Honey was previously considered to be one of the main food sources human pyrrolizidine alkaloid (PA) exposure in Europe. However, comprehensive analyses honey and tea sampled Berlin retail market revealed unexpected high PA amounts teas. This study comprised analysis 87 as well 274 samples including black, green, rooibos, melissa, peppermint, chamomile, fennel, nettle, mixed herbal or fruit tea. Total concentrations ranged from < LOD 5647 µg kg−1, while a mean value about 10 kg−1 found...

The water-soluble organic fractions of aerosol samples collected in Riverside, CA, summer 2005 were analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Elemental compositions about 1000 molecular species determined the range m/z 220-420, and four series compounds identified, fulvic acids, S-containing, N-containing, S- N-containing molecules. Low-resolution product spectra proved presence organosulfates, organonitrates, mixed...

Pyrrolizidine alkaloids (PAs) are secondary metabolites of plant families such as Asteraceae or Boraginaceae and suspected to be genotoxic carcinogens. Recent investigations revealed their frequent occurrence in honey particularly tea. To obtain a comprehensive overview the PA content animal- plant-derived food from European market, provide basis for future risk analysis, total 1105 samples were collected 2014 2015. These comprised milk products, eggs, meat (herbal) teas, supplements...

Dissolved organic matter isolated from the deep Atlantic Ocean and fractionated into a so-called hydrophobic (HPO) fraction very hydrophilic (HPI) was analyzed for first time by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) to resolve molecular species, determine their exact masses, calculate formulas. The elemental composition of about 300 molecules identified. Those in HPO (14C age 5100 year) are similar much younger freshwater fulvic acids, but less aromatic more...

A method was developed for the analysis of humic and fulvic acids by size-exclusion chromatography-electrospray ionization-tandem mass spectrometry using a completely volatile eluent. Humic were separated into three peaks. These fractions occupied different ranges showed differences in fine structure their spectra. The low-molecular-weight (LMW) fraction is most sensitively determined ESI-MS, it appears that previous results obtained infusion-ESI-MS primarily this acid fraction. average...

Pyrrolizidine alkaloids (PAs) and their corresponding N-oxides (PANOs) have been determined in food feed at levels relevant for consumer health. More than 660 different PAs detected, but few are available as reference substances analytical demands. In the context of European legislation on maximum products, a defined scope 21 determination has suggested. An expansion from to 35 PAs, including 14 structural isomers, is currently under discussion. present study, target screening method was...

Lipophilicity and blood partitioning are important determinants for predicting toxicokinetics using physiologically-based toxicokinetic (PBTK) modeling. In this study, the logarithm of n-octanol:water partition coefficient (logP) blood-to-plasma concentration ratio (Rb ) were first time experimentally determined pyrrolizidine alkaloids (PAs) intermedine, lasiocarpine, monocrotaline, retrorsine their N-oxides (PANOs). Validated in vitro assays logP (miniaturized shake-flask method) Rb...

Fulvic acids are one of the largest classes dissolved organic matter, but they poorly defined and unclear origin. Three fulvic acid isolates different origin were analyzed by size-exclusion chromatography coupled to electrospray ionization-Fourier-transform ion cyclotron resonance (FTICR)-mass spectrometry, molecular formulas for 700-1900 species in these derived. All three show same pattern elemental composition their molecules a large congruence sets. It is proposed that structural...

Size exclusion chromatography (SEC) coupled to electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF-MS) was used analyze the elemental composition and structure of low-molecular-weight fulvic acid molecules. It is shown that set hundreds individual molecules form a homogeneous structurally unique class compounds can be clearly differentiated from any other biogenic matter investigated date. The molecular acids in isolates very different origin (surface water,...

Pyrrolizidine alkaloid (PA) forming plants are found worldwide and may contaminate food products at levels being of concern for human health. Due to the high biodiversity PA producing many different types structures formed. PAs themselves not toxic but require metabolic activation exert toxicity. To investigate if structure affects their in vitro metabolism, we incubated a set 22 compared degradation rates amount formed glutathione (GSH) conjugates. With liver microsomes, no monoesters was...

1,2-unsaturated pyrrolizidine alkaloids and their N-oxides (PA/PANO) are plant toxins that produced by several hundreds of species. Due to the pronounced liver toxicity carcinogenicity certain PAs, presence in food feed has raised concern. However, since PA-producing weeds cannot generally be prevented on grassland Senecio species often occur high densities, transfer PAs into muscle dairy cattle, goat sheep was determined. In 28-day feeding studies extracts tansy ragwort (Jacobaea vulgaris...

A method was developed to link size exclusion chromatography electrospray ionization mass spectrometry (SEC-ESI-MS) analyses of fulvic and humic acids with SEC organic carbon detection (SEC-OCD), the latter providing an absolute measure amount matter eluting from column. This approach allows us determine which molecular weight fraction complex polydisperse mixtures is detectable by ESI-MS. It could be shown that cone voltage setting for ESI interface has strong impact on ESI-MS detection....

Abstract Size‐exclusion chromatography was coupled to a quadrupole time‐of‐flight mass spectrometer using electrospray ionization in the negative ion mode analyze Suwannee River fulvic acid. About 220 exact masses of low molecular weight acids (FAs) were measured range from m/z 190 350, and formulas could be deduced for all these masses. All can described by superimposition three homologous series FA mixture: (a) hydrogen homologs constituted five six members given number carbons oxygens;...

Size-exclusion chromatography coupled to quadrupole time-of-flight mass spectrometry (SEC−Q-TOF-MS) was used study changes in the molecular composition of a Suwannee River fulvic acid isolate by ozonation. The all three SEC fractions showed strong and relative increase low weight anions. Further spectrometric investigations focused on molecules, where preferential removal molecules with oxidation state (low O/C ratio) high degree unsaturation H/C observed. Besides their elemental...

Scope 1,2‐Unsaturated pyrrolizidine alkaloids (PA) are found in plants such as Asteraceae and Boraginaceae families. Acute PA poisoning via contaminated food or feed causes severe damage to liver depending on species‐specific oral bioavailability. For assessing bioavailability, their passage across the intestinal barrier was investigated using Caco‐2 cells. Methods Differentiated cells were exposed transport chambers heliotrine (Hn), echimidine (Em), senecionine (Sc), senkirkine (Sk). Cell...