A cutting-edge electrochemical sensing platform for the simultaneous determination of the residues of antimicrobial drugs, rifampicin and norfloxacin, in water samples.

BACKGROUND: The widespread use and abuse of antibiotics has resulted in the pollution of water sources with antibiotic residues, posing a threat to human health, the environment, and the economy. Therefore, a highly sensitive and selective method is required for their detection in water samples. Herein, advanced ultrasensitive electrochemical sensor platform was developed by integrating gold-silver alloy nanocoral clusters (Au-Ag-ANCCs) with functionalized multi-walled carbon nanotube-carbon paste electrode (f-MWCNT-CPE) and choline chloride (ChCl) nanocomposites for simultaneously determining the residues of antimicrobial drugs, rifampicin (RAMP) and norfloxacin (NFX), in water samples. RESULTS: The developed sensor (Au-Ag-ANCCs/f-MWCNTs-CPE/ChCl) was extensively characterized using several analytical (UV-Vis, FT-IR, XRD, SEM, and EDX) and electrochemical (EIS, CV, and SWV) techniques. It exhibited outstanding performance in a wide linear range, from 14 pM to 115 µM for RAMP, and from 0.9 nM to 200 µM for NFX, with a limit of detection (LOD, 3σ/m, S/N = 3, n = 5) and a limit of quantification (LOQ, 10σ/m, S/N = 3, n = 5) values of 2.7 pM and 8.85 pM for RAMP, and 0.14 nM and 0.47 nM for NFX, respectively. The sensor also exhibited exceptional reproducibility, stability, and resistance to interference. SIGNIFICANCE: The developed sensor was effectively utilized to determine RAMP and NFX residues in hospital wastewater, river, and tap water samples, yielding recoveries within the range of 96.8-103 % and relative standard deviations below 5 %. Generally, the proposed sensor demonstrated remarkable performance in detecting the target analytes, making it an ideal tool and the first of its kind for addressing global antibiotic residue pollutants in water sources.

Hypersensitive electrochemical sensor based on thermally annealed gold-silver alloy nanoporous matrices for the simultaneous determination of sulfathiazole and sulfamethoxazole residues in food samples.

In this study, we have developed a novel, hypersensitive, and ultraselective electrochemical sensor containing thermally annealed gold-silver alloy nanoporous matrices (TA-Au-Ag-ANpM) integrated with f-MWCNTs-CPE and poly(l-serine) nanocomposites for the simultaneous detection of sulfathiazole (SFT) and sulfamethoxazole (SFM) residues in honey, beef, and egg samples. TA-Au-Ag-ANpM/f-MWCNTs-CPE/poly(l-serine) was characterized using an extensive array of analytical (UV-Vis, FT-IR, XRD, SEM, and EDX), and electrochemical (EIS, CV and SWV) techniques. It exhibited outstanding performance over a wide linear range, from 4.0 pM to 490 µM for SFT and 4.0 pM to 520 µM for SFM, with picomolar detection and quantification limits (0.53 pM and 1.75 pM for SFT, 0.41 pM and 1.35 pM for SFM, respectively). The sensor demonstrated exceptional repeatability, reproducibility, and anti-interference capability, with percentage recovery of 95.6-102.4% in food samples and RSD below 5%. Therefore, the developed sensor is an ideal tool to address the current antibiotic residue crisis in food sources.

A novel electrochemical sensor for the detection of metronidazole residues in food samples.

The widespread use and misuse of antibiotics in pharmaceuticals and animal farming has resulted in their accumulation in food sources and the environment, posing significant threats to human health, the environment, and the global economy. In this study, we have developed a hypersensitive, and ultra-selective electrochemical sensor, the first of its kind, by integrating a thermally annealed gold-silver alloy nanoporous matrix (TA-Au-Ag-ANpM) with reduced graphene oxide (r-GO) and poly(glycine) at the surface of a glassy carbon electrode (GCE). This sensor aims to detect life-threatening metronidazole (MTZ) residues in food samples. TA-Au-Ag-ANpM/r-GO/poly(glycine)/GCE was thoroughly characterized using a range of analytical techniques, including UV-Vis, FT-IR, XRD, SEM, and EDX. Furthermore, its electrochemical properties were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). The sensor exhibited outstanding performance, with a broad linear range of 2.0 pM-410 µM. The limits of detection (LOD) and quantification (LOQ) were determined to be 0.0312 pM and 0.104 pM, respectively. The TA-Au-Ag-ANpM/r-GO/poly(glycine)/GCE exhibited exceptional reproducibility, repeatability, stability, and resistance to interferences. Moreover, the sensor demonstrated outstanding performance in detecting MTZ residues in milk powder, pork, and chicken meat samples, achieving very good recoveries (96.9%-101.4%) with a relative standard deviation (RSD) below 5%. This performance highlights the potential for practical applications in food safety and quality monitoring. Therefore, the developed sensor contributes to the advancement of electrochemical sensing technology and its application in ensuring food safety and integrity by combating antibiotic residues.

Effect of Processing Methods on Antinutritional Factors (Oxalate, Phytate, and Tannin) and Their Interaction with Minerals (Calcium, Iron, and Zinc) in Red, White, and Black Kidney Beans.

The purpose of this study was to assess how different processing techniques affected mineral compositions, antinutritional factors, and their interactions in red, white, and black kidney beans consumed in Ethiopia. Mineral contents were found to be 41-44, 58-78, and 112-126 mg Ca/100 g in the raw, soaked, and cooked samples, respectively. Iron content in the raw, soaked and cooked samples were found to be 2.77-2.97, 1.94-2.20 and 2.87-3.28 mg Fe/100 g, respectively, showing 26-30% loss on soaking followed by 33-48% increase on cooking. While Zn content in the raw, soaked and cooked samples were found to be 2.47-3.26, 3.34-4.68 and 2.83-3.31 mg Zn/100 g, respectively, showing 35-43% increase on soaking followed by 15-29% decrease on cooking. In the case of antinutrients, both treatments showed incredible decrements. Phytate in the raw samples was 178-179 mg/100 g and showed a 12-16% decrement on soaking and a 37-38% decrement up on cooking, oxalate was 1.5-1.8 mg/100 g in the raw samples and showed a 4.4-13% decrement during treatments, and tannin in the raw samples was 102-160 mg/100 g and showed a 23-30% decrement on soaking, followed by 21-41% during cooking. Phytate : Ca and oxalate : Ca molar ratios in soaked and cooked samples were within the critical values in the raw samples. In contrast, phytate : Zn and Ca × phytate : Zn in all treatments were found to be within the critical value, confirming the good bioavailability of zinc in all the samples, while phytate : Fe was found over the critical value, showing its poor availability.

Electrochemical determination of zinc(II) using N1-hydroxy-N1,N2-diphenylbenzamidine and multi-walled carbon nanotubes modified carbon paste electrode.

In this study, a new carbon paste electrode modified with a laboratory-synthesized ligand, N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) and multi-walled carbon nanotubes (MWCNTs) (HDPBA‒MWCNTs/CPE) has been developed. The modified electrode was applied for preconcentration and voltammetric determination of zinc ions (Zn(II)) by square wave anodic stripping voltammetry (SWASV). The preconcentration of Zn(II) on the electrode surface was performed in 0.1 M Brinton Robinson (B-R) buffer solution (pH 6) at an applied potential of -1.30 V versus Ag/AgCl for 120 s, followed by stripping in the positive potential scan of the SWASV after a quit time of 10 s. Under optimized experimental conditions, the proposed electrode exhibited a wider linear dynamic response for Zn(II) in a concentration range of 0.02-10.00 µM with a detection limit of 2.48 nM. This is due to the excellent metal-chelation property of the ligand, and the good conductivity and large surface area of MWCNTs which significantly improved the sensing performance of the nanocomposite modified electrode. The selectivity of the electrode was studied by evaluating the interference effects of various foreign ions on the peak current of Zn(II). The method exhibited high reproducibility with a relative standard deviation (RSD) of 3.1%. The present method was applied for the determination of zinc ions in water samples. The recovery values in the tested samples were found to be 98.50-106.0%, indicating a good accuracy of the proposed electrode. Furthermore, the electrochemical behavior of HDPBA in acetonitrile and aqueous solutions has been studied.

Health and ecological risk assessment of potentially toxic metals in road dust at Lalibela and Sekota towns, Ethiopia.

The ecological and health problems resulted from heavy metals (Mn, Fe, Ni, Co, Cu, Zn, Cd, Hg, Pb, As, and Cr) in the road dust in the towns of Sekota and Lalibela, Ethiopia were assessed. The average heavy metal concentrations were ranged from 0.088 (Cd) to 2.714 (Fe) mg/kg. Individual metal and cumulative metals pollution levels in both towns revealed that Lalibela is moderately polluted by Zn, Pb, and Ni and Sekota being moderately polluted by Zn, Pb, Ni, As, Hg, and Cu. Furthermore, the United States Environmental Protection Agency's health risk evaluation model showed that the total heavy metal health risk levels in the road dust ranged from 5.71 × 10-3 (adult) to 2.57 × 10-2 (children), with an average risk of 7.35 × 10-2. Lalibela was found to have higher chance of risk than Sekota. The total lifetime cancer risk varied from 4.51 × 10-9 (for adults, Sekota) to 7.75 × 10-9 (for children, Lalibela), with a mean risk of 6.12 × 10-9 implying a low chance of getting cancer. The hazard quotient and hazard index of all the metals were below the limit. In general, children were found to be more susceptible than adults.

Validation of modified QuECHERS extraction method for quantitative enrichment of seven multiclass antibiotic residues from vegetables followed by RP-LC-UV analysis.

A modified rapid, simple quick, cheap, effective, robust and safe (QuEChERS) extraction method was developed for the simultaneous extraction and purification of seven antibiotic residues in lettuce, carrot and tomato using liquid chromatography UV detector. The method was validated for linearity, sensitivity, accuracy, repeatability, and reproducibility at six concentration levels for all matrices, according to the guidelines of UNODC. A matrix-matched calibration method was used for the quantitative analysis. Linear range of 0.01-250 µg kg-1 for target compounds with correlation coefficient (R2) 0.9978-0.9995 was obtained. The limits of detections (LODs) and quantifications (LOQs) were 0.02-2.48 µg kg-1 were 0.06-7.52 µg kg-1, respectively. The average recoveries of the seven antibiotics ranged from 74.5 to 105.9%, with relative standard deviation RSD (%) < 11, for all matrices and matrix effects were less than 20% for most of compounds. This comprehensive simple QuEChERS extraction method can be used for the investigation of multi-residue drugs belonging to different chemical families in vegetables.

Ascorbic Acid Content and Antioxidant Activities of White and Brown Teff [Eragrostic tef (Zucc.)Trotter] Grains and Injera.

Teff [Eragrostis tef (Zuccagni) Trotter] is a cereal grain originating in Ethiopia as a staple food for millions of people. Its grain is a gluten-free superfood and got acceptance as a medicinal ingredient. Therefore, it is worthwhile to determine the antioxidative activities and L-ascorbic acid contents of teff grain and its baked food (injera). This study aimed to determine the ascorbic acid contents and antioxidant activities in the aqueous extract of the white and brown teff grains and their injera samples using iodimetric titration and UV-Vis spectrophotometric methods, respectively. The ascorbic acid contents in the white and brown teff ranged from 67.9-112.6 mg/100 g and 69.2-117.2 mg/100 g, respectively, and those in injera of the selected teff samples ranged from 30.5-32.9 mg/100 g and 37.3-43.0 mg/100 g, respectively. The antioxidant activities ranged from 1.26-7.04 µmol AAE/g for the white teff grains, 1.44-6.29 µmol AAE/g for the brown teff grains, 1.81-2.47 µmol AAE/g for white teff injera, and 3.89-4.86 µmol AAE/g for the brown teff injera samples. Findings of the present study have revealed that white teff and brown teff grains and their injera were found to have a higher content of ascorbic acid than commonly consumed grains and vegetables. No significant difference (α = 0.05) has been observed between the two varieties of teff grains with respect to the ascorbic acid content and antioxidant activities. However, there was a statistically significant difference (α = 0.05) in the ascorbic acid content and antioxidant activities between the teff grains and their injera samples. Therefore, this study indicated that teff grains and injera are rich in ascorbic acid content and antioxidant activities as compared to other cereal grains and are very crucial for human nutrition and health.

Development of a new electrochemical method for the determination of copper(ii) at trace levels in environmental and food samples.

This paper presents the fabrication of a new modified carbon paste electrode (CPE) with N 1-hydroxy-N 1,N 2-diphenylbenzamidine (HDPBA) and functionalized multi-walled carbon nanotubes (MWCNTs) (HDPBA-MWCNTs/CPE) for highly sensitive and selective determination of Cu(ii) using the square wave anodic stripping voltammetry (SWASV) technique. The fabricated electrode was characterized using various spectroscopic techniques to study its morphological, structural, and electrochemical properties. The accumulation of Cu(ii) on the surface of HDPBA-MWCNTs/CPE was done in 0.1 M ammonium chloride (NH4Cl, pH 5) solution at an applied potential of -0.70 V versus Ag/AgCl for 180 s, followed by electrochemical stripping in the positive scan of the voltammetry after a resting time of 10 s. The developed HDPBA-MWCNTs/CPE was found to be highly selective, sensitive and reproducible. At optimal conditions of the experiment, the proposed method exhibited a very low limit of detection (0.0048 nM Cu(ii)), a wide linear dynamic range (0.00007-1.5000 µM Cu(ii)), and good reproducibility with relative standard deviation (RSD) value of 3.7%. The effect of various foreign ions on the voltammetric response of Cu(ii) was investigated and the electrode was found to be highly selective to Cu(ii). The practical applicability of the proposed HDPBA-MWCNTs/CPE was studied by applying the electrode for the quantification of Cu(ii) contents in environmental water (wastewater and tap water), soft drink (Fanta and Sprite), and food supplement (commercially available multi-mineral/vitamin tablets) samples. The present method was validated with atomic absorption spectrometry (AAS). The results found from the two methods are in good agreement with a 95% confidence level.

Development of Green UV-Vis Method for Direct Determination of Total Sugars in the Aqueous Extract of Teff (Eragrostis tef (Zuccagni) Trotter) Grains and Other Cereals.

There is no ultraviolet visible (UV-Vis) spectrophotometric method for the direct determination of total sugars in the aqueous extract of teff grain samples. Therefore, the objective of this study was to develop a green UV-Vis spectrophotometric method to determine total sugars in the aqueous extract of white teff, brown teff, white rice, and red wheat grain samples. The calibration curve was established in the range of 20.11-7,907 mg/L using sucrose as a standard with R 2 = 0.9996. The limit of detection and limit of quantification were 4.4 and 14.6 mg/L, respectively. The relative standard deviation (6.9%) of the method for the sucrose standard was within the acceptable range indicating that the method is precise. The amount of total sugars determined in the white teff (5.48-9.44% (w/w), brown teff (6.17-10.32% (w/w)), white rice (3.19% (w/w)), and red wheat (9.22% (w/w)) grain samples was comparable with other reported cereal grains. Furthermore, the accuracy of the developed analytical method was also evaluated by spiking the known amount of the sucrose standard solution to the white teff, brown teff, white rice, and red wheat sample extracts, and percentage recoveries found were in the acceptable range (85 ± 2 - 105 ± 4%) with an average recovery of 93%, confirming that the new green method is quantitatively reproducible. Hence, a fast, simple, inexpensive, widely used, selective, sensitive, precise, and accurate green UV-Vis method was developed and validated for the direct determination of total sugars in the aqueous extract of teff, white rice, and red wheat grain samples.

Development and validation of liquid chromatography method for simultaneous determination of multiclass seven antibiotic residues in chicken tissues.

BACKGROUND: Antibiotics are routinely used on poultry for therapy and prevention of diseases and to enhance animal growth. The objective of this study was to develop and validate a sensitive and reliable liquid chromatography with UV detection (LC-UV) method for the simultaneous determination of seven multiclass antibiotic residues (amoxicillin, ampicillin, penicillin, sulfamethoxazole, gentamicin, ciprofloxacin, and erythromycin) in chicken tissues. METHODS: The liquid chromatography method with UV detection was optimized for complete separation of the seven selected antibiotic compounds with reversed phase and isocratic elution using Hypersil BDS-C18 (3 µm, 100 mm × 4 mm) column. The mobile phase consisted a ratio of 0.05 M Na2HPO4, acetonitrile and methanol (70:10:20), at UV absorption wavelength of 230 nm. The column thermostat was set at 40 °C, the mobile phase flow rate was 1 mL min-1, and the injection volume was 20 µL. RESULTS: All the seven standard compounds were eluted within 14 min. The results for: linearity, precision, sensitivity, accuracy, specificity, decision limit (CCα), detection capability (CCß), suitability and method robustness were validated according to the criteria of Commission Decision 2002/657/EC guidelines. Calibration plot correlation coefficients ranged from 0.9983 to 0.9998 and the percent relative standard deviations for repeated analysis were below 5% indicating acceptable method precision. The limits of detection (LODs) and quantification (LOQs) ranged from 0.098-0.255 µg kg-1 to 0.297-0.574 µg kg-1, respectively. The accuracy study yielded recoveries in the ranges 98.1-107% for the pure compounds and 94.0-102% for the spiked drug free chicken tissue samples. CONCLUSIONS: The method was found to be appropriate for simultaneous determination of five different classes of seven antibiotic residues in chicken tissues. Furthermore, this is the first instance for the simultaneous determination of seven multiclass, multi-residues analysis using LC-UV from chicken tissue samples. This is a cost-effective and alternative method with simple instrumentation approach for laboratories that lack highly specialized state-of-the-art instrumentation.

Development of Analytical Methods for Determination of ß-Carotene in Pumpkin (Cucurbita maxima) Flesh, Peel, and Seed Powder Samples.

Vegetables are consumed worldwide in fresh as well as processed forms. Pumpkin is considered as an important vegetable due to its nutritional values. The objective of this study was to evaluate all the analytical parameters and improve the performance of the methods for the determination of ß-carotene in pumpkin flesh, peel, and seed samples using UV-VIS, NIR, and FTIR methods. ß-Carotene was measured at 453 nm using the UV-VIS method which showed linear range, 0.1 to 12 µg/mL; R 2, 0.999; LOD, 0.034 µg/mL; LOQ, 0.1 µg/mL; RSD, 1.5% to 11%; and percent recovery, 83% to 93%. ß-Carotene was also measured at 1415 nm using NIR and at 1710 cm-1 using FTIR spectroscopic methods. The NIR method exhibited linear range, 12.5 to 250 µg/mL; R 2, 0.999; LOD, 3.4 µg/mL; LOQ, 10, µg/mL; RSD, 1.8% to 11%; and percent recovery, 92% to 96%, while the FTIR method exhibited linear range, 4 to 100 µg/mL; R 2, 0.999; LOD, 1.3 µg/mL; LOQ, 3.9 µg/mL; RSD, 0.69% to 10%; and percent recovery, 95% to 96%. The characteristic analytical data indicated that any of the three newly developed methods could be used for the determination of ß-carotene in the pumpkin flesh, peel, and seeds. Acetone was used as the extraction solvent for the UV-VIS and NIR spectroscopic methods, and acetonitrile was used as the extraction solvent for the FTIR method. Content of ß-carotene was found higher in pumpkin peel (340-445 µg/g), followed by pumpkin flesh (317-341 µg/g) and pumpkin seed (12-17 µg/g) by the UV-VIS method. ß-Carotene content was obtained ((376-451 µg/g) and (289-313 µg/g); (210-287 µg/g) and (102-148 µg/g)) using NIR and FTIR methods in pumpkin peel and flesh, respectively. ß-Carotene was obtained higher from pumpkin peel by all the three methods than from pumpkin flesh and seed. The ß-carotene content in the pumpkin seed was not detected by NIR and FTIR spectroscopic methods.

Solid-phase optimisation for simultaneous determination of thirteen pharmaceuticals in Ethiopian water samples with HPLC-DAD detection: an initial assessment.

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.

Indoor air pollution from cook-stoves during Injera baking in Ethiopia, exposure, and health risk assessment.

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%.

In Vitro Antibacterial and Antioxidant Activities of Roasted and Green Coffee Beans Originating from Different Regions of Ethiopia.

Coffee is among the most traded commodities and consumed beverages worldwide primarily for its stimulating effects. Moreover, coffee is known to contain various bioactive compounds with significant health benefits including antibacterial and antioxidant activities. However, Ethiopia as the origin of coffee and producer and exporter of varieties of Coffea arabica has made little study on the health aspects of this beverage. The aim of this study was to examine the antibacterial and antioxidant activities and content of coffee samples from different localities of Yorgacheffe and Jimma; and roasted, ground, and packed samples purchased from a coffee shop in Addis Ababa. Medium-roasted-boiled and lyophilized coffee extracts were tested on eight gram-negative and gram-positive bacterial strains. The agar-well diffusion method was used to test the extracts determining the minimum inhibitory and bactericidal concentrations. For coffee antioxidant activity and content, light-roasted (both field and shop samples) and green coffee bean extracts were tested using the free radical 2.2-diphenyl-l-pict1hydrazyl (DPPH) IC50 percent inhibition protocol. The samples showed strong antibacterial and antioxidant activity and substantial antioxidant content. Significant variation was noted in the antibacterial activities of the different coffee samples. Moreover, the growth-inhibitory strength of each coffee sample was variable for different test bacteria. A coffee sample with the best antibacterial activity had also the highest antioxidant activity/content. The shop coffee had the lowest bioactivity. The observed variations in the antibacterial and antioxidant activities among the samples probably indicate the diversity of the Ethiopian coffee related, among other factors, to the coffee plant genetics and agroecology.

Effect of altitude of coffee plants on the composition of fatty acids of green coffee beans.

BACKGROUND: The fatty acids of green coffee beans are one of the major components that determine the quality of coffee. Fatty acids composition of green coffee beans is affected by soil composition and altitude of coffee plants. This study was aimed to evaluate the effect of altitude of the coffee plants on the composition of fatty acids in green coffee beans. METHODS: Fatty acids contents of 40 green coffee beans samples collected from the coffee plants grown at different altitudes (group 1: 1500-1700, group 2: 1701-1900 and group 3: > 1900 m.a.s.l.) in Ethiopia were determined using gas chromatography-mass spectrometry (GC-MS). Chemometric data analyses were performed to determine the effects of altitude on the fatty acid composition of the green coffee beans. RESULTS: The green coffee beans contained main saturated fatty acid, palmitic acid with an average value of 55.5 mg/g and unsaturated fatty acid, linoleic acid with an average value of 51.6 mg/g. The other major constituents of fatty acids present in green coffee beans were stearic and oleic acids with the value of 12.3 mg/g and 8.92 mg/g, respectively. Palmitic acid content in lowland green coffee beans is significantly different than in the other two regions. On the other hand, stearic and oleic acids contents in the green coffee beans did not show a significant difference between the three topographical regions. While linoleic acid content in the green coffee beans showed significant difference between group 1 and 3 but did not show significant differences between group 1 and 2 and between group 2 and 3. The four major fatty acids, palmitic (R = - 0.574), linoleic (R = - 0.506), stearic (R = - 0.43) and oleic acids (R = - 0.291) in green coffee beans showed a moderate negative correlation with the altitude of coffee plants. CONCLUSION: The fatty acids contents decreases with increasing altitude of the coffee plants and hence affects the quality of coffee. The fatty acid composition of green coffee beans can also be used to determine the topographical origin of coffee plants.

Salting-out assisted liquid-liquid extraction for the determination of ciprofloxacin residues in water samples by high performance liquid chromatography-diode array detector.

BACKGROUND: The occurrence of emerging pollutants like pharmaceuticals and related compounds in the aquatic and terrestrial environments is of increasing concern. Ciprofloxacin is one of the pharmaceuticals which is active against a wide range of bacteria. The main objective of this research is to develop a simple method for the extraction and determination of ciprofloxacin residues in environmental water samples. RESULTS: A salting-out assisted liquid-liquid extraction (SALLE) method for the determination of ciprofloxacin in water samples by high-performance liquid chromatography with diode array detector (HPLC-DAD) was developed. The calibration curve was linear over the range of 0.1-100 µg/L with coefficient of determination (r2) of 0.9976. The limits of detection (LOD) and quantification (LOQ) of the method were 0.075 and 0.25 µg/L, respectively. The reproducibility in terms of relative standard deviation (% RSD) was less than 10%. The applicability of the developed method was investigated by analyzing tap water, bottled mineral water and waste water and demonstrated satisfactory recoveries in the ranges of 86.4-120%. CONCLUSION: The method offered a number of features including wide linear range, good recovery, short analysis time, simple operation process and environmental friendly. The developed method can be utilized as an attractive alternative for the determination of ciprofloxacin residues in environmental water matrices.

Levels of trace elements in PM10 collected at roadsides of Addis Ababa, Ethiopia, and exposure risk assessment.

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.

GC-MS profiling of fatty acids in green coffee (Coffea arabica L.) beans and chemometric modeling for tracing geographical origins from Ethiopia.

BACKGROUND: This study was aimed at the development of objective analytical method capable of verifying the production region of the coffee beans. One hundred samples of green coffee (Coffea arabica L.) beans from the major producing regions, comprising various sub-regional types, were studied for variations in their fatty acid compositions by using gas chromatography coupled with mass spectrometry. Principal component analysis (PCA) was used to visualize data trends. Linear discriminant analysis (LDA) was used to construct classification models. RESULTS: Twenty-one different fatty acids were detected in all of the samples. The total fatty acid content varied from 83 to 204 g kg-1 across the regions. Oleic, linoleic, palmitic, stearic and arachidic acids were identified as the most discriminating compounds among the production regions. The recognition and prediction abilities of the LDA model for classification at regional level were 95% and 92%, respectively, and 92% and 85%, respectively, at sub-regional level. CONCLUSION: Fatty acids contain adequate information for use as descriptors of the cultivation region of coffee beans. Chemometric methods based on fatty acid composition can be used to detect fraudulently labeled coffees, with regard to the production region. These can benefit the coffee production market by providing consumers with products of the expected quality. © 2019 Society of Chemical Industry.

Improvement in Analytical Methods for Determination of Sugars in Fermented Alcoholic Beverages.

The main objective of this study was to improve the performance of analytical methods for the determination of sugars in fermented alcoholic beverages based on mid-infrared-partial least squares (MIR-PLS), high-performance liquid chromatography with the ultraviolet detector (HPLC-UV), high-performance liquid chromatography with the refractive index detector (HPLC-RI), and sulfuric acid methods. The MIR-PLS method was found to give good prediction of individual sugars: glucose, fructose, sucrose, and maltose in the alcoholic beverages with less than 4% error. The HPLC-UV method can be used for the determination of glucose in alcoholic beverages after derivatization with p-aminobenzoic acid ethyl ester. The HPLC-RI method was found to be applicable for the determination of individual sugars: glucose, fructose, sucrose, and maltose in the alcoholic beverages. The limit of detection (%, w/w) and recovery (%) of the individual sugars by the HPLC-RI method were fructose 0.001, 89.4-106; glucose 0.002, 92.4-109; and sucrose 0.002, 94.2-95.1. The sulfuric acid method was found to be useful for the determination of total sugar in the alcoholic beverages. The limit of detection (%, w/w) and recovery (%) of the total sugar by the sulfuric acid method were found to be 0.009, 98.2-109. The HPLC-RI method was applied to determine the level of individual sugars, while the sulfuric acid method was used to determine total sugar in Ethiopian traditional fermented alcoholic beverages: Tella, Netch Tella, Filter Tella, Borde, Tej, Korefe, Keribo, and Birz. The sugar contents in the real samples were found in the ranges (%): glucose 0.07-5.60, fructose 0.09-8.50, sucrose and maltose 0.08-3.00, and total sugar 12.0-64.5. The levels of sugars in Ethiopian traditional fermented alcoholic beverages were found to be comparable with literature data.