Development of in-situ produced CO2 switchable fatty acid microextraction based solidification of floating organic droplet for quantification of morin and quercetin in tea, vegetable and fruit juice samples by HPLC

An in-situ produced CO2 switchable fatty acid microextraction based on solidification of floating organic droplet (In-situ-CO2-SFA-ME-SFO) was evaluated for microextraction of two antioxidant flavonoids (morin and quercetin) in tea, fruit juice and vegetable samples prior to HPLC-UV. Medium-chain fatty acids (e.g. nonanoic acid) were investigated as switchable hydrophilicity solvents via pH adjustment. Sodium carbonate (Na2CO3) was used to solubilize immiscible fatty acid in water as well as, to provide effervescence. The addition of H2SO4 into the solution led to the in-situ chemical reaction with excess Na2CO3 which resulted in effective dispersion of fatty acid through generated CO2 and separation of phases. Subsequently, solidification of the fatty acid enabled facile separation without the need for sophisticated equipment. To optimize extraction process, the effects of some important parameters on the extraction recovery were investigated. At the optimum conditions, the limits of detection (LODs) and the limits of quantification (LOQs) were found 0.5 and 1.3 µg L−1 and 1.6 and 4.3 µg L−1 for morin and quercetin respectively. The preconcentration factors were 105 while, the relative standard deviations (RSDs %) of the method were < 3.5 % for both flavonoids. The recoveries of the analytes in tea, vegetable and fruit juice samples were in the range of 95.5 and 98.2

Adherence to a Paleolithic Diet in Combination With Lifestyle Factors Reduces the Risk for the Presence of Non-Alcoholic Fatty Liver Disease: A Case-Control Study

BackgroundEvidence suggests the role of changing traditional lifestyle patterns, such as Paleolithic, to the modern lifestyle in the incidence and epidemic of chronic diseases. The purpose of this study was to investigate the associations between the Paleolithic diet (PD) and the Paleolithic-like lifestyle and the risk of non-alcoholic fatty liver disease (NAFLD) among an adult population.Materials and MethodsThis case-control study was carried out among 206 patients with NAFLD and 306 healthy subjects aged &gt;18 years. PD score was evaluated using a validated 168-item quantitative food frequency questionnaire. In addition, to calculate the Paleolithic-like lifestyle score, the components of physical activity, body mass index (BMI), and smoking status of the participants were combined with the score of the PD.ResultsThe mean PD and Paleolithic-like lifestyle scores were 38.11 ± 5.63 and 48.92 ± 6.45, respectively. After adjustment for potential confounders, higher scores of adherence to the PD diet conferred a protection for the presence of NAFLD [odds ratio (OR): 0.53; 95% confidence interval (CI): 0.28–0.98; P for trend = 0.021]. Furthermore, PD and healthy lifestyle habits were negatively associated with NAFLD (OR = 0.42, 95% CI 0.23–0.78; P for trend = 0.007).ConclusionOur data suggest that the PD alone and in combination with lifestyle factors was associated with decreased risk of NAFLD in a significant manner in the overall population. However, prospective studies are needed to further investigate this association

Analysis of chlorpheniramine in human urine samples using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography

A simple and environmentally friendly microextraction technique was used for determination of chlorpheniramine (CPM), an antihistamine drug, in human urine samples using dispersive liquid-liquid microextraction (DLLME) followed by high performance liquid chromatography with diode array detection (HPLC-DAD). In this extraction technique, an appropriate mixture of acetonitrile (disperser solvent) and carbon tetrachloride (extraction solvent) was rapidly injected into the urine sample containing the target analyte. Tiny droplets of extractant were formed and dispersed into the sample solution and then sedimented at the bottom of the conical test tube by centrifugation. Under optimal conditions, the calibration curve was linear in the range of 0.055-5.5 µg mL-1, with a detection limit of 16.5 ng mL-1. This proposed method was successfully applied to the analysis of real urine samples. Low consumption of toxic organic solvents, simplicity of operation, low cost and acceptable figures of merit are the main advantages of the proposed technique

Numerical Study of Progressive Collapse in Intermediate Moment Resisting Reinforced Concrete Frame Due to Column Removal

Progressive collapse is a chain reaction of failures propagating throughout a portion of the structure disproportionate to the original local failure occurring when a sudden loss of a critical load‐bearing element initiates a structural element failure, eventually resulting in partial or full collapse of the structure. Both General Services Administration (GSA) and United States Department of Defense (DoD) guidelines incorporate a threat-independent approach to progressive collapse analysis. Therefore, there is an international trend for updating structural design requirements to explicitly design structures to resist progressive collapse. This paper presents simple analytical approach for evaluating progressive collapse potential of typical concrete buildings, comparing four methods for progressive collapse analysis by studying 5 and 10-story intermediate moment-resistant reinforced concrete frame buildings, employing increasingly more complex analytical procedures: linear-elastic static, nonlinear static, linear-elastic dynamic, and nonlinear dynamic methodologies. Each procedure is thoroughly investigated and its common shortcomings are identified. The evaluation uses current GSA progressive collapse guidelines and can be used in routine design by practicing engineers. These analyses for three column-removal conditions are performed to evaluate the behavior of RC buildings under progressive collapse. Based on obtained findings, dynamic analysis procedures -easy to perform for progressive collapse determination- yielded more accurate results

Equilibrium sampling through membrane based on a hollow fiber for determination of naproxen and diclofenac in sludge slurry using Taguchi orthogonal array experimental design

A three-phase hollow fiber liquid phase microextraction (HF-LPME) method was evaluated for the extraction and preconcentration of naproxen and diclofenac using a polypropylene membrane followed by analysis using HPLC or LC/MS. In this technique, the drugs were extracted into di-n-hexyl ether immobilized in the wall pores of a porous hollow fiber from 50mL of sludge slurry sample as a donor phase with pH 3, and then back-extracted into the acceptor phase located in the lumen of the hollow fiber. Experimental factors were studied in 16 trials using a Taguchi orthogonal array experimental design with an OA(16) (4(5)) matrix. The significance of these factors was investigated using analysis of variance. The extraction time was statistically demonstrated as the main factor for the extraction of naproxen and diclofenac, while ionic strength played the role of the second most important factor for HF-LPME extraction of diclofenac. The method permitted a detection limit of 0.2-0.7ngg(-1) with relative standard deviation values of 3-5%. Enrichment factors of 2,300 for naproxen and 1,400 for diclofenac were achieved. The method was applied to determine naproxen and diclofenac in sewage sludge from sewage treatment plant, Kallby (Lund, Sweden)

Determination of non-steroidal anti-inflammatory drugs in sewage sludge by direct hollow fiber supported liquid membrane extraction and liquid chromatography-mass spectrometry

In this study, a three-phase hollow fiber liquid-phase microextraction (HF-LPME) method combined with liquid chromatography-mass spectrometry was developed for direct determination of four non-steroidal anti-inflammatory drugs (ketoprofen, naproxen, diclofenac and ibuprofen) in sewage sludge. The drugs were extracted from non-spiked and spiked slurry samples with different amounts of sludge into an organic phase and then back-extracted into an aqueous phase held in the lumen of the hollow fiber. High enrichment factors ranging from 2761 to 3254 in pure water were achieved. In sludge samples, repeatability and inter-clay precision were tested with relative standard deviation values between 10-18% and 7-15%, respectively. Average concentrations of 29 +/- 9, 138 +/- 2, 39 +/- 5 and 122 +/- 7 ng/g were determined in dried sludge from Kallby sewage treatment plant (Sweden) for ketoprofen, naproxen, diclofenac and ibuprofen, respectively. (C) 2010 Elsevier B.V. All rights reserved