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1.
Anal Bioanal Chem ; 411(27): 7261-7272, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31494688

RESUMO

In the recent decade, metal pyrithione complexes have become important biocides for antifouling purposes in shipping. The analysis of metal pyrithione complexes and their degradation products/species in environmental samples is challenging because they exhibit fast UV degradation, transmetalation, and ligand substitution and are known to be prone to spontaneous species transformation within a chromatographic system. The environmental properties of the pyrithione species, e.g., toxicity to target and non-target organisms, are differing strongly, and it is therefore inevitable to identify as well as quantify all species separately. To cope with the separation of metal pyrithione species with minimum species transformation during analysis, a capillary electrophoresis (CE)-based method was developed. The hyphenation of CE with selective electrospray ionization- and inductively coupled plasma-mass spectrometry (ESI-, ICP-MS) provided complementary molecular and elemental information for the identification and quantification of pyrithione species. To study speciation of pyrithiones, a leaching experiment of several commercial antifouling paints containing zinc pyrithione in ultrapure and river water was conducted. Only the two species pyrithione (HPT) and dipyrithione ((PT)2) were found in the leaching media, in concentrations between 0.086 and 2.4 µM (HPT) and between 0.062 and 0.59 µM ((PT)2), depending on the paint and leaching medium. The limits of detection were 20 nM (HPT) and 10 nM ((PT)2). The results show that complementary CE-MS is a suitable tool for mechanistical studies concerning species transformation (e.g., degradation) and the identification of target species of metal pyrithione complexes in real surface water matrices, laying the ground for future environmental studies. Graphical abstract Hyphenation of CE with ESI- and ICP-MS provided complementary molecular and elemental information. Metal pyrithione species released from commercial antifouling paints could be identified and quantified in ultrapure and river water matrices.


Assuntos
Eletroforese Capilar/métodos , Espectrometria de Massas/métodos , Piridinas/análise , Tionas/análise , Limite de Detecção , Pintura , Padrões de Referência , Poluentes Químicos da Água/análise
2.
Anal Chim Acta ; 1077: 87-94, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31307725

RESUMO

The most challenging part in performing a single cell ICP-MS (sc-ICP-MS) approach is the sample preparation, in particular the reduction of the ionic background. This step is, in many cases, time-consuming and required for each sample separately. Furthermore, sc-ICP-MS measurements are mostly carried out "manually", given the fact that present systems are not allowing for an automated change of samples. Thus, within this work, we developed an approach based on a HPLC system coupled on-line with sc-ICP-MS via a set of switching valves as well as an in-line filter for automated cell washing. This set-up enables the ionic background removal as well as analysis of single cells completely automated without any manual sample pretreatment. Our approach was applied for the analysis of the single celled diatom species Cyclotella meneghiniana, a marine diatom species, on the basis of 24Mg and facilitates testing in 11 min per sample, requiring only around 10,000 cells in a volume of 10 µL and approx. 10 mL of a 5% MeOH/95% deionized water (v/v) mixture. Even at extremely saline culturing media concentrations (up to 1000 mg L-1 magnesium) our on-line approach worked sufficiently allowing for distinction of ionic and particulate fractions. Furthermore, a set of diatom samples was analyzed completely automated without the need for changing samples manually. So, utilizing this approach enables analyzing a high quantity of samples in a short time and therefore in future the investigation of ecotoxicological effects is simplified for example in terms of metal accumulation by taking biovariability into account.


Assuntos
Diatomáceas/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Magnésio/química , Espectrometria de Massas/métodos
3.
Anal Bioanal Chem ; 411(19): 4647-4660, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30848316

RESUMO

The introduction of fluorine into organic molecules leads to new chemical/physical properties. Especially in the field of pharmaceutical as well as technical applications, fluorinated organic substances gain in importance. The OECD identified and categorized 4730 per- and polyfluoroalkyl substances-related CAS numbers. Thus, an increasing release of fluorinated compounds into the environment is expected. In particular, perfluorinated compounds often show higher environmental stability leading to the risk of bioaccumulation. Polyfluorinated compounds undergo decomposition; thus, further possible fluorine species occur, which may exhibit different toxic/chemical properties. However, current target methods based on, e.g., HPLC/MS-MS, are not applicable for a comprehensive screening of fluorinated substances as well as assessment of pollution. Thus, within this work, a sum parameter method for quantitative determination of extractable organically bound fluorine (EOF) in surface waters was developed. The method is based on solid-phase extraction (SPE) for extraction of fluorinated compounds as well as separation of interfering inorganic fluoride in combination with high-resolution-continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) for organic fluorine quantification. Upon optimization of the SPE procedure (maximum concentration of extractable organic fluorine), enrichment factors of about 1000 were achieved, allowing for highly sensitive fluorine detection. HR-CS GF MAS allows for selective fluorine detection upon in situ formation of a diatomic molecule ("GaF"). Next to a species-unspecific response, limits of detection in the low nanogram per liter range (upon enrichment) were achieved. Upon successful method development, surface water samples (rivers Moselle and Rhine) were analyzed. Furthermore, a sampling campaign along the river Rhine (from the south-close to the French border; to the north-close to The Netherlands border) was conducted. EOF values in the range of about 50-300 ng/L were detected. The developed method allows for a fast and sensitive as well as selective/screening detection of organically bound fluorine (EOF) in surface water samples, helping to elucidate pollution hotspots as well as discharge routes. Graphical abstract A solid phase extraction (SPE) HR-CS GF MAS screening method was developed for the quantitative analysis/screening of extractable organically bound fluorine (EOF) in river water samples. Highly sensitive EOF analysis (low ppq range) was obtained upon SPE and HR-CS GF MAS analysis. Sampling campaign along the river Rhine was conducted.

4.
Environ Sci Technol ; 52(15): 8309-8320, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29998733

RESUMO

The iodinated X-ray contrast medium (ICM) iopromide and its aerobic transformation products (TPs) are frequently detected in the effluents of wastewater treatment plants and in different compartments of the aquatic environment. In this study, the anaerobic transformation of iopromide and its aerobic TPs was investigated in water-sediment systems. Iopromide, its final aerobic TP didespropanediol iopromide (DDPI), and its primary aniline desmethoxyacetyl iopromide (DAMI) were used as model substances. Five biologically formed anaerobic TPs of iopromide and DAMI and six of DDPI, and the respective transformation pathways, were identified. The TPs were formed by successive deiodination and hydrolysis of amide moieties. Quantification of the iodinated TPs was achieved by further development of a complementary liquid chromatography (LC)-quadrupole time-of-flight mass spectrometry (Q-ToF-MS) and LC-inductively coupled plasma - mass spectrometry (ICP-MS) strategy without needing authentic standards, despite several TPs coeluting with others. A database with predicted anaerobic TPs of ICMs was derived by applying the transformation rules found for the anaerobic transformation pathways of iopromide and diatrizoate to further ICMs (iomeprol and iopamidol) and their aerobic TPs already reported in the literature. The environmental relevance of the identified transformation pathways was confirmed by identifying an experimental TP and two predicted TPs using suspect screening of water taken from anaerobic bank filtration zones.


Assuntos
Meios de Contraste , Poluentes Químicos da Água , Anaerobiose , Iohexol/análogos & derivados , Raios X
5.
Anal Bioanal Chem ; 409(30): 6949-6958, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28975375

RESUMO

In addition to beneficial health effects, fluoride can also have adverse effects on humans, animals, and plants if the daily intake is strongly elevated. One main source of fluoride uptake is water, and thus several ordinances exist in Germany that declare permissible concentrations of fluoride in, for example, drinking water, mineral water, and landfill seepage water. Controlling the fluoride concentrations in aqueous matrices necessitate valid and fast analytical methods. In this work an alternative method for the determination of fluoride in surface waters based on high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) was applied. Fluoride detection was made possible by the formation of a diatomic molecule, GaF, and detection of characteristic molecular absorption. On HR-CS-GFMAS parameter optimization, the method was adapted to surface water sample analysis. The influence of potential main matrix constituents such as Na+, Ca2+, Mg2+, and Cl- as well as surface water sampling/storage conditions on the molecular absorption signal of GaF was investigated. Method validation demonstrated a low limit of detection (8.1 µg L-1) and a low limit of quantification (26.9 µg L-1), both sufficient for direct river water sample analysis after 0.45-µm filtration. The optimized HR-CS-GFMAS method was applied for the analysis of real water samples from the rivers Rhine and Moselle. For method validation, samples were also analyzed by an ion chromatography (IC) method. IC and HR-CS-GFMAS results both agreed well. In comparison with IC, HR-CS-GFMAS has higher sample throughput, a lower limit of detection and a lower limit of quantification, and higher selectivity, and is a very suitable method for the analysis of dissolved fluoride in river water. Graphical abstract High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) was applied for the quantitative analysis of dissolved fluoride in river water samples from the Rhine and the Moselle. Fluoride detection was made possible by the addition of Ga for GaF formation and analysis of characteristic molecular absorption at 211.248 nm. Good agreement between HR-CS-GFMAS and ion chromatography (IC) results was obtained. In comparison with IC, HR-CS-GFMAS had a faster sample throughput and lower limit of detection and limit of quantification.

6.
PLoS One ; 12(1): e0168926, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28060850

RESUMO

Today, basic requirements for construction works include the protection of human health and of the environment. In the tension area between economic demands, circular flow economy and environmental safety, a link between the results from standardized leaching tests and the respective environmental quality standards must be created. To derive maximum release limits of metals and metalloids for armourstones in hydraulic engineering, this link is accomplished via a simple model approach. By treating natural materials and industrial by-products the same way, the article delivers an overview on the recent regulative situation in Europe as well as describes and discusses an innovative approach to derive maximum release limits for monolithic construction products in hydraulic engineering on a conceptual level. On a practical level, a list of test parameters is derived by connecting an extensive dataset (seven armourstone materials with five repetitions and 31 elements tested with the worldwide applied dynamic surface leaching test) with surface water quality standards and predicted no effect concentrations. Finally, the leaching tests results are compared with the envisaged maximum release limits, offering a direct comparison between natural materials and industrial by-products.


Assuntos
Conservação dos Recursos Naturais , Recursos Naturais , Água , Europa (Continente) , Humanos , Modelos Teóricos
7.
Anal Bioanal Chem ; 407(10): 2665-74, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25577354

RESUMO

Since its introduction in the early 1990s, the on-line coupling of field-flow fractionation to inductively coupled plasma-mass spectrometry (FFF/ICP-MS) has evolved from a "niche" method into an established technique, especially in the field of natural-colloid analysis. Around the turn of the millennium engineered nanomaterials became prominent in research as a result of new properties, and in recent years FFF/ICP-MS has been revealed to be a promising tool for their analysis. Given the beneficial properties of this technique (e.g., no stationary phase, high separation power, multi-elemental capabilities, and high sensitivity) further applications, especially in the field of biomolecule analysis, will be discovered in the near future, and FFF will evolve further as a complementary tool to well-established chromatographic techniques (e.g. high-performance liquid chromatography, size-exclusion chromatography). The focus of this article is on recent application trends of FFF/ICP-MS, revealing the applicability of this technique within several fields of research, especially natural colloids and engineered nanoparticles. Possible future application trends, based on the author's opinion, are outlined in the "Concluding remarks and outlook" section.

8.
Environ Sci Technol ; 48(17): 10145-54, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25140788

RESUMO

The iodinated X-ray contrast medium diatrizoate is known to be very persistent in current wastewater treatment as well as in environmental compartments. In this study, the potential of anaerobic processes in soils, sediments, and during wastewater treatment to remove and transform diatrizoate was investigated. In anaerobic batch experiments with soil and sediment seven biologically formed transformation products (TPs) as well as the corresponding transformation pathway were identified. The TPs resulted from successive deiodinations and deacetylations. The final TP 3,5-diaminobenzoic acid (DABA) was stable under anaerobic conditions. However, DABA was further transformed under air atmosphere, indicating the potential for the mineralization of diatrizoate by combining anaerobic and aerobic conditions. With the development of a methodology using complementary liquid chromatography-electrospray ionization-tandem mass spectrometry and liquid chromatography-inductively coupled plasma-mass spectrometry techniques, all identified TPs were quantified and the mass balance could be closed without having authentic standards for four of the TPs available. The detection and quantification of diatrizoate TPs in groundwater, in technical wetlands with anaerobic zones, and in a pilot wastewater treatment plant established for anaerobic treatment highlights the transferability and up-scaling of the results attained by laboratory experiments to environmental conditions.


Assuntos
Meios de Contraste/isolamento & purificação , Diatrizoato/isolamento & purificação , Anaerobiose , Técnicas de Cultura Celular por Lotes , Biodegradação Ambiental , Biotransformação , Cromatografia Líquida , Meios de Contraste/química , Diatrizoato/química , Água Subterrânea/química , Compostos de Iodo/isolamento & purificação , Limite de Detecção , Projetos Piloto , Solo , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Atômica , Fatores de Tempo , Águas Residuárias/química , Purificação da Água , Áreas Alagadas , Raios X
9.
Front Chem ; 2: 39, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25003102

RESUMO

The European COoperation in Science and Technology (COST) Action ES1205 on the transfer of Engineered Nano materials from wastewater Treatment and stormwatEr to Rivers (ENTER) aims to create and to maintain a trans European network among scientists. This perspective article delivers a brief overview on the status quo at the beginning of the project by addressing the following aspects on engineered nano materials (ENMs) in the urban systems: (1) ENMs that need to be considered on a European level; (2) uncertainties on production-volume estimations; (3) fate of selected ENMs during waste water transport and treatment; (4) analytical strategies for ENM analysis; (5) ecotoxicity of ENMs, and (6) future needs. These six step stones deliver the derivation of the position of the ES1205 network at the beginning of the projects runtime, by defining six fundamental aspects that should be considered in future discussions on risk evaluation of ENMs in urban water systems.

10.
J Trace Elem Med Biol ; 28(2): 125-130, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24613139

RESUMO

Because of its bactericidal and fungicidal properties, thimerosal is used as a preservative in drugs and vaccines and is thus deliberately injected into the human body. In aqueous environment, it decomposes into thiosalicylic acid and the ethylmercury cation. This organomercury fragment is a potent neurotoxin and is suspected to have similar toxicity and bioavailability like the methylmercury cation. In this work, human whole blood and physiological simulation solutions were incubated with thimerosal to investigate its behaviour and binding partners in the blood stream. Inductively coupled plasma with optical emission spectrometry (ICP-OES) was used for total mercury determination in different blood fractions, while liquid chromatography (LC) coupled to electrospray ionisation time-of-flight (ESI-TOF) and inductively coupled plasma-mass spectrometry (ICP-MS) provided information on the individual mercury species in plasma surrogate samples. Analogous behaviour of methylmercury and ethylmercury species in human blood was shown and an ethylmercury-glutathione adduct was identified.


Assuntos
Técnicas In Vitro/métodos , Plasma/metabolismo , Timerosal/sangue , Cromatografia Líquida , Cisteína/sangue , Glutationa/sangue , Humanos , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Atômica
11.
Anal Bioanal Chem ; 406(2): 467-79, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24292431

RESUMO

Validated and easily applicable analytical tools are required to develop and implement regulatory frameworks and an appropriate risk assessment for engineered nanoparticles (ENPs). Concerning metal-based ENPs, two main aspects are the quantification of the absolute mass concentration and of the "dissolved" fraction in, e.g., (eco)toxicity and environmental studies. To provide information on preparative aspects and on potential uncertainties, preferably simple off-line methods were compared to determine (1) the total concentration of suspensions of five metal-based ENP materials (Ag, TiO2, CeO2, ZnO, and Au; two sizes), and (2) six methods to quantify the "dissolved" fraction of an Ag ENP suspension. Focusing on inductively coupled plasma-mass spectrometry, the total concentration of the ENP suspensions was determined by direct measurement, after acidification and after microwave-assisted digestion. Except for Au 10 nm, the total concentrations determined by direct measurements were clearly lower than those measured after digestion (between 61.1 % for Au 200 nm and 93.7 % for ZnO). In general, acidified suspensions delivered better recoveries from 89.3 % (ZnO) to 99.3 % (Ag). For the quantification of dissolved fractions two filtration methods (ultrafiltration and tangential flow filtration), centrifugation and ion selective electrode were mainly appropriate with certain limitations, while dialysis and cloud point extraction cannot be recommended. With respect to precision, time consumption, applicability, as well as to economic demands, ultrafiltration in combination with microwave digestion was identified as best practice.

12.
ACS Nano ; 6(7): 5767-83, 2012 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-22659047

RESUMO

The in vitro labeling of therapeutic cells with nanoparticles (NPs) is becoming more and more common, but concerns about the possible effects of the NPs on the cultured cells are also increasing. In the present work, we evaluate the effects of poly(methacrylic acid)-coated 4 nm diameter Au NPs on a variety of sensitive and therapeutically interesting cell types (C17.2 neural progenitor cells, human umbilical vein endothelial cells, and PC12 rat pheochromocytoma cells) using a multiparametric approach. Using various NP concentrations and incubation times, we performed a stepwise analysis of the NP effects on cell viability, reactive oxygen species, cell morphology, cytoskeleton architecture, and cell functionality. The data show that higher NP concentrations (200 nM) reduce cell viability mostly through induction of reactive oxygen species, which was significantly induced at concentrations of 50 nM Au NPs or higher. At these concentrations, both actin and tubulin cytoskeleton were deformed and resulted in reduced cell proliferation and cellular differentiation. In terms of cell functionality, the NPs significantly impeded neurite outgrowth of PC12 cells up to 20 nM concentrations. At 10 nM, no significant effects on any cellular parameter could be observed. These data highlight the importance of using multiple assays to cover the broad spectrum of cell-NP interactions and to determine safe NP concentrations and put forward the described protocol as a possible template for future cell-NP interaction studies under comparable and standardized conditions.


Assuntos
Ouro/toxicidade , Nanopartículas Metálicas/toxicidade , Animais , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/toxicidade , Citoesqueleto/efeitos dos fármacos , Endocitose , Adesões Focais/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanotecnologia , Células-Tronco Neurais/efeitos dos fármacos , Células PC12 , Tamanho da Partícula , Ácidos Polimetacrílicos/toxicidade , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
13.
Anal Bioanal Chem ; 403(6): 1501-22, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22481380

RESUMO

Method development and applications of hyphenated techniques as tools for speciation analysis of metal-based pharmaceuticals are summarized within this review. Advantages and limitations of the separation modes-high-performance liquid chromatography (HPLC), capillary electrophoresis (CE), and gas chromatography (GC)-as well as the detection modes-inductively coupled plasma-mass spectrometry (ICP-MS) and electrospray ionization-mass spectrometry (ESI-MS)-are discussed. ICP-MS detection is found to be advantageous for the quantification of drugs containing metals and other heteroatoms. The species-independent sensitivity and multielement capabilities of ICP-MS allow it to be used for quantification even when species-specific standards are not available, as well as to determine the stoichiometry in metallodrug-biomolecule interactions. Molecular information that is totally destroyed when ICP is applied as ionization source and is therefore not obtainable via ICP-MS detection can be accessed by the complementary technique of ESI-MS. Speciation analysis combining both elemental and molecular information is therefore a powerful tool for the analysis of metal-based pharmaceuticals and their metabolites in body fluids and other relevant matrices.


Assuntos
Metais/química , Preparações Farmacêuticas/química , Animais , Cromatografia Líquida de Alta Pressão , Eletroforese Capilar , Humanos , Espectrometria de Massas por Ionização por Electrospray
14.
Anal Chem ; 84(5): 2395-401, 2012 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-22304524

RESUMO

During the development of a new drug compound, its metabolism needs to be unraveled. For quantification of the metabolites formed, the drug under investigation is traditionally synthesized with a radiolabel ((14)C or (3)H) and the metabolites present in different matrixes (blood, urine, feces) upon drug administration are determined by means of high-performance liquid chromatography (HPLC) coupled to radiodetection. This approach allows for quantification of the metabolites formed and enables a straightforward distinction between exogenous (i.e., drug-related) and endogenous species (as only the radiolabeled species are detected). However, in some cases, the use of a radiolabeled compound in human in vivo studies is not advisible, e.g., for drug compounds or their metabolites showing a long plasma or tissue half-life. In cases where the candidate drug molecule contains an element detectable by means of inductively coupled plasma mass spectrometry (ICP-MS), HPLC/ICP-MS is a promising alternative approach. However, the method lacks specificity when a distinction between drug-related species and endogenous compounds containing the same target element needs to be accomplished. As a result, we have developed an HPLC/ICP-MS-based method combined with "reverse" online isotope dilution ("reverse" online ID) for metabolite quantification. The methodology was evaluated by the analysis of feces samples from rats dosed with a (81)Br-labeled drug compound. The method allows for both (i) valid quantification of the drug metabolites and (ii) distinction among endogenous, exogenous, and "mixed" species, based on their isotopic "fingerprint". A good repeatability (relative standard deviation of 4.2%) and limit of detection (0.35 mg of drug compound L(-1) of feces extract), of the same order of magnitude as those observed for "normal" online ID HPLC/ICP-MS and HPLC/radiodetection, were achieved.


Assuntos
Cromatografia Líquida de Alta Pressão , Preparações Farmacêuticas/análise , Espectrometria de Massas por Ionização por Electrospray , Animais , Antituberculosos/análise , Antituberculosos/metabolismo , Bromo/química , Radioisótopos de Carbono/química , Fezes/química , Humanos , Marcação por Isótopo , Isótopos/química , Preparações Farmacêuticas/metabolismo , Ratos , Trítio/química
15.
Anal Bioanal Chem ; 402(1): 439-48, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21877185

RESUMO

The aim of this work was speciation analysis of metabolites in feces samples collected within a clinical study during which a bromine-containing anti-tuberculosis drug (TMC207) was administered to patients with multi-drug resistant tuberculosis infection. Owing to slow elimination of the drug, no (14)C label was used within this study. Quantification of the bromine species was accomplished using high performance liquid chromatography coupled to inductively coupled plasma-mass spectrometry (HPLC/ICP-MS) in combination with on-line isotope dilution (on-line ID), while structural elucidation of the species was performed using HPLC coupled to electrospray ionization-mass spectrometry. The ICP-MS-based method developed shows a good intra- and inter-day reproducibility (relative standard deviation = 3.5%, N = 9); the limit of detection (1.5 mg TMC207 L(-1)) is of the same order of magnitude as that for HPLC/radiodetection; the dynamic range of the method covers more than two orders of magnitude. Furthermore, the column recovery was demonstrated to be quantitative (recoveries between 90.6% and 99.5%). Based on the excellent figures of merit, the "cold" HPLC/ICP-MS approach could be deployed for the actual human in vivo metabolism study, such that exposure of the human volunteers to the (14)C radiolabel was avoided.


Assuntos
Antituberculosos/metabolismo , Fezes/química , Quinolinas/metabolismo , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Antituberculosos/análise , Antituberculosos/uso terapêutico , Bromo/análise , Radioisótopos de Carbono/administração & dosagem , Radioisótopos de Carbono/análise , Cromatografia Líquida de Alta Pressão/métodos , Diarilquinolinas , Feminino , Humanos , Técnicas de Diluição do Indicador , Isótopos/análise , Masculino , Quinolinas/análise , Quinolinas/uso terapêutico , Espectrometria de Massas por Ionização por Electrospray/métodos
16.
Anal Bioanal Chem ; 397(8): 3503-13, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19777217

RESUMO

Succinimidylferrocenyl propionate (SFP) is introduced as labelling agent for amino functions in peptides and proteins. The resulting derivatives are characterised by considerably lower polarity compared with the native analytes and can thus be well separated by means of reversed phase liquid chromatography (RP-LC). The reaction products are characterised by electrospray ionisation mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS). A further advantage of the method is a simple and straightforward derivatisation protocol. Different basic and acidic model proteins as lysozyme, beta-lactoglobulin A and insulin were derivatised using SFP. Furthermore, the first dual-labelling strategy of thiol and amino groups with ferrocene-based reagents is presented. Whereas the amino groups were derivatised with SFP, the thiol groups were functionalised by reaction with ferrocenecarboxylic acid(2-maleimidoyl)ethylamide. Again, LC/ESI-MS is a suitable tool to characterise the modified peptides and proteins.


Assuntos
Compostos Ferrosos/química , Insulina/química , Lactoglobulinas/química , Muramidase/química , Peptídeos/química , Coloração e Rotulagem/métodos , Animais , Bovinos , Galinhas , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Metalocenos , Espectrometria de Massas por Ionização por Electrospray
17.
Anal Bioanal Chem ; 395(6): 1929-35, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19768643

RESUMO

To investigate the effects of mercury species intoxication and to test the efficiency of different commonly applied antidotes, human whole blood and plasma surrogate samples were spiked with inorganic mercury (Hg2+) and methylmercury (MeHg+, CH3Hg+) prior to treatment with the antidotes 2,3-dimercaptopropan-1-ol (British Anti Lewisite), 2,3-dimercaptosuccinic acid (DMSA), and N-acetylcysteine (NAC). For mercury speciation analysis in these samples, liquid chromatography was coupled to either inductively coupled plasma mass spectrometry (ICP-MS) or electrospray ionisation time-of-flight mass spectrometry (ESI-TOF-MS). Adduct formation between mercury species and physiological thiols (cysteine and glutathione) was observed as well as the release of glutathione under treatment with the antidotes DMSA and NAC.


Assuntos
Antídotos/química , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Mercúrio/farmacocinética , Compostos de Metilmercúrio/farmacocinética , Adulto , Feminino , Humanos , Inativação Metabólica , Masculino , Mercúrio/sangue , Compostos de Metilmercúrio/sangue , Modelos Biológicos
18.
Environ Sci Technol ; 43(8): 2884-90, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19475966

RESUMO

The behavior of Gd chelates used in magnetic resonance imaging (MRI) within the process of sewage treatment is widely unknown. Due to the varying toxicity of the particular Gd species [J. M. Idee et al. Fundam. Clin. Pharmacol. 2006, 20, 563-576], it is important to not only investigate total Gd concentrations, but the Gd species as well. This work describes a novel method for speciation analysis of the most important gadolinium chelates in wastewaters. This novel approach consists of coupling hydrophilic interaction chromatography (HILIC) with inductively coupled plasma mass spectrometry (ICP-MS). HILIC/ICP-MS exhibits high separation efficiency for the simultaneous separation of the five predominantly applied MRI contrast agents and the required selectivity and sensitivity for trace determination in wastewater samples. For the first time, the distribution of particular Gd chelate complexes was determined in hospital effluent, municipal sewage, and wastewater treatment plant (WWTP) samples. The data were compared with the total concentration of Gd as determined by ICP-MS. The active compounds of Multihance, Dotarem, and Gadovist were identified in local WWTP samples. Interestingly, the macrocyclic, nonionic compound Gd-BT-DO3A (Gadovist) was found to be the most abundant Gd complex in all investigated samples. This is in contrast to prevalent assumptions that linear ionic Gd chelates such as Gd-DTPA (Magnevist) would be the predominant species [G. Morteani et al. Environ. Geochem. Health 2006, 28, 257-264 and M. Bau and P. Dulski, Earth Planet. Sci. Lett. 1996, 143, 245-255]. Although contrast agent concentrations tend to be reduced during wastewater treatment, Gd-BT-DO3A was still found in WWTP effluents.


Assuntos
Quelantes/química , Gadolínio/química , Hospitais , Resíduos Industriais , Espectrometria de Massas/métodos , Esgotos , Poluentes Químicos da Água/química , Padrões de Referência
19.
Anal Chem ; 80(24): 9769-75, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19072274

RESUMO

For the risk assessment of drug candidates, the identification and quantification of their metabolites is required. The majority of analytical techniques is based on calibration standards for quantification of the metabolites. As these often are not readily available, the use of inductively coupled plasma mass spectrometry (ICPMS) is an attractive alternative for drugs containing heteroatoms. In this work, the online coupling of electrochemistry (EC), liquid chromatography (LC), and ICPMS is presented. The antiarrhythmic agent amiodarone, which contains two iodine atoms, is oxidized in an electrochemical flow-through cell under N-dealkylation and deiodination. The metabolites that are generated at different EC potentials are identified by electrospray ionization (ESI) mass spectrometry, compared to those from rat liver microsomal incubations and quantified by ICPMS. Phase-optimized LC, a recent approach for high-performance isocratic separations, is used to avoid the ICPMS calibration problems known to occur with gradient separations. The potential of the complementary use of ESI-MS and ICPMS for the qualitative and quantitative analysis of drug metabolites becomes apparent in this work.


Assuntos
Amiodarona/análise , Antiarrítmicos/análise , Eletroquímica , Iodo/química , Espectrometria de Massas por Ionização por Electrospray , Amiodarona/metabolismo , Animais , Antiarrítmicos/metabolismo , Cromatografia Líquida , Microssomos Hepáticos/metabolismo , Ratos
20.
Electrophoresis ; 29(12): 2731-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18512677

RESUMO

CE was coupled to inductively coupled plasma MS (ICP-MS) and ESI-MS to identify and quantify the arsenic species arsenobetaine (AsB), arsenite (As(III)), arsenate (As(V)), and dimethylarsinic acid (DMA). A GC-flame ionization detector (FID)-based German standard method and ICP-MS were used for validation of the data obtained for arsenobetaine and total arsenic, respectively. LODs obtained with the CE-ESI-TOF-MS method were 1.0x10(-7) M for AsB, 5.0x10(-7) M for DMA, and 1.0x10(-6) M for As(III) and As(V). For the CE-ICP-MS method, LODs were 8.5x10(-8) M for AsB, 9.5x10(-8) M for DMA, 9.3x10(-8) M for As(III), and 6.2x10(-8) M for As(V). While CE-ICP-MS provided high sensitivity and better reproducibility for quantitative measurements, CE-ESI-MS with a TOF mass analyzer proved to be valuable for species identification. With this setup, fish samples were prepared and analyzed and the obtained data were successfully validated with the independent methods.


Assuntos
Arsenicais/análise , Peixes , Animais , Arseniatos/análise , Arsenitos/análise , Ácido Cacodílico/análise , Eletroforese Capilar , Espectrometria de Massas/métodos
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