The presence of unknown organofluorine compounds in environmental samples has prompted the development of nontargeted analytical methods capable of detecting new perfluoroalkyl and polyfluoroalkyl substances (PFASs). By combining high volume injection with high performance liquid chromatography (HPLC) and ultrahigh resolution Orbitrap mass spectrometry, a sensitive (0.003-0.2 ng F/mL for model mass-labeled PFASs) untargeted workflow was developed for discovery and characterization of novel PFASs in water. In the first step, up to 5 mL of water is injected to in-line solid phase extraction, chromatographed by HPLC, and detected by electrospray ionization with mass spectral acquisition in parallel modes cycling back and forth: (i) full scan with ultrahigh resolving power (RP = 120,000, mass accuracy ≤3 ppm), and (ii) in-source fragmentation flagging scans designed to yield marker fragment ions including [C2F5](-) (m/z 118.992), [C3F7](-) (m/z 168.988), [SO4H](-) (m/z 96.959), and [Cl](-) (m/z 34.9). For flagged PFASs, plausible empirical formulas were generated from accurate masses, isotopic patterns, and fragment ions. In the second step, another injection is made to collect high resolution MS/MS spectra of suspect PFAS ions, allowing further confirmation of empirical formulas while also enabling preliminary structural characterization. The method was validated by applying it to an industrial wastewater, and 36 new PFASs were discovered. Of these, 26 were confidently assigned to 3 new PFAS classes that have not previously been reported in the environment: polyfluorinated sulfates (CnFn+3Hn-2SO4(-); n = 5, 7, 9, 11, 13, and 15), chlorine substituted perfluorocarboxylates (ClCnF2nCO2(-); n = 4-11), and hydro substituted perfluorocarboxylates (HCnF2nCO2(-); n = 5-16). Application of the technique to environmental water samples is now warranted.

No abstract

Recebido em 22/1/01; aceito em 25/7/01 PROPOLIS: 100 YEARS OF RESEARCH AND FUTURE PERSPECTIVES. Propolis is a multifunctional material used by bees in the construction and maintenance of their hives. The chemical composition and pharmacological properties have been studied for centuries. Today they represent an important raw material for many health products and constitute a new interdisciplinary area for research. Among others they show important antimicrobial and cytotoxic activities and various pharmacological properties. This paper presents an overview of the scientific literature and patents concerning propolis.Keywords: propolis; patents; chemical composition; biological activity. INTRODUÇÃOAo longo da história, o homem apreendeu a utilizar os produtos naturais na medicina. Uma revisão recente sobre esse assunto foi apresentada em Química Nova por Barreiro 1 . Das várias formas de utilização destacam-se as plantas brutas (ex.: ervas) além das tradicionais preparações Galênicas (ex.: extratos). Um dos muitos produtos naturais utilizados durante séculos pela humanidade tem sido a própolis (CAS No. 9009-62-5) administrada sob diversas formas. Seu emprego já era descrito pelos assírios, gregos, romanos, incas e egípcios. No antigo Egito (1700 A.C.; "cera negra") era utilizada como um dos materiais para embalsamar os mortos.A própolis é uma mistura complexa, formada por material resinoso e balsâmico coletada pelas abelhas dos ramos, flores, pólen, brotos e exsudados de árvores; além desses, na colméia as abelhas adicionam secreções salivares 2-5 . Vários trabalhos têm sido publicados divulgando e revisando as propriedades biológicas da própolis como, por exemplo, as antimicrobiana, antifúngica, antiprotozoária, antioxidante e antiviral 4-6 . Na África do Sul, na guerra ao final do século XIX, foi amplamente utilizada devido às suas propriedades cicatrizantes 5 e na segunda guerra mundial foi empregada em várias clínicas soviéticas 7 . Na antiga URSS, a própolis mereceu especial atenção em medicina humana e veterinária, com aplicações inclusive no tratamento da tuberculose, observando-se a regressão dos problemas pulmonares e recuperação do apetite 8 .Os gregos, entre os quais Hipócrates, a adotaram como cicratizante interno e externo. Plínio, historiador romano, refere-se à própolis como medicamento capaz de reduzir inchaços e aliviar dores 7 . O termo própolis já era descrito no século XVI na França 5 e, em 1908 surgiu o primeiro trabalho científico 9 sobre suas propriedades químicas e "composição", indexado no Chemical Abstracts (referência n° 192). Em 1968 surgiu no Chemical Abstracts o resumo da primeira patente utilizando a própolis 10 (Romena, para a produção de loções para banho).Historicamente o primeiro trabalho 9 (indexado pelo Chemical Abstracts) sobre a própolis foi publicado 10 anos depois que o professor Heinrich Dresser da Bayer, proclamou o surgimento de uma milagrosa droga batizada como heroína; 5 anos depois do surgimento do primeiro barbitúrico e 14 anos antes do descobrimento da vitamina D, ...

The Canadian oil sands industry stores toxic oil sands process-affected water (OSPW) in large tailings ponds adjacent to the Athabasca River or its tributaries, raising concerns over potential seepage. Naphthenic acids (NAs; C(n)H(2n-Z)O(2)) are toxic components of OSPW, but are also natural components of bitumen and regional groundwaters, and may enter surface waters through anthropogenic or natural sources. This study used a selective high-resolution mass spectrometry method to examine total NA concentrations and NA profiles in OSPW (n = 2), Athabasca River pore water (n = 6, representing groundwater contributions) and surface waters (n = 58) from the Lower Athabasca Region. NA concentrations in surface water (< 2-80.8 μg/L) were 100-fold lower than previously estimated. Principal components analysis (PCA) distinguished sample types based on NA profile, and correlations to water quality variables identified two sources of NAs: natural fatty acids, and bitumen-derived NAs. Analysis of NA data with water quality variables highlighted two tributaries to the Athabasca River-Beaver River and McLean Creek-as possibly receiving OSPW seepage. This study is the first comprehensive analysis of NA profiles in surface waters of the region, and demonstrates the need for highly selective analytical methods for source identification and in monitoring for potential effects of development on ambient water quality.

This article provides a review of the routine methods currently utilized for total naphthenic acid analyses. There is a growing need to develop chemical methods that can selectively distinguish compounds found within industrially derived oil sands process affected waters (OSPW) from those derived from the natural weathering of oil sands deposits. Attention is thus given to the characterization of other OSPW components such as oil sands polar organic compounds, PAHs, and heavy metals along with characterization of chemical additives such as polyacrylamide polymers and trace levels of boron species. Environmental samples discussed cover the following matrices: OSPW containments, on-lease interceptor well systems, on- and off-lease groundwater, and river and lake surface waters. There are diverse ranges of methods available for analyses of total naphthenic acids. However, there is a need for inter-laboratory studies to compare their accuracy and precision for routine analyses. Recent advances in high- and medium-resolution mass spectrometry, concomitant with comprehensive mass spectrometry techniques following multi-dimensional chromatography or ion-mobility separations, have allowed for the speciation of monocarboxylic naphthenic acids along with a wide range of other species including humics. The distributions of oil sands polar organic compounds, particularly the sulphur containing species (i.e., OxS and OxS2) may allow for distinguishing sources of OSPW. The ratios of oxygen- (i.e., Ox) and nitrogen-containing species (i.e., NOx, and N2Ox) are useful for differentiating organic components derived from OSPW from natural components found within receiving waters. Synchronous fluorescence spectroscopy also provides a powerful screening technique capable of quickly detecting the presence of aromatic organic acids contained within oil sands naphthenic acid mixtures. Synchronous fluorescence spectroscopy provides diagnostic profiles for OSPW and potentially impacted groundwater that can be compared against reference groundwater and surface water samples. Novel applications of X-ray absorption near edge spectroscopy (XANES) are emerging for speciation of sulphur-containing species (both organic and inorganic components) as well as industrially derived boron-containing species. There is strong potential for an environmental forensics application of XANES for chemical fingerprinting of weathered sulphur-containing species and industrial additives in OSPW.

No abstract

No abstract

In hydrophilic interaction chromatography (HILIC), best results are obtained with high concentrations of ACN. In the framework of green chromatography and the present shortage and very high price of this hazardous solvent, reversing the stationary phase to apolar and the mobile phase to aqueous can be of interest for several applications. The features of the aqueous RP technique called per aqueous LC (PALC) are illustrated with the analysis of catecholamines, nucleobases, acids, and amino acids. The ca. three‐fold higher viscosity of water compared to ACN has consequences on the shape of the Van Deemter plot. For dopamine (N = 26.450 on a 25 cm×4.6 mm id, 5 μm bare silica column), a reduced plate height of 1.9 at an uopt of 0.3 mm/s was calculated. The plate number, however, strongly depends on pH and ionic strength. As in RP separations, retention is shortened by adding an organic modifier. In the framework of green chromatography, the biodegradable ethanol was used. On the other hand, retention increased by lengthening the carbon chain of ion‐pair reagents supporting the RP mechanism as well.