Specific Extraction Procedure Research Articles

Integrated Analysis of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls: A Comparison of the Effectiveness of Selected Methods on Dried Fruit Matrices

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are groups of chemical substances commonly found in the environment. Because of large differences in the concentrations of PAHs and PCBs in the materials tested, separate analytical methods specific to each group of compounds are usually used. The aim of this study was to compare methods for the determination of PAHs and PCBs that permit the simultaneous determination of these compounds from one solvent extract. The analysis of the content of 15 PCB congeners and 16 PAHs was conducted using dried fruits. The analyses were performed with gas chromatography coupled with mass spectrometry. PAHs and PCBs were determined separately in each fruit sample using specific extraction and cleanup procedures for the respective groups of compounds. Analyses were also performed with two methods that permitted the simultaneous analysis of PAHs and PCBs in one solvent extract. The integrated methods did not provide adequate extract cleanup of interfering substances; consequently, the results of determinations of PAHs and PCBs using these methods were significantly different from the values obtained with proven determination methods for PAHs and PCBs.

Reconstructing AGN X-ray spectral parameter distributions with Bayesian methods

X-ray spectra of active galactic nuclei (AGN) consist of several different emission and absorption components. To determine the spectral parameters, these components are often fitted manually with models chosen on a case-by-case basis. However, this approach has two problems. First, it becomes very hard for a survey with a large number of sources. Second, when the signal-to-noise ratio (S/N) is low, there is a tendency to adopt an overly simplistic model, biasing the parameters and making their uncertainties unrealistic. We developed a Bayesian method for automatically fitting AGN X-ray spectra obtained by XMM-Newton with a consistent and physically motivated model. Our model includes all spectral components, even when the data quality is low. We used a physical model for the X-ray background and an empirical model for the non-X-ray background. Noninformative priors were applied on the parameters of interest, the photon index (Γ) and the hydrogen column density (NH), while informative priors obtained from deep surveys were used to marginalize over the parameter space of the nuisance parameters. To improve speed, we developed a specific spectral extraction and fitting procedure. We tested this method using a realistic sample of 5000 spectra, which was simulated based on our source model, reproducing typical population properties. Spectral parameters were randomly drawn from the priors, taking the luminosity function into account. Well-constrained or meaningful posterior probability density distributions (PDFs) were obtained for the most relevant spectral parameters, for instance, NH, Γ, and LX, even at low S/N, but in this case, we were unable to constrain the parameters of secondary components such as the reflection and soft excess. As a comparison, a maximum-likelihood approach with model selection among six models of different complexities was also applied to this sample. We find clear failures in the measurement of Γ in most cases, and of NH when the source is unabsorbed (NH < 1022 cm−2). The results can hardly be used to reconstruct the parent distributions of the spectral parameters, while our Bayesian method provides meaningful multidimensional posteriors that will be used in a subsequent paper to infer the population.

Electron donating properties of humic acids in saltmarsh soils reflect soil geochemical characteristics

In saltmarsh soils, humic acids (HA) are involved in geochemically important redox processes. The electron donating capacity (EDC) of HA depends on their molecular structure, but also reflects the intensity of biological reduction in tidal environments. We examined twelve soils in three saltmarshes located along a geographical gradient and applied a specific sequential extraction procedure for the isolation of HA fractions bound (BHA) or not (FHA) to the mineral matrix by Ca2+ bridges, and investigated the relationships of their properties, in particular their EDC, with the biogeochemical characteristics of the soils. Spectroscopic assessment was carried out by UV–vis, FTIR and 13C NMR, quantification and characterization of radicals was performed by electron paramagnetic resonance (EPR) spectroscopy. The EDC was determined by using the 2,2′-azinobis-(3-ethylbenzothiazolinesulfonic acid) (ABTS) decolorization assay and experimental data were fitted to a biphasic model to calculate the contributions of the fast and slow reactions to electron transfer. The results confirmed that the two HA fractions possess different structural characteristics and that BHA present higher EDC values compared to FHA. The EDC of both fractions is strongly related to the geochemical characteristics of soils, and represents an easily measured and highly informative parameter to understand mechanisms affecting redox processes in transitional environments.

Three-in-One Simultaneous Extraction of Proteins, Metabolites and Lipids for Multi-Omics.

Elucidation of complex molecular networks requires integrative analysis of molecular features and changes at different levels of information flow and regulation. Accordingly, high throughput functional genomics tools such as transcriptomics, proteomics, metabolomics, and lipidomics have emerged to provide system-wide investigations. Unfortunately, analysis of different types of biomolecules requires specific sample extraction procedures in combination with specific analytical instrumentation. The most efficient extraction protocols often only cover a restricted type of biomolecules due to their different physicochemical properties. Therefore, several sets/aliquots of samples are needed for extracting different molecules. Here we adapted a biphasic fractionation method to extract proteins, metabolites, and lipids from the same sample (3-in-1) for liquid chromatography-tandem mass spectrometry (LC-MS/MS) multi-omics. To demonstrate utility of the improved method, we used bacteria-primed Arabidopsis leaves to generate multi-omics datasets from the same sample. In total, we were able to analyze 1849 proteins, 1967 metabolites, and 424 lipid species in single samples. The molecules cover a wide range of biological and molecular processes, and allow quantitative analyses of different molecules and pathways. Our results have shown the clear advantages of the multi-omics method, including sample conservation, high reproducibility, and tight correlation between different types of biomolecules.

Evaluation of a New Histoplasma spp. Quantitative RT-PCR Assay

Laboratory diagnosis of histoplasmosis is based on various methods, including microscopy, culture, antigen, and DNA detection of Histoplasma capsulatum var. capsulatum or Histoplasma capsulatum var. duboisii. To improve sensitivity of existing real-time quantitative PCR (qPCR) assays, we developed a new RT-qPCR assay that allows amplification of whole nucleic acids of Histoplasma spp. validated on suspected cases. The limit of detection was 20 copies, and the specificity against 114 fungal isolates/species was restricted to Histoplasma spp. Whole nucleic acids of 1319 prospectively collected consecutive samples from 907 patients suspected of having histoplasmosis were tested routinely between May 2015 and May 2019 in parallel with standard diagnostic procedures performed in parallel. Forty-four had proven histoplasmosis attributable to H. capsulatum var. capsulatum (n = 40) or H.capsulatum var. duboisii (n = 4) infections. The results of RT-qPCR were positive in 43 of 44 patients (97.7% sensitivity) in at least one specimen. Nine of 863 cases (99% specificity) were RT-qPCR positive and therefore classified as possible cases. RT-qPCR was positive in 13 of 30 (43.3%) blood samples tested in proven cases. A positive RT-qPCR result in blood was significantly associated with H. capsulatum var. capsulatum progressively disseminated histoplasmosis with a positive RT-qPCR result in 92.3% of the immunocompromised patients with disseminated disease. This new Histoplasma RT-qPCR assay enabling amplification of H. capsulatum var. capsulatum and H. capsulatum var. duboisii is highly sensitive and allows the diagnosis of histoplasmosis advantageously from blood and bronchoalveolar lavage fluid.

Molecular characterization of fertile hydatid cysts from the liver of the sheep and cows and associated environmental influence factors

The aim of the study is characterizing of hydatid cysts that have been isolated from sheep and cow liver fertile hydatid cysts using mitochondrial cytochrome c oxidase subunit 1(cox1) gene. DNA samples of nineteen sheep and one cow were extracted from protoscoleces and germinal layers of the parasites in Koya city-Erbil, Iraq, using specific extraction procedures. Mitochondrial cox1 gene region was amplified by polymerase chain reaction (PCR), and the expected gene sizes were confirmed by gel electrophoresis. All DNA isolates were then sequenced. Nucleotide sequence alignments were then performed to verify the sequenced isolated according to the database, which showed that all samples were belonging to the (G1) sheep strain. Phylogenetic analysis was also carried out for the sequenced isolated to find out the highest similarities with closest organisms to E. granulosus’ conserved gene and to reveal sharing common ancestor, which has been confirmed. Electrocatalytic reduction of DNA where detected through applying cyclic-voltammetry technique, which referred to the environmentally strong protection features of these strains against any effects of external factors, such as heavy metals and has revealed the secret behind the potent preservation of the DNA structure of this parasite from being affect by mutations, or alterations, along the different lineages over a long period of time.

Extraction of Protein from Four Different Seaweeds Using Three Different Physical Pre-Treatment Strategies.

Seaweeds are a rich source of protein and can contain up to 47% on the dry weight basis. It is challenging to extract proteins from the raw biomass of seaweed due to resilient cell-wall complexes. Four species of macroalgae were used in this study-two brown, Fucus vesiculosus and Alaria esculenta, and two red, Palmaria palmata and Chondrus crispus. Three treatments were applied individually to the macroalgal species: (I) high-pressure processing (HPP); (II) laboratory autoclave processing and (III) a classical sonication and salting out method. The protein, ash and lipid contents of the resulting extracts were estimated. Yields of protein recovered ranged from 3.2% for Fucus vesiculosus pre-treated with high pressure processing to 28.9% protein recovered for Chondrus crispus treated with the classical method. The yields of protein recovered using the classical, HPP and autoclave pre-treatments applied to Fucus vesiculosus were 35.1, 23.7% and 24.3%, respectively; yields from Alaria esculenta were 18.2%, 15.0% and 17.1% respectively; yields from Palmaria palmata were 12.5%, 14.9% and 21.5% respectively, and finally, yields from Chondrus crispus were 35.2%, 16.1% and 21.9%, respectively. These results demonstrate that while macroalgal proteins may be extracted using either physical or enzymatic methods, the specific extraction procedure should be tailored to individual species.

Setup of an Extraction Method for the Analysis of Carotenoids in Microgreens.

Microgreens are gaining increasing interest as a potential functional food due to their relevant contents of micronutrients and bioactive compounds, including carotenoids. Nevertheless, the analysis of carotenoids is inherently difficult, due to their thermal and chemical susceptibility, as well as to their varying polarity. From this point of view, extraction is the most critical step, compared to chromatographic separation and detection. Thus, the reliability of data on carotenoids should be guaranteed by a constant focus on analytical issues, with appropriate adaptations to each sample matrix. In this research, a specific extraction procedure for the analysis of carotenoids in microgreens was developed. Solvent composition, extraction time, solvent/sample ratio, and repeated extractions were evaluated. The obtained protocol showed recovery of 97.2%, limits of quantitation of 5.2 μg·g−1 for lutein and 15.9 μg·g−1 for β-carotene, as well as intra-day mean repeatability of 5.7% and inter-day mean repeatability of 4.7%.

Current direction and advances in analytical sample extraction techniques for drugs with special emphasis on bioanalysis.

Analytical techniques may not be compatible or sufficiently sensitive to the analytes, unless it undergoes a specific sample extraction procedure. Sample extraction can be considered as one of the key steps in analysis. Analysis of a poorly treated sample may produce inferior quality of analytical data. Continuous advancement and development of newer sample extraction techniques such as solid phase microextraction, ultrasound, magnetically and microwave assisted magnetic extraction; electro-membrane extraction and dried blood spotting are to address the shortcomings of the existing techniques and to provide more automation, minimizing preparation time and make them high throughput. This review summarizes the suitability of application of the advanced sample preparation techniques available for chemical and bioanalysis in a comprehensive manner. This review also provides a scientific guidance for selecting the appropriate sample extraction technique based on sample type.

Rice‐Endosperm and Rice‐Bran Proteins: A Review

AbstractRice protein is the most preferred protein among all other cereal proteins in terms of its amino acid structure, and it contains the second highest content of lysine, the limiting amino acid in cereals. Processing rough rice into edible rice yields different by‐products including rice bran. Rice‐endosperm and rice‐bran proteins are known to be hypoallergenic, nutritious, and healthful, which gives them high potential in the food‐ingredient industry, especially in gluten‐free preparations and in infant formulas. Multiple methods can be used for the extraction of rice‐endosperm and rice‐bran proteins, including chemical and enzymatic extraction methods. The functional properties, including emulsification, foaming, gelation, and water and oil absorption, of rice‐endosperm and rice‐bran proteins require enhancement before utilizing them in food applications because of their low solubilities, which affects the other functionalities. Enhancement methods include manipulating pH and salt concentration of extracting solvents and selecting specific extraction procedures. Rice‐endosperm and rice‐bran peptides are known to exhibit different bioactivities. These peptides can be generated by different hydrolysis approaches, including the enzymatic, chemical, or microbial assays. Some of the confirmed bioactivities of rice‐endosperm and rice‐bran peptides are the antioxidant, antihypertensive, anticancer, anti‐inflammatory, and antimicrobial activities. These bioactivities increase the potential of rice‐endosperm and rice‐bran proteins to be utilized in food applications, as natural preservatives, or in pharmaceutical applications.

Chemical Bonds of Cations in Grapevine Berries and Stems of Some Important Cultivars of Vitis vinifera (L.) and Their Relevance for Viticulture and Enology

Cations are essential for plant growth, tissue build-up and its stabilization. Divalent cations are necessary for cell wall stability and other interstitial tissues. They may be cross-linked with pectins or form looser ionic bindings. This is of importance for grape processing during the technical operations of juice extraction. Monovalent ions are more involved in vacuolar homeostasis and pH stabilization.With a specific extraction procedure H2O-soluble, 1N NaCl-soluble, 2% CH3COOH-soluble, and 5% HCl-soluble fractions as well as the total content of K, Ca, and Mg were analyzed in grapevine berries and stems. The monovalent K is only found in the water and the NaCl fraction; both in berries and stems. But only 50-60% of the total K can be extracted with both solutes. The divalent cation Ca is found in all four fractions with differing amounts, but water soluble Ca is in most cases highest. Ca may also have an indicator value for BSN, because the water soluble fraction is lowest in the most susceptible variety. Mg is not found in HCl fraction.An analysis of variance shows that the varieties have a significant influence on nutrient distribution in different tissues. It seems that the relation Ca/Mg (NaCl fraction) in stems is a good indicator for BSN because susceptible varieties show lower ratios than resistant ones. Some more research is necessary to clear up this possible relationship.

Protocol: a fast, comprehensive and reproducible one-step extraction method for the rapid preparation of polar and semi-polar metabolites, lipids, proteins, starch and cell wall polymers from a single sample.

BackgroundThe elucidation of complex biological systems requires integration of multiple molecular parameters. Accordingly, high throughput methods like transcriptomics, proteomics, metabolomics and lipidomics have emerged to provide the tools for successful system-wide investigations. Unfortunately, optimized analysis of different compounds requires specific extraction procedures in combination with specific analytical instrumentation. However, the most efficient extraction protocols often only cover a restricted number of compounds due to the different physico-chemical properties of these biological compounds. Consequently, comprehensive analysis of several molecular components like polar primary metabolites next to lipids or proteins require multiple aliquots to enable the specific extraction procedures required to cover these diverse compound classes. This multi-parallel sample handling of different sample aliquots is therefore not only more sample intensive, it also requires more time and effort to obtain the required extracts.ResultsTo circumvent large sample amounts, distributed into several aliquots for the comprehensive extraction of most relevant biological compounds, we developed a simple, robust and reproducible two-phase liquid–liquid extraction protocol. This one-step extraction protocol allows for the analysis of polar-, semi-polar and hydrophobic metabolites, next to insoluble or precipitated compounds, including proteins, starch and plant cell wall components, from a single sample. The method is scalable regarding the used sample amounts but also the employed volumes and can be performed in microcentrifuge tubes, enabling high throughput analysis. The obtained fractions are fully compatible with common analytical methods, including spectroscopic, chromatographic and mass spectrometry-based techniques. To document the utility of the described protocol, we used 25 mg of Arabidopsis thaliana rosette leaves for the generation of multi-omics data sets, covering lipidomics, metabolomics and proteomics. The obtained data allowed us to measure and annotate more than 200 lipid compounds, 100 primary metabolites, 50 secondary metabolites and 2000 proteins.ConclusionsThe described extraction protocol provides a simple and straightforward method for the efficient extraction of lipids, metabolites and proteins from minute amounts of a single sample, enabling the targeted but also untargeted high-throughput analyses of diverse biological tissues and samples.Electronic supplementary materialThe online version of this article (doi:10.1186/s13007-016-0146-2) contains supplementary material, which is available to authorized users.

How sotolon can impart a Madeira off-flavor to aged beers.

4,5-Dimethyl-3-hydroxy-2(5H)-furanone or sotolon is known to impart powerful Madeira-oxidized-curry-walnut notes to various alcoholic beverages. It has been much studied in oxidized Jura flor-sherry wines, aged Roussillon sweet wines, and old Port wines, in which it contributes to the characteristic "Madeira-oxidized" aroma of these beverages. No scientific paper describes how sotolon might be involved in the Madeira off-flavor found in aged beers. The specific extraction procedure applied here allowed us to quantify this lactone in 7 special beers, at levels sometimes well above its threshold (from 5 to 42 μg/L after 6, 12, 18, and 24 months of natural aging, while unquantifiable in fresh beer). Investigation of spiked beers led us to highlight the key role of pro-oxidants and acetaldehyde. Addition of ascorbic acid without sulfites should be avoided by brewers, as the former would intensify sotolon synthesis. Acetoin, a beer fermentation byproduct, also emerged as possible precursor in beer when combined with serine.

NaCl alleviates Cd toxicity by changing its chemical forms of accumulation in the halophyte Sesuvium portulacastrum.

It has previously been shown that certain halophytes can grow and produce biomass despite of the contamination of their saline biotopes with toxic metals. This suggests that these plants are able to cope with both salinity and heavy metal constraints. NaCl is well tolerated by halophytes and apparently can modulate their responses to Cd. However, the underlying mechanisms remain unclear. This study explores the impact of NaCl on growth, Cd accumulation, and Cd speciation in tissues of the halophyte Sesuvium portulacastrum. Seedlings of S. portulacastrum were exposed during 1 month to 0, 25, and 50 μM Cd combined with low salinity (LS, 0.09 mM NaCl) or high salinity (HS, 200 mM NaCl) levels. Growth parameters and total tissue Cd concentrations were determined, in leaves, stems, and root. Moreover, Cd speciation in these organs was assessed by specific extraction procedures. Results showed that, at LS, Cd induced chlorosis and necrosis and drastically reduced plant growth. However, addition of 200 mM NaCl to Cd containing medium alleviated significantly Cd toxicity symptoms and restored plant growth. NaCl reduced the concentration of Cd in the shoots; nevertheless, due to maintenance of higher biomass under HS, the quantity of accumulated Cd was not modified. NaCl modified the chemical form of Cd in the tissues by increasing the proportion of Cd bound to pectates, proteins, and chloride suggesting that this change in speciation is involved in the positive impact of NaCl on Cd tolerance. We concluded that the tolerance of S. portulacastrum to Cd was enhanced by NaCl. This effect is rather governed by the modification of the speciation of the accumulated Cd than by the reduction of Cd absorption and translocation.

Comparative study of antibacterial activity between <i>Cynodon dactylon</i> crude and solid phase extraction extracts against selected bacterial pathogens

Previous studies have shown Cynodon dactylon extracts possess broad spectrum of antibacterial activity against common-known Gram positive and negative bacteria. It is believed that specific extraction procedure can enhance the efficacy of extracting antibacterial compounds in plants, thus influence the biological activity of the extract. The present study compared the antibacterial activity of C. dactylon crude and Solid Phase Extraction (SPE) extracts against some common bacterial pathogens using disc diffusion and broth micro-dilution assays. This study also revealed the flush fraction of C. dactylon ethanol and ethyl acetate SPE extracts with greater antibacterial activity compared to the plant crude extracts. MIC tests confirmed the greatest antibacterial activity is from flush fraction of C. dactylon ethanol SPE extract with MIC values of 10.00-20.00 mgmL-1. Comparative study suggests extraction using SPE to obtain the plant extract can produce greater antibacterial activity in contrast to conventional method of extraction. Discover

Evaluation of tannins interactions in grape (Vitis vinifera L.) skins

Tannins have a central role in grapevine berries both for their physiological and enological implications. In the skin tissue they can be in vacuolar solution, or associated to the cell walls through weak or strong physicochemical interactions. The present work aims to separate vacuolar, non-covalently and covalently bonded tannins fractions. A specific extraction procedure was developed. A first extraction in ethanol at low temperature allowed the quantification of vacuolar tannins. An urea treatment followed by an ethanol extraction at room temperature was able to separate non-covalently bonded compounds. Finally an acid catalysis was used to break down proanthocyanidin covalent bonds. The method was validated on ripe grape samples of three cultivars, on berries developed in two sun exposure conditions. The Ethephon treatment effect was also evaluated. Beside the method development, a preliminary evaluation of the cultivar, exposition and Ethephon treatment effects are discussed.

Rapid method based on immunoassay for determination of paraquat residues in wheat, barley and potato

The detection of bipyridine herbicides residues in food samples is hampered due to their particular physico-chemical features, which requires the application of specific extraction and analytical procedures, which disqualifies them from being incorporated into the multi-residue methods (MRMs). There is a need for alternative robust and efficient analytical screening methods, and in this respect, we present here a fast and reliable immunochemical analytical procedure for the detection of paraquat (PQ) residues in food samples, particularly potato, barley and wheat. The procedure involves the extraction with 1 N HCl:MeOH at 80 °C, followed by centrifugation and filtration, and the extracts can be directly measured by a microplate-based ELISA without any other sample treatment or clean-up, except from buffering the solution and adjusting the pH. Selective polyclonal antibodies, were raised against N-(4-carboxypent-1-yl)-N′-methyl bipyridilium acid (hapten PQ1), and used to establish a high sensitive immunochemical analytical assay, able to measure simultaneously many samples. Under these conditions the accuracy is very good, with almost quantitative recoveries. The non-specific interferences caused by the matrix are negligible for the case of potato and wheat, while for barley it is necessary to further dilute the extract or using a negative certified extract to build the standard calibration curve. The method of extraction consisted in acidic extraction and after a dilution is able to be measured. The analysis method results simply, achieving good detectabilities. The limits of detection (LODs) achieved were between 0.037 ± 0.01 μg kg−1 in wheat, 0.71 ± 0.3 μg kg−1 in barley and 0.56 ± 0.10 μg kg−1 in potatoes, values that are far below the Maximum Residue Level (20 μg kg−1) established by the EU policies for paraquat residues in these foodstuff products. The results demonstrate the high potential of these methods as screening tools for food safety and inspection controls.

Magnetic Mixed Hemimicelles Solid-Phase Extraction of Three Food Colorants from Real Samples

Introducing a specific clean extraction procedure with a minimal matrices effect for food colorant determination is still a challengeable topic and highly recommended. Mixed hemimicelle solid-phase extraction method, based on cetyltrimethylammonium bromide-coated Fe3O4/SiO2 nanoparticles as a novel, simple, and fast preconcentration method, was applied for preconcentration and fast isolation of three synthetic food colorants in foodstuff matrices prior to HPLC-UV-vis determination. The influence of different parameters on extraction efficiency such as surfactant amount, sample pH, time of extraction, desorption condition, and nanoparticles concentration was optimized. Under the optimized conditions, a preconcentration factor of 100 was achieved by extracting 10 mL sample. The limit of detection for the three synthetic food colorants including Tartrazine, Sunset yellow FCF, and Quinoline yellow is 2.50, 1.25, and 2.12 μg/L, respectively. The proposed method was applicable for extraction and preconcentration of three food colorants in various food samples with the food dye contents in the range of 13–105 μg/L.

Trace analysis of pollutants by use of honeybees, immunoassays, and chemiluminescence detection

Specific and sensitive analysis to reveal and monitor the wide variety of chemical contaminants polluting all environment compartments, feed, and food is urgently required because of the increasing attention devoted to the environment and health protection. Our research group has been involved in monitoring the presence and distribution of agrochemicals by monitoring beehives distributed throughout the area studied. Honeybees have been used both as biosensors, because the pesticides affect their viability, and as "contaminant collectors" for all environmental pollutants. We focused our research on the development of analytical procedures able to reveal and quantify pesticides in different samples but with a special attention to the complex honeybee matrix. Specific extraction and purification procedures have been developed and some are still under optimization. The analytes of interest were determined by gas or liquid chromatographic methods and by compound-specific or group-specific immunoassays in the ELISA format, the analytical performance of which was improved by introducing luminescence detection. The range of chemiluminescent immunoassays developed was extended to include the determination of completely different pollutants, for example explosives, volatile organic compounds (including benzene, toluene, ethylbenzene, xylenes), and components of plastics, for example bisphenol A. An easier and portable format, a lateral flow immunoassay (LFIA) was added to the ELISA format to increase application flexibility in these assays. Aspects of the novelty, the specific characteristics, the analytical performance, and possible future development of the different chromatographic and immunological methods are described and discussed.

Abstract 1603: Relevance of myosmine in cigarette filter butt

Abstract Risk assessment of tobacco involves the evaluation of toxicological ingredients and their pathway of uptake in human body. Some relevant and significant aspects regarding the conversion of tobacco constituents to cancer suspect and toxicological important substances during tobacco pyrolysis are known. Albeit some mechanisms as shown in the case of tobacco specific N-nitrosamine (TSNA) formation could have been recovered, the majority of these procedures remain obscure and rare knowledge is available concerning the conversion of tobacco constituents to activated reactive intermediates due to tobacco pyrolysis. The concentrations of nicotine and TSNA are balanced using their metabolic profile or biomarkers in urine, blood and saliva to correlate their realistic uptake. Recently the conversion of nicotine to myosmine during peroxidation reaction was demonstrated which could be similar to processes during tobacco pyrolysis. In the case of both tobacco alkaloids nicotine and myosmine problems may arise from classification of their origin. The amount of myosmine which is formed from nicotine would add to the natural given concentration in tobacco, on the other hand nicotine concentration would be diminished by this conversion. This effect would cause uncertainty of validation and biomarkers of these substances and their derived TSNA in urine, blood and saliva. As reported in the literature the filter analyses of cigarette promises a practicable methodology which would lead to preliminary insights not only in constituents of mainstream smoke (MS), in relation to environmental smoke (ETS), but also about possible candidates up taken in human organism. At the moment the effect under the concern of toxicology is not clear, but the conversion of nicotine to myosmine may be demonstrated by the analysis of cigarette filter butts from smoked cigarettes. For this reason cigarette butts were collected and the filters separated. The filters were shredded and subjected to the specific extraction procedure. The resulting extract was further cleaned up, enriched by solid-phase-extraction (SPE) procedure and analysed by high performance liquid chromatography - diode array detection (HPLC-DAD), whereupon myosmine was detected. These preliminary results clearly demonstrate that the investigation of effects from tobacco smoke in biological model systems and human being demands an accurate quantification of its most toxic relevant ingredients including the profile from conversion of nicotine to myosmine via pyrolysis. Considering the discussion of carcinogenic and toxicological risk assessment of tobacco use, the problems correlating nicotine, myosmine and TSNA from cigarette smoke requires further declaration. Acknowledgement: This work was supported by DFG grant Zwi59/2-2, and TY 81/1-2 Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1603. doi:1538-7445.AM2012-1603