scholarly journals Novel Method of Extraction for Radiocarbon Measurements of Atmospheric Carbon dioxide

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1867-1877
Author(s):  
K L Pugsley ◽  
T D J Knowles ◽  
S O’Doherty

ABSTRACTIn this paper, we present the first data from an alternative extraction method for atmospheric 14CO2 analysis, based on the direct trapping of whole air samples onto a molecular sieve zeolite (13X) trap, incorporated into a commercially available automated graphitization system. Results are presented for both inter-laboratory comparison samples and an in-house reference standard. The in-house reference was used to calculate the standard deviation of measurements (2.0‰). This newly developed method will facilitate faster sample processing and therefore lower cost per analysis, critical for scaling up such studies.

2004 ◽  
Vol 59 (3-4) ◽  
pp. 197-200 ◽  
Author(s):  
Maique W. Biavatti ◽  
Cesar A. Koerich ◽  
Carlos H. Henck ◽  
Enderson Zucatelli ◽  
Fernanda H. Martineli ◽  
...  

The ‘guaco’ lianous herb Mikania laevigata, which is widespread in Southern Brazil, is traditionally used to treat bronchitis, asthma and cough. This work investigates the influence of the extraction method, solvent:drug ratio, ethanol proportion, harvest season (summer or winter) and solvent heating on the physicochemical profile of the extracts (dry weight, density, pH) and the coumarin (1,2-benzopyrone) content determined by LC. Among the results obtained, it is observed that higher ethanol content increases the amount of coumarin in the extract. Leaves harvested in summer also produce an extract with a high coumarin yield. The most efficient method of extraction is percolation, independent of the solvent used.


2007 ◽  
Vol 1143 (1-2) ◽  
pp. 36-40 ◽  
Author(s):  
Guido Flamini ◽  
Marianna Tebano ◽  
Pier Luigi Cioni ◽  
Lucia Ceccarini ◽  
Andrea Simone Ricci ◽  
...  

Author(s):  
Aniek Setiya Budiatin ◽  
Samirah ◽  
Maria Apriliani Gani ◽  
Wenny Putri Nilamsari ◽  
Chrismawan Ardianto ◽  
...  

Bovine bone is a considerable source for the production of hydroxyapatite. The recent study reported a novel method to extract hydroxyapatite from bovine bone without producing hazardous residue. The bovine bones were cut and boiled in the opened chamber followed by boiling in pressurized tank. The bones were then soaked into 95% ethanol. Calcination was then conducted in 800°C, 900°C and 1,000°C, for 2 hours. The result was then grinded and sieved. The powder then was characterized using Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) to measure the purity of hydroxyapatite. It is concluded that the hydroxyapatite derived from this process showed 100% purity, resulting 35.34 ± 0.39% w/w from the wet bone weight and 72.3% w/w from the dried weight. The present extraction method has been proven to yield high amount of pure hydroxyapatite as well as reducing the use of hazardous reagent.


1999 ◽  
Vol 437 (5) ◽  
pp. 695-701 ◽  
Author(s):  
L. D. Allhouse ◽  
J. D. Potter ◽  
C. C. Ashley

2020 ◽  
Vol 17 (2) ◽  
pp. 765-772
Author(s):  
Noorashikin Md Saleh ◽  
N. M. Hafiz ◽  
Nik Nur Atiqah NikWee

A straightforward and efficient way for extraction of parabens that is methylparaben, ethylparaben, propylparaben and benzylparaben in environmental water samples was developed through optimizing parameters for each method of extraction. In this study, methods involved were cloud point extraction, vortex extraction, and liquid–liquid extraction. The parameters affecting the method of extraction were such as salt concentration, surfactant concentration, type of solvent, temperature, ratio of solvent to water and extraction time. The optimum parameter for cloud point extraction method were 1.0 M of salt, 1.0% v/v of surfactant, ratio of surfactant to water is 1:1, extraction time is 1 minute at 30 °C while vortex extraction method, optimum parameter is 1.0 M salt, using acetonitrile as a solvent, ratio 1 solvent: 4 water, and extracted at 1 minute. For the liquid–liquid extraction method, the optimum parameter was at 1.0 M salt, acetonitrile as a solvent, ratio of solvent to water is 1:1 and extraction time at 1 minute. The correlation coefficient for the calibration of paraben at concentration 0.2 ppm–1.0 ppm was in the range from 0.9703 to 0.9942. The limit of detection of studied paraben were 0.1627, 0.0837, 0.1156 and 0.1918 ppm, respectively. Percentage recovery for cloud point extraction, vortex extraction and liquid–liquid extraction were between 41%–147.9%, 26.5%–134.7%, and 31.4%–142.4% respectively. Each sample is repeated with triplication which the value of the relative standard deviation is less than 17.9%. Thus, the most suitable, efficient and effective method in extraction of paraben from water samples is cloud point extraction. The cloud point extraction shows the potential to be explore on the future extraction of others organic pollutants from water samples.


2011 ◽  
Vol 688 ◽  
pp. 326-333
Author(s):  
Huan Xu ◽  
Qiu Ming Gao

Zeolite-13X/MCM-48 biporous molecular sieve has been synthesized in the mode of overgrowth of MCM-48 on the surface of pre-added zeolite 13X. This kind of biporous molecular sieve has been taken as the template to prepare nanoporous carbons by a two-step casting process with furfuryl alcohol and acetonitrile as the precursors. The structures and textures are characterized by X-ray diffraction, nitrogen sorption at 77 K and high-resolution transmission electron microcopy. The electrochemical performances of the as-prepared porous carbons were tested by cyclic voltammetry and galvanostatic charge-discharge cycling in aqueous electrolyte. One of the carbon samples (labeled as C3-3) which is prepared by adding 5% zeolite-13X in the MCM-48 sol as the template and conducting acetonitrile chemical vapor deposition for 4 h after the impregnation of furfuryl alcohol. The C3-3 nanoporous carbon keeps the structure ordering and has the capacitance of 197 F g-1 at 2 mV s-1. The cycling performance of this carbon sample is excellent, which can maintain above 90% capacitance after 1000 cycles at 1 A g-1.


2010 ◽  
Vol 76 (10) ◽  
pp. 3378-3382 ◽  
Author(s):  
Özgül İnceoǧlu ◽  
Eelco F. Hoogwout ◽  
Patrick Hill ◽  
Jan Dirk van Elsas

ABSTRACT Four extraction methods, including a novel one, were compared for their efficiencies in producing DNA from three contrasting agricultural soils. Molecular analyses (PCR-denaturing gradient gel electrophoresis [DGGE] and clone libraries) focusing on different microbial groups were used as assessment criteria. Per soil, the DNA yields differed between extraction methods. Clear effects of method on apparent richness and community structure were found. Actinobacterial diversity based on soil DNA produced by two divergent methods revealed that a hitherto-undescribed group was obtained by the novel method.


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