Preliminary experiments for the analysis of tetrahydrotetrols of benz[a]anthracene and benzo[a]pyrene derived from their hemoglobin adducts using a coupled-column high-performance liquid chromatographic system

Improved technologies for the detection of polycyclic aromatic hydrocarbon adducts are required for human biomonitoring. Therefore, a coupled-column high-performance liquid chromatographic method, with system-integrated sample processing, has been developed and its applicability for determination of tetrahydrotetrols of polycyclic aromatic hydrocarbons in acid hydrolysates of human hemoglobin has been investigated. A novel column-switching technique applying "thermotransfer' is used to separate tetrahydrotetrols of benzo[a]pyrene and benz[a]anthracene more efficiently. Derivatives of polycyclic aromatic hydrocarbons from blood hydrolysates are concentrated on a pre-column and then transferred to the analytical column by applying an electrical current to heat the solvent eluting the pre-column. This method allows for rapid and quantitative transfer of the analytes from the pre-column to the analytical column, after HPLC-integrated sample processing.

Evanescent fluorobiosensor for the detection of polyaromatic hydrocarbon based on DNA intercalation

A flow-injection analysis (FIA) system coupled with an evanescent wave (EW) biosensor employing total internal reflection of fluorescence radiation (TIRF) for the detection of polyaromatic hydrocarbon that intercalates into DNA is reported. A highly fluorescent intercalator, "ethidium bromide," has been used as the reference compound for detection. The EW biosensor was developed according to the procedure described earlier (1,2). Data on the analysis of Naphthalene, 3-methylcholanthrene, 7,12-dimethylbenz(a)anthracene, 1,2-benzanthracene, and some standard reference materials supplied by the National Institute of Standards and Technology are reported. The relative ability of the polyaromatic hydrocarbon to displace ethidium bromide, based on the relative binding ratio, is found to be on the order of 7,12-dimethylbenz[a]anthracene > 3-methylcholanthrene > 1,2-benzanthracene > napthalene.

Polycyclic aromatic hydrocarbons in placenta, maternal blood, umbilical cord blood and milk of Indian women

Human placenta, umbilical cord blood, maternal blood and breast milk samples from mothers were analysed for the presence of selected polycyclic aromatic hydrocarbons (PAHs). Benzo(a) pyrene (B(a)P), dibenzo(a,c)anthracene (DBA) and chrysene (Chy) were detected in all the four types of sample. Levels of dibenzo(a,c)anthracene were higher in the above samples compared with the other two PAHs. Umbilical cord blood and breast milk samples showed relatively high concentrations of all the three PAHs and thus demonstrated that the developing foetus/new born were exposed to these carcinogenic environmental contaminants. The possible implications of PAHs in relation to human health are discussed.

Improved high-performance liquid chromatographic method for the determination of polycyclic aromatic hydrocarbon metabolites in human urine

A reversed-phase HPLC method with fluorescence detection was evaluated for utility in determination of urinary metabolites of polycyclic aromatic hydrocarbons as biomarkers of environmental exposure. The method, which was developed for use in studies of high-level occupational exposure, was found to be unreliable for relatively low-level environmental exposures. The method was modified to include quantitation by standard addition in order to compensate for matrix effects at levels as low as 0.1 ng/ml. The standard addition modification increased both qualitative and quantitative performance, with recovery of 1-hydroxypyrene spikes improved from 164% to 114% at 0.36 ng/ml. The modified method was successfully applied in an environmental exposure study.

Analysis of polycyclic aromatic hydrocarbons in cooking oil fumes

Various samples of cooking oil fumes were analyzed to an effort to study the relationship between the high incidence of pulmonary adenocarcinoma in Chinese women and cooking oil fumes in the kitchen. Polycyclic aromatic hydrocarbons (PAHs) in samples of cooking oil fumes were extracted, chromatographed, and measured by fluorescence spectrophotometer. The samples included oil fumes from three commercial cooking oils and fumes from three catering shops. All samples contained benzo(a)pyrene (BaP) and dibenzo (a,h)anthracene (DBahA). In addition, the concentration of DBahA was 5.7 to 22.8 times higher than that of BaP in the fume samples. Concentrations of BaP and DBahA were, respectively, 0.463 and 5.736 micrograms/g in refined vegetable oil, 0.341 and 3.725 micrograms/g in soybean oil, and 0.305 and 4.565 micrograms/g in vegetable oil. Investigation of PAH concentrations at three catering shops showed that the level of BaP at a Youtiao (deep-fried twisted dough sticks) shop was 4.18 micrograms/100 m3, 2.28 micrograms/100 m3 at a Seqenma (candied fritters) workshop, and 0.49 micrograms/100 m3 at a kitchen of a restaurant; concentrations of DBahA were 33.80, 14.41, and 3.03 micrograms/100 m3, respectively. The high concentration of carcinogens, such as BaP and DBahA, in cooking oil fumes might help explain why Chinese women, who spend more time exposed to cooking oil fumes than men, have a high incidence of pulmonary adenocarcinoma.

Detection of multiple polycyclic aromatic hydrocarbon-DNA adducts by a high-performance liquid chromatography-32P-postlabeling method

A 32P-postlabeling procedure for identifying and quantifying hydrophobic DNA adducts was developed (by modifying the method of Randerath and co-workers) in which labeled adducts are separated by high-performance liquid chromatography (HPLC) and quantified by liquid scintillation counting. This method was first developed for fluoranthene-DNA adducts, and methods for optimal detection and quantification of DNA adducts with diol epoxide metabolites of benzo[a]pyrene (BPDE), chrysene (CHDE), and benz[a]anthracene (BADE) have now been established. Analytical conditions slightly different from those adopted for fluoranthene-DNA adducts are required for accurate quantification of BPDE-, CHDE-, and BADE-DNA adducts. In particular, HPLC analysis requires generation of nucleotide 5'-[32P]monophosphate adducts by treatment with nuclease P1, and polycyclic aromatic hydrocarbon adducts demonstrate variable sensitivity to nuclease P1, mediated dephosphorylation. Thus, multiple adducts can be detected in one sample as long as the recovery of adducts under the applied conditions has been determined and chromatographic separation of labeled adducts is achieved. A battery of postlabeling assays can thus make it possible to detect optimally multiple adducts in one DNA sample. Results from these studies indicate that the HPLC- 32P-postlabeling assay is complementary to immunoassays in which related polycyclic aromatic hydrocarbon diol epoxide adducts cross-react for the quantification of adducts.

Detection of PAH:DNA adducts from auto-oxidation using 32P-postlabeling

The binding of benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene, 3-methylcholanthrene, benz[a]anthracene, dibenz[a,c]anthracene and phenanthrene to calf thymus DNA in vitro in the absence of enzymatic or chemical activation was investigated using the 32P-postlabeling assay. Reactions were performed in the dark or under white light in 1 ml of Tris-HCl buffer (pH 7.5), containing 150 mM KCl, 250 micrograms of DNA and 0.12 nmol-600 nmol of hydrocarbon. Reactions were incubated for 1 h at 37 degrees C and the extent of hydrocarbon:DNA adduct formation was determined. With the exception of phenanthrene, all of the hydrocarbons investigated formed DNA adducts that were easily detected with the 32P-postlabeling assay. The multiplicity and level of hydrocarbon:DNA adducts varied for each hydrocarbon. A dose related increase in adduct formation was observed. Adduct levels ranged from 0.07 to 15.28 adducts per 10(7) nucleotides. Highest adduct levels were detected with 7,12-dimethylbenz[a]anthracene (DMBA) and benzo[a]-pyrene (B[a]P). Hydrocarbon: DNA adduct formation was enhanced when reactions were performed under white light. A comparison of the adduct levels formed from auto-oxidation and enzymatic activation suggests that 0.05 and 0.26% of the adducts detected in the enzymatic activation of B[a]P and DMBA, can be attributed to auto-oxidation, respectively. These data demonstrate that in the absence of enzymatic or chemical activation, polycyclic aromatic hydrocarbons can undergo auto-oxidation in vitro and form hydrocarbon:DNA adducts that are detectable with the 32P-postlabeling assay.

Selective determination of altertoxins by high-performance liquid chromatography with electrochemical detection with dual "in-series" electrodes

A selective method for the determination of altertoxin-I and altertoxin-II by high-performance liquid chromatography with electrochemical detection is described. Altertoxins were separated on a reversed-phase column with methanol-water containing 0.1 M sodium nitrate and 1 mM nitric acid (60:40) as eluent and detected with dual in-series electrodes operating in the "redox" mode (generator electrode +1.0 V, indicator electrode -0.1 V). The method was applied successfully to the determination of sub-ppm levels of altertoxins in samples of maize, rice and tomatoes infected by Alternaria alternata.

Natural occurrence of Alternaria mycotoxins in sorghum and ragi from North Bihar, India

The natural occurrence of major Alternaria mycotoxins i.e. alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT), altertoxin-1 (ATX-1) and tenuazonic acid (TA) has been investigated in sorghum (Sorghum vulgare Pers.) and ragi (Eleusine coracana Gaertn.) collected from North Bihar. Nine out of 20 sorghum samples, and three out of eight ragi samples, were found to be contaminated with one to three Alternaria mycotoxins. The toxin elaborating potential of Alternaria alternata (Fr.) Keissler strains isolated from sorghum and ragi have also been investigated. Out of 16 isolates of A. alternata (Fr.) Keissler, mycotoxins were detected in only 10.

Derivatization of benz[a]anthracene metabolites for detection by laser excited Shpol'skii spectrometry

The polar metabolites of polycyclic aromatic compounds (PACs) are of significant oncological interest. In contrast to parent PACs, isomer selective detection of polar PACs by laser excited Shpol'skii spectrometry (LESS) is severely limited by excessively broadened spectra and rapid photodegradation in n-alkane solvents. To minimize these limitations a 10-min derivatization procedure was developed to produce corresponding methoxy compounds, that exhibit the Shpol'skii effect. By use of the extraction and permethylation procedure, the selective detection of a mixture of hydroxy-benz[a]anthracene isomers spiked at the low picogram level into urine and blood matrices was achieved. A detection limit for 1-hydroxybenz[a]anthracene was 0.6 part per trillion, or 12 fg (0.05 fmol) on a 20-microL sample.

Electronic spectra of hypocrellin A, B and their derivatives

In this paper, the electronic spectra of hypocrellin A and B (HA and HB) are studied in detail. It has been proved that their three visible absorption bands come respectively from the pi pi transition of their conjugated systems and intramolecular proton transfer. In dilute solutions, their fluorescence spectra consist of the fluorescence peak of the neutral monomolecule and that of the zwitter-ions that are formed through proton transfer of excited states. In concentrated solution, the longer wavelength emission band is composed of the overlapped fluorescence peaks of zwitter-ions and excimers. The fluorescence spectra of the crystalline hypocrellin A and B consist of the fluorescence peaks of zwitter-ions and excimers and the fluorescence of neutral monomolecules could could not be observed. Their relative intensities are closely related to the excitation wave-length.

[Polar neutral organic compounds (POCN) in city aerosols. 3. Comparative studies of emission and immission particles in West Berlin]

After the concentration of the polar organic compounds (= POCN), especially from the neutral fraction, was investigated in urban suspended particulates over a longtime period in Berlin (West) (March 1983-January 1984 at three emission measurement stations loaded by different sources) and some emissions were taken during 1985 from vehicle diesel-engines and private coal firing (domestic fuel) a comparison between all these measurements are given now. The following results were gained: The amount of the ether-extractable organic matter (= EEOM) was higher for the emission samples (less than or equal to 80% of the total suspended particulate matter = TPM) than for the emission measurements (less than or equal to 40% of the TPM). Most of the EEOM was found for particle sizes less than or equal to 1.5-2 micron aerodynamic diameter. Making further separation of the EEOM, then the neutral fraction (= NF) showed the highest percentage of about 60-90% (of the EEOM) for emission measurements and of 60-80% for emission measurements. The values of the acidic fraction (= AF) were with 5-30% (emissions) and 10-25% (emissions). Quite the same results were found for the basic fraction (= BF) with 1-20% (emissions) and 5-20% (emissions). Of the neutral fraction, further separation was done into aliphatic compounds (= AIP), polycyclic aromatic hydrocarbons (= PAH) and polar neutral organic compounds (= POCN). From these compounds, the aliphatics amounted to 30-40% (of the NF) for the vehicle emission measurements and to only 10-20% for the coal firing emissions. The percentages of the PAH and POCN varied and were quite similar with 10-50% (PAH) and 25-50% (POCN). For the emission measurements, the PAH amounted to lower values (5-30%) and the POCN to (30-60%). Some differences between the measurements were found in the gas chromatographic analysis of single PAH and POCN compounds. Then, for the vehicle samples (diesel engines and highway traffic tunnel) higher concentrations were found for perylene and coronene (of the PAH) and for mainly 1-nitropyrene (of the POCN) in comparison with coal firing emissions. There, we found higher concentrations for phenanthrene, benzo(a)pyrene and dibenz(a,h) anthracene (of the PAH) and for 9-fluorenone (of the POCN). The concentration of the nitro-groups containing substances (included in the POCN-fraction) amounted here generally to higher values in comparison with the vehicle emissions (except of 1-nitropyrene).(ABSTRACT TRUNCATED AT 400 WORDS)

Elution order-absolute configuration relationship of K-region dihydrodiol enantiomers of benz[a]anthracene derivatives in chiral stationary phase high-performance liquid chromatography

The direct resolution of K-region cis- and trans-dihydrodiol enantiomers of 14 unsubstituted and methyl- and bromo-substituted benz[a]anthracene (BA) derivatives was investigated by high-performance liquid chromatography with commercially available columns, packed with gamma-aminopropylsilanized silica to which either (R)-N-(3,5-dinitrobenzoyl)phenylglycine (R-DNBPG) or (S)-N-(3,5-dinitrobenzoyl)leucine (S-DNBL) is either ionically or covalently bonded. BA derivatives used in this study include: BA, 1-methyl-BA, 4-methyl-BA, 7-methyl-BA, 8-methyl-BA, 10-methyl-BA, 11-methyl-BA, 12-methyl-BA, 7,12-dimethyl-BA, 7-bromo-BA, 7-bromo-1-methyl-BA, 7-bromo-11-methyl-BA, 7-bromo-12-methyl-BA, and 3-methylcholanthrene. The enantiomers of BA trans-5,6-dihydrodiol were the only compounds not resolved by any of the four chiral stationary phases (CSPs) tested. The results indicate that conformational preference of the hydroxyl group is one of the most important factor in determining the elution order of dihydrodiol enantiomers. The presence and the location of a substituent and the molecular size and shape of the dihydrodiols can significantly affect the efficiency of enantiomeric resolution. In general, the ionically bonded R-DNBPG provides the best resolution of enantiomeric quasidiequatorial trans-dihydrodiols and the R,R enantiomers are consistently more strongly retained. In contrast, the enantiomeric pairs of quasidiaxial trans-dihydrodiols are generally better resolved by the covalently bonded R-DNBPG, and the S,S enantiomers are more strongly retained. The enantiomers of cis-dihydrodiols having hydroxyl groups that adopt quasiequatorial-quasiaxial and/or quasiaxial-quasiequatorial conformations are more consistently resolved by the ionically bonded S-DNBL and in all cases the S,R enantiomers are more strongly retained. Thus, it is possible to choose a CSP which resolves the K-region dihydrodiol enantiomers with a predictable elution order.

Mutagenicity of the Alternaria metabolites altertoxins I, II, and III

The Ames Salmonella typhimurium assay was used to demonstrate that an extract of the mold Alternaria alternata was mutagenic. The mutagenic extract was fractionated, and the Ames test was used to determine which fractions were mutagenic. Subsequently, altertoxins I and II and a new compound referred to as altertoxin III were isolated by liquid chromatography and shown to be hydroxyperylenequinone compounds by mass spectrometry and infrared, ultraviolet, and proton magnetic resonance spectroscopy. Altertoxins I, II, and III were mutagenic to S. typhimurium TA98, TA100, and TA1537 with and without metabolic activation.

A sensitive method to monitor trace quantities of benzanthrone in workers of dyestuff industries

Dyestuff workers coming in contact with benzanthrone (an intermediate used for the synthesis of a variety of dyes) develop skin lesions, gastritis, liver malfunctions, and sexual disturbances. A highly sensitive fluorometric method to monitor trace quantities of benzanthrone in urine, serum, and biological tissues for experimental studies, has been developed. Coupled with simple extraction and resolution, optimum fluorescence is obtained in an equal mixture of chloroform:methanol, detecting as low as 2 ng benzanthrone. This method is approximately 250 times more sensitive than currently available colorimetric assay.

The presence of the mutagenic polycyclic aromatic hydrocarbons benzo[a]pyrene and benz[a]anthracene in creosote P1

Several fractions of creosote P1 separated by TLC showed mutagenicity towards Salmonella typhimurium TA98. Thus mutagenicity is probably caused by the presence of mutagenic aromatic hydrocarbons. The mutagenic polycyclic aromatic hydrocarbons, benzo[a]pyrene and benz[a]anthracene, were detected in concentrations of 0.18 and 1.1% respectively. Because these compounds are probably not essential for the wood-preserving properties of creosote , a more selective composition of the product should be considered.

Direct enantiomeric resolution of cyclic alcohol derivatives of polycyclic aromatic hydrocarbons by chiral stationary phase high-performance liquid chromatography

The enantiomers of some cyclic alcohol derivatives of phenanthrene, benz[a]anthracene, benzo[a]pyrene, cholanthrene, and 3-methylcholanthrene were resolved by high-performance liquid chromatography using a commercially available preparative column packed with an (R)-N-(3,5-dinitrobenzoyl)phenylglycine ionically bonded to gamma-aminopropylsilanized silica. Resolution of enantiomers was confirmed by ultraviolet-visible absorption, mass and circular dichroism spectral analyses. This method has been applied to the determination of optical purity of 1-hydroxycholanthrene and 1-hydroxy-3-methylcholanthrene formed in the metabolism of cholanthrene and 3-methylcholanthrene, respectively, by rat liver microsomes.