POLYCYCLIC AROMATIC HYDROCARBONS (PAH) IN DANISH SMOKED FISH AND MEAT PRODUCTS

Twenty seven PAH were detected in 45 selected smoked food samples produced in Denmark, including mackerel, herring, trout, small sausages, salami, and bacon. The sum of PAH in smoked meat products ranged from 24 μg/kg for salami to 64 μg/kg in bacon, while those in fish products ranged from 22 μg/kg in smoked mackerel prepared in an electric oven to 1387 μg/kg in herring smoked by direct smoking. The concentration of benzo[a]pyrene for all sample types were below the maximum level of 5 μg/kg for smoked fish and meat set by the European Commission. Results from this survey confirm that the actual level of individual PAH in fish products is dependent on variables such as the type of wood used in the smoking process. Furthermore, the use of the benzo[a]pyrene approach for estimation of the carcinogenicity of PAH in food is confirmed. The Danish intake of benzo[a]pyrene from these smoked products is 2 to 4 ng/person/day.     

DETECTION OF POLYCYCLIC AROMATIC COMPOUNDS IN SINGLE LIVING CELLS USING OPTICAL NANOPROBES

Exposure of mammalian cells to polycyclic aromatic compounds (PACs) such as the carcinogen benzo[a]pyrene (BaP) leads to the formation of DNA adducts N²-deoxyguanosine (dG) and N⁶-deoxyadenosine (dA) with adenine and guanine nucleotides, which are integral parts of DNA, RNA, and ATP. DNA adduct formation causes alteration of the DNA (RNA) sequence since neither adenine nor guanine can normally bind to its complementary nucleotide base, thymine (uracil) and cytosine respectively. The inability to form these bonds leads to mutations in the DNA double-helix structure during DNA replication, and eventually carcinogenesis. Therefore, the capability to detect and measure PAC species such as BaP in single living cells is important for studies required to establish the limits of BaP exposure necessary for carcinogenesis. Along these lines, we have developed antibody-based optical nanoprobes capable of detecting and measuring BaP in single living cells. The results obtained in this work demonstrate the practical application of antibody-based nanoprobes for performing measurements inside single living cells with their elements and their relationships intact.     

AN ISOTOPE DILUTION HIGH-RESOLUTION MASS SPECTROMETRY METHOD FOR QUANTITATIVE MEASUREMENT OF ISOMERIC BENZO[A]PYRENE TETROL METABOLITES DERIVED FROM ALBUMIN-BAPDE ADDUCTS AS INDICATORS OF HUMAN EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS

We evaluated in a pilot study a newly developed method of gas chromatography isotope dilution high-resolution mass spectrometry selected ion monitoring (GC-ID-HRMS-SIM). This method measures benzo[a]pyrene (B[a]P) tetrol metabolites released after albumin-BaPDE adduct hydrolysis. We isolated albumin adducts from the blood of a cohort of adult male and female smokers and nonsmokers randomly selected as exposed and nonexposed groups. Isomeric B[a]P tetrols released after adduct hydrolysis and silyl derivatization were quantified by GC-ID-HRMS-SIM using ¹³ C ₆ -isotopically labeled BaP tetrol isomer standards (+/?)-BaP-r-7,t-8,t-9,c-10-tetrol (BPTI-1), (+/?)-BaP-r-7,t-8,t-9,t-10-tetrol (BPTI-2), (+/?)-BaP-r-7,t-8,c-9,t-10-tetrol (BPTII-1) and (+/?)-BaP-r-7,t-8,c-9,c-10-tetrol (BPTII-2). In all donor samples analyzed the method was sensitive enough to detect BPTII-1 and BPTI-1 in the low fmol range. In both smokers and nonsmokers BPTI-1 levels were higher than BPTII-1 levels. The mean levels of BPTII-1 and BPTI-1 in smokers were 0.16 ± 0.04 fmol/mg albumin (ranging from 0.09 to 0.28 fmol/mg albumin) and 0.40 ± 0.06 fmol/mg albumin (ranging from 0.25 to 0.75 fmol/mg albumin), respectively. The mean levels of BPTII-1 and BPTI-1 in nonsmokers were 0.22 ± 0.07 fmol/mg albumin (ranging from 0.09 to 0.41 fmol/mg albumin) and 0.47 ± 0.06 fmol/mg albumin (ranging from 0.30 to 0.75 fmol/mg albumin), respectively. The results from this study are the first reported quantitative levels of specific benzo[a]pyrene tetrol isomers detected by isotope dilution high-resolution mass spectrometry measurements of BaPDE-albumin adducts using ¹³ C ₆ -isotopically labeled BaP tetrol isomer standards.     

EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS AND EXCRETION OF URINARY 3-HYDROXYBENZO[A]PYRENE: ASSESSMENT OF AN APPROPRIATE SAMPLING TIME

Biomonitoring of workers was carried out in seven workplaces—two aluminium plants, an electrometallurgy plant, two carbon brake disk factories, a creosoting workshop, and an artificial target factory—to assess exposure to polycyclic aromatic hydrocarbons (PAHs). At least all the 48 h voided urine samples were collected, the first urine before the preshift at the beginning of the week and the last one after the preshift of the third day. The 3-hydroxybenzo[a]pyrene (3-OHBaP) and 1-hydroxypyrene (1-OHPy) in each urine sample were then analyzed separately by methods developed by INRS. Concentration profiles were determined. They indicate a considerable lag between the maximum excretion of the two metabolites. Including the previously published data obtained with workers exposed to PAHs, this varies from 3 to 24 h (mean lag = 15 h, n = 42). In order to determine the most appropriate sampling time for 3-OHBaP, the time of the 3-OHBaP maximum concentration is compared with the preshift.     

CERTIFIED CALIBRATION SOLUTION REFERENCE MATERIAL FOR THE DETERMINATION OF BENZO[A]PYRENE FROM THE NATIONAL METROLOGY INSTITUTE OF JAPAN (NMIJ)

A new calibration solution reference material (NMIJ CRM 4213-a) for benzo[a]pyrene (BaP) analysis was prepared and certified by the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). Certification of CRM 4213-a was carried out at NMIJ using a freezing point depression method and gravimetric preparation. Certified concentration of this CRM was obtained by multiplying the dilution ratio of raw material BaP in a prepared solution with purity of the raw material. Purity of our raw material was calibrated by a gas chromatograph with flame ionization detection using that of high-purity BaP purified by using a high performance liquid chromatograph with a normal phase column, because purity determination of the raw material by a differential scanning calorimeter (DSC) couldn't be assessed directly. The purity of high-purity BaP was assessed in the molar fraction by DSC, and then the purity of the mass fraction was calculated based on average molecular weight of impurities and the purity of the molar fraction. CRM 4213-a has been developed with a certified value of 99.2 mg/kg. Uncertainty was evaluated from purity assessment as well as homogeneity and stability of the CRM, and expanded uncertainty was estimated as 3.9 mg/kg with coverage factor k = 2, corresponding to an estimated confidence interval of approximately 95%.     

URINARY 3-HYDROXYBENZO[A]PYRENE AS A BIOMARKER OF EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS: AN APPROACH FOR DETERMINING A BIOLOGICAL LIMIT VALUE

Atmospheric and biological monitoring was carried out on 38 people exposed to polycyclic aromatic hydrocarbons in different workplaces. The relationship between the atmospheric BaP and the 3-OHBaP urinary concentration peaks was determined. To avoid misinterpretation due to dermal exposure, only people with mainly respiratory exposure were chosen. The selection was carried out from observation of working conditions and from urinary data. For the limit value determination, BaP concentrations higher than 5,000 ng/m³ were discarded and the 3-OHBaP values were adjusted to a 8 h exposure time. A close relationship was observed between the two variables: n = 17, r = 0.89, p < .0001 (C 3-OHBaP = 0.001835*C BaP + 0.1729). To estimate the 3-OHBaP limit concentration, the French recommended value of 150 ng/m³ for atmospheric BaP was used. The corresponding 3-OHBaP was 0.45 nmol/mol creatinine. This value could be used as a sound basic element for determining a biological exposure index.     

用LC/APCI/MS方法检测粉尘中的炸药成分

采用高选择性和灵敏度的LC(液相色谱)/APCI(大气压化学电离源)/MS(质谱)方法定量分析粉尘样品中的HMX、RDX、PETN、CE、NQ和TNT。采用ASE萃取,GPC净化浓缩作为前处理方法,在粉尘中分别添加所测炸药组分,用丙酮作为ASE萃取溶剂,乙酸乙酯和环己烷(体积比为1∶1)作为GPC净化时的流动相并抛弃杂质500s,收集1 520s。在LC/MS分析时,通过在流动相中添加1mmol/L甲酸与样品形成[M+HCOO]-的甲酸加合离子。结果表明,HMX、RDX、PETN、CE、NQ、TNT的方法检测限分别为0.78,1.44,1.69,0.77,1.06,1.72ng/mL,回收率为49.0%～88.4%,相对标准偏差为3.5%～10.3%。该方法可以用来系统排查及定量分析爆炸残留物及环境样品中的NQ、RDX、PETN、CE、HMX、TNT成分。     

IDENTIFICATION OF THE C30H16 POLYCYCLIC AROMATIC HYDROCARBON BENZO[cd]NAPHTHO[1,2,3-lm]PERYLENE AS A PRODUCT OF THE SUPERCRITICAL PYROLYSIS OF A SYNTHETIC JET FUEL

Using high-pressure liquid chromatography (HPLC) with ultraviolet-visible (UV) diode-array and mass spectrometric detection, we have analyzed the products of a Fischer-Tropsch synthetic jet fuel pyrolyzed, under supercritical conditions, at 710°C and 42 atm. An eight-ring polycyclic aromatic hydrocarbon, benzo[cd]naphtho[1,2,3-lm]perylene, has been unequivocally identified among the product components by its characteristic ultraviolet-visible absorbance spectrum. First, the unknown product component's HPLC elution behavior and UV absorbance characteristics indicated that it was a planar benzologue of dibenzo[cd,lm]perylene, having a high length-to-breadth ratio. Next, the mass spectrum established the isomer family of the unknown compound as C₃₀H₁₆. The UV absorption spectrum was then progressively analyzed with different solvents to achieve the final identification of benzo[cd]naphtho[1,2,3-lm]perylene. Benzo[cd]naphtho[1,2,3-lm]perylene has never before been reported as a product in any combustion or pyrolysis study.     

Evolutionary computing approach for evaluating flory distribution curves in gel permeation chromatography: Study of the poly(1‐octene) system

We carried out deconvolution of the molecular weight distribution curves from gel permeation chromatography for polyolefins into individual active sites considering Flory distribution by an evolutionary‐computing‐based real‐coded genetic algorithm, a nonlinear multivariate optimization algorithm. We applied the deconvolution to homopolymers of 1‐octene synthesized using heterogeneous Ziegler–Natta catalysts with different amounts of hydrogen. The molecular weight distribution was deconvoluted in to five Flory distributions, which showed a sensitivity to hydrogen amounts. With no hydrogen presence, the peaks corresponding to high‐molecular‐weight fractions were intense. As the amount of hydrogen was increased, not only did the intensities of the high‐molecular‐weight peaks decrease, but also peaks corresponding to low‐molecular‐weight fractions were observed. The method allowed us to determine the active site distribution of the polymer molecular weight distribution obtained from gel permeation chromatography. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

DEVELOPMENT OF AN ISOTOPE-DILUTION GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC METHOD FOR THE ANALYSIS OF POLYCYCLIC AROMATIC COMPOUNDS IN ENVIRONMENTAL MATRICES

An isotope-dilution GC-MS (GC-IDMS) method for the analysis of polycyclic aromatic hydrocarbons (PAHs) in various environmental matrices, including soils, sediments and an extended application to air particulate, has been developed. This method allows for the quantification of each target analyte against its isotope-labelled analogue as well as for the correction of analyte recovery during sample preparation and analysis. Using isotope-dilution mass spectrometric analysis, the isotope-labelled internal standards can significantly reduce systematic error (bias) from several sources including sample stability prior to analysis, analyte loss during both the extraction procedure and post-extraction sample workup and from the calibration procedure. Sample analysis and quantification was carried out using a multi-point calibration technique with continuing single-point calibration (daily single-point checks of the calibration) in order to assess daily instrumental performance; various other new quality control measures have also been employed. Faster methods of gas chromatographic analysis were evaluated using different types of GC columns, stationary phases and methods of detection. Overall, this method has improved the quality and accuracy of PAH data produced and has significantly reduced the time required for sample preparation.     

Synthesis and characterization of biodegradable block copolymers of poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol)

The synthesis of two low molecular weight linear unsaturated oligoester precursors, poly(propylene fumarate‐co‐sebacate) (PPFS) and poly(ethylene fumarate‐co‐sebacate) (PEFS), are described. PPFS, PEFS, and poly(ethylene glycol) are then used to prepare poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PPFS‐co‐PEG) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PEFS‐co‐PEG) block copolymers. The products thus obtained are investigated in terms of the molecular weight, composition, structure, thermal properties, and solubility behavior. A number of design parameters including the molecular weights of PPFS, PEFS, and PEG, the reaction time in the polymer synthesis, and the weight ratio of PEG to PPFS or to PEFS are varied to assess their effects on the product yield and properties. The hydrolytic degradation of PPFS‐co‐PEG and PEFS‐co‐PEG in an isotonic buffer (pH 7.4, 37°C) is investigated, and it is found that the fumarate ester bond cleaves faster than does the sebacate ester bond. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 295–300, 2004     

Ultrasonic degradation of poly(acrylic acid)

The ultrasonic degradation of poly(acrylic acid), a water‐soluble polymer, was studied in the presence of persulfates at different temperatures in binary solvent mixtures of methanol and water. The degraded samples were analyzed by gel permeation chromatography for the time evolution of the molecular weight distributions. A continuous distribution kinetics model based on midpoint chain scission was developed, and the degradation rate coefficients were determined. The decline in the rate of degradation of poly(acrylic acid) with increasing temperature and with an increment in the methanol content in the binary solvent mixture of methanol and water was attributed to the increased vapor pressure of the solutions. The experimental data showed an augmentation of the degradation rate of the polymer with increasing oxidizing agent (persulfate) concentrations. Different concentrations of three persulfates—potassium persulfate, ammonium persulfate, and sodium persulfate—were used. It was found that the ratio of the polymer degradation rate coefficient to the dissociation rate constant of the persulfate was constant. This implies that the ultrasonic degradation rate of poly(acrylic acid) can be determined a priori in the presence of any initiator. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of the medium on the stereostructure of poly(methyl methacrylate) synthesized in ionic liquids

Poly(methyl methacrylate) (PMMA) was synthesized in different ionic liquids (IL) by free radical polymerization. The average molecular weight and polydispersity of the PMMA were measured by gel permeation chromatography. It is found that ILs have effect not only on the molecular weights but also on the stereostructure of PMMA. From the FTIR and NMR analysis, it was confirmed that the chemical structure of PMMA synthesized in ILs was similar to the one obtained in conventional solvents while the stereostructure was influenced by the different IL used. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2199–2202, 2006     

LEAVES OF NERIUM OLEANDER L. AS BIOACCUMULATORS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) IN THE AIR OF PALERMO (ITALY): EXTRACTION AND GC-MS ANALYSIS,DISTRIBUTION AND SOURCES

Polycyclic Aromatic Hydrocarbons (PAH) were determined in the leaves of Nerium oleander L. an evergreen plant that occurs widely in both urban and rural areas, to monitor the degree of pollution in the urban area of Palermo (Italy) compared to remote areas. Twenty sites (urban roadside, urban, urban park, suburban and rural) in and around Palermo city were investigated.

The purpose of this research was to investigate concentration levels and distribution patterns and relate them to possible sources. Analysis of 19 PAH was performed by gas chromatography/mass spectrometry (GCMS) using selected ion monitoring (SIM). The total amount of PAH ranged from 10 to 166 μg/Kg d.w.

Each source gives rise to a characteristic PAH pattern, and it is therefore possible to get access to the processes that generate the compounds. To this aim, the recommended as priority pollutants by the Environmental Protection Agency (EPA), perylene and three additional alkylated compounds were analyzed.

Positive correlations were found between total PAH content of the leaves with CO, benzene and particulate levels measured in air of Palermo.     

Measurement of the unperturbed dimensions of stereoregular poly(methyl methacrylate)

The results of measurements of unperturbed dimensions for a series of stereoregular poly(methyl methacrylates) are reported. The measurements were made by a recently developed method involving a gel permeation chromatograph coupled with an on-line low angle laser light scattering photometer. Measurements were performed in a thermodynamically good solvent, tetrahydrofuran at 25°C. The unperturbed dimensions were obtained by means of viscosity plots. Comparison of the results obtained by this method with those currently available in the literature, as well as with values predicted by statistical calculations, show good agreement. It was determined that a measurable difference occurs in the Mark-Houwink relationship between isotactic and syndiotactic poly(methyl methacrylate); isotactic poly(methyl methacrylate) is 30% more extended than syndiotactic poly(methyl methacrylate) in its unperturbed state; and isotactic poly(methyl methacrylate) exhibits a smaller degree of polymer solvent interaction than the syndiotactic form.     

Effect of Caloric Restriction on the Metabolism of Benzo[a]pyrene (BaP) and the Formation of BaP-DNA Adducts in Male Fischer 344 Rats

Abstract

The effect of caloric restriction (CR) on activities of xenobiotic metabolizing enzymes results in alterations in the metabolic activation of chemical carcinogens, with a resultant impact on DNA-carcinogen adduct formation. Using benzo[a]pyrene (BaP) as a model carcinogen, we have studied the effect of CR on the metabolic activation of BaP, in terms of both BaP metabolism and BaP-DNA adduct formation. Male Fischer 344 rats fed CR diets (60% of the food consumption of ad libitum?fed rats) showed higher activities of BaP metabolizing enzymes resulting in increases of BaP metabolism in vitro and BaP-DNA adduct formation in vivo. The results of the study of the effect of CR on the in vitro metabolism of BaP showed that CR increased the total BaP metabolism, as well as BaP-t-9, 10-diol and BaP-t-4, 5-diol formation. However, BaP-t-7, 8-diol, a proximate carcinogenic metabolite of BaP, was decreased by liver microsomes from CR-rats. Our results indicate that the effect of CR on metabolic activation of a chemical carcinogen was dependent upon the selected xenobiotic metabolizing enzymes whose activity may be significantly altered by CR.     

Synthesis of poly(vinyl acetate) by degenerative transfer polymerization in the presence of iodine

A new curing agent containing maleimide and biphenyl moieties (MIBP) was synthesized by the condensation polymerization of 4,4′-bismethoxymethylbiphenyl and N-(4-hydroxyphenyl)maleimide (HPM). The chemical structure was characterized with Fourier transform infrared (FTIR) spectroscopy, and the molecular weight of the new curing agent was determined by gel permeation chromatography. Curing reactions of O-cresol formaldehyde epoxy (CNE) resin with MIBP were investigated under nonisothermal differential scanning calorimetry, and the exotherm exhibited two overlapping exothermic peaks during the curing process; this was demonstrated by FTIR traces. The Flynn–Wall–Ozawa and Friedman methods were used to examine the kinetic parameters and the kinetic models of the curing processes of the CNE/MIBP mixtures. Both reactions turned out to be nth-order curing mechanisms. Values of the reaction order (n) = 1.42 and activation energy (E_a) = 91.2 kJ/mol were obtained for the first reaction of the curing of the CNE/MIBP system, and values of n = 1.11 and E_a = 78.7 kJ/mol were obtained for the second reaction. The thermal properties of the cured resin were measured with thermogravimetric analysis, and the results show a high glass-transition temperature (T_g = 155°C), good thermal stability (temperature at 10% weight loss, under nitrogen and in air, ≈ 400 and 408°C, respectively), and high char yield (temperature = 800°C, char residue = 44.5% under nitrogen). These excellent thermal properties were due to the introduction of the maleimide and biphenyl groups of MIBP into the polymer structure. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of aluminum chloride and Pt/ TiO2 on the thermal degradation of poly(vinyl chloride) in solution

The effect of two catalysts, Pt/TiO₂ and aluminum chloride, on the degradation of poly (vinyl chloride) (PVC) in solution was investigated at various temperatures. The molecular weight distribution of the polymer was obtained by analyzing the samples by gel permeation chromatography. Experimental data indicated that the catalysts enhanced the degradation rate of PVC compared to the thermal degradation of PVC. Continuous distribution kinetic models were used to evaluate the degradation rate coefficients. The activation energy, calculated from the temperature dependence of rate coefficients, was 26.5, 31.5, and 43.7 kcal/mol for the thermal degradation of PVC in solution, in the presence of Pt/TiO₂ and in the presence of AlCl₃, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3532–3535, 2003     

Effect of the chain‐transfer‐agent content on the emulsion polymerization process and adhesive properties of poly(n‐butyl acrylate‐co‐acrylic acid) latexes

The effect of water on regenerated silkworm silk fibers has been studied and compared with that of water on natural silkworm silk fibers. Regenerated fibers are spun from an N‐methylmorpholine‐N‐oxide (NMMO) fibroin solution through a wet‐spinning process, leading to fibers with two distinct tensile behaviors, labeled as brittle and ductile, respectively. Regenerated fibers show a significant contraction when immersed in water. Contraction increases further after drying. In contrast, natural silkworm silk fibers show a negligible contraction when submerged in water. Regenerated fibers tested in water are considerably more compliant than samples tested in air, though their stiffness and tensile strength are significantly reduced. It has been shown that the tensile properties of brittle regenerated fibers can be modified by a wet‐stretching process, which consists of deforming the fiber while immersed in water. Regenerated wet‐stretched fibers always show a ductile behavior independent from their initial tensile behavior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008