Comparison of electrothermal and hydride generation atomic absorption spectrometry for the determination of total arsenic in broiler chicken

The purpose of this study was to estimate total arsenic concentration in different tissues (leg, breast, liver and heart) of broiler chicken by hydride generation atomic absorption spectrometry (HGAAS) and graphite furnace atomic absorption spectrometry (GFAAS), prior to microwave assisted acid digestion. The accuracy of the techniques was evaluated by using certified reference material DORM-2. The percentage recoveries of total As were observed as 100.6% and 99.4% for HGAAS and GFAAS, respectively. The precision of the techniques, expressed as relative standard deviation, was observed as 1.71% and 4.18% for HGAAS and GFAAS measurements, respectively. The limits of detection for HGAAS and GFAAS were 0.025 μg/g and 0.052 μg/g, respectively. The concentrations of total arsenic in different tissues of broiler chicken were found in the range of 2.19–5.28, 2.15–5.22, 2.97–7.17 and 2.68–6.36 μg/g for leg, breast, liver and heart tissues, respectively. At a mean level of chicken consumption (60 g/person/day), people may ingest in the range of 72.0–85.1 μg arsenic/person/day from chicken alone.     

A new sensor for the simultaneous determination of paracetamol and mefenamic acid in a pharmaceutical preparation and biological samples using copper(II) doped zeolite modified carbon paste electrode

A new chemically modified electrode is constructed based on a copper(II) doped zeolite modified carbon paste electrode (Cu²⁺Y/ZMCPE). It is demonstrated that this novel sensor could be used for the simultaneous determination of the pharmaceutically important compounds paracetamol (PAR) and mefenamic acid (MEF). The measurements were carried out using the differential pulse voltammetry (DPV) method. The prepared modified electrode shows voltammetric responses of high sensitivity, selectivity and stability for PAR and MEF under optimal conditions, which makes it a suitable sensor for simultaneous submicromolar detection of PAR and MEF in solution. The oxidation peak current for PAR in Briton Robinson buffer (pH = 10) was measured at various concentrations between 0.25 and 900 μM. (The detection limit was 0.1 μM and S/N was 3.) It proved linear (the correlation coefficient was 0.9987). For the MEF a linear correlation between oxidation peak current and concentration of MEF over the range 0.3–100 μM, with a correlation coefficient of 0.9991 and a detection limit of 0.04 μM, was obtained. The analytical performance of this sensor has been evaluated for the detection of PAR and MEF in human serum, human urine and a pharmaceutical preparation.     

Hazardous impact of toxic metals on tobacco leaves grown in contaminated soil by ultrasonic assisted pseudo-digestion: multivariate study

Tobacco leaves (Nicotiana tabacum L.), agricultural soil and pollute irrigated lake water samples were collected during 2005–2006 and analyzed for Cd and Ni by electrothermal atomic absorption spectrometry (ETAAS). A simple and efficient procedure was investigated for the complete decomposition of tobacco leaves using ultrasonic assisted acid pseudo-digestion method (UPDM). A Plackett–Burman experimental design was used as a multivariate strategy for the evaluation of seven factors/variables at once, while central composite were used to found optimum values of significant variables. The accuracy of the proposed methods was assessed by analyzing certified reference (CRM); Virginia tobacco leaves (CTA-VTL-2). The results being compared with those obtained by conventional wet acid digestion method. The result obtained by optimized method showed good agreement with the certified values and sufficiently high recovery 97.8 and 98.7% for Cd and Ni, respectively. Under optimal conditions, the detection limits (3σ) were evaluated to be 0.019 μg g⁻¹ for Cd and 0.37 μg g⁻¹ for Ni. The proposed method was successfully applied to the determination of Cd and Ni in raw, processed tobacco and different branded cigarettes samples.     

A multivariate study: variation in uptake of trace and toxic elements by various varieties of Sorghum bicolor L

The aim of present study was to evaluate the variation in uptake of elements (As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn) by different varieties of Sorghum bicolor L., plants grown in soil amended with untreated industrial waste water sewage sludge (SUIS), on same experimental plots. The power of chemometrics was also used in exploring the potential natural and/or anthropogenic sources responsible for elemental contents in different varieties of sorghum. Hierarchical cluster analysis was used to explore the different variety of sorghum grouping according to corresponding their SUIS samples as additional information to the output obtained by principal component analysis. Significant genotypic variation was detected in the fourteen elements concentrations in sorghum grains, indicating the possibility to reduce the concentration of toxic elements in grains through breeding approach. It was observed that high tolerance limit of toxic elements was observed in sorghum variety PARC-SV-1.     

Design of multiplex PCR for simultaneous detection of rope-forming Bacillus strains in Iranian bread dough

BACKGROUND: The objective of this study was optimisation of multiplex polymerase chain reaction (PCR) by a new primer set for simultaneous detection of ropiness agents as the main bacterial spoilage of Iranian bread. After inoculation of bread dough with activated Bacillus licheniformis (ATCC 9789) and Bacillus subtilis (ATCC 6633), DNA was extracted from the dough and subjected to PCR. Then simplex and multiplex PCR tests were optimised. RESULTS: From the results obtained, the optimum PCR conditions for simultaneous detection of the target genes in Bacillus species were an annealing temperature of 59 °C and an MgCl₂ concentration of 2.5 mmol L^?1. To design primers for these two bacteria, owing to close homology and the existence of similar conserved sequences in their 16S rRNA genes, lpaL and aprE genes (497 and 744 bp target sequences) respectively were chosen. Finally, by sequencing of PCR products, accurate and specific detection of the two desired Bacillus species was confirmed. The results were registered with GenBank under accession numbers HQ877873 and HQ871154. CONCLUSION: Compared with culture‐dependent methods, this procedure offers significantly higher accuracy and speed, which are crucial criteria when it comes to food safety and high volumes of referred samples respectively. Copyright © 2012 Society of Chemical Industry     

Accumulation of arsenic in different fresh water fish species – potential contribution to high arsenic intakes

The aim of the study was to evaluate total arsenic (As) in five tissues (gills, mouthpiece, intestine, liver and muscles) of 10 fish species caught from As contaminated Manchar Lake (26°3′N: 67°6′E) Sindh Pakistan during 2006–2007. The total As concentration was determined by hydride generation atomic absorption spectrometry (HG-AAS), prior to microwave assisted acid digestion. The certified reference material DORM-2 (dogfish muscle) was used to check the quality control of the technique. The good agreement with the certified value at 95% confidence limit confirmed the validity of As determination method. The limit of detection (LOD) and limit of quantitation (LOQ) of As were 0.034 and 0.11 μg/g, respectively.     

Respiratory effects in people exposed to arsenic via the drinking water and tobacco smoking in southern part of Pakistan

In this study, a survey has been conducted during 2005-2007 on surface and groundwater arsenic (As) contamination and its impact on the health of local population, of villages located on the banks of Manchar lake, southern part of Sindh, Pakistan. We have also assessed the relationship between arsenic exposure through respiratory disorders in male subjects with drinking water and smoking cigarettes made from tobacco grown in agricultural land irrigated with As contaminated lake water. The biological samples (blood and scalp hair) were collected from As exposed subjects (100% smokers) and age matched healthy male subjects (40.2% smoker and 59.8% non smokers) belong to unexposed areas for comparison purposes. The As concentration in drinking water (surface and underground water), agricultural soil, cigarette tobacco and biological samples were determined by electrothermal atomic absorption spectrometry. The range of As concentrations in lake water was 35.2-158 µg/L (average 97.5 µg/L), which is 3-15 folds higher than permissible limit of World Health Organization (WHO, 2004). While the As level in local cigarette tobacco was found to be 3-6 folds higher than branded cigarettes (0.37-0.79 µg/g). Arsenic exposed subjects (with and without RD) had significantly elevated levels of As in their biological samples as compared to referent male subject of unexposed area. These respiratory effects were more pronounced in individuals who had also As induced skin lesions. The linear regressions showed good correlations between As concentrations in water versus hair and blood samples of exposed subjects with and without respiratory problems.     

Is There Any Relationship between Serum Levels of IL‐10 and Atherosclerosis in Hemodialysis Patients?

Background:  Cardiovascular complications due to atherosclerosis (AS) are the major cause of mortality in hemodialysis (HD) patients. Inflammation may play an important role in the development of AS. Several studies have demonstrated the association of acute-phase proteins and cytokines with AS in the general population and in HD patients. Interleukin-10 (IL-10) is an anti-inflammatory cytokine. The aim of study was to compare serum levels inflammatory and anti-inflammatory indicators in HD patients according to the presence or absence of AS.
Methods:  Thirty-three HD patients were enrolled. AS was defined as the detection of plaques by Doppler ultrasonography. The patients were subgrouped according to the presence or absence of plaques. Serum levels of IL-1, IL-2, IL-6, IL-10, C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) were measured. The factors for AS such as age, gender, hypertension, hyperlipidemia, and HD duration were also evaluated.
Results:  We found that the patients with AS had significantly higher hs-CRP and lower IL-10. Blood pressure values were also increased in patients with AS. Additionally, there was an increased correlation between CRP and IL-10.
Conclusions:  AS(+) patients undergoing HD had low serum levels of anti-inflammatory cytokine IL-10 and high serum levels of hs-CRP. These results may suggest that the limitation of anti-inflammatory response in atherosclerotic uremic patients is a triggering or contributing factor for AS.     

Preparation of cerium oxide–MWCNTs nanocomposite bulk modified carbon ceramic electrode: a sensitive sensor for tamoxifen determination in human serum samples

In this study, cerium oxide and multi-walled carbon nanotubes nanocomposite were incorporated into the carbon ceramic electrode (CeO₂–MWCNTs/CCE) as a renewable electrode for the electrocatalytic purposes. To demonstrate capability of the fabricated electrode, determination of tamoxifen as an important anticancer drug with differential pulse voltammetry technique was evaluated in details. Linear range, limit of detection and sensitivity of the developed sensor were found to be 0.2–40 nM, 0.132 nM and 1.478 µA nM^?1 cm^?2, respectively. Ease of production, low cost and high electron transfer rate of the CeO₂–MWCNTs/CCE promises it as a novel electro-analytical tool for determination of important species in real samples.

     

High level modeling and automated generation of heterogeneous SoC architectures with optimized custom reconfigurable cores and on-chip communication media

In this paper we propose a framework for modeling and automated generation of heterogeneous SoC architectures with emphasis on reconfigurable component integration and optimized communication media. In order to facilitate rapid development of SoC architectures, communication-centric platforms for data intensive applications, high level modeling of reconfigurable components for quick simulation and a tool for generation of complete SoC architectures is presented. Four different communication-centric platforms based on traditional bus, crossbar, hierarchical bus and novel hybrid communication media are proposed. These communication-centric platforms are proposed to cater for the different communication requirement of future SoC architectures. Multi-Standard telecommunication application is chosen as our target application domain and a case study of WiMAX is used as a real world example to demonstrate the effectiveness of our approach. A system consisting of an ARM processor, reconfigurable FFT and reconfigurable Viterbi decoder is considered with the option of system scalability for future upgrades. Behavior of system with different communication platforms is analyzed for its throughput and power characteristics with different reconfigurable scenarios to show the effectiveness of our approach.