Quantification Approaches in Non-Target LC/ESI/HRMS Analysis: An Interlaboratory Comparison.

Nontargeted screening (NTS) utilizing liquid chromatography electrospray ionization high-resolution mass spectrometry (LC/ESI/HRMS) is increasingly used to identify environmental contaminants. Major differences in the ionization efficiency of compounds in ESI/HRMS result in widely varying responses and complicate quantitative analysis. Despite an increasing number of methods for quantification without authentic standards in NTS, the approaches are evaluated on limited and diverse data sets with varying chemical coverage collected on different instruments, complicating an unbiased comparison.

Relationship between Composition and Environmental Degradation of Poly(isosorbide--diol oxalate) (PISOX) Copolyesters.

To reduce the global CO footprint of plastics, bio- and CO-based feedstock are considered the most important design features for plastics. Oxalic acid from CO and isosorbide from biomass are interesting rigid building blocks for high polyesters. The biodegradability of a family of novel fully renewable (bio- and CO-based) poly(isosorbide--diol) oxalate (PISOX-diol) copolyesters was studied.

Simultaneous detection of pesticides and pharmaceuticals in three types of bio-based fertilizers by an improved QuEChERS method coupled with UHPLC-q-ToF-MS/MS.

Bio-based fertilizers (BBFs) have the potential to contain both pesticides and pharmaceutical residues, which may pose a threat to soils, crops, and human health. However, no analytical screening method is available currently to simultaneously analyze a wide range of contaminants in the complex origin-dependent matrices of BBFs. To fill this gap, our study tested and improved an original QuEChERS method (OQM) for simultaneously analyzing 78 pesticides and 18 pharmaceuticals in BBFs of animal, plant, and ashed sewage sludge origin.

Analytical research of pesticide biomarkers in wastewater with application to study spatial differences in human exposure.

Wastewater-based epidemiology (WBE) relies on the assessment and interpretation of levels of biomarkers in wastewater originating from a well-defined community. It has provided unique information on spatial and temporal trends of licit and illicit drug consumption, and has also the potential to give complementary information on human exposure to chemicals. Here, we focus on the accurate quantification of pesticide biomarkers (i.

Effect-directed analysis and chemical identification of agonists of peroxisome proliferator-activated receptors in white button mushroom.

Obesity has a serious effect on human health. It relates to metabolic syndrome, including the associated disorders such as type 2 diabetes, heart disease, stroke and hyperemia. The peroxisome proliferator-activated receptors (PPARs) are important receptors to control fat metabolism in the human body.

Antagonistic activity towards the androgen receptor independent from natural sex hormones in human milk samples from the Norwegian HUMIS cohort.

In this paper, we investigated the possible presence of endocrine disrupting chemicals (EDCs) based on measuring the total estrogenic and androgenic activity in human milk samples. We used specific bioassays for analysis of the endocrine activity of estrogens and estrogen-like EDCs and androgens and androgen-like EDCs and developed a separation method to evaluate the contribution from natural hormones in comparison to that of EDCs to total endocrine activities. We extracted ten random samples originating from the Norwegian HUMIS biobank of human milk and analyzed their agonistic or antagonistic activity using the ERα- and AR CALUX® bioassays.

Chemical attribution of the homemade explosive ETN - Part II: Isotope ratio mass spectrometry analysis of ETN and its precursors.

In this follow-up study the collaboration between two research groups from the USA and the Netherlands was continued to expand the framework of chemical attribution for the homemade explosive erythritol tetranitrate (ETN). Isotope ratio mass spectrometry (IRMS) analysis was performed to predict possible links between ETN samples and its precursors. Carbon, nitrogen, hydrogen and oxygen isotope ratios were determined for a wide variety of precursor sources and for ETN samples that were prepared with selected precursors.

Saponin-based adjuvants induce cross-presentation in dendritic cells by intracellular lipid body formation.

Saponin-based adjuvants (SBAs) are being used in animal and human (cancer) vaccines, as they induce protective cellular immunity. Their adjuvant potency is a factor of inflammasome activation and enhanced antigen cross-presentation by dendritic cells (DCs), but how antigen cross-presentation is induced is not clear. Here we show that SBAs uniquely induce intracellular lipid bodies (LBs) in the CD11b+ DC subset in vitro and in vivo.

The use of δ(2)H and δ(18)O isotopic analyses combined with chemometrics as a traceability tool for the geographical origin of bell peppers.

Two approaches were investigated to discriminate between bell peppers of different geographic origins. Firstly, δ(18)O fruit water and corresponding source water were analyzed and correlated to the regional GNIP (Global Network of Isotopes in Precipitation) values. The water and GNIP data showed good correlation with the pepper data, with constant isotope fractionation of about -4.

Determination of n-alkanes in C. annuum (bell pepper) fruit and seed using GC-MS: comparison of extraction methods and application to samples of different geographical origin.

An efficient extraction and analysis method was developed for the isolation and quantification of n-alkanes from bell peppers of different geographical locations. Five extraction techniques, i.e.

Investigation of the presence of prednisolone in bovine urine.

Over the past two years low levels of prednisolone have been reported in bovine urine by a number of laboratories in European Union member states. Concentrations vary, but are reported to be below approximately 3 µg l(-1). Forty per cent of bovine urine samples from the Dutch national control plan had concentrations of prednisolone between 0.

Confirmation and 3D profiling of anabolic steroid esters in injection sites using imaging desorption electrospray ionisation (DESI) mass spectrometry.

In this study, desorption electrospray ionisation (DESI) linear ion trap tandem mass spectrometry (MS(n)) was applied for the confirmation and three-dimensional profiling of anabolic steroid esters in an injection site of bovine muscle. The spatial resolution of the DESI-MS(n) was demonstrated by scanning hormone esters and marker ink lines drawn at various distances on a microscopic slide at set distances, using an x-scanner with manual y and z adjustment. Tissue slices of bovine muscle injected with a hormone cocktail were analysed.

Saponin-based adjuvants create a highly effective anti-tumor vaccine when combined with in situ tumor destruction.

Today's most commonly used microbial vaccines are essentially composed of antigenic elements and a non-microbial adjuvant, and induce solid amounts of antibodies. Cancer vaccines mostly aim to induce anti-tumor CTL-responses, which require cross-presentation of tumor-derived antigens by dendritic cells (DCs). Adjuvants that improve DC function and antigen cross-presentation are therefore advantageous for inducing anti-tumor immunity.

New developments in umami (enhancing) molecules.

As health has become one of the main drivers in nutrition, the scientific interest in taste receptors and taste molecules has increased considerably. Academia as well as flavor and food companies are searching for molecules that make food more healthy but not less appetizing. In the savory area, salt and umami taste are being investigated.

LC-MS study to reduce ion suppression and to identify N-lactoylguanosine 5'-monophosphate in bonito: a new umami molecule?

In this study a specific taste modulating flavor ingredient, N-lactoylguanosine 5'-monophosphate (N-lactoyl GMP), was determined in bonito (Japanese, Katsuobushi, dried fermented skipjack) and in powdered bonito using liquid chromatography-electrospray ionization (+) mass spectrometry-mass spectrometry (LC-ESI(+)-MS/MS) with a methanol/ammonium acetate or formate gradient. Furthermore, the influence of ion suppression due to sample matrix effect was investigated and was found to substantially influence the total MS response of N-lactoyl GMP; by adjusting the LC conditions the response could be approximately 5-fold-enhanced. The N-lactoyl GMP concentrations in different types of bonito products were between 0.

Identification of N-gluconyl [corrected] ethanolamine in wine by negative electrospray ionization with post-column chloride attachment and accurate mass determination on a triple-quadrupole mass spectrometer.

In this study a specific taste modulating flavour-ingredient, N-gluconyl [corrected] ethanolamine, was determined in two Beerenauslese wines using two different LC-MS techniques. For a first screening LC-MS(2) on an ion-trap mass spectrometer with negative electrospray ionization (ESI(-)) was applied. Sensitivity (and selectivity) was successfully increased approx.

Liquid chromatography with accurate mass measurement on a triple quadrupole mass-spectrometer for the identification and quantification of N-lactoyl ethanolamine in wine.

In this study a specific taste-modulating flavor ingredient, N-lactoyl ethanolamine, was determined in two Beerenauslese wines using preparative LC, as a first isolation and concentration step, followed by LC-MS/MS on a triple quadrupole in accurate mass (AM) mode. The accurate masses of the analyte and three characteristic fragments were determined with mass accuracies between 8 and 20 ppm. N-lactoyl ethanolamine concentrations in the wines were 0.

Analytical separation and detection methods for flavonoids.

Flavonoids receive considerable attention in the literature, specifically because of their biological and physiological importance. This review focuses on separation and detection methods for flavonoids and their application to plants, food, drinks and biological fluids. The topics that will be discussed are sample treatment, column liquid chromatography (LC), but also methods such as gas chromatography (GC), capillary electrophoresis (CE) and thin-layer chromatography (TLC), various detection methods and structural characterization.

Changed isoflavone levels in red clover (Trifolium pratense L.) leaves with disturbed root nodulation in response to waterlogging.

The effect of disturbed root nodulation on the quantitative and qualitative composition of the main isoflavonoid glucoside malonates, glucosides, and aglycones in the leaves of Trifolium pratense L. grown under waterlogging conditions was investigated. Isoflavonoids are involved in the regulation of root nodule activity and the establishment of the mycorrhizal association.

Liquid chromatography coupled to nuclear magnetic resonance spectroscopy for the identification of isoflavone glucoside malonates in T. pratense L. leaves.

Previous studies revealed that the main isoflavones in extracts of leaves of T. pratense L. are biochanin A and formononetin, their 7-O-glucosides, and two glucoside malonate isomers of each of them.

Flavonoids in Leguminosae: analysis of extracts of T. pratense L., T. dubium L., T. repens L., and L. corniculatus L. leaves using liquid chromatography with UV, mass spectrometric and fluorescence detection.

Reversed-phase LC on C-18 bonded silica with a methanol-ammonium formate gradient was used to determine the main flavonoids in leaves of four species of the Leguminosae family. The detection modes were diode-array UV absorbance, fluorescence, and (tandem) mass spectrometry. LC-UV was used for a general screening, sub-classification, and the calculation of total flavonoid contents.

Liquid chromatography with atmospheric pressure chemical ionization and electrospray ionization mass spectrometry of flavonoids with triple-quadrupole and ion-trap instruments.

With 15 flavonoids as test compounds, the analytical performance of four modes of LC-MS, multiple MS (MSn) and tandem MS operation (atmospheric pressure chemical ionization (APCI), electrospray ionization, positive and negative ionization) was compared for two mass spectrometers, a triple-quadrupole and an ion-trap instrument. Two organic modifiers, methanol and acetonitrile, and two buffers, ammonium acetate and ammonium formate, were used. In general, the use of APCI in the negative ion mode gave the best response, with the signal intensities and the mass-spectral characteristics not differing significantly between the two instruments.

Determination of isoflavone glucoside malonates in Trifolium pratense L. (red clover) extracts: quantification and stability studies.

Isoflavones, their glucosides and their glucoside malonates were determined in red clover leaf extracts using reversed-phase LC coupled to atmospheric pressure chemical ionisation mass spectrometry (APCI-MS), UV and fluorescence detectors and the stability of the malonates was investigated. Extracts can be stored at least 1-2 weeks at -20 degrees C without loss of malonates. In LC-separated fractions the malonates are most stable when stored at low temperature after evaporation to dryness.

Immunoadjuvant activities of E. coli- and plasmid-expressed recombinant chicken IFN-alpha/beta, IFN-gamma and IL-1beta in 1-day- and 3-week-old chickens.

In the present study we assessed the capacity of recombinant E. coli- or plasmid-expressed chicken interferons (IFN) and chicken IL-1beta, to exert immunostimulatory activities for humoral immune responses, in day-old and adult chickens. We observed that both recombinant E.