LAC-UFF STATUS REPORT: CURRENT PROTOCOLS AND RECENT DEVELOPMENTS

Radiocarbon ◽  
2021 ◽  
pp. 1-13
Author(s):  
Fabiana Oliveira ◽  
Kita Macario ◽  
Carla Carvalho ◽  
Vinicius Moreira ◽  
Eduardo Q Alves ◽  
...  

ABSTRACT The Radiocarbon Laboratory of the Fluminense Federal University was installed in 2009, and its NEC Single Stage Accelerator Mass Spectrometry system has been operational since 2012. As the first 14C-AMS facility in Latin America, the LAC-UFF became a reference center for radiocarbon (14C) dating in Brazil. Over the years we have implemented pretreatment protocols for several kinds of materials, such as cellulose, soil, bone, and biofuels. In the present paper we describe our current protocols for the preparation of these types of samples. Moreover, after 10 years of operation, with the aim of expanding the range of materials we are able to analyze, we report the results of several tests to improve accuracy, precision and background levels. For example, here we discuss how isotopic fractionation during the graphitization and measurement steps has been controlled. Concerning results interpretation, our research group has been using OxCal chronological models to analyze different contexts such as stromatolite growth, tree rings, soil deposition and marine reservoir effect (MRE) determination.

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 755-760 ◽  
Author(s):  
G W Farwell ◽  
P M Grootes ◽  
D D Leach ◽  
F H Schmidt

During the past year we have continued to work toward greater stability and flexibility in nearly all elements of our accelerator mass spectrometry (AMS) system, which is based upon an FN tandem Van de Graaff accelerator, and have carried out measurements of 14C/12C and 10Be/9Be isotopic abundance ratios in natural samples. The principal recent developments and improvements in the accelerator system and in our sample preparation techniques for carbon and beryllium are discussed, and the results of a study of 10Be cross-contamination of beryllium samples in the sputter ion source are presented.


Radiocarbon ◽  
2014 ◽  
Vol 56 (3) ◽  
pp. 1189-1194 ◽  
Author(s):  
Fusa Miyake ◽  
Kimiaki Masuda ◽  
Masataka Hakozaki ◽  
Toshio Nakamura ◽  
Fuyuki Tokanai ◽  
...  

A rapid yearly increase in the radiocarbon content has been detected for the period from AD 993 to 994. However, this event is supported by the 14C measurements of only one cedar tree sample, and verification is necessary to confirm this event more reliably. For this purpose, this study measured the 14C content in Japanese Hinoki tree rings corresponding to the period from AD 988 to 997 using the accelerator mass spectrometry system at Yamagata University (YU-AMS). The result shows a significant 14C increase from AD 993 to 994, and is consistent with the previously measured data for the Japanese cedar tree. This marks the second case detecting an increased 14C level corresponding to the AD 994 event.


2019 ◽  
Vol 16 (4) ◽  
pp. 267-276
Author(s):  
Qurat ul Ain Farooq ◽  
Noor ul Haq ◽  
Abdul Aziz ◽  
Sara Aimen ◽  
Muhammad Inam ul Haq

Background: Mass spectrometry is a tool used in analytical chemistry to identify components in a chemical compound and it is of tremendous importance in the field of biology for high throughput analysis of biomolecules, among which protein is of great interest. Objective: Advancement in proteomics based on mass spectrometry has led the way to quantify multiple protein complexes, and proteins interactions with DNA/RNA or other chemical compounds which is a breakthrough in the field of bioinformatics. Methods: Many new technologies have been introduced in electrospray ionization (ESI) and Matrixassisted Laser Desorption/Ionization (MALDI) techniques which have enhanced sensitivity, resolution and many other key features for the characterization of proteins. Results: The advent of ambient mass spectrometry and its different versions like Desorption Electrospray Ionization (DESI), DART and ELDI has brought a huge revolution in proteomics research. Different imaging techniques are also introduced in MS to map proteins and other significant biomolecules. These drastic developments have paved the way to analyze large proteins of >200kDa easily. Conclusion: Here, we discuss the recent advancement in mass spectrometry, which is of great importance and it could lead us to further deep analysis of the molecules from different perspectives and further advancement in these techniques will enable us to find better ways for prediction of molecules and their behavioral properties.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ali S. Abdelhameed ◽  
Adnan A. Kadi ◽  
Hatem A. Abdel-Aziz ◽  
Rihab F. Angawi ◽  
Mohamed W. Attwa ◽  
...  

A new approach was recently introduced to improve the structure elucidation power of tandem mass spectrometry simulating the MS3of ion trap mass spectrometry system overcoming the different drawbacks of the latter. The fact that collision induced dissociation in the triple quadrupole mass spectrometer system provides richer fragment ions compared to those achieved in the ion trap mass spectrometer system utilizing resonance excitation. Moreover, extracting comprehensive spectra in the ion trap needs multistage fragmentation, whereas similar fragment ions may be acquired from one stage product ion scan using the triple quadrupole mass spectrometer. The new strategy was proven to enhance the qualitative performance of tandem mass spectrometry for structural elucidation of different chemical entities. In the current study we are endeavoring to prove our hypothesis of the efficiency of the new pseudo-MS3technique via its comparison with the MS3mode of ion trap mass spectrometry system. Ten pharmacologically and synthetically important (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones (enaminones4a–j) were chosen as model compounds for this study. This strategy permitted rigorous identification of all fragment ions using triple quadrupole mass spectrometer with sufficient specificity. It can be used to elucidate structures of different unknown components. The data presented in this paper provide clear evidence that our new pseudo-MS3may simulate the MS3of ion trap spectrometry system.


2017 ◽  
Vol 10 (1) ◽  
pp. 5-29 ◽  
Author(s):  
F. Berthiller ◽  
C. Brera ◽  
M.H. Iha ◽  
R. Krska ◽  
V.M.T. Lattanzio ◽  
...  

This review summarises developments in the determination of mycotoxins over a period between mid-2015 and mid-2016. Analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes and zearalenone are covered in individual sections. Advances in proper sampling strategies are discussed in a dedicated section, as are methods used to analyse botanicals and spices and newly developed liquid chromatography mass spectrometry based multi-mycotoxin methods. This critical review aims to briefly discuss the most important recent developments and trends in mycotoxin determination as well as to address limitations of presented methodologies.


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