Search results for "tandem"
showing 10 items of 560 documents
STR genotyping and mtDNA sequencing of latent fingerprint on paper
2003
A systematic study was conducted to investigate whether DNA can be successfully extracted from latent fingerprints deposited on ordinary paper and analysed using short tandem repeat profiling and mitochondrial DNA sequencing. In order to evaluate the performance of latent fingerprint analysis in a criminal case, experiments with varying conditions were carried out to improve our understanding of low copy number (LCN) DNA typing. After optimising the extraction methods to achieve increased sensitivity, the examination of touched paper can routinely yield the STR profile of the individual who has touched it. A fingerprint can therefore be considered as a potential source of DNA for genetic id…
Analysis of perfluorinated compounds in sewage sludge by pressurized solvent extraction followed by liquid chromatography–mass spectrometry
2011
Perfluorinated compounds (PFCs) are widely used in everyday life and one of the main recipients of these compounds is waste water treatment plants (WWTPs). Due to the structure and physicochemical properties of PFCs, these compounds could be redistributed from influent water to sludge. This work reports a new validated protocol for the analysis of 13 perfluorinated acids, 4 perfluorosulfonates and the perfluorooctanesulfonamide. The present work has been focused to develop a sensitive and robust method for the analysis of 18 PFCs in sewage sludge, based on pressurized solvent extraction (PSE) followed by solid phase extraction (SPE) clean-up, analytes separation by liquid chromatography and…
Molecular Classification of Pesticides Including Persistent Organic Pollutants, Phenylurea and Sulphonylurea Herbicides
2014
Pesticide residues in wine were analyzed by liquid chromatography–tandem mass spectrometry. Retentions are modelled by structure–property relationships. Bioplastic evolution is an evolutionary perspective conjugating effect of acquired characters and evolutionary indeterminacy–morphological determination–natural selection principles; its application to design co-ordination index barely improves correlations. Fractal dimensions and partition coefficient differentiate pesticides. Classification algorithms are based on information entropy and its production. Pesticides allow a structural classification by nonplanarity, and number of O, S, N and Cl atoms and cycles; different behaviours depend …
Mycotoxin Incidence in Some Fish Products: QuEChERS Methodology and Liquid Chromatography Linear Ion Trap Tandem Mass Spectrometry Approach
2019
The inclusion of vegetal raw materials in feed for fish farming has increased the risk of mycotoxin occurrence in feed, as well as in edible tissues from fish fed with contaminated feed, due to the carry-over to muscle portions. Therefore, the objective of this study was to evaluate the occurrence of 15 mycotoxins in processed fish products, which are commonly consumed, such as smoked salmon and trout, different types of sushi, and gula substitutes. A QuEChERS method was employed to perform the mycotoxin extraction from fish samples. For mycotoxin identification and quantitation, the selected technique was the liquid chromatography-tandem mass spectrometry linear ion trap (LC-MS/MS-LIT). Sm…
Sensitive screening of synthetic cannabinoids using liquid chromatography quadrupole time-of-flight mass spectrometry after solid phase extraction.
2021
Analysis of synthetic cannabinoids still poses a challenge for many institutions due to the number of available substances and the constantly changing drug market. Both new and well-known substances keep appearing and disappearing on the market, making it hard to adapt analytical methods in a timely manner. In this study, we developed a qualitative screening approach for synthetic cannabinoids and their metabolites by means of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Samples were measured in data-dependent auto-MS/MS mode and identified by fragment spectra, retention time and accurate mass. Two established solid phase extractions were compared using fo…
Analytical utility of quadrupole time-of-flight mass spectrometry for the determination of pesticide residues in comparison with an optimized column …
2009
Abstract A multiresidue method for the analysis of 30 pesticides with different physicochemical properties in fruits and vegetables was developed. The method involves a rapid and small-scale extraction procedure based on matrix solid-phase dispersion using octadecylsilyl (C18) as the dispersant and dichloromethane as the eluent. The target pesticides were determined using column high-performance liquid chromatography/triple quadrupole-tandem mass spectrometry (LC/QqQ-MS/MS). The method was validated for sensitivity, linearity, reproducibility, and accuracy. A recovery study was conducted at 3 different levels, and the average ranged from 74 to 99 for all of the studied compounds, with relat…
Synthesis of 2H-Imidazo[2',1':2,3] [1,3]thiazolo[4,5-e]isoindol-8-yl-phenylureas with promising therapeutic features for the treatment of acute myelo…
2022
Despite progressive advances in understanding the molecular biology of acute myeloid leukemia (AML), the conventional therapeutic approach has not changed substantially, and the outcome for most patients is poor. Thus, continuous efforts on the discovery of new compounds with improved features are required. Following a multistep sequence, we have identified a new tetracyclic ring system with strong antiproliferative activity towards several haematological cell lines. The new compounds possess structural properties typical of inactive-state-binding kinase inhibitors and are structurally related to quizartinib which is known as type-II tyrosine kinase inhibitor. In particular, the high activi…
INTERFERENCE REMOVAL IN ICP-MS USING HE COLLISION CELL WITH TANDEM MS
2021
Half-life ofTi44
1983
The half-life of $^{44}\mathrm{Ti}$ has been measured to be ${T}_{\frac{1}{2}}=54.2\ifmmode\pm\else\textpm\fi{}2.1$ yr, somewhat higher than previously published values of 46.4\ifmmode\pm\else\textpm\fi{}1.7 and 48.2\ifmmode\pm\else\textpm\fi{}0.9 yr. The present value was obtained from the specific activity and the radioisotope concentration of several Ti${\mathrm{O}}_{2}$ samples, each spiked with a $^{44}\mathrm{Ti}$ activity of about 1.2 \ensuremath{\mu}Ci. The specific activity was measured via the 1157 keV $\ensuremath{\gamma}$ line from the decay of the $^{44}\mathrm{Sc}$ daughter. $^{44}\mathrm{Ti}$/Ti concentrations were measured with the Argonne FN tandem accelerator in conjunctio…
Resolution of nuclear ground and isomeric states by a Penning trap mass spectrometer.
1992
Ground and isomeric states of a nucleus have been resolved for the first time by mass spectrometry. Measurements on $^{78}\mathrm{Rb}^{\mathit{m},}$g and $^{84}\mathrm{Rb}^{\mathit{m},}$g were performed using a tandem Penning trap mass spectrometer on-line with the isotope separator ISOLDE/CERN. The effects of ion-ion interaction were investigated for two ion species differing in mass and stored simultaneously in the trap.