The paper summarizes critically the current approaches for the calculation of the limits of detection and quantification. In the context of the description of the method based on the calibration line, the arguments concerning the underlying experimental design, the choice of the appropriate model in the univariate regression, the effects of the dispersion characteristics of the data are deeply ...

background: organic acids refer to a family of compounds that are intermediates in a variety of metabolic pathways. many organic acids are present in urine from clinically normal individuals. elevated levels of urine organic acids cause to the organic acidurias, disorders in which some metabolic pathways in organic acid metabolism are blocked. the present work identified major and minor urinary...

Present study aims the optimisation and validation of the extraction procedures for the determination of polycyclic aromatic hydrocarbons (PAHs) in sediment samples. As analytical techniques, gas chromatographymass detector (GC-MS) and gas chromatography-flame ionization detector (GC-FID). The optimized methods were soxhlet extraction, ultrasonic bath extraction and solid phase micro extraction...

Metabolite profiling is the multiparallel relative quantification of a mixture of compounds or compound classes using chromatography and universal detection technologies (GC-MS, LC-MS). In this respect it is an extension of classical single-target methods from which it can be distinguished by its broader view on profiling major biochemical events. This broader scope of analysis outweighs the di...

Thermal ionization mass spectrometry (T I M S). Fast atom bombardment mass spectrometry (F A B M S). . Inductively coupled mass spectrometry (I C P M S) Electron impact mass spectrometry (E I M S) and gas chromatography mass spectrometry (GCMS). Dosage considerations. Intrinsic or extrinsic tag. Intestinal transit time and study length Endogenously excreted elements .

Ferrocene is a popular template in material science due to its exceptional characteristics that offer the ability to optimize the selectivity and activity of catalysts by the addition of carefully selected substituents. In combinatorial catalyst development, the high susceptibility to electrophilic substitution reactions offers the opportunity for the rapid introduction of molecular diversity. ...

The investigation into whether Mars contains signatures of past or present life is of great interest to science and society. Amino acids and nucleobases are compounds that are essential for all known life on Earth and are excellent target molecules in the search for potential Martian biomarkers or prebiotic chemistry. Martian meteorites represent the only samples from Mars that can be studied d...

Mass spectrometry is fundamental to measurements of isotope ratios for applications in isotope geochemistry, geochronology, and cosmochemistry. Magnetic-sector mass spectrometers are most common because these provide the best precision in isotope ratio measurements. Where the highest precision is desired, chemical separation followed by mass spectrometric analysis is carried out with gas (noble...