A PRELIMINARY trial in the translocation of the herd of kob antelope (Adenota kob thomasi) at Lugari in Kenya was made in June of last year (Buechner, H. K., Harthoorn, A. M., and Luck, C. P., unpublished work). The h...
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A PRELIMINARY trial in the translocation of the herd of kob antelope (Adenota kob thomasi) at Lugari in Kenya was made in June of last year (Buechner, H. K., Harthoorn, A. M., and Luck, C. P., unpublished work). The herd in question numbers some 500 head, and is the only herd of kob in Kenya. Its existence in this number on the farm- and ranch-land of Lugari cannot be supported by the landowners. Moving part of the herd to other areas is the only alternative to destruction.
Database Management Systems (DBMS) are used ubiquitously. To efficiently access data, they apply sophisticated optimizations. Incorrect optimizations can result in logic bugs, which cause a query to compute an incorre...
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A rapid, sensitive and selective method based on LC-MS/MS has been developed for the direct determination of acrylamide residues in water in compliance with the current European Union (EU) 98/83 Drinking Water Directi...
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A rapid, sensitive and selective method based on LC-MS/MS has been developed for the direct determination of acrylamide residues in water in compliance with the current European Union (EU) 98/83 Drinking Water Directive. Given the high polarity of acrylamide, the application of a rapid on-line solid phase extraction step, commonly used for preconcentrating low analyte levels, was not found to be completely satisfactory. Therefore, an alternative approach based on the use of direct large-volume injection into the LC-MS/MS system has been used. Three atmospheric-pressure interfaces (ESI, APCI and Ion Sabre APCI) were checked to reach the required sensitivity (0.1 mu g/l). All three interfaces were tested by analysis of six different water samples (surface water, groundwater, drinking water and three treated water samples) spiked at three concentration levels each (0.1, 1 and 10 mu g/l). When using ESI, poor sensitivity and high matrix effects were observed. This situation improved when APCI was used as the interface because no matrix effect was found, although sensitivity was not completely satisfactory. The best results were obtained by interfacing the Ion Sabre APCI;its higher sensitivity for acrylamide (LOD 0.03 mu g/l) and the absence of matrix effects recommended its selection. Using this approach, satisfactory recoveries (90-97%) and precision (< 12%) were obtained for all water samples studied. Besides, the acquisition of two different MS/MS transitions allowed not only the quantification but also the confirmation of acrylamide in water at concentration levels around 0.1 mu g/l. Copyright (c) 2006 John Wiley & Sons, Ltd.
In recent years, deep eutectic solvent (DES) has attracted a great deal of attention as an environmentally friendly solvent and could be used as an alternative to conventional solvents. In this study, 34 choline and b...
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In recent years, deep eutectic solvent (DES) has attracted a great deal of attention as an environmentally friendly solvent and could be used as an alternative to conventional solvents. In this study, 34 choline and betaine-based deep eutectic solvents were prepared and investigated the ability to extract apigenin and luteolin from the celery seed. The results showed that DES composed of betaine hydrochloride and pro-pylene glycol had the best extraction efficiency. Using one factor at a time combined with response surface methodology, the optimal conditions of extraction were determined as follows: time of extraction: 19 min, extraction temperature: 75 degrees C, the water content in solvent: 40% (w/w). Antisolvent (water) combined with distillation was proposed as an efficient method to recover apigenin and luteolin from the DES extract. The relationship between components of DES and solubility of apigenin, luteolin was also established which was the starting point for the prediction of extractability of DES. Molecular dynamics revealed that betaine hydrochloride and propylene glycol could interact with each other by the formation of two types of hy-drogen bond while water molecules might play an important role in the ability to dissolve apigenin and luteolin of DES. (c) 2021 Elsevier B.V. All rights reserved.
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