Laurent Paturel

Evaluation of chromatographic and spectroscopic methods for the analysis of petroleum-derived compounds in the environment

SummaryAnalytical protocols have been adapted for the study of hydrocarbons at the trace level in the environment. Various samples, including sediments and biota, were collected from the Kuwaiti environment, treated according to the protocol and analyzed by chromatographic and spectroscopic methods. The methods used were synchronous scanning fluorescence spectroscopy (SSFS); high-performance liquid chromatography (HPLC) on C18 reversed-phase and NH2 normal-phase columns with UV and fluorescence detectors; gas chromatography on fused-silica capillary columns (GC) with flame ionization detector (FID), mass spectrometer (MS) and flame photometric detector (FPD); and high-resolution molecular spectrofluorimetry in Shpolskii matrix at 10 K (HRSS). The different methods were found to give complementary information. SSFS was useful for fast evaluation and preliminary assessment of oil pollution during extended programs; it permitted sample selection for deeper analyses but, when applied to biota, needed special care in the clean-up procedure. GC/FID, was used to analyze saturated and ethylenic compounds and was useful for obtaining information on the origin of hydrocarbons but inconvenient for analyzing the aromatic fraction. GC/FPD was difficult to use with sediment samples and yielded little information on biota samples, although it did permit confirmation of high oil contamination in some examples. HPLC on a normal-phase column with UV and fluorescence detectors was useful for the fractionation of samples and for the separation of different families of aromatic compounds according to aromatic carbon number. GC/MS was used to quantify polycyclic aromatic hydrocarbons (PAHs) of less than four cycles but was not sensitive enough for PAHs of higher molecular weight. HRSS, however, was useful for the quantification of heavy PAHs and was also faster, could be automated, and gave accurate results. However, in an oil-pollution study, it must be backed up by the other techniques. In fact, no single analytical technique was found to be sufficient, and only judicious combinations of the tested techniques yielded adequate information on the origin of hydrocarbons in the environment.

Application of the high-resolution low temperature spectrofluorometry to analysis of PAHs in lake sediments, marine intertidal sediments and organisms

SummaryThis study presents an application of high-resolution low temperature spectrofluorometry (Shpolskii effect) to quantitative analysis of PAHs in lake sediments, marine intertidal sediments and marine organisms. The main characteristics of the analytical computerized set-up are developed and show the selectivity, the sensitivity and the high speed of the experimental procedure, necessary for routine analysis of hydrocarbon traces. A correlation assay between PAHs distribution in sediments of an Alpine lake and that determined in vehicle exhaust emissions weighted from the accurate representation of the total number of passenger cars in France has been studied. We also present an investigation of concentration profiles and PAHs distributions in intertidal sediments and biota bivalves in the Gulf of Kuwait.

Realisation d'un dispositif experimental pour le dosage des hydrocarbures aromatiques polycycliques par spectrofluorimetrie shpol'skii a 10 K

Abstract (An experimental device for determination of polynuclear aromatic hydrocarbons by Shpolskii spectrofluorimetry at 10 K.) An experimental device is described comprising a triple-stage cell and a fast heat excharger, so as to optimise the spectrofluorimetric determination of polynuclear aromatic hydrocarbons in polycrystalline octane matrices at 10 K. The temperature difference between the two end compartments of the cell, 0.8 K, is not sufficient to change the Shpolskii spectra. The fast heat exchanger allows quick crystallisation and reheating of the samples. This device is used for the identification and determination of the limits of detection for ten such compounds, including the compounds defined by the European Economic Community for drinking water standards. An example of direct assay for each substance in a mixture is given.

Analysis of PAH Emissions from Passenger Cars by High Resolution Shpol'skii Spectrofluorometry

Abstract Twenty-five passenger cars (10 conventional petrol engined cars, 10 vehicles equipped with a 3-way catalyst and 5 diesel engined vehicles) were tested on a chassis dynamometer. Exhaust gases were collected in a Constant Volume Sampling system using Teflon filter and XAD2 adsorber. Identification and quantification of PAHs were carried out by high resolution Shpolskii spectrofluorometry over two INRETS cycles (urban and road cycles) representative of real – world driving conditions under hot or cold start. The results obtained in μg per km exhibit for the three technologies: - the influence of average speed - the efficiency of catalyst, under hot and cold start - higher emissions by conventional petrol engined cars, particularly under cold start and low speed conditions.

Analyse quantitative des hydrocarbures aromatiques polynucleaires par spectrofluorimetrie shpol'skii a 10 k: utilisation de la raie de mercure excitatrice diffusee par la matrice comme intensite lumineuse de reference

Abstract (Quantitative analysis by Shpolskii spectrofluorimetry of polynuclear aromatic hydrocarbons at 10 K with the mercury excitation line scattered by the matrix used as a standard intensity.) High-resolution Shpolskii spectrometry in a matrix is particularly suitable for the determination of trace polynuclear aromatic hydrocarbons in complex mixtures. In the usual technique, the method of standard additions is backed up by internal calibration, which is tedious. A direct calibration technique is proposed in which the mercury excitation line, scattered by the polycrystalline matrix, serves as the standard intensity. Detection limits vary from 0.3 ng ml−1 for benzo(a)pyrene to 48 ng ml−1 for pyrene, with linear response over about 2 orders of magnitude. The dynamics and a statistical analysis of the confidence interval for the results are discussed.

Computerized data acquisition and processing for Shpol'skii high-resolution spectrofluorimetry

Abstract The program described provides simultaneously digital control of a high-resolution spectrofluorimeter, acquisition of analog signals and data storage, and contains graphics processing to visualize spectra. Automatic evaluation software, which evaluates peak heights and calculates concentrations is included. The program runs on an IBM PC-AT2 (or compatible) equipped with interface cards; it is composed of distinct modules which are obtained through a menu. The system has been applied to the determination of 13 polynuclear aromatic hydrocarbons (PAHs); it offers high selectivity, excellent detection limits, and rapidity of data acquisition. Results obtained for 9 PAHs in a standard urban dust (SRM-1649) were satisfactory.

Analysis of Polycyclic Aromatic Hydrocarbons in Lacustral Sediments by High Resolution Shpol' skii Spectrofluorimetry at 10K

Abstract Among the numerous sensitive analytical methods developed, the high resolution Shpolskii spectrofluorimetry at 10 K is particularly suitable for quantitative determination of traces of Polycyclic Aromatic Hydrocarbons (PAH) in complex mixture, because of its high selectivity and high sensitivity. Indeed PAH incorporated into n-alkane matrix at low temperature yield high resolution fluorescence spectra of quasi lines with multiplet structure related to several insertion sites. A method for qualitative and quantitative analysis has been developed from these Shpolskii spectra. Quantitative results have been obtained from various origins, water and air. In this paper, this method is carried out for quantitative determination of PAHs in lacustral sediments (Benzo(a)Pyrene, Benzo(k)Fluoranthene, Indeno(1,2,3-cd)Pyrene, Benzo(ghi)Perylene, Benzo(b)Fluoranthene, Benzo(j)Fluoranthene, Benzo(b)Chrysenes, Benzo(e)Pyrene, Pyrene, Perylene). An extraction and purification procedure of samples must be adapted...

A Data Acquisition and Processing Software for High-Resolution Shpol'Skii Spectrofluorometry

Abstract This study describes a software called “HAP”, realized in our laboratory for rapid data acquisition and processing on a high-resolution low-temperature spectrofluorometer. The main characteristics of the setup developed and the utilities offered by “HAP” will contribute to a routine analysis of hydrocarbon traces and prove the great analytical capability of this luminescence method. Using this new computerized system six parent priority PAHs in sediment and natural water samples from an alpine river near Annecy (France) have been determined.