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The metals Al, As V and Zn and the non-metal Se are considered ''trace elements''(TE) because of their essentiality and very limited quantity in humans. Therefore, this study aims to understand the heavy metal contents in human biological materials, using different digestion methods and to recommend the most appropriate digestion method making this measurement. Three reference materials from different sources were selected to be digested by five methods to determine the contents of these trace elements by ICP-MS. The five digestion methods were nitric acid, nitric acid -hydrogen peroxide, nitric -sulfuric acid, nitric–perchloric acid and sulfuric acid methods. Analytical results indicated that the nitric acid procedure was the most efficient for recovering Br, Ca, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn from most certified reference materials. The sulfuric acid procedure yielded the lowest recovery of Pb from the certified reference material. The nitric acid procedure ...
Critical Evaluating for Five Digestion Methods Using Icp MS
Journal of Pharmaceutical & Scientific Innovation, 2014
and Zn and the non-metal Se are considered ''trace elements''(TE) because of their essentiality and very limited quantity in humans. Therefore, this study aims to understand the heavy metal contents in human biological materials, using different digestion methods and to recommend the most appropriate digestion method making this measurement. Three reference materials from different sources were selected to be digested by five methods to determine the contents of these trace elements by ICP-MS. The five digestion methods were nitric acid, nitric acid-hydrogen peroxide, nitric-sulfuric acid, nitric-perchloric acid and sulfuric acid methods. Analytical results indicated that the nitric acid procedure was the most efficient for recovering Br, Ca, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn from most certified reference materials. The sulfuric acid procedure yielded the lowest recovery of Pb from the certified reference material. The nitric acid procedure was recommended as the method for digesting the human biological materials samples herein, based on recovery analysis, cost and time taken. Nitric-perchloric acid procedure was not recommended because perchloric acid is potentially hazardous during digestion and it recovers relatively little heavy metal.
Journal of physics, 2019
Purification of NRL protein was accompanied by extraction of waste proteins using salting out and multiple centrifugation methods. Both methods contributes to varying degree of yield and purified protein characteristics. However both methods produces protein that can bind metal efficiently. Conventionally, salting out method was used and it is uncommon to use multiple centrifuge to extract protein. The key aspects discussed here, were on how the pH condition exposed to the NRL waste leads to variation in hevea protein extracted amount and how metal binding featured in FTIR spectroscopy. The purified protein were reacted with metal solution of different strength to study the binding characteristics. Molecular weight cutoff (MWCO) size of dialyzing tube shows greater effect on the final protein extracted amount by about 50% when smaller size were used. Acidic condition favors part of proteins from waste in purification while some favors basic condition. Standard salting out method shows consistent profile in extracting metal compared to multiple centrifugation method from 30 to 80%.
In pasture-based dairy herds where silage is a widely adopted supplement, optimized feeding requires reliable estimations of nutritional quality of this conserved forage. Metabolizable energy, an important nutritional fraction, can be predicted from digestibility-related traits, such as the digestible organic matter contained in the dry matter (D-value). The aim of the present study was to evaluate the prediction of D-value and dry matter digestibility (DMD) of grass silages made from four different pastures and maturity stages, using the pepsin-cellulase method. Fungal cellulase was used, applying different enzyme concentrations, incubation times and types of final wash. The silages were prepared from permanent pasture (Dactylis glomerata L., Lolium perenne L., Bromus catharticus Vahl var. catharticus, Trifolium repens L. and Holcus lanatus L.), rotation pasture (Lolium multiflorum Lam. cv. Tama), oats (Avena sativa L.), and mixed pasture (L. perenne-T. repens). These were harvested at three different physiological stages (vegetative, ear emergence and dough grain). The treatment using an incubation time of 24 h, a cellulase concentration of 6.25 g L -1 and final wash with water (Treatment 3) presented the best prediction capacity of the in vivo D-value (R 2 = 0.78) and in vivo DMD (R 2 = 0.71). In vivo D-value prediction improved (R 2 = 0.8) when a chemical determination (crude fibre, gross energy, neutral detergent fibre, total ash or acid detergent fibre) was included in addition (multiple regression) to D-value obtained with cellulases (Treatment 3). Results of DMD obtained with cellulases show good precision, but underestimate in vivo values, and are closer to those obtained with ruminal fluid. Suitable equations could be used to improve accuracy. , g kg -1 CP, g kg -1 DM CF, g kg -1 DM NDF, g kg -1 DM ADF, g kg -1 DM Ash, g kg -1 DM pH Ammonium N, g kg -1 N GE, Mcal kg -1 DM DMD in vivo, g kg -1 ME in vivo, Mcal kg -1 DM DMD ruminal fluid, g kg -1 ME ruminal fluid, Mcal kg -1 DM OMD ruminal fluid, g kg -1
Evaluation of the use of internal and external markers in digestibility studies
Results of experiments in which digestibility estimates were made using indigenous components, in particular the crude fibre, hydrolysis resistant ash, and hydrolysis resistant organic matter COnkntS, of the feed(s) as markers are summarized. The merits of using indigenous components as markers, as opposed to a n artificial marker such as Cr, O, , are evaluated.
Evolution of in vitro digestibility techniques: a systematic review
Theory and practice of meat processing
The inability to reproduce certain digestive processes in vivo, high research costs and ethical aspects have led to the development of a large number of in vitro digestion models. These models allow us to take into account various factors of modeling complex multistage physiological processes occurring in the gastrointestinal tract, which makes them promising and widely used. A significant part of in vitro methods includes assessment by enzymatic digestion and are based on the calculation of nitrogen remaining after digestion in relation to the initial total nitrogen (according to the Dumas, Kjeldahl method, spectrophotometric or chromatographic method). There are also a number of titrometric methods (pH‑stat), which are mainly used to assess the digestibility of feed, most successfully for aquatic animals due to the simplicity of their digestive tract. Methods for assessing the digestibility of food products by enzymatic digestion have undergone various stages of evolution (since 1...
Journal of Chromatography & Separation Techniques
2022
Objective: The objective of present work is to develop and validate HPTLC method for simultaneous estimation of Curcumin and Azadirachtin in marketed formulation Materials and methods: HPTLC method was developed using a solvent system Toluene: Ethyl acetate: Ammonia: Formic acid (4:3:2.5:0.5 v/v/v/v) using a stationary phase Silica Gel 60 F254 and the saturation time is 15 min. The developed method was standardized in terms of validation parameters such as specificity, linear range, precision, robustness, ruggedness and reproducibility as per ICH guidelines. Newly developed and validated method was successfully applied for estimation of Curcumin and Azadirachtin in marketed formulation. Results: The linearity range for the both Curcumin and Azadirachtin was found to be 1.5-15 µl/spot. The limit of detection found to be 0.383213 µl/spot for the Curcumin and 0.46572 µl/spot for Azadirachtin. The limit of quantification is found to be 1.16125 µl/spot for the Curcumin and 1.411272 µl/spot for Azadirachtin. Recovery of Azadirachtin in marketed formulation was observed in the range of 91%-109% and recovery of Curcumin in marketed formulation was observed in the range of 91%-105%. All the precision and repeatability results were within acceptance range less than 2%. Assay of Curcumin and Azadirachtin was found to be 92.95% and 91.79% respectively. The Rf value of Curcumin is found to be 0.5 ± 0.03 and the Rf value of Azadirachtin is found to be 0.57 ± 0.04. Conclusion: The method was found to be simple, accurate, environment friendly, reproducible and can be used for routine estimation analysis of Curcumin and Azadirachtin in marketed formulation.