Trace analysis of perchlorate anion in selected food products by reverse-phase liquid chromatography-tandem mass spectrometry.

An alternative, rapid, and reproducible method of analysis for perchlorate in selected food products (fruit and vegetable juice, milk, and bottled water) was developed and validated. Improvements over previous methods were achieved by the use of a rugged and inexpensive C18 column, a multi-mode OASIS HLB solid-phase extraction cartridge for sample clean-up, and acetic acid for pH adjustment and protein precipitation. The hydrophobicity of the perchlorate anion gives it good retention and separation characteristics on C18 chromatographic columns. The C18 column allowed for the use of 90% of acetonitrile at a low flow rate (0.3 ml min(-1)), without splitting, and could also be regenerated with organic solvents, unlike an ion-exchange column. Perchlorate levels in selected commercial food samples were: <1.0-2.1 ng g(-1) (fruit and vegetable juices, reported here for the first time), <1.0-5.0 ng g(-1) (milk), and <1.0 ng g(-1) (bottled water).     

High-performance liquid chromatographic method for the simultaneous detection of the adulteration of cereal flours with melamine and related triazine by-products ammeline, ammelide, and cyanuric acid

Melamine has been used for the adulteration of cereal flours in order to increase their apparent protein content. Crude melamine may contain several by-products, i.e. ammeline, ammelide, and cyanuric acid. The simultaneous analysis of all four chemicals is difficult because of the formation of an insoluble salt between melamine and cyanuric acid. A simple and convenient high-performance liquid chromatography (HPLC) method for the detection of the adulteration of cereal flours with all four chemicals is proposed herein. The precipitate formation between melamine and cyanuric acid was prevented by using alkaline conditions (pH 11-12) for both standards preparation and sample extraction. The method uses matrix-matching, which involves the construction of a calibration curve on a blank (negative control) matrix, which is then used for the quantitation of melamine and by-products in adulterated (positive) samples. Matrix-matching compensates for analyte losses during sample preparation, and for matrix effects. The method was successfully applied to wheat, corn, and rice flours, and is expected to be applicable (with some modifications) to soy flour as well. The method allows for the detection of melamine, ammeline, and ammelide at approximately 5 µg g^-1, and cyanuric acid at approximately 90 µg g^-1 in wheat flour.     

Detection of guaiacol produced by Alicyclobacillus acidoterrestris in apple juice by sensory and chromatographic analyses, and comparison with spore and vegetative cell populations

Spoilage of fruit juice by Alicyclobacillus acidoterrestris is characterized by a distinct medicinal or antiseptic off odor attributed to guaiacol, a metabolic by product of the bacterium. Detection of low populations of A. acidoterrestris that would precede sensory detection of guaiacol would enable juice processors to select appropriate processing and storage conditions that would minimize or eliminate spoilage. The objective of this study was to determine the recognition threshold of guaiacol in apple juice by sensory analysis and the population of A. acidoterrestris and incubation time at 21 and 37 degrees C necessary for chemical detection of guaiacol. Commercially sterilized apple juice (pH 3.54 +/- 0.04, 11.3 +/- 0.3 degrees Brix) was inoculated with a five-strain mixture of A. acidoterrestris spores (2.98 log10 CFU/ml) and stored at 21 or 37 degrees C for up to 61 days. Using an experienced sensory panel and the forced-choice ascending concentration method of limits, the best estimate threshold (BET) for recognition of guaiacol added to uninoculated apple juice was 2.23 ppb. Numbers of A. acidoterrestris spores and cells in inoculated juice remained constant during the 61-day storage period; however, the panel detected (P < or = 0.01) guaiacol in juice stored at 37 degrees C within 8 days. At three of four sampling times ranging from 13 to 61 days at which the sensory panel detected (P < or = 0.001) guaiacol, concentrations of 8.1 to 11.4 ppb were detected by chromatographic analysis. The panel detected (P < or = 0.1 to P < or = 0.01) guaiacol in five samples stored at 21 to 37 degrees C for 8 to 61 days in which the compound was not detected by chromatographic analyses. It appears that guaiacol content in apple juice inoculated with A. acidoterrestris is not always correlated with numbers of cells, and the limit of sensitivity of chromatographic quantitation of the compound is higher than the BET.     

Food insecurity,school absenteeism and educational attainment of adolescents in Jimma Zone Southwest Ethiopia: a longitudinal study

Background  

Food insecurity not only affects physical growth and health of children but also their intellectual development, school attendance and academic performance. However, most evidences are based on studies in high income countries. Although food insecurity is common in Ethiopia, to what extent it affects school attendance and educational attainment of adolescents is not explored. We hypothesized that food insecure adolescents would be more likely to be absent from school and have lower grades attained after 1 year compared to their food secure peers.     

Experimental study on combustion of torrefied palm kernel shell (PKS) in oxy‐fuel environment

Oxy‐combustion of biomass can be a major candidate to achieve negative emission of CO₂ from a pulverized fuel (pf)‐firing power generation plants. Understanding combustion behavior of biomass fuels in oxy‐firing conditions is a key for design of oxy‐combustion retrofit of pulverized fuel power plant. This study aims to investigate a lab‐scale combustion behavior of torrefied palm kernel shell (PKS) in oxy‐combustion environments in comparison with the reference bituminous coal. A 20 kW_th‐scale, down‐firing furnace was used to conduct the experiments using both air (conventional) and O₂/CO₂ (30 vol% for O₂) as an oxidant. A bituminous coal (Sebuku coal) was also combusted in both air‐ and oxy‐firing condition with the same conditions of oxidizers and thermal heat inputs. Distributions of gas temperature, unburned carbon, and NO_x concentration were measured through sampling of gases and particles along axial directions. Moreover, the concentrations of SO_x and HCl were measured at the exit of the furnace. Experimental results showed that burnout rate was enhanced during oxy‐fuel combustion. The unburnt carbon in the flue gas was reduced considerably (~75%) during combustion of torrefied PKS in oxy‐fuel environment as compared with air‐firing condition. In addition, NO emission was reduced by 16.5% during combustion of PKS in oxy‐fuel environment as compared with air‐firing condition.     

Effects of coal characteristics to performance of a highly efficient thermal power generation system based on pressurized oxy‐fuel combustion

Because of its fuel flexibility and high efficiency, pressurized oxy‐fuel combustion has recently emerged as a promising approach for efficient carbon capture and storage. One of the important options to design the pressurized oxy‐combustion is to determine method of coal (or other solid fuels) feeding: dry feeding or wet (coal slurry) feeding as well as grade of coals. The main aim of this research is to investigate effects of coal characteristics including wet or dry feeding on the performance of thermal power plant based on the pressurized oxy‐combustion with CO₂ capture versus atmospheric oxy‐combustion. A commercial process simulation tool (gCCS: the general carbon capture and storage) was used to simulate and analyze an advanced ultra‐supercritical(A‐USC) coal power plant under pressurized and atmospheric oxy‐fuel conditions. The design concept is based on using pure oxygen as an oxidant in a pressurized system to maximize the heat recovery through process integration and to reduce the efficiency penalty because of compression and purification units. The results indicate that the pressurized case efficiency at 30 bars was greater than the atmospheric oxy‐fuel combustion (base line case) by 6.02% when using lignite coal firing. Similarly, efficiency improvements in the case of subbituminous and bituminous coals were around 3% and 2.61%, respectively. The purity of CO₂ increased from 53.4% to 94% after compression and purification. In addition, the study observed the effects of coal‐water slurry using bituminous coal under atmospheric conditions, determining that the net plant efficiency decreased by 3.7% when the water content in the slurry increased from 11.12% to 54%. Copyright © 2016 John Wiley & Sons, Ltd.     

Food Insecurity and Associated Factors among HIV-infected individuals receiving highly active antiretroviral therapy in Jimma zone Southwest Ethiopia

ABSTRACT: BACKGROUND: In resource limited settings, many People Living with HIV/AIDS (PLWHA) lack access to sufficient quantities of nutritious foods, which poses additional challenges to the success of antiretroviral therapy (ART). Maintaining adequate food consumption and nutrient intake levels and meeting the special nutritional needs to cope up with the disease and the ART are critical for PLWHA to achieve the full benefit of such a treatment. OBJECTIVE: To determine the prevalence and correlates of food insecurity among HIV-infected individuals receiving highly active antiretroviral therapy in resource-limited settings. METHODS: A cross sectional study was carried out from January 1, 2009 to March 3, 2009 at ART clinic at Jimma University specialized hospital (JUSH) in Ethiopia. We used multivariable logistic regression model to compare independent risk factors by food insecurity status among 319 adult PLWHA ([greater than or equal to]18 years) attending ART Clinic. RESULTS: A total of 319 adult PLWHA participated in the study giving a response rate of 100%. Out of 319 PLWHA the largest numbers of participants, 46.4% were in the age group of 25-34 years. The overall 201(63.0%) PLWHA were food insecure. Educational status of elementary or lower [OR=3.10 (95%CI; (1.68-5.71)], average family monthly income <100 USD [OR=13.1 (95% CI; (4.29-40.0)] and lower food diversity [OR=2.18 (95%CI; (1.21--3.99)] were significantly and independently associated with food insecurity. CONCLUSION: Food insecurity is a significant problem among PLWHA on HAART. Lower educational status and low family income were the predictors of food insecurity. Food security interventions should be an integral component of HIV/AIDS care and support programs. Special attention need to be given to patients who have lower educational status and are members of households with low income. KEYWORDS: Food insecurity, HAART, PLWHA, HIV/AIDS, Ethiopia.     

Integrated watershed management: A planning methodology for construction of new dams in Ethiopia

Integrated watershed management (IWM) is emerging as an alternative to the centrally planned and sectoral approaches that currently characterize the planning process for dam construction in Ethiopia. This report clarifies the concept of IWM, and reviews the major social, environmental and economic problems caused by dams in Ethiopia and elsewhere. Dams are planned from a top‐down perspective in Ethiopia, some people are relocated against their will, haphazard land‐use changes can occur, and soil erosion and reservoir sedimentation can increase. Many communities affected by dam constructions have not been sufficiently recognized or compensated, and environmental protection measures such as land‐use planning and soil and water conservation have not been adopted in watersheds in which construction of dams is occurring. Furthermore, revenues generated from hydropower and water supplies often benefit urban dwellers, or the national economy, at the expense of rural inhabitants in watersheds. Creation of a multistakeholder platform, integration of soft system methodology with hard system tools, and completion of environmental protection measures should be among the major components of an improved planning methodology for construction of new dams in Ethiopia. This translates into an environment wherein science and knowledge can help watershed inhabitants create a diversity of locally appropriate resource management solutions. Effective implementation of environmental policies and strategies could improve the quality of watershed‐based developments. The conclusion is that the IWM approach is a good alternative to effectively address the social, environmental and economic problems associated with planning and constructing new dams in Ethiopia.