ABSTRACT
A microwave-assisted extraction (MAE) procedure has been developed and optimized for the extraction of six regulated polycyclic aromatic hydrocarbons (PAHs) from muscle samples of polluted fish. The procedure involves the simultaneous microwave-assisted extraction of PAHs with n-hexane and the lipids hydrolysis with potassium hydroxide. Experimental design methodology allows a quick and robust optimization of operational parameters such as the extraction time, temperature, and solvent volumes. In these final optimized conditions, the procedure can be applied to a vast range of fat containing fish samples without significant changes, thus enabling its routine use. Recoveries around 90% for the studied compounds benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, and indene[1,2,3-cd]pyrene and quantification limits (between 0.07 and 0.53 ng/g dry weight) far below the regulated limits, have been obtained. The procedure is applied to several different fish samples. Further, accuracy validation using NIST SRM 2977 reference material was carried out.
Subject(s)
Fishes , Microwaves , Muscles/chemistry , Polycyclic Compounds/analysis , Animals , Chromatography, High Pressure Liquid , Spectrometry, FluorescenceABSTRACT
The performance of matrix solid-phase dispersion (MSPD) for the extraction of polycyclic aromatic hydrocarbons (PAHs) in fish tissue is described. The suitability of different solid supports was tested as well as the influence on the extraction efficiency of the natural fat content in samples. Under optimal conditions 0.6-0.8 g of tissue sample, are dispersed with 2 g of octadecylsiloxane (C18) and 0.5 g of anhydrous sodium sulphate and transferred to the top of a polyethylene solid-phase extraction cartridge which already contains 2 g of florisil and 1 g of C18. Cartridges were eluted with acetonitrile. The analysis of the extracts was carried out by high-performance liquid chromatography (HPLC) coupled with fluorescence detection. The proposed method provides detection limits between 0.04 and 0.32 ng/g for the different considered PAHs, below the maximum levels established by the some regulatory bodies for the six PAHs after recent oil spill episodes and European Union regulations. Recoveries over 80% were obtained for all compounds. Accuracy validation was carried out using the US National Institute of Standards and Technology (NIST) SRM 2977 reference material.
Subject(s)
Fishes , Polycyclic Compounds/analysis , Animals , Chromatography, High Pressure Liquid/methods , Food Analysis/methods , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, FluorescenceABSTRACT
La radical separación original entre demencia precoz y locura maniacodepresiva, consideradas incluso incompatibles, tiene su correlato en los sistemas nosológicos actuales que acogen con dificultad cuadros clínicos en los que lo afectivo conviva con lo psicótico. El trastorno esquizoafectivo es la única categoría que incluye específicamente esta combinación en las clasificaciones internacionales CIE-10 y DSM-IV; sin embargo, se trata de una entidad bastante restrictiva. El concepto de psicosis marginales, desaparecido como categoría específica, constituyó un acercamiento a estas entidades «fronterizas» que, a la vista de las dificultades diagnósticas que plantean cuadros como el que ilustra este caso, podría resultar interesante recuperar
The original radical separation between early dementia and manic-depressive illness, even considered incompatible, has its correlate in the present nosological systems that difficultly include clinical pictures in which the affective co-exists with the psychotic. The schizoaffective disorder is the only category that specifically includes this combination in the ICD-10 and DSM-IV international classifications. However, this is a very restrictive category. The concept of marginal psychosis, which has disappeared as a specific category, constituted an approach to those borderline cases, which in view of the diagnostic difficulties posed by pictures like the case presented, could be interesting to recover
Subject(s)
Female , Humans , Mood Disorders/diagnosis , Mood Disorders/psychology , Psychotic Disorders/diagnosis , Psychotic Disorders/psychology , Diagnosis, DifferentialABSTRACT
The original radical separation between early dementia and manic-depressive illness, even considered incompatible, has its correlate in the present nosological systems that difficulty include clinical pictures in which the affective co-exists with the psychotic. The schizoaffective disorder is the only category that specifically includes this combination in the ICD-10 and DSM-IV international classifications. However, this is a very restrictive category. The concept of marginal psychosis, which has disappeared as a specific category, constituted an approach to those borderline cases, which in view of the diagnostic difficulties posed by pictures like the case presented, could be interesting to recover.
Subject(s)
Mood Disorders/diagnosis , Mood Disorders/psychology , Psychotic Disorders/diagnosis , Psychotic Disorders/psychology , Adult , Diagnosis, Differential , Female , HumansABSTRACT
The screening of polycyclic aromatic hydrocarbons in water samples by means of the strategic sample composition (SSC) technique is presented. SSC uses special supersaturated composition matrices to perform sample composition and analysed the results obtained in the analytical determination of these composite samples by means of evolutionary assisted regression procedures providing estimations of the concentration levels of analytes in each individual sample specimen. Here, 12 composite samples were prepared by departing from 26 water sample specimens, five of which were spiked with known amounts of several polycyclic aromatic hydrocarbons (PAHs). These composite samples were analysed by HPLC using fluorescence detection. Concentration levels spiked were, in some cases clearly higher than allowed limits for drinking waters, whereas in other cases are just in the limit or even down these limits. The study shows the ability of SSC to detect the really contaminated samples and guiding the analyst in taking the adequate decisions.
Subject(s)
Chromatography, High Pressure Liquid/methods , Polycyclic Compounds/analysis , Spectrometry, Fluorescence/methods , Water Supply/analysisABSTRACT
A simple and rapid microwave-assisted extraction (MAE) procedure was developed and optimized for benzo[a]anthracene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene in wood samples. The spiked wood used was prepared 3 months before analysis to simulate weathering processes and to allow the formation of analyte-matrix interaction. The samples, immersed in acetonitrile were irradiated with microwaves in a closed-vessel system. Optimization of the method was achieved by using a factorial design approach on parameters such as extraction time, temperature and sample amount. The analysis of extracts has been carried out by reversed-phase high-performance liquid chromatography with fluorescence detection for quantification and UV-diode-array detection for confirmation. The MAE procedure yielded extracts that could be analyzed directly without any preliminary clean-up or solvent exchange steps.
Subject(s)
Polycyclic Compounds/isolation & purification , Wood , Chromatography, High Pressure Liquid/methods , Microwaves , Reproducibility of Results , Spectrometry, FluorescenceABSTRACT
BACKGROUND: The aim of this study was to evaluate the etiology of phlebitis (chemical or infectious) and the prevalence of infections related to intravascular catheters (IRIC) in patients with HIV infection admitted to a 22-bed Infectious Disease Unit with a high rate of HIV infection. MATERIAL AND METHODS: A 3-month prospective study from November 1, 1994 to January 31, 1995 was carried out following a formula for data collection of all the intravenous catheters used during that time period. Cultures of the catheters withdrawn on Wednesdays and those with signs of phlebitis were performed. RESULTS: One hundred fifty-two intravenous catheters in 71 patients with HIV infection with a mean age of 37 years (range: 21-73) and mean hospital stay of 10.2 days were reported. During the study period 42 phlebitis were produced, of which 37 catheters (7 central and 30 peripheral) were processed. Of the 37 phlebitis processed, 29 (78.9%) were considered to be of physiochemical origin. Of the 21 catheters withdrawn Wednesday, 18 were processed, 8 with phlogotic signs, 2 with IRCI, equivalent to 1.9 IRCI/100 days of catheterization. During the study period no local or severe systemic infections related to the catheter were reported. Staphylococcus epidermidis was the organism involved in all the cases of IRCI. CONCLUSIONS: Despite the high number of immunosuppressed patients in related to HIV infection, a greater incidence of IRCI was not found in these patients. The most frequent cause of phlebitis by catheter was of chemical origin.
