Relationships of structures of nitro-polycyclic aromatic hydrocarbons with high-performance liquid chromatography retention order

IR and Raman spectra of nitroanthracene isomers: substitional effects based on density functional theory study

Structure, IR and Raman spectra of 1-, 2- and 9-nitroanthracene isomers (1-NA, 2-NA and 9-NA) were calculated and analyzed through density functional theory computations using the B3LYP functional with the 6-311+G** basis set. Steric and π-conjugative effects determine the characteristic ONCC dihedral angles, which vary from 0° (2-NA) to 28-29° (1-NA) and 59° (9-NA), influencing the relative order of stability along the series 9-NA<1-NA<2-NA. The spectral regions at wavenumber values>3000 cm(-1) and <1000 cm(-1) little depend on the substituent position. The Raman and IR intensity values of the characteristic symmetric nitro group stretching transition, appearing between 1310 and 1345 cm(-1), are rather sensitive to the position of the substituent, decreasing regularly on passing from the planar to the NO2-rotated isomers (9-NA<1-NA<2-NA). In the medium-energy spectral region (1000-1700 cm(-1)), the number and the relative position of the strongest Raman bands are of potential utility to discriminate the NA isomers. Structural and spectroscopic results suggest that the unknown mutagenic activity of 1-NA is expected to be between that of 9-NA and 2-NA.

Chromatographic methods for carcinogenic/mutagenic nitropolycyclic aromatic hydrocarbons

Nitropolycyclic aromatic hydrocarbons (NPAHs), which are known to be carcinogenic and/or mutagenic, are considered to be one of the air pollutants that cause lung cancer. In the last two decades, a number of sensitive and selective methods have been developed for the determination of NPAHs and related compounds in environmental and biological samples. This paper describes the state of the art of the methods and applications.

Determination of 1-nitropyrene in herbs after selective enrichment by a sol-gel-generated immunoaffinity column

Using the determination of 1-nitropyrene as an example the paper demonstrates the advantages of including a highly selective sol-gel-generated immunoaffinity column in the sequence of clean-up steps necessary to determine haptens in complex matrices. The sol-gel method to immobilise antibodies enlarges the variety of immunoaffinity columns available and leads to mechanically stable columns with constant retention characteristics. The sample preparation scheme proposed combines acetonitrile extraction, size-exclusion and immunoaffinity chromatography. 1-Nitropyrene is then separated by reversed-phase HPLC from interfering compounds and determined after catalytic on-line reduction to the corresponding amine by spectrofluorimetry. Concentrations in the range from 0.1 to 1.4 microg/kg 1-nitropyrene were detected in herbs.

Analysis of nitro-PAHs in food matrices by on-line reduction and high performance liquid chromatography

Two different approaches to the analysis of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) in food samples are presented, based on liquid chromatography with fluorescence detection and gas chromatography with a mass selective detector as the alternative method. For the HPLC analysis the nitro-PAHs at trace level concentrations are efficiently reduced to primary aromatic amines on a catalyst column packed with 5 microns alumina coated with platinum and rhodium. The particulate extraction/fractionation procedure is discussed and the results of both methods are compared. The concentrations of seven nitro-PAHs in grilled and smoked food are presented.

Monitoring of nitropolycyclic aromatic hydrocarbons in food using gas chromatography

Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) were determined in different kinds of food. The investigation of food matrices necessitates the development of appropriate analytical procedures for sensitive monitoring and determination of these compounds. The analysis of the nitro-PAHs was carried out by GC/MSD, GC plus mass spectrometry, and GC/NPD (nitrogen-phosphorus detection) GC plus nitrogen-phosphorus detection. Seven nitro-PAHs were positively identified and quantified in vegetables, smoked and grilled foods, oil, tea, coffee and spices.