Currently, the environmental problems associated with plastic production and waste, such as the consequences of worldwide pollution of natural waters with microplastics, have led to the seeking of alternative materials that can at least partially replace conventional petroleum-based plastics. Substitute materials include bioplastics and similar plant-based materials or their composites. However, their fate when disposed of in unintended environments (e.g., water bodies) remains largely unknown, while such information is highly desirable prior to massive expansion of exploiting such materials. This study aims to contribute filling this knowledge gap. Specifically, 19 different types of bioplastic and similar plant-based material debris (corresponding to the size of microplastics) were kept in long-term contact with water to mimic their behaviour as water pollutants, and the leachates were continuously analysed. Eighteen of the 19 investigated materials released significant amounts of dissolved organic carbon-up to 34.0 mg per g of debris after 12 weeks of leaching. Each leachate also contained one or more of the following elements: Al, B, Ba, Ca, Fe, K, Mg, Mn, N, Na, P, Si, Ti, and Zn. Non-targeted analysis aimed at providing more specific insight into the leachate composition tentatively revealed 91 individual chemicals, mostly fatty acids and other carboxylic acids, phthalates, terephthalates, adipates, phenols, amides, alcohols, or organophosphates. Based on the compound characteristics, they might be additives, non-intentionally added substances, as well as their degradation products. In general, the current results imply that bioplastics and similar plant-based materials should be considered complex materials that undergo industrial processing and comprise additives rather than harmless natural matter. Additionally, various compounds can release from the bioplastic and similar plant-based material debris when deposited in water. It might have consequences on the fluxes of carbon, metals and specific organic contaminants, and it resembles some properties of conventional petroleum-based microplastics.
- Klíčová slova
- Bio-based materials, Biodegradable materials, Dissolved organic carbon (DOC), Microplastics, Non-targeted analysis, Water quality,
- MeSH
- chemické látky znečišťující vodu * analýza MeSH
- kovy * analýza MeSH
- mikroplasty analýza MeSH
- monitorování životního prostředí * metody MeSH
- plastické hmoty analýza MeSH
- uhlík * analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chemické látky znečišťující vodu * MeSH
- kovy * MeSH
- mikroplasty MeSH
- plastické hmoty MeSH
- uhlík * MeSH
The aim of the current research was to develop a simple and rapid mass spectrometry-based assay for the determination of 15 steroid hormones in human plasma in a single run, which would be suitable for a routine practice setting. For this purpose, we designed a procedure based on the 2D-liquid chromatography-tandem mass spectrometry with a minimalistic sample pre-treatment. In our arrangement, the preparation of one sample takes only 10 min and can accommodate 40 samples per hour when tested in series. The following analytical run is 18 min long for all steroid hormones. In addition, we developed an independent analytical run for estradiol, significantly increasing the assay accuracy while taking an additional 10 min to perform an analytical run of a sample. The optimized method was applied to a set of human plasma samples, including chylous. Our results indicate the linearity of the method for all steroid hormones with squared regression coefficients R2 ≥ 0.995, within-run and between-run precision (RSD < 6.4%), and an accuracy of 92.9% to 106.2%. The absolute recovery for each analyzed steroid hormone ranged between 101.6% and 116.5%. The method detection limit for 15 steroid hormones ranged between 0.008 nmol/L (2.88 pg/mL) for aldosterone and 0.873 nmol/L (0.252 ng/mL) for DHEA. For all the analytes, the lowest calibration point relative standard deviation was less than 10.8%, indicating a good precision of the assay within the lowest concentration of interest. In conclusion, in this method article, we describe a simple, sensitive, and cost-effective 2D-LC/MS/MS method suitable for the routine analysis of a complex of steroid hormones allowing high analytical specificity and sensitivity despite minimal sample processing and short throughput times.
- Klíčová slova
- 2D-LC/MS/MS, QuEChERS method, multiplexed analysis of steroid hormones, two dimensional-liquid chromatography with tandem mass spectrometry,
- MeSH
- chromatografie kapalinová metody MeSH
- estradiol MeSH
- krevní plazma chemie MeSH
- lidé MeSH
- reprodukovatelnost výsledků MeSH
- steroidy * analýza MeSH
- tandemová hmotnostní spektrometrie * metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- estradiol MeSH
- steroidy * MeSH
Although phototherapy (PT) is a standard treatment for neonatal jaundice, no validated clinical methods for determination of bilirubin phototherapy products are available. Thus, the aim of our study was to establish a such method for clinical use. To achieve this aim, a LC-MS/MS assay for simultaneous determination of Z-lumirubin (LR) and unconjugated bilirubin (UCB) was conducted. LR was purified after irradiation of UCB at 460 nm. The assay was tested on human sera from PT-treated neonates. Samples were separated on a HPLC system with a triple quadrupole mass spectrometer detector. The instrument response was linear up to 5.8 and 23.4 mg/dL for LR and UCB, respectively, with submicromolar limits of detection and validity parameters relevant for use in clinical medicine. Exposure of newborns to PT raised serum LR concentrations three-fold (p < 0.01), but the absolute concentrations were low (0.37 ± 0.16 mg/dL), despite a dramatic decrease of serum UCB concentrations (13.6 ± 2.2 vs. 10.3 ± 3.3 mg/dL, p < 0.01). A LC-MS/MS method for the simultaneous determination of LR and UCB in human serum was established and validated for clinical use. This method should help to monitor neonates on PT, as well as to improve our understanding of both the kinetics and biology of bilirubin phototherapy products.
- MeSH
- bilirubin analogy a deriváty krev chemie MeSH
- chromatografie kapalinová MeSH
- fototerapie metody MeSH
- lidé MeSH
- molekulární struktura MeSH
- novorozenec MeSH
- novorozenecká žloutenka krev terapie MeSH
- sérum chemie MeSH
- tandemová hmotnostní spektrometrie MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bilirubin MeSH
- lumirubin MeSH Prohlížeč
- Publikační typ
- časopisecké články MeSH
- tisková chyba MeSH
Saffron is one of the oldest and most expensive spices, which is often target of fraudulent activities. In this research, a new strategy of saffron authentication based on metabolic fingerprinting was developed. In the first phase, a solid liquid extraction procedure was optimized, the main aim was to isolate as maximal representation of small molecules contained in saffron as possible. In the second step, a detection method based on liquid chromatography coupled with high-resolution mass spectrometry was developed. Initially, principal component analysis (PCA) revealed clear differences between saffron cultivated and packaged in Spain, protected designation of origin (PDO), and saffron packaged in Spain of unknown origin, labeled Spanish saffron. Afterwards, orthogonal partial least square discriminant analysis (OPLS-DA) was favorably used to discriminate between Spanish saffron. The tentative identification of markers showed glycerophospholipids and their oxidized lipids were significant markers according to their origin.
- Klíčová slova
- Authenticity, Chemometrics, Metabolic fingerprinting, Saffron, Traceability, UHPLC-QTOF,
- MeSH
- analýza hlavních komponent MeSH
- analýza potravin přístrojové vybavení metody MeSH
- Crocus chemie metabolismus MeSH
- diskriminační analýza MeSH
- extrakce na pevné fázi MeSH
- koření * analýza normy MeSH
- metabolom MeSH
- metoda nejmenších čtverců MeSH
- multivariační analýza MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Španělsko MeSH
Structures and formation pathways of compounds responsible for pink discoloration of onion and leek were studied. A procedure was developed for the isolation and purification of the color compounds from various model systems and their identification by HPLC-DAD-MS/MS. In total, structures of 15 major color compounds were tentatively determined. It was found that the pigment is a complex mixture of highly conjugated species composed of two N-substituted 3,4-dimethylpyrrole-derived rings linked by either a methine or a propenylidine bridge. These two-ring units are further modified by various C1- and C3-side chains. Experiments with isotope-labeled thiosulfinates revealed that the methine bridge and C1-side chains originate from the methyl group of methiin, whereas the C3 units are derived from the propenyl group of isoalliin.
- Klíčová slova
- Allium, dipyrromethane, discoloration, isoalliin, leek, onion, pinking, plant pigment, pyrrole, thiosulfinate,
- MeSH
- barva MeSH
- biologické pigmenty analýza chemie izolace a purifikace MeSH
- česneky chemie MeSH
- cystein analogy a deriváty chemie MeSH
- kyseliny sulfinové chemie MeSH
- tandemová hmotnostní spektrometrie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- alliin MeSH Prohlížeč
- biologické pigmenty MeSH
- cystein MeSH
- kyseliny sulfinové MeSH
- methiin MeSH Prohlížeč
- S-propyl cysteine sulfoxide MeSH Prohlížeč
- thiosulfinic acids MeSH Prohlížeč
In the present study, a novel analytical approach for the simultaneous determination of 27 brominated flame retardants (BFRs), namely polybrominated diphenyl ethers (PBDEs), isomers of hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and several novel BFRs (NBFRs), together with 18 perfluoroalkyl substances (PFASs) in indoor dust was developed and validated. To achieve integrated isolation of analytes from the sample and their fractionation, a miniaturized method based on matrix solid phase dispersion (MSPD) was employed. Principally, after mixing the dust (<0.1 g) with the Florisil(®), the mixture was applied on the top of a sorbent (Florisil(®)) placed in glass column and then analytes were eluted using solvents with different polarities. For the identification/quantification of target compounds largely differing in polarity, complementary techniques represented by gas and liquid chromatography coupled to tandem mass spectrometry (GC-MS/MS and LC-MS/MS) were used. The results of validation experiments, which were performed on the SRM 2585 material (for PBDEs, HBCDs and TBBPA), were in accordance with the certified/reference values. For other analytes (NBFRs and PFASs), the analysis of an artificially contaminated blank dust sample was realized. The method recoveries for all target compounds ranged from 81 to 122% with relative standard deviations lower than 21%. The quantification limits were in the range of 1-25 ng g(-1) for BFRs and 0.25-1 ng g(-1) for PFASs. Finally, 18 samples (6 households × 3 sampling sites) were analyzed. The high variability between concentrations of PFASs and BFRs in the dust samples from various households as well as collecting sites in a respective house was observed. The total amounts of PFASs and BFRs were in the range of 1.58-236 ng g(-1) (median 10.6 ng g(-1)) and 39.2-2320 ng g(-1) (median 325 ng g(-1)), respectively. It was clearly shown that dust from the indoor environment might be a significant source of human exposure to various organohalogen pollutants.
- Klíčová slova
- Brominated flame retardants, Dust, Matrix solid phase dispersion, Perfluoroalkyl substances,
- MeSH
- chromatografie kapalinová MeSH
- halogeny analýza MeSH
- organické látky analýza MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- prach analýza MeSH
- referenční standardy MeSH
- tandemová hmotnostní spektrometrie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
- Názvy látek
- halogeny MeSH
- organické látky MeSH
- prach MeSH
Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (MS) and an alternative technology represented by direct analysis in real time coupled with quadrupole time-of-flight MS were investigated for metabolic fingerprinting of 343 red and white wine samples. Direct injection of pure wine and an extraction procedure optimized for isolation of polyphenols were used to compare different analytical and data handling strategies. After data processing and data pretreatment, principal component analysis was initially used to explore the data structure. Initially, the unsupervised models revealed a notable clustering according to the grape varieties, and therefore supervised orthogonal partial least squares discriminant analysis models were created and validated for separation of red and white wines according to the grape variety. The validated orthogonal partial least squares discriminant analysis models based on data (ions) recorded in positive ionization mode were able to classify correctly 95% of samples. In parallel, authentication parameters, such as origin and vintage, were evaluated, and they are discussed. A tentative identification of markers was performed using accurate mass measurement of MS and MS/MS spectra, different software packages and different online libraries. In this way, different flavonol glucosides and polyphenols were identified as wine markers according to the grape varieties.
This study focused on the detection and quantification of organic micelle-type nanoparticles (NPs) with polysorbate components (polysorbate 20 and polysorbate 80) in their micelle shells that could be used to load biologically active compounds into fruit juice. Several advanced analytical techniques were applied in the stepwise method development strategy used. In the first phase, a system consisting of ultrahigh-performance liquid chromatography employing a size exclusion column coupled with an evaporative light scattering detector (UHPLC-SEC-ELSD) was used for the fractionation of micelle assemblies from other, lower molecular weight sample components. The limit of detection (LoD) of these polysorbate micelles in spiked apple juice was 500 μg mL(-1). After this screening step, mass spectrometric (MS) detection was utilized to confirm the presence of polysorbates in the detected micelles. Two alternative MS techniques were tested: (i) ambient high-resolution mass spectrometry employing a direct analysis in real time ion source coupled with an Orbitrap MS analyzer (DART-Orbitrap MS) enabled fast and simple detection of the polysorbates present in the samples, with a lowest calibration level (LCL) of 1000 μg mL(-1); (ii) ultrahigh-performance reversed-phase liquid chromatography coupled with high-resolution time-of-flight mass spectrometry (UHPLC-HRTOF-MS) provided highly selective and sensitive detection and quantification of polysorbates with an LCL of 0.5 μg mL(-1).
- MeSH
- hmotnostní spektrometrie přístrojové vybavení metody MeSH
- Malus chemie MeSH
- micely MeSH
- nanočástice analýza MeSH
- nápoje analýza MeSH
- ovoce chemie MeSH
- polysorbáty analýza MeSH
- potravinářské přísady analýza MeSH
- vysokoúčinná kapalinová chromatografie přístrojové vybavení metody MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- Názvy látek
- micely MeSH
- polysorbáty MeSH
- potravinářské přísady MeSH
We have developed and optimized high throughput method for reliable detection and quantification of 56 Fusarium, Alternaria, Penicillium, Aspergillus and Claviceps mycotoxins in a wide range of animal feed samples represented by cereals, complex compound feeds, extracted oilcakes, fermented silages, malt sprouts or dried distillers' grains with solubles (DDGS). From three tested extraction approaches (acetonitrile, acetonitrile/water, and QuEChERS), the QuEChERS-based method (Quick, Easy, Cheap, Effective, Rugged and Safe) was selected as the best in terms of analytes recoveries and low matrix effects. For separation and detection of target mycotoxins, method based on ultra-high performance liquid chromatography coupled with sensitive tandem mass spectrometry (U-HPLC-MS/MS) was employed. With regards to a high complexity of most of investigated feed samples, optimization of extraction/purification process was needed in the first phase to keep the method as rugged as possible. A special attention was paid to the pH of extraction solvents, especially with regard to the pH-sensitive silages. Additionally, purification of the acetonitrile extract by dispersive solid phase clean-up was assessed. Significant elimination of lipidic compounds was observed when using C18 silica sorbent. Matrix co-extracts were characterized by ultra-high performance liquid chromatography coupled with ultra-high resolution mass spectrometry (U-HPLC-HRMS). Large variability of matrix effects depending on the nature of examined feed was demonstrated in depth on a broad set of samples. Simple and unbiased strategies for their compensation were suggested.
- Klíčová slova
- Animal feed, Dispersive solid phase extraction, Matrix effects, Mycotoxins, QuEChERS, Ultra-high performance liquid chromatography coupled with tandem mass spectrometry,
- MeSH
- krmivo pro zvířata analýza MeSH
- mykotoxiny analýza toxicita MeSH
- tandemová hmotnostní spektrometrie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- mykotoxiny MeSH
