Impurity profiling of trinitrotoluene using vacuum-outlet gas chromatography-mass spectrometry

In this work, a reliable and robust vacuum-outlet gas chromatography-mass spectrometry (GC-MS) method is introduced for the identification and quantification of impurities in trinitrotoluene (TNT). Vacuum-outlet GC-MS allows for short analysis times the analysis of impurities in TNT was performed in 4. min. This study shows that impurity...

Identifying inhibitory compounds in lignocellulosic biomass hydrolysates using an exometabolomics approach

Background: Inhibitors are formed that reduce the fermentation performance of fermenting yeast during the pretreatment process of lignocellulosic biomass. An exometabolomics approach was applied to systematically identify inhibitors in lignocellulosic biomass hydrolysates.Results: We studied the composition and fermentability of 24 different...

Metabolite profiling of small cerebrospinal fluid sample volumes with gas chromatography-mass spectrometry: Application to a rat model of multiple sclerosis

Analysis of metabolites in biofluids by gas chromatography-mass spectrometry (GC-MS) after oximation and silylation is a key method in metabolomics. The GC-MS method was modified by a modified vial design and sample work-up procedure in order to make the method applicable to small volumes of cerebrospinal fluid (CSF), i. e. 10 μL, with similar...

Metabolomics of cerebrospinal fluid reveals changes in the central nervous system metabolism in a rat model of multiple sclerosis

Experimental Autoimmune Encephalomyelitis (EAE) is the most commonly used animal model for Multiple Sclerosis (MScl). CSF metabolomics in an acute EAE rat model was investigated using targetted LC-MS and GC-MS. Acute EAE in Lewis rats was induced by co-injection of Myelin Basic Protein with Complete Freund's Adjuvant. CSF samples were collected...

Semi-targeted metabolomic approaches to validate potential markers of health for micronutrients: Analytical perspectives

Recommended dietary allowances for micronutrients fluctuate noticeably within European Union countries. The Network of Excellence EURRECA (EURopean micronutrient RECommendations Aligned) aims at harmonising micronutrient intake recommendations through population groups. The lack of proper markers of status for some micronutrients limits progress...

Discovery of early-stage biomarkers for diabetic kidney disease using ms-based metabolomics (FinnDiane study)

Diabetic kidney disease (DKD) is a devastating complication that affects an estimated third of patients with type 1 diabetes mellitus (DM). There is no cure once the disease is diagnosed, but early treatment at a sub-clinical stage can prevent or at least halt the progression. DKD is clinically diagnosed as abnormally high urinary albumin...

Semi-automated non-target processing in GC × GC-MS metabolomics analysis: Applicability for biomedical studies

Due to the complexity of typical metabolomics samples and the many steps required to obtain quantitative data in GC × GC-MS consisting of deconvolution, peak picking, peak merging, and integration, the unbiased non-target quantification of GC × GC-MS data still poses a major challenge in metabolomics analysis. The feasibility of using...

In-depth characterization of prebiotic galactooligosaccharides by a combination of analytical techniques

A commercial prebiotic galacto-oligosaccharide mixture (Vivinal GOS) was extensively characterized using a combination of analytical techniques. The different techniques were integrated to give complementary information on specific characteristics of the oligosaccharide mixture, ranging from global information on degree of polymerization (DP) to...

Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary-secondary amine and graphitized carbon black) and large-volume (20 μL) injection. The same extract, before clean-up and after...

A strategy for modelling dynamic responses in metabolic samples characterized by GC/MS

A multivariate strategy for studying the metabolic response over time in urinary GC/MS data is presented and exemplified by a study of drug-induced liver toxicity in the rat. The strategy includes the generation of representative data through hierarchical multivariate curve resolution (H-MCR), highlighting the importance of obtaining resolved...

Effects of growth conditions and processing on Rehmannia glutinosa using fingerprint strategy

Metabolite profiling in combination with multivariate statistics is a sophisticated method for quality assessment of natural products. For the development of a quality control strategy in Traditional Chinese Medicine (TCM), we have measured the metabolite fingerprints of Rehmannia glutinosa by GC-MS. Plants were grown under different climate and...

Adhesion strength study between plasma treated polyester fibres and a rubber matrix

In this work, the adhesion strength between poly(ethylene terephthalate) (PET) fibres and styrene-butadiene rubber (SBR) was studied. The effects of atmospheric plasma treatment, used to increase adhesion strength between PET fibres and the rubber matrix, were investigated and compared. It was confirmed that lubricants on the fibres caused a...

Analytical possibilities for the detection of stanozolol and its metabolites

In sports doping, as well in man as in horseracing, stanozolol (Stan) was abused and became the subject of metabolism research. Also in veterinary practice, stanozolol became an important misused anabolic steroid. Like most other anabolic steroids, stanozolol has poor gas chromatographic behavior. It is difficult to detect in urine, because of...