Shpol'skii spectroscopy as a tool in environmental analysis for amino- and nitro-substituted polycyclic aromatic hydrocarbons: A critical evaluation.

Aiming at the development of an alternative isomer-specific spectral method favourable for identification of mutagenic amino- and nitro-substituted polycyclic aromatic hydrocarbons (PAHs) in environmental samples, the possibility to utilize Shpol'skii spectroscopy, a high-resolution cryogenic molecular luminescence technique, is critically investigated. New data representing specific, vibrationally resolved cryogenic fluorescence and phosphorescence spectra of a number of individual amino-substituted naphthalenes, anthracenes and fluorenes are presented in addition to spectra of four- and five-membered ring amino-PAHs reported earlier. Room temperature fluorescence, photostability of the amino-PAHs and the influence of the cooling rate on spectral quality are considered. For determination of the nitro-PAHs, an off-line chemical reduction with zinc powder was optimized to convert these non-fluorescent compounds to the corresponding aromatic amines. Furthermore, the Shpol'skii technique was successfully applied to a mixture of certified standard reference materials (SRM 1587 and SRM 1647), containing a range of parent and nitro-PAHs. Finally, in combination with normal-phase liquid chromatographic separation, the methods developed enabled the determination of 1-nitropyrene in a diesel particulate SRM 1650

Near-infrared laser-induced fluorescence detection in column liquid chromatography. A comparison of various lasers and detection systems. 1. Continuous wave lasers.

Several lasers, i.e. HeNe lasers, diode lasers and an argon-ion-dye laser combination, are compared as excitation sources for near-infrared laser-induced fluorescence detection in column liquid chromatography. Using a model gradient liquid chromatography system, detection limits for disulphonated aluminum phthalocyanine (A1PcS2) were compared after optimization of the signal processing scheme for each laser. The best detection limit (1.5 · 1

SHPOLSKII SPECTROFLUORIMETRIC DETERMINATION OF POLYCYCLIC AROMATIC-HYDROCARBONS IN BIOTA

The applicability of high-resolution Shpol'skii spectrofluorimetry to the direct analysis of polycyclic aromatic hydrocarbons (PAHs) in tern and mussel samples was investigated. The sensitivity of the measurements suffered considerably from the large amounts of interfering (e.g., fatty components) in the crude extracts, resulting in a poor-quality Shpol'skii matrix and a high sample absorbance. Nevertheless, after a thorough study of these limiting factors, optimum conditions could be defined and a number of PAHs were detected directly without any sample clean-up. Results obtained after sample pretreatment are also presented for comparison

SHPOLSKII FLUOROMETRIC-DETERMINATION OF POLYCYCLIC AROMATIC-HYDROCARBONS IN COMPLEX ENVIRONMENTAL-SAMPLES

High-resolution fluorimetry in low-temperature n-alkane Shpol'skii matrices is a powerful technique for the analysis of rigid, non-polar compounds like polycyclic aromatic hydrocarbons. Because of the method's sensitivity and selectivity, sample clean-up, preconcentration and even chromatographic separation can often be left out. The Shpol'skii analysis of pyrene in crude extracts from marine sediments and from bird meat is demonstrated. Special attention is focussed on the extra possibilities acquired when a laser is used as excitation source (Laser Excited Shpol'skii Spectroscopy, LESS)