Capillary Electrochromatography: Analysis of Polycyclic Aromatic Hydrocarbons (original) (raw)
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Analytical Chemistry, 1993
Capillary electrophoresis with UV-laser-excited native fluorescence has been employed for ultrasensitive determination of polycyclic aromatic hydrocarbons, including anthracene, phenanthrene, benz[ alanthracene, methylanthracene, pyrene, fluoranthene, and perylene. The separation is based on solvophobic association of the analytes with tetraalkylammonium ions in mixed acetonitrile/water solvent. With both near-UV (325-nm) and deep-UV (257-nm) laser excitation, background fluorescence from the fused silica capillary and the nonaqueous electrolyte was the limiting factor in detection sensitivity. Effective rejection of the intense capillary wall fluorescence was achieved by the use of a high-numericalaperture microscope objective coupled with an adjustable precision slit in a confocal configuration. The achieved mass detection limits were in the range of (3-15) X 10"O mol, with linear fluorescence response spanning over 4 orders of magnitude. This sensitivity is expected to be sufficient for analyzing chemical carcinogens, anticancer drugs, and their metabolites in individual mammalian cells.
Analytical Chemistry, 1997
Sodium dodecylbenzenesulfonate (SDBS) was used as an additive in separating a broad range of polycyclic aromatic hydrocarbons (PAHs) by capillary electrophoresis. In the absence of micelles, using an acetonitrile-water (40:60) electrolyte, the separation mechanism was predicted as solvophobic association of the PAH molecules with hydrophobic chains of the SDBS surfactant and a possible p-p interaction between aromatic groups of PAHs and SDBS. The effects of voltage, acetonitrile and SDBS concentrations on separation were investigated. SDBS provides a good selectivity for PAHs not only between different ring numbers (1 to 5) but also between the pairs of structural isomers. Under optimum conditions, 11 aromatic compounds were separated with efficiencies between 130 000 and 230 000 theoretical plates. Reproducibilities of migration times range between 1.15 and 1.55% RSD and peak areas between 2 and 9% RSD.
Journal of Chromatography A, 2011
A methacrylate-based monolithic capillary column has been evaluated for the preconcentration of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. For this purpose, the monolyte was in situ synthesized in a 6 cm × 0.32 mm id fused-silica capillary. The microextraction unit was fitted to a micro-HPLC pump to pass 10 mL of sample. The isolated pollutants were eluted by means of 10 L of methanol, the organic phase being directly collected in a specific interface that can be fitted to the injection port of the gas chromatograph without modification. The interface allows the on-line thermal desorption of the PAHs, avoiding the dilution and providing enough sensitivity to reach the legal limits established for these pollutants in the matrices selected. The limits of detection achieved for 10 mL of water ranged between 2.8 ng/L (indeno(1,2,3-cd)pyrene) and 11.5 ng/L (acenaphthene) with acceptable precision (between 4.5 and 18.2% RSD). The method was applied to the determination of the selected PAHs in tap, river waters and sewage, being fluoranthene and pyrene detected in all of them at concentrations lower than the legal limits established for these compounds in the matrices assayed.
1993
In this article, we report a high-performance liquid chromatography-particle beam-mass spectrometric (HPLC-PB-MS) method for the determination of polycyclic aromatic hydrocarbons (PAHs). The PB interface consists of a concentric ultrasonic nebulizer with temperature-controlled desolvation chamber and a three-stage momentum separator. The HPLC-PB-MS method showed greater sensitivity for PAHs with molecular weights above 178 than for those PAHs with molecular weights below 178. The percent relative standard deviations for the determination of 0.5 ng chrysene, 1.0 ng dibcnzola.hlanthracenc, 1.0 ng benzo[g,h,i]perylene, and 2.5 ng coronene were 20%, 2.5%, 13.7%, and 6%, respectively. The detection limits at signal/noise~3 were 0.2 ng for chrysene, 1.0 ng for dibenzola.hjanthracene, 0.5 ng for benzo[g,h,i]perylene, and 1.5 ng for coronene.
Analytical Techniques for Identification and Quantification of Polycyclic Aromatic Hydrocarbons
2016
Several analytical techniques have been developed and applied for identification and quantification of polycyclic aromatic hydrocarbons (PAHs) present in different samples. These analytical techniques include gas chromatography coupled with flame ionization detectior (GC/FID), gas chromatography coupled with a mass spectrometry (GC/MS), high performance liquid chromatography (HPLC) coupled with an ultraviolet or fluorescence detector, and thin-layer chromatography (TLC) with fluorescence detection. Since sensitive analytical techniques were essential in the determination of the presence and levels of these toxic compounds, some aspects of standard preparation and suitable instrumental condition for quantification of the sixteen PAHs listed by the U.S. environmental protection agency (EPA) have been reviewed in this article. The quantification performance of each technique has been comparable for different samples matrix.
Analytica Chimica Acta, 1981
Current advances in the technology of capillary columns for gas chromatography permit extension of the range of polycyclic aromatic compounds which may be eluted. High-performance liquid chromatography (h.p_l.c.) in the non-aqueous, reversed-phase mode shows promise forseparation of even larger molecules: an inquiry into the feasibility of capillary h.p.1.c. in this area has resulted in elution of polycyclic compounds containing up to eleven aromatic rings. The detrimental health effects caused by polycyclic aromatic compounds (PAC) that are generated in various combustion processes are wellestablished. Certain of these substances are known to be mutagenic and carcinogenic. While various analytical procedures have been developed in numerous labortories for their determination, chromatographic separations play a prominent role in this field [ 11. Mixtures of PAC isolated from various products of combustion (e.g., soot, coal tar, or smoke condensates) are frequently very complex, and the same is true for materials derived from petroleum or coal. When highefficiency gas chromatographic columns are employed, it is not unusual to observe 1OW200 compounds in such mixtures [2-41 in the range of 2-ring to 6-ring PAC structures. Capillary gas chromatography (g-c.) and high-performance liquid chromatography (h.p.1.c.) have been developed over the years as successful methods for PAC separation. Both methods hold advantages and disadvantages of their own. As has been established in previous studies [2-41, relatively short thin-film glass capillary columns (yielding typically 30 OOO-80 000 theoretical plates for such separations) can clute PAC containing up to six rings within the usual temperature range of modem g.c. The typical
Solid-Phase Analysis of Polycyclic Aromatic Hydrocarbons by Fluorimetric Methods
Applied Spectroscopy, 2011
Polycyclic aromatic hydrocarbons (PAHs) adsorbed on the surface of particulates collected in a working environment have been analyzed using fluorescence techniques. In particular, fluorescence measurements were carried out directly on the sampling filters, in solid phase, and for comparison, on the extract samples in solution. Fluorescence synchronous acquisitions allowed the detection of signals from different PAH compounds and, on the basis of the 0-0 transition energy, the assignment of the emission signals to chemical structures. In particular, the contribution of benzo-a-pyrene was easily detected and used to evaluate the sensitivity of the measurements, which is a few nanograms per milliliter, comparable with other analytical tools. The results of the fluorimetric investigation were validated through the comparison with the data obtained by gas chromatography (GC) analysis on the extracted samples, which allowed identification of the PAHs and the quantification of their distribution on the filters with different cut sizes. The agreement between the two series of data led to the conclusion that fluorimetric analysis directly on the sampling filter could be a new and cost-effective approach for the analysis of PAHs.
Analytical and bioanalytical chemistry, 2016
A method has been developed for the sensitive and rapid analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental samples using liquid chromatography time-of-flight mass spectrometry as well as the selective atmospheric pressure laser ionization (APLI) process (LC-APLI-MS). Upon analyzing 34 PAHs, the limits of detection of this method were found to range from 0.008 to 1.824 pg (0.024 pg for benzo[a]pyrene). The method therefore provides 30-fold to 5,400-fold increased sensitivity compared with the established GC-MS technique. This LC-APLI-MS method was optimized for higher molecular weight PAHs (C24-C30 PAHs with 6-8 rings), which are difficult to detect or cannot be detected by GC-MS. Using the LC-APLI-MS method, various 6- to 8-ring PAHs were detected in environmental samples for the first time. After developing the method, it was successfully validated in ruggedness tests. The concentrations determined by the LC-APLI-MS method were in good accord with the certified co...