farms also surpassed irrigation water guideline limits, which might be a case for high accumulation of metals in the soils. However, the soil pH (6.5–7.6) and high cation exchange capacity (CEC), 38.41–50.18, coupled with high clay content, 37–51%, of the soil seemed to limit metal uptake by the vegetables. The physical parameters, pH (7.43–7.89) and electrical conductivity (0.33–1.54dS/m) of irrigation waters measured at 25°C were found within the acceptable range. [Copyright &y& Elsevier]

Estimation of personal exposure to air pollution is needed to identify high-risk population and to develop mitigation strategies. In this study, an assessment of the potential effects of short-term exposure to PM10 and the elements bound within PM10 was conducted. Samples were obtained from the ten sub-cities of Addis Ababa (three sampling points from each) during the commuting time (traffic congestion and taxi queues). A particle counter consisting of a portable sampling unit with multi-fraction dust samplers was used for sample collection. The elemental composition was analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentrations of PM10 ranged from 206 to 308 μg m−3. The highest concentrations of pollutants were found in the major open-market part of the city, Addis Ketema. The lowest concentrations were found at the old-town, Arada sub-cities. The concentration of trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu, and Zn) bound in PM10 ranged from below detectable limit to 0.981 μg m−3. Regardless of the sampling sub-city, the overall patterns of the mean concentration of elements bound in PM10 were found in the following increasing order of Cr < Cd < As < Co < Ni < Cu < Fe < Pb < Sn < B < Zn < Mn. The results showed that the primary source of Zn, Cr, and Cd may be emissions from on-road vehicles, tire and brake wear. Pb originates mainly from industries and suspended soil dust at the roadside, whereas As, Mn, and B are associated with dust resuspension and biomass and biofuel combustion, respectively. The carcinogenic and non-carcinogenic risks due to chronic exposure to trace elements bound in PM10 at the roadside were assessed in accordance with the U.S. Environmental Protection Agency (US EPA) guidelines. It was determined that Mn, As, and Cd contributed substantially to the inducement of non-carcinogenic health problems to children and adults as a result of exposure while in close proximity to the roadsides. [ABSTRACT FROM AUTHOR]