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Conclusion
Published in Nate F. Cardarelli, Tin as a Vital Nutrient:, 2019
In Chapter 7 Dr. Larry Sherman provided further data showing the universal presence of tin in various mammalian organs, and that water-soluble and hydrocarbon-soluble chemical species exist. The normal mouse thymus contains 11.1 ± 1.29 ppm tin and the human thymus 12.8 ± 0.9 ppm tin, higher than any other examined organ and confirmatory of earlier results (Chapter 5). Analysis of tissue samples and extracts were made after wet oxidation with sulfuric acid and hydrogen peroxide which would prevent the loss of volatile species. In accordance with the Cardarelli hypothesis an elemental analysis of the human thymus showed a relatively high zinc content — 23 ppm. Also, Dr. Sherman notes the high discrepancy between tumor tin content and nontumor tin in the same organ.
Tissue Preparation for Liquid Scintillation and Gamma Counting — the Counting Processes
Published in Lelio G. Colombetti, Principles of Radiopharmacology, 2019
Howard J. Glenn, Lelio G. Colombetti
Wet oxidation includes methods that either partially degrade and solubilize or completely oxidize to water and carbon dioxide, intractable, or highly colored specimens. In contrast to direct solubilizing agents, most of which are alkaline, most wet oxidation methods are acidic in nature. Nitric acid at 70°C has been used by O’Brien4 to digest rat skin and insect cuticle; Belcher21 used a mixture of nitric acid and 60% perchloric acid to oxidize samples of urine, feces, blood, and other body tissues. The use of a mixture of 60% perchloric acid and 30% hydrogen peroxide to oxidize whole blood, plasma, tissue, fluids, and bone directly in the counting vial has been reported; the entire procedure requires about 2 hr at 70 to 80°C.5 After oxidation, the resulting solutions are neutralized, frequently with tris buffer, before mixing with the scintillation counting liquid. Acid oxidative digestion avoids extraneous luminescence frequently associated with alkaline tissue solubilization, but in an open system the loss of volatile oxidation products such as water and carbon dioxide may be considerable. To determine such loss, it may be necessary to process standards of the original labeled compound mixed with nonradioactive tissue samples under the identical conditions used with the unknown samples. To avoid loss of volatile substances a closed wet oxidative system may be used. The tritiated water formed must be distilled. Such a system may not serve too well when the combustion product, tritiated water, is to be counted, but works well with carbon-14 dioxide. A modification of the Van Slyke-Folch method is usually used. Figure 5 shows one such apparatus.3 An alkaline carbon dioxide absorber is placed in flask B and the sample in flask A. The system is evacuated, sealed off, and the oxidizing mixture C is then added. The reaction flask is heated cautiously to promote complete oxidation and the carbon dioxide generated is trapped in the absorbent. Some of the trapping agents used for collecting the carbon dioxide in similar procedures have been ethanolamine, phenethylamine, and Hyamine 10-X.® Review articles relating to oxidative methods for preparing samples for counting which contain calcium-45, iron-55 and −59, and other metals as well as tritium, carbon-14, and sulfur-35 are available. 22,23
Preparation of Samples for Liquid Scintillation and Gamma Counting
Published in Howard J. Glenn, Lelio G. Colombetti, Biologic Applications of Radiotracers, 2019
Wet oxidation includes methods that either partially degrade and solubilize or completely oxidize to water and carbon dioxide intractable or highly colored specimens. In contrast to direct solubilizing agents, most of which are alkaline, most wet oxidation methods are acidic in nature. Nitric acid at 70°C has been used by O’Brien3 to digest rat skin and insect cuticle; Belcher26 used a mixture of nitric acid and 60% perchloric acid to oxidize samples of urine, feces, blood, and other body tissues. The use of a mixture of 60% perchloric acid and 30% hydrogen peroxide to oxidize whole blood, plasma tissue, tissue fluids, and bone directly in the counting vial has been reported; the entire procedure requires about 2 hr at 70 to 80°C.4 After oxidation, the resulting solutions are neutralized, frequently with tris buffer, before mixing with the scintillation counting liquid. Acid oxidative digestion avoids extraneous luminescence frequently associated with alkaline tissue solubilization, but in an open system, the loss of volatile oxidation products such as water and carbon dioxide may be considerable. To determine such loss, it may be necessary to process standards of the original labeled compound mixed with nonradioactive tissue samples under the identical conditions used with the unknown samples. To avoid loss of volatile substances, a closed wet oxidative system may be used. The tritiated water formed must be distilled. Such a system may not serve too well when the combustion product, tritiated water, is to be counted, but works well with 14C dioxide. A modification of the Van Slyke-Folch method is usually used. Figure 3 shows one such apparatus.2 An alkaline carbon dioxide absorber is placed in flask B, the sample placed in flask A, the system evacuated, sealed off, and the oxidizing mixture C then added. The reaction flask is heated cautiously to promote complete oxidation and the carbon dioxide generated is trapped in the absorbent. Some of the trapping agents used for collecting the carbon dioxide in similar procedures have been ethanolamine, phenethylamine, and Hyamine 10X. Review articles relating to oxidative methods for preparing samples for counting that contain 45Ca, 55Fe, 59Fe and other metals as well as tritium, 14C, and 35S are available.27, 28
Carbohydrate-derived fulvic acid wellness drink: its tolerability, safety and effect on disease markers in pre-ART HIV-1 positive subjects
Published in South African Family Practice, 2018
ME Botes, IS Gilada, JR Snyman, JPL Labuschagne
Fulvic acids, such as Shilajit, that are mined from natural sources contain high concentrations of heavy metals, including mercury, aluminium, chromium, lead and cadmium and are not consistent from batch to batch with regard to efficacy and quality and are therefore not appropriate for use in medical, pharmaceutical and cosmetic preparations. Carbohydrate sources such as glucose, sucrose, fructose, starches and cellulose have successfully been treated by wet oxidation to produce a CHD-FA composition that is now internationally patented because of its uniqueness (SA Patent 2001/2419). This CHD-FA (of unique molecular weight and purity) is suitable for use in medical, pharmaceutical and cosmetic preparations as it contains only a negligible, if any, amount of heavy metals and is consistent from batch to batch.9
Infrared analyzers for the measurement of breastmilk macronutrient content in the clinical setting
Published in Expert Review of Molecular Diagnostics, 2020
Cristina Borràs-Novell, Ana Herranz Barbero, Victoria Aldecoa-Bilbao, Georgina Feixas Orellana, Carla Balcells Esponera, Erika Sánchez Ortiz, Oscar García-Algar, Isabel Iglesias Platas
The Kjeldahl method is a wet oxidation to determine total nitrogen, which can then be used to calculate total protein (crude protein) by a conversion factor of 6.38 [19] (volume needed 5–10 ml) [14,20]. This approach does not take into consideration the presence of non-protein nitrogen (urea, amino acids like taurine and glutamine, nucleotides), which accounts for 20–25% of total nitrogen in human milk, so it will overestimate protein content. A corrected Kjeldahl measures the total nitrogen first, and then nonprotein nitrogen after precipitating protein by trichloroacetic acid. Total nitrogen minus nonprotein nitrogen equals true protein [21], after applying a conversion factor of 6.25 in this case, based on the fact that proteins contain approximately 16% of nitrogen [19]. The Bradford method is a spectrophotometric technique that involves the binding of Coomassie Brilliant Blue G-250. It measures protein content or ‘true protein’, rather than total nitrogen. Upon protein binding, the dye acquires a blue color and its absorbance maximum shifts from 465 to 595 nm, and absorbance at this wavelength is read by the device. For quantification, the absorbance is compared to a standard calibration curve previously constructed from dilutions of a protein solution of known concentration. This procedure is completed in approximately 2 min and requires 1 ml of starting sample [5,22]. It is less susceptible than other assays to interference by compounds such as salts or reducing substances like some carbohydrates, but it is affected by the presence of detergents. Also, the degree of protein-to-protein variation is high, which means the result will be influenced by the selection of standard, most frequently bovine serum albumin [5]. Some authors have proposed to use dilutions of mature human milk or milk proteins as a standard, after previously determining their concentration by another reference method like Kjeldhal [23,24]. Elemental analysis is a technique that uses pure oxygen at a high temperature to achieve complete oxidation of a sample, with ulterior measurement of the combustion products (mainly carbon, hydrogen, nitrogen, and sulfur for organic compounds) present in the sample (volume needed 0.5 ml) [17,25,26,27]. To determine the total protein content in milk, the protein nitrogen content is multiplied by a conversion factor.