Fingerprinting Techniques for Herbal Drugs Standardization
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
This is one of the most popular and simple chromatographic techniques used for separation of compounds before instrumental chromatography methods such as GC and HPLC were established. TLC is used as an easier method of initial screening with a semi-quantitative evaluation together with other chromatographic techniques as there is relatively less change in the simple TLC separation of herbal medicines than with instrumental chromatography. Thin layer chromatography is a technique in which a solute undergoes distribution between two phases, a stationary phase acting through adsorption and a mobile phase in the form of a liquid (Wagner et al., 1996). The adsorbent is a relatively thin, uniform layer of dry, finely powdered material applied to a glass, plastic or metal sheet or plate. Glass plates are most commonly used (Figure 12.2). Separation may also be achieved on the basis of partition or a combination of partition and adsorption, depending on the particular type of support, its preparation, and its use with different solvents (Stahl, 1969). In the phytochemical evaluation of herbal drugs, TLC is employed extensively for the following reasons: It enables rapid analysis of herbal extracts with minimum sample clean-up requirement.It provides qualitative and semi-quantitative information of the resolved compounds.
Trauma and Poisoning
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss in Understanding Medical Terms, 2020
Absorption of poisons from the GI tract may also be reduced by administering an adsorbent such as activated charcoal to adsorb the toxin and either remove it with lavage or allow it to pass through the gut without absorption into the body. Adsorbents are often administered in conjunction with saline cathartics, most frequently sorbitol although magnesium sulfate (Epsom salt) was used more commonly in the past. Saline laxatives decrease the GI transit time, so they may be administered with an adsorbent to reduce the amount of time the poison is available for absorption.
Silicones in Cosmetics
E. Desmond Goddard, James V. Gruber in Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
The low surface energy characteristic of silicone polymers renders them excellent water-repellent lubricants (contact angles against water droplets ) and good antifoam agents (3). Polydimethylsiloxane fluids have a pronounced antifoaming action and are the basic components of special defoamers. The latter usually contain a small amount of an activating solid such as fumed silica, generally in the range of . Unmodified silicones readily satisfy the basic criteria for effective defoaming action; i.e. they are insoluble in the foaming media, they have a very low surface tension, and they rapidly spread out over the foaming media, displacing foam-forming agents from the surface. This gives rise to increased capillary and gravitational drainage, excessive localized thinning of the bubble wall, increased Marongonni flow, and ultimately breakage. Figure 2 illustrates the mechanism of foam collapse resulting from silicone fluids in foaming solutions . Incorporation of activating solids such as fumed silica will promote more rapid destruction of foam through a pinholing effect on the bubble lamella. It has been shown that the defoaming action of silicone antifoams is dependent upon the surfactant and electrolyte concentrations in solution and the particular foaming system in question. Adsorption of
First report on the presence of aflatoxins in fig seed oil and the efficacy of adsorbents in reducing aflatoxin levels in aqueous and oily media
Published in Toxin Reviews, 2022
Of course, prevention of mold contamination and toxin production is the best solution to aflatoxin problem (Luo et al. 2018). However, it is not that easy in practice due to moderate temperature, high humidity, sudden rains, etc. and developing decontamination strategies are inevitable. Among these, adsorption is regarded as superior to other processes such as heat treatment, oxidation etc. since the former does not change the chemical structure of the toxin and does not cause the formation of toxic by- and degradation-products (Olopade et al.2019). Adsorbents are currently used in a wide range of applications including pollution control, purification, separation, and others across a large number of industrial sectors (Jenkins 2015). Moreover, the effectiveness of the adsorbents for reducing various mycotoxins from different food products have been examined in scientific studies (Var et al. 2008, Liu et al. 2021, Muaz and Riaz 2021) and successful results have been obtained. On the other hand, causing loss of some bioactive components contributing to nutritional value of the product was reported as the main disadvantage of adsorption process (Gokmen et al. 2001). A number of authors investigated different techniques to decontaminate dried figs (Altug et al. 1990, Zorlugenc et al. 2008, Karaca and Nas 2009); however, to our knowledge, there is no information regarding the employment of adsorption for aflatoxin removal from figs.
Spatial distribution of heavy metals in rice grains, rice husk, and arable soil, their bioaccumulation and associated health risks in Haryana, India
Published in Toxin Reviews, 2021
Renu Daulta, Tallapragada Sridevi, Vinod Kumar Garg
Rice husk is an important by-product of rice processing industries. It is used as fodder, fuel, fertilizer and raw material for rice bran oil extraction. Rice bran oil is widely used in cooking and chemical industries. Hence, heavy metals may indirectly enter in food chain via rice husk also. Various authors have used it as an adsorbent also for pollutant removal from water and wastewater. Therefore, it is important to evaluate heavy metals content in rice husk. Heavy metal concentration in rice husk is given in Table 3. Fe content was in the range of 8.5–301.3 mg/kg, Cu content 2.10−11.20 mg/kg, Cd content <0.01–2.26 mg/kg, Pb content 0.05–11.3 mg/kg, Ni content 0.09–2.9 mg/kg, Zn content 6.2–39.7 mg/kg, Cr content <0.05–1.63 mg/kg and Co content <0.05–0.70 mg/kg. Mean heavy metal concentration in rice husk was in the following order: Fe (106.9 mg/kg) > Zn (14.6 mg/kg) >Cu (4.6 mg/kg) > Pb (3.1 mg/kg) > Ni (1.5 mg/kg) > Cd (0.71 mg/kg) > Cr (0.62 mg/kg) > Co (0.22 mg/kg). In 2015 rice husk samples Fe ranged 6.2–286.2 mg/kg, Cu ranged 3.3–13.2 mg/kg, Cd ranged <0.01–3.45 mg/kg, Pb ranged BDL–8.5 mg/kg, Ni ranged 0.09–3.11 mg/kg, Zn ranged 5.2–36.2 mg/kg, Cr ranged <0.05–3.54 mg/kg and Co ranged <0.05–0.66 mg/kg. Mean heavy metals concentration in rice husk in 2015 samples was in the following order: Fe (98.4 mg/kg) > Zn (12.5 mg/kg) > Cu (3.9 mg/kg) > Pb (2.8 mg/kg) > Ni (1.3 mg/kg) > Cr (0.71 mg/kg) >Cd (0.68 mg/kg) > Co (0.21 mg/kg).
Green and eco-friendly adsorption of dyes with organoclay: isothermal, kinetic and thermodynamic studies
Published in Toxin Reviews, 2022
Shahzaib Tariq, Muhammad Saeed, Usman Zahid, Maimoona Munir, Azeem Intisar, Muhammad Asad Riaz, Aqsa Riaz, Muhammad Waqas, Hafiz Muhammad Waqar Abid
During the last few decades, adsorptive removal of dyes has gained considerable research interest in modification that results in increased adsorption capacity. Based on experimental results, about 99% of the dyes can be removed from the solution via the adsorption process (Adeyemo et al. 2017). Adsorption is considered to be one of the most popular techniques for dyes removal owing to its high efficacy, cost efficiency, simple operation, and tolerant of processing conditions (Lee et al. 2006). Commonly used adsorbents are graphene nanoplates (Zhang et al. 2018), mesoporous silica (Huang et al. 2011), magnetic carbon (Wang, Zhang et al. 2018), activated alumina (Wasti and Ali Awan 2016), activated charcoal (Iqbal and Ashiq 2007), mesoporous carbon (Galán et al. 2013), etc. but they exhibit lower adsorption capacity as compared to a clay material.
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