Standardization of Herbal Drugs
Ravindra Kumar Pandey, Shiv Shankar Shukla, Amber Vyas, Vishal Jain, Parag Jain, Shailendra Saraf in Fingerprinting Analysis and Quality Control Methods of Herbal Medicines, 2018
Contamination by toxic metals can either be accidental or intentional. Contamination by heavy metals such as mercury, lead, copper, cadmium, and arsenic in herbal remedies can be attributed to many causes, including environmental pollution, and can pose clinically relevant dangers for the health of the user and should, therefore, be limited. Arsenic and heavy metals are dangerous even in trace amounts and must be removed from herbal drugs. Arsenic is abundant in nature and its presence in herbal materials should be no different from its wide occurrence in foods. Atomic absorption spectrometry (AAS) is used for the determination of the amount or concentration of specific heavy metals. AAS uses the phenomenon that atoms in the ground state absorb light of a specific wavelength, characteristic of the particular atom, when the light passes through an atomic vapor layer of the element to be determined. The contamination of medicinal plant materials with arsenic and heavy metals can be attributed to many causes, including environmental pollution and traces of pesticides. The contents of lead and cadmium may be determined by inverse voltametry or by atomic emission spectrophotometry. The following maximum amounts in dried plant materials, which are based on the ADI values, are proposed for lead (10 mg/kg) and cadmium (0.3 mg/kg).
Dictionary
Mario P. Iturralde in Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990
Atomic absorption spectroscopy. This is a method of chemical analysis where a flame photometer measures the absorption of particular wavelengths of light when passing through a flame in which atoms from metal salts (e.g., sodium and potassium) are being ionized. Small samples of body fluids are aspirated into a nebulizer and injected into a flame of propane or natural gas, or into a flameless electrothermal arc (e.g., carbon rod furnaces). Light is passed through the flame generated by a hollow cathode lamp lined with a coating of the metal to be analyzed. The characteristic spectral lines of the metal in question are radiated from the lamp and partially absorbed in the flame. A photometer detecting the radiation passing out of the flame can measure the quantity absorbed. Light emitted in the flame is separated from that absorbed, by pulsing the light source.
Inorganic Particulates in Human Lung: Relationship to the Inflammatory Response
William S. Lynn in Inflammatory Cells and Lung Disease, 2019
Classical chemical techniques for elemental analysis may also be used for the measurement of inorganic particulates in the human lung. Neutron activation analysis33 has received considerable attention in recent years, perhaps because of the ease of sample preparation and the high degree of elemental sensitivity. Electrothermal atomization atomic absorption spectrometry and inductively coupled argon plasma atomic emission spectrometry may also prove quite useful, with sensitivities for many elements in the parts per billion range. However, both these methods require extensive sample preparation for the elemental analysis of human lung tissue. Bulk chemical methods provide a useful cross-check on data obtained by the less conventional microanalytical techniques described above. More detailed discussion of sample preparation and comparative sensitivities for elements of interest in pulmonary toxicology for these and other analytical techniques is provided elsewhere.12
Assessment of trace element toxicity in surface water of a fish breeding river in Bangladesh: a novel approach for ecological and health risk evaluation
Published in Toxin Reviews, 2022
Md. Refat Jahan Rakib, Yeasmin Nahar Jolly, Bilkis Ara Begum, Tasrina Rabia Choudhury, Konika Jannat Fatema, Md. Saiful Islam, Mir Mohammad Ali, Abubakr M. Idris
All chemicals used in this study were of analytical grade, while deionized water was used for solution preparation. About 500 ml of river water was filtered using Whatman® 41 filter paper. Water samples were filtered through 0.45 µm filters, cellulose nitrate. Then the water was acidified by adding 1 ml of 65% HNO3 acid, taken into two individual 300 ml beaker by dividing the water samples into 250 ml, reduced to 25 ml by using hotplate. For metal analysis, 20 ml water sample was treated with 5 ml 69% HNO3 acid and 2 ml 30% H2O2 in a closed Teflon vessel and was digested in a Microwave Digestion System. For arsenic analysis 0.5 ml of potassium iodide, 0.5 ml of ascorbic acid and 3 ml of HNO3 was added. Further dilution was made as per required for metal analysis by Atomic Absorption Spectrophotometer (AAS).
Influence of heavy metals on thermal conductivity of clay as a building material
Published in Egyptian Journal of Basic and Applied Sciences, 2019
Egbeyale Godwin Babatunde, Adegoke James Adeyemo
Clay sample was collected from Isan, southwestern part of Nigeria. The sample was processed and prepared for used in the Physics laboratory, University of Ibadan. A 1.0 g of the clay was poured into Teflon beaker and digested (using nitric acid extraction method). Digested solution was analyzed for heavy metal presence using Atomic Absorption Spectrophotometer (AAS). The remaining portion of the clay sample was further divided into six. Each of the five portions was mixed with different concentration of nitrate of lead, copper, nickel, zinc and iron, respectively, at 400, 800, 1600, 3200 and 6400 ppm while the sixth serves as control. Slabs were made from the mixture and oven dried up to 110 °C for 300 s. The thermal performances of the slabs were determined by using a KD2 probe thermal analyzer.
Ecological and health risk assessment of heavy metals in the Hattar industrial estate, Pakistan
Published in Toxin Reviews, 2020
Shah Jehan, Seema Anjum Khattak, Said Muhammad, Rafiq Ahmad, Muhammad Farooq, Sardar Khan, Abdullah Khan, Liaqat Ali
Samples of blanks, and known standards (SRM 2709) for soil were incorporated in each step following the above digestion process. Each sample solution was analyzed in triplicate, and average values were used for result presentation. For calibration and standardization of AAS, the diluted standards of HMs were prepared with deionized water using the certified standards Fluka Kamica (Buchs, Switzerland). The standards (2.5, 5.0, and 10.0 mg/L) and blanks along with samples of the study area were measured on atomic absorption spectrophotometer (Perkin Elmer AAS-PEA 700, Waltham, MA). Recoveries of HMs standards were observed at 93 ± 10%.
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