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A Comparative Study of Organic Pollutants in Seawater, Sediments, and Oyster Tissues at Hab River Delta, Balochistan Coast, Pakistan
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Sadar Aslam, Malik Wajid Hussain Chan, Grzegorz Boczkaj, Ghazala Siddiqui
The seawater and sediments samples were collected from the same place in sterile glass bottles and jars, respectively. After collection, the samples were stored in an icebox before transportation to the lab. After transportation the samples were stored in refrigerator (−20 n-HexaneC). For the extraction of hydrocarbons from water and sediments, the liquid–liquid extraction technique was used. An n-Hexane (a solvent of choice based on previous papers in this field, Weisman, 1998; Johnson, 2016) was used for extraction. Anhydrous sodium sulfate was used for removing water from the extract. The same approach was used by Adeniji et al., 2017.
Approaches for Identification and Validation of Antimicrobial Compounds of Plant Origin: A Long Way from the Field to the Market
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Lívia Maria Batista Vilela, Carlos André dos Santos-Silva, Ricardo Salas Roldan-Filho, Pollyanna Michelle da Silva, Marx de Oliveira Lima, José Rafael da Silva Araújo, Wilson Dias de Oliveira, Suyane de Deus e Melo, Madson Allan de Luna Aragão, Thiago Henrique Napoleão, Patrícia Maria Guedes Paiva, Ana Christina Brasileiro-Vidal, Ana Maria Benko-Iseppon
Although the choice of the solvent is based on the polarity of the antimicrobial compound of interest, other molecules of opposite polarity may be extracted. Partitioning (or liquid-liquid extraction) is an optional technique that separates the compounds from the crude extract according to their polarity. For this, a solvent that is immiscible or partially miscible is added to the suspended extract (Long et al. 2018). For example, when adding hexane, chloroform or ethyl acetate to a crude extract in an acidic medium (e.g., 3.6% HCl or 2.0% H2SO4), some simple polyphenols and alkaloids will be found in the aqueous phase, while terpenoids, hydrophobic and higher carbon chain compounds will partition into the organic phase (Abdelgaleil et al. 2020; Zhao et al. 2020).
Exploring the Potential of Using Micro- and Macroalgae in Cosmetics
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
W.A.J.P. Wijesinghe, N.E. Wedamulla
The selection of proper solvents is vital in order to extract bioactive substances from raw biomass. Some disadvantages have been identified in relation to conventional extraction methods, which include extraction in Soxhlet apparatus, solid–liquid extraction and liquid–liquid extraction. One of the major constraints associated with these extraction techniques is the use of a high volume of solvents. Thus, these techniques are gradually being replaced by alternative methods like supercritical fluid extraction (Pan et al., 2012). Moreover, the use of eco-friendly and nontoxic solvents coupled with efficient and sustainable extraction techniques has gained considerable attention (Anastas and Warner, 1998).
Nicotine forms: why and how do they matter in nicotine delivery from electronic cigarettes?
Published in Expert Opinion on Drug Delivery, 2020
Vinit V Gholap, Leon Kosmider, Laleh Golshahi, Matthew S Halquist
Under the Dilution approach, El-Hellani et al. established a Liquid-Liquid Extraction method for calculating the free base nicotine yield in e-liquids [68]. A study carried out by Gholap et al. [65] and Duell et al. [66] have shown that Liquid-Liquid Extraction method suffers a drawback of inaccurate quantification of free base nicotine yield in e-liquids. The extraction method is not specific for nicotine and can be affected by flavoring chemicals in the e-liquids. Additionally, e-liquids diluted in water can be a mixture of weak acids or bases and according to Le Chatelier’s principle, after a single extraction of free base nicotine (Nic) in organic solvent, there can be a change in equilibrium between Nic and NicH+ before the second extraction. Thus, results obtained in Liquid-Liquid Extraction method can be overestimated [65].
A sensitive LC-MS/MS method to determine ginkgolide B in human plasma and urine: application in a pharmacokinetics and excretion study of healthy Chinese subjects
Published in Xenobiotica, 2020
Chenlin Shen, Xiaoqin Jin, Maomao Wu, Xiaohui Huang, Jun Li, Hong Huang, Feilong Li, Jiatao Liu, Genxiang Rong, Shuai Song
Deproteinisation using methanol or acetonitrile was initially assessed as an effective approach in the optimisation of sample preparation (for both plasma and urine); however, we noted a significant ion suppression effects (more than 55%) and obtained poor absolute recoveries (less than 50%) that were unacceptable for the preparation of plasma samples. Thus, we examined the use of liquid–liquid extraction with diethyl ether, ethyl acetate, petroleum ether, methyl-tert butyl ether, and dichloromethane, and different combination ratios of these solvents. Diethyl ether was finally selected since it provided acceptable recovery and minor ion suppression. Furthermore, the stability results indicated that sample preparation should be performed at temperatures below freezing point within 1 h, and thus the extent of the conversion from the lactone to carboxylate form was assumed to be negligible during sample preparation (details of the data are shown in Tables 2 and 3). Conversion of the lactone to the carboxylate form of GB occurs under physiological conditions, thereby producing misleading information regarding quantification of the naturally occurring GB. Therefore, a simple low-temperature pre-treatment is essential to stabilise GB hydrolysis (minimising the conversion between the hydrolysed GB and the lactone form) and for accurate quantification of the lactone form (Li et al., 2015).
Enhancement of dissolution and oral bioavailability of lacidipine via pluronic P123/F127 mixed polymeric micelles: formulation, optimization using central composite design and in vivo bioavailability study
Published in Drug Delivery, 2018
Ahmed R. Fares, Aliaa N. ElMeshad, Mohamed A. A. Kassem
All frozen plasma samples were thawed at ambient temperature. A liquid–liquid extraction procedure was used. Plasma samples (0.5 mL) were placed in 10 mL glass tubes, and 50 μL of hydrochlorothiazide solution (100 ng/mL) as internal standard (IS) was added to each and vortexed for 30 s. About 4 mL of tertiary butyl methyl ether was then added, and samples were then vortexed for 3 min. The tubes were then centrifuged for 10 min at 4000 rpm. The upper organic phases were then transferred to clean glass tubes, and evaporated to dryness using centrifugal vacuum concentrator (Eppendorf 5301, Germany) at 40°C. Dry residues were then reconstituted with 200 μL of mobile phase and vortex mixed for 1 min, and 20 μL was injected using the autosampler.