Analytical Protocol for U-Th-Pb Chemical Dating of Monazite using CAMECA SXFive EPMA Installed at the Mantle Petrology Laboratory, Department of Geology, Banaras Hindu University, Varanasi, India

2019 ◽  
Vol 93 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Mayuri Pandey ◽  
Dinesh Pandit ◽  
Devsamridhi Arora ◽  
N. V. Chalapathi Rao ◽  
N. C. Pant
Author(s):  
F. Olmo ◽  
A. Rodriguez ◽  
A. Colina ◽  
A. Heras

AbstractUV/Vis absorption spectroelectrochemistry is a very promising analytical technique due to the complementary information that is simultaneously obtained from electrochemistry and spectroscopy. In this work, this technique is used in a parallel configuration to study the oxidation of folic acid in alkaline medium. Herein, UV/Vis absorption spectroelectrochemistry has been used to detect both the oxidation products and the folic acid consumed at the electrode/solution interface, allowing us to develop an analytical protocol to quantify vitamin B9 in pharmaceutical tablets. Linear ranges of three orders of magnitude have been achieved in basic medium (pH = 12.9), obtaining high repeatability and low detection limits. The spectroelectrochemical determination of folic acid in pharmaceutical tablets at alkaline pH values is particularly interesting because of the changes that occur in the optical signal during the electrochemical oxidation of FA, providing results with very good figures of merit and demonstrating the utility and versatility of this hyphenated technique, UV/Vis absorption spectroelectrochemistry.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 437
Author(s):  
Marta Tikhomirov ◽  
Błażej Poźniak ◽  
Tomasz Śniegocki

The precise and reliable determination of buprenorphine concentration is fundamental in certain medical or research applications, particularly in pharmacokinetic studies of this opioid. The main challenge is, however, the development of an analytical method that is sensitive enough, as the detected in vivo concentrations often fall in very low ranges. Thus, in this study we aimed at developing a sensitive, repeatable, cost-efficient, and easy HPLC analytical protocol for buprenorphine in rabbit plasma. In order to obtain this, the HPLC-MS2 system was used to elaborate and validate the method for samples purified with liquid-liquid extraction. Fragment ions 468.6→396.2 and 468.6→414.2 were monitored, and the method resulted in a high repeatability and reproducibility and a limit of quantification of 0.25 µg/L with a recovery of 98.7–109.0%. The method was linear in a range of 0.25–2000 µg/L. The suitability of the analytical procedure was tested in rabbits in a pilot pharmacokinetic study, and it was revealed that the method was suitable for comprehensively describing the pharmacokinetic profile after buprenorphine intravenous administration at a dose of 300 µg/kg. Thus, the method suitability for pharmacokinetic application was confirmed by both the good validation results of the method and successful in vivo tests in rabbits.


Author(s):  
Oskar Hansson ◽  
Sandra Rutz ◽  
Henrik Zetterberg ◽  
Ekaterina Bauer ◽  
Teresa Hähl ◽  
...  

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2652-2664 ◽  
Author(s):  
E. Grammatikakis ◽  
Kyriakidis ◽  
D. Demadis ◽  
Cabeza Diaz ◽  
Leon-Reina

Ceramic objects in whole or in fragments usually account for the majority of findings in an archaeological excavation. Thus, through examination of the values these items bear, it is possible to extract important information regarding raw materials provenance and ceramic technology. For this purpose, either traditional examination protocols could be followed, focusing on the macroscopic/morphological characteristics of the ancient object, or more sophisticated physicochemical techniques are employed. Nevertheless, there are cases where, due to the uniqueness and the significance of an object of archaeological value, sampling is impossible. Then, the available analytical tools are extremely limited, especially when molecular information and mineral phase identification is required. In this context, the results acquired from a multiphase clay ceramic dated on Early Neopalatioal period ΜΜΙΙΙΑLMIA (1750 B.C.E.–1490 B.C.E.), from the Minoan Bronze Age site at Philioremos (Crete, Greece) through the application of Raman confocal spectroscopy, a nondestructive/ noninvasive method are reported. The spectroscopic results are confirmed through the application of Xray microdiffraction and scanning electron microscopy coupled with energy dispersive Xray spectrometry. Moreover, it is demonstrated how it is made possible through the application of microRaman (μRaman) spectroscopy to examine and collect crucial information from very small inclusions in the ceramic fabric. The aim of this approach is to develop an analytical protocol based on μRaman spectroscopy, for extracting firing temperature information from other ceramic finds (figurines) where due to their uniqueness sampling and analyses through other techniques is not possible. This information can lead to dating but also to firing kiln technology extrapolations that are very significant in archaeology.


2010 ◽  
Vol 7 (1) ◽  
pp. 111 ◽  
Author(s):  
Manjula Sunkara ◽  
Martha J. M. Wells

Environmental context. Excretion of pharmaceuticals and their metabolites by humans and animals, flushing unused pharmaceuticals and inadequate water treatment result in the occurrence of these chemicals as pollutants in wastewater, surface water and drinking water. In this research, the pharmaceutical agent acetaminophen (paracetamol, Tylenol) and its glucuronide and sulfate metabolites were examined as a model system for monitoring wastewater influent and effluent. The true risk to ecosystems and humans from the occurrence of pharmaceuticals in our water supply can only be estimated if accurate concentrations of parent pharmaceutical chemicals as well as their metabolites are measured. Abstract. An analytical method was developed to separately determine acetaminophen and its Phase II metabolites, acetaminophen glucuronide and acetaminophen sulfate, from wastewater in a single extract. The method developed will serve as a model for screening for the presence of other non-steroidal pharmaceutical compounds and their Phase II metabolites in wastewater. Acetaminophen glucuronide was not present in the wastewater influent tested to verify the analytical protocol, whereas concentrations of acetaminophen and acetaminophen sulfate in the influent were reproducible over time. A Phase I metabolite, p-aminophenol, was also determined to occur in the wastewater influent. Concentrations of the analytes-of-interest, detected in effluent samples collected after secondary treatment, but before UV treatment, were highly variable and were undetectable after UV treatment before release to surface water.


2009 ◽  
Vol 266 (3-4) ◽  
pp. 218-230 ◽  
Author(s):  
Frank S. Spear ◽  
Joseph M. Pyle ◽  
Daniele Cherniak
Keyword(s):  

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