Pyrene In Water Research Articles

Highly sensitive and selective fluorescence optosensor to detect and quantify benzo[ a]pyrene in water samples

We describe here a method for detecting and quantifying the highly carcinogenic polycyclic aromatic hydrocarbon (PAH) benzo[ a]pyrene (BaP) in water, based on a flow-trough optical sensor. The technique is fast (response time of 40 s) and simple and at the same time meets the standards of sensitivity and selectivity required by the European Guidelines on Water for Human Consumption. The optosensor is based on the on-line immobilization of BaP on a non-ionic resin (Amberlite XAD-4) solid support in a continuous-flow system. BaP was analyzed in a 15 mM H 2PO 4 −/HPO 4 2− buffer solution with 25% (v/v) 1,4-dioxane at pH 7. Fluorescence intensity was measured at λ ex/em=392/406 nm. The experimental conditions (reagent phase, pH, type and concentration of buffer solution and organic solvent) and flow-injection values (flow rate and injection volume) were carefully controlled. Under these conditions the optosensor was sensitive to a linear concentration range of between 3.0 and 250.0 ng l −1 with a detection limit of 3.0 ng l −1 and a standard deviation of 1.5% at 150 ng l −1. The optosensor was applied to the quantification of BaP in drinking and waste water samples (95–105% recovery) in presence of the other 15 EPA PAHs at 1000 ng l −1 concentration level. The influence of other fluorescent polycyclic aromatic hydrocarbons and potential interference from ions usually present in water was also evaluated.

Laser-induced fluorescence with an OPO system. Part I. Optimisation of the analytical system by use of experimental design methodology. Application to the direct quantification of traces of benzo[ a]pyrene.

This study deals with the optimisation and application of a method for direct analysis of trace pollutants in water by laser-induced fluorescence. The arrangement used consisted of an Nd:YAG Laser coupled with an optical parametric oscillator (LYOPO) and connected to a spectrophotometer and a high-sensitivity camera. Optimisation was achieved by developing an experimental design methodology to maximise the signal-to-noise ratio and reduce the limit of detection. The technique was then applied to the detection of benzo[ a]pyrene in water. The experimental results were evidence of its high sensitivity and time-resolution potential. The detection limit for benzo[ a]pyrene was 0.7 ng L(-1) in drinking water and 4 ng L(-1) in raw water containing 1 mg L(-1) humic acids.

Direct Fluorometric Analysis of PAHs in Water and in Urine Following Liquid Solid Extraction

A method for the determination of PAHs in aqueous media based on synchronous fluorescence analysis directly on a solid phase after extraction was evaluated. Tests were conducted for (i) the simultaneous analysis of naphthalene, phenanthrene, anthracene, and pyrene in water at a parts per billion concentration level using a 0V1 sorbing phase block and (ii) the analysis of 1-hydroxyphenanthrene (1-OHPh) and 1-hydroxypyrene (1-OHPy) in human urine using a small sheet cut from a C18 silica fiberglass extraction disk (ENVI-Disk). Because the linear dynamic concentration range is dependent on both the immersion time and the concentration range, in all cases, an optimum immersion time must be determined to preserve linearity of intensity versus concentration. Calibration curves were determined for a concentration lower than 15 ppb in the case of 1-OHPh and at a concentration lower than 1.5 ppb in the case of 1-OHPy. In all cases the limits of detection were estimated to be lower than 0.2 ppb, i.e., for 1-OHPh and 1-OHPy, in the lowest concentration limit these metabolites were found in the urine of persons unexposed or weakly exposed to PAHs.

Synthesis of Poly(4-methylphenoxyphosphazene)-graft-poly(2-methyl-2-oxazoline) Copolymers and Their Micelle Formation in Water

Poly(4-methylphenoxyphosphazene)-graft-poly(2-methyl-2-oxazoline) was prepared, and micelle formation of the copolymer in water was studied. Poly(dichlorophosphazene) of a low molecular weight (<104) was obtained by the thermal polymerization of hexachlorocyclotriphosphazene in the presence of aluminum chloride (10 wt %). The chloro groups were replaced by 4-methylphenoxy groups, and then methyl groups were brominated. The brominated unit content was controlled to be 5% and 20%. The brominated polymers were used as macroinitiators for polymerization of 2-methyl-2-oxazoline to give amphiphilic graft copolymers. Micelle formation of the copolymers in water was investigated by measuring surface tensions and a fluorescence study. The micelles were found to solubilize hydrophobic pyrene in water effectively in the fluorescence study and expected to use as drug carriers.

Dendrimers with Alternating Amine and Ether Generations

Dendrimers having alternating aryl benzyl ether and tertiary amine generations and up to 16 bis(2-methoxyethyl)amine end groups and four internal tertiary amines were synthesized by sequential etherification, amidation of secondary amines, and LiAlH4 reduction to tertiary amines. The bis(2-methoxyethyl)amine dendrimers are soluble in common organic solvents and in aqueous buffer solutions at pH < 4.7. At 2.8 mM, the dendrimer increases the solubility of pyrene in water 30-fold, and the solvated pyrene is not aggregated.

Combined ozone and microbiological degradation of the six‐membered ring PAH indeno (1,2,3cd)pyrene in water solution

The aim of this work is to investigate between ozone and the model substance lndeno(1,2,3‐cd)pyrene in water as the first step of chemical and microbiological degradation. Ozonation is kept for one hour in an ozone stirring reactor with ozone concentrations of 5–10 mg/1 at low pH value. The mixture of reaction products contains ozonides at low concentration of ozone and hydroxy/keto‐compounds at high ozone concentration. Subsequent biological degradation of ozone products was carried out with a mixed bacterial culture. First experiments show a partial transformation of these products.

Solid-Phase microextraction with Whatman 1PS paper and direct room-temperature solid-matrix luminescence analysis

Solid-phase microextraction has been combined with solid-matrix luminescence for the detection of a variety of compounds at sub-nanogram levels for the first time. Whatman 1PS paper was placed in water solutions of polar and nonpolar compounds for the selective removal of the nonpolar compounds such as benzo(a)pyrene. Distribution constants were obtained for 4-phenylphenol, benzo(f)quinoline, benzo(h)quinoline, phenanthrene, and benzo(a)pyrene. The distribution constants showed that phenanthrene and benzo(a)pyrene in water had a very strong affinity for the 1PS paper. Once the solutes were extracted for a fixed period of time, the 1PS paper was dried, and either the solid-matrix fluorescence or solid-matrix phosphorescence was detected from the adsorbed lumiphors by using the appropriate excitation wavelengths. It was a simple matter to detect at least three adsorbed compounds on the 1PS paper by solid-matrix luminescence. Benzo(a)pyrene was easily detected at a level of 0.02 ng ml −1 in water.

Sensitive and selective determination of metabolically formed trans -dihydrodiols and phenols of benzo[ a ]pyrene in water and urine samples by HPLC with amperometric detection

A method has been developed to separate hydroxylated metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene, i. e. trans-4,5-, 7,8-, 9,10-dihydrodiol and 1-, 3-, 7-, and 9-phenol, by HPLC with amperometric detection employing an isocratic methanol/water eluent (70:30, v/v) containing 0.5 g/L sulfuric acid and 1 g/L lithium perchlorate. Compared with the usually applied fluorescence (λex = 265 nm, λem = 460 nm) and ultraviolet (λ = 265 nm) detection, the amperometric technique is about 2–12 times more sensitive for the determination of all metabolites investigated. The method was applied to the determination of the seven metabolites of benzo[a]pyrene in different water samples and in urine after solid-phase extraction (SPE). The results obtained by HPLC with amperometric detection after SPE enrichment from an aqueous extract of a soil sample and from the urine of a rat intragastrically treated with benzo[a]pyrene agreed well with the values determined with fluorescence and/or UV detection.

Preferential Solvation Studied by the Fluorescence Spectrum of Pyrene in Water-Alcohol Binary Mixtures

Abstract The local mole fraction of an alcohol such as methanol, ethanol, and 1-propanol was determined on the basis of the polarity variation sensed by pyrene in water-alcohol binary mixtures. The data indicate that alcohol molecules preferentially solvate pyrene in water; the degree of preferential solvation increases with an increase in the extent of the hydrophobic interaction between pyrene and alcohols.

Hepatic CYP1A induction in rainbow trout (Oncorhynchus mykiss) after exposure to benzo[a]pyrene in water

Juvenile rainbow trout were exposed to unlabelled benzo[a]pyrene BaP and 3H benzo a pyrene (3H BaP), in a static exposure system for 2 days. The initial concentration was 30 μg l-1 and 0.625 μCi l-1, corresponding to 6 mg kg-1 body weight and 125 μCi kg-1 body weight. Hepatic 7-ethoxyresorufin-O-deethylase (EROD) activity was measured during the exposure and depuration periods, elucidating the time course pattern of CYP1A induction. Maximum induction (11-fold) of EROD activity was observed on day 2 after addition of BaP to the water. Tissue distribution of 3H-BaP was studied by liquid scintillation counting and whole body autoradiography. The concentration of 3H-BaP-derived radioactivity was highest in the bile at all sampling times. High levels of radiolabelled compound were also present in the gills, liver and the olfactory organ. There was an overall decrease in all tissues during the depuration period. The elimination of 3H-BaP-derived radioactivity from the gills, however, was slow compared with liver and blood (6.2 days vs 2.7 and 2.9 days, respectively).

On-site solid phase extraction and coupled-column high-performance liquid chromatographic determination of six polycyclic aromatic hydrocarbons in water

A high-performance liquid chromatographic method for the determination of fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene in water is presented. The analytical procedure consists of on-site solid-phase extraction of the analytes on a selective sample column using a new device, transport and integration of the loaded sample column into a HPLC-system and coupled-column HPLC-analysis. The method allows reliable quantification of the PAHs at the low ng/l-level in particle-free as well as in particle-containing surface water.

Pyrene Sorption in Organic-Layered Double-Metal Hydroxides

Myristic, hexanoic, and succinic acids were incorporated into a lithium- and aluminum-containing layered double-metal hydroxide (LDH), resulting in materials with interlayer spacings of 21.6, 17.8, and 7.5 [angstrom], respectively. Comparison of these spacings with the dimensions of the all-trans form of the acid molecules indicates an interlayer monolayer arrangement for myristic and succinic acids, and a bilayer arrangement for hexanoic acid. Sorption isotherms of pyrene by these organic-exchange LDH's were carried out in methanol/water mixtures, because of the limited solubility of pyrene in water. Using cosolvent theory, partition coefficients (log K[sub oc]) for pyrene into myristic acid-LiAl-LDH and hexanoic acid-LiAl-LDH were determined to be 4.38 and 3.44, respectively. No sorption of pyrene was observed in succinic acid-LiAl-LDH, suggesting that partitioning into the interlayer space was controlled by the width of the interlayer spacings. Infrared studies showed distortion of the acid chain packing upon incorporation of pyrene into hexanoic acid-LiAl-LDH. The conclusions of this study are that organic-exchanged LDH's exhibit novel sieving effects toward hydrophobic compounds based on interlayer spacings, and that the interlayer packing of the alkyl chains influences the extent of sorption. 33 refs., 7 figs., 1 tab.

Determination of Benzo(a)pyrene in Water by Synchronous Fluorimetry Following Preconcentration on Sephadex Gels

Abstract Benzo(a)pyrene (BaP) which presents native fluorescence in solution has been determined in waters by synchronous solid-phase spectrofluorimetry. The relative fluorescence intensity of BaP fixed in Sephadex G-25 gel is measured after being packed in an 1-mm silica cell. Spectral characteristics of BaP-gel system are described. The applicable concentration range was 0.52–3.45 μg.L−1 with a relative standard deviation of 1.2% and detection limit of 0.07 μg.L−1. The method was applied to the analysis of waters with different provenances.

Interaction of slightly cross‐linked gels of poly(diallyldimethylammonium bromide) with sodium dodecyl sulfate. Diffusion of surfactant ions in gel

AbstractThe dynamics of the changing microenvironment of the fluorescent probe pyrene in slightly cross‐linked networks of poly(diallyldimethylmmonium bromide) during diffusion of sodium dodecyl sulfate (SDS) in the gel phase has been investigated by fluorescence spectroscopy. Values of the spectral ratio I3/I1 for pyrene monomer included in SDS micelles in the swollen networks fall between the corresponding values for pyrene in water and for pyrene dissolved in SDS micelles in aqueous solution. In the narrow interval of the surfactant concentrations in the gel phase, the formation of pyrene excimers is observed. The values of the critical micelle concentration in the gel phase (ca. 5 × 10−4 to 8 × 10−4 mol/L) are tenfold lower than in aqueous solutions of the surfactant. The effective micellar diffusion coeffecient D in the gel phase increases with increasing swelling of the network. © 1993 John Wiley &amp; Sons, Inc.

006 Development of a time-resolved fluoroimmunoassay of benzo(a)pyrene in water

006 Development of a time-resolved fluoroimmunoassay of benzo(a)pyrene in water

Micropolarities of lipid bilayers and micelles. 5. Localization of pyrene in small unilamellar phosphatidylcholine vesicles.

The excimer/monomer ratio of emission intensities (IE/IM) and the enhancement of the 0-0 vibronic transition in the fluorescence spectra of pyrene (PY) and 16-(1-pyrenyl)hexadecanoic acid (C16PY) were used to investigate the localization of PY in the bilayers of small unilamellar vesicles constituted of phosphatidylcholine (SUV-PC). First, from comparison of the fluorescence characteristics of PY in water with those of PY incorporated into the SUV-PC membranes, we concluded that the probe is incorporated preferentially in the lipid phase of the vesicles and not in the bulk aqueous phase. In addition, we found that, contrary to what happens with the pyrenyl moiety of C16PY, the location of PY varies with its relative concentration in the membrane space. The critical concentration was observed to be around 1.0 mol% of incorporated PY. At concentrations below this value, PY is located in the hydrocarbon core of the lipid bilayers. Above 1.0 mol%, the PY molecules reside preferentially in the neighbourhood of the glyceryl moiety region of the PC vesicles.

Formation of 1-nitropyrene by photolysis of pyrene in water containing nitrite ion

The ether extract from the pyrene suspended in water containing nitrite ion, which was irradiated with a high-pressure mercury lamp, exhibited strong mutagenicity toward S. typhimurium TA98 in the absence of S9. The mutagenicity of the ether extract increased with increasing nitrite concentration and irradiation time and with lowering in pH of the solution. The major mutagen in the ether extract was isolated by means of silicagel column chromatography and identified to be 1-nitropyrene on the basis of the spectral data of MS and NMR. A pyrequinone as minor mutagen was also isolated and tentatively identified.

The toxicity of pyrene in the fish [formula omitted][formula omitted]: Synergism by piperonyl butoxide and by ultraviolet light

A saturated solution of pyrene in water was not toxic to the fish Pimepnales promelas , even in the presence of ultraviolet light. A survival curve possessing one minimum, and therefore defining two LC 50 values, was obtained when fish placed in water containing increasing amounts of a pyrene solution in dimethylsulfoxide were exposed to ultraviolet light after a short incubation period. The phototoxicity was linked to the presence of undissolved pyrene. A normal survival curve with only one LC 50 value was found when pyrene was solubilized with the surfactant Tween-20. Practically no phototoxicity was produced when the pyrene mixtures were filtered before use, or when a saturated aqueous solution of pyrene was used. Piperonyl butoxide, present at a concentration where it was not toxic, synergized the toxicity of pyrene in the dark . The environmental significance of this observation may be considerable.

Interaction of neutral arenes with poly(vinylbenzo-18-crown-6) and poly(vinylbenzoglyme) in aqueous media

Aromatic hydrocarbons, especially pyrene and benzo[ a]pyrene, are strongly solubilized in aqueous solutions containing the polysoap-type macromolecules poly(vinylbenzo-18-crown-6) (P18C6) or poly(vinylbenzoglyme)(PVBG), a polystyrene with two CH 3O(CH 2CH 2O) 2- substituents attached to each benzene ring. The binding of pyrene was also studied spectrophotometrically utilizing the 7-nm bathochromic shift of the 334-nm transition band of pyrene in water when it transfers to the polymer domain. Intrinsic binding constants, measured between 35 and 10°C, range from 2–6 × 10 5 M −1, with Δ H = −7.2 kcal/mole and Δ S = 1 e.u. A maximum of one pyrene molecule per about 10 monomer base units can be solubilized into the polymers. In the presence of 0.1 M CsCl the solubility of pyrene in the Cs +-charged P18C6 is increased by nearly a factor of 3, but the solubility in PVBG to which no Cs + ions bind remains unchanged.

A rapid routine method for quantitative determination of benzo( a)pyrene in water by low-temperature spectrofluorimetry

Some limitations of the analytical method for the determination of polynuclear aromatic hydrocarbons (PAH) in water have led the authors to study the quantitative application of low-temperature spectrofluorimetry as a rapid routine method for the screening of benzo( a)pyrene (B aP) in the aquatic environment. Experiments on the technique of recovery of B aP from distilled water samples utilizing liquid-liquid extraction have given good results; trials concerned with evaluation of any quenching effects on B aP by other PAH and with the applicability to real water samples (river, rain and drinking waters) have shown the promise of this method for screening analysis of environmental waters. The reproducibility of the method is adequate and the required time of total analysis is very short, especially for drinking water samples.