Determination of sixteen polycyclic aromatic hydrocarbons in aqueous and solid samples from an Italian wastewater treatment plant

Microfabricated devices integrating sample filtration, solid-phase extraction, and chromatographic separation with solvent programming were demonstrated. Filtering of the sample was accomplished at the sample inlet with an array of seven channels each 1 μm deep and 18 μm wide. Sample concentration and separation were performed on channels 5 μm deep and 25 μm wide coated with a C18 phase, and elution was achieved under isocratic, step, or linear gradient conditions. For the solid-phase extraction, signal enhancement factors of 400 over a standard injection of 1.0 s were observed for a 320-s injection. Four polycyclic aromatic compounds were resolved by open channel electrochromatography in under 50 s. Chip operation was unaffected by the presence of the 5-μm silica particles at the filter entrance.

Sample filtration, concentration, and separation integrated on microfluidic devices.

The acid-induced liquid−liquid phase separation of anionic surfactants in aqueous solutions, and its applicability to cloud point extraction methodology, were examined. The phase diagrams obtained (e.g., [HCl] vs [surfactant]) consisted of three regions:  a homogeneous liquid region, two coexisting isotropic phases, and a solid region. The breadth of each region was found to depend on the surfactant structure. The behavior of each phase was also examined in relation to temperature and added salts. The anionic surfactants investigated were sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonic acid (SDBSA), sodium dodecanesulfonic acid (SDSA), and sodium dioctylsulfosuccinate (Aerosol OT). The use of anionic surfactant-mediated phase separations provided very high extraction efficiencies (80−100%) for pyrene in aqueous samples and various PAHs in a certified reference material (dried sewage sludge). The preconcentration factor achieved was found to be a function of both surfactant and acid concentrati...

An Acid-Induced Phase Cloud Point Separation Approach Using Anionic Surfactants for the Extraction and Preconcentration of Organic Compounds

Solid-phase extraction of polycyclic aromatic compounds.

Developments in the analysis of petroleum hydrocarbons in oils, petroleum products and oil-spill-related environmental samples by gas chromatography

Both the separation of polycyclic aromatic hydrocarbons (PAH's) on tailor made HPLC phases, and their chromatographic enrichment and quantitative determination are of great interest. Because of the generally low concentrations of PAH's in the environment, and the low limiting values in German legislation for drinking water, methods for selective enrichment and sensitive detection are indispensable. On account of their relatively high amounts in soil, the determination of PAH's is valuable for the assessment of the potential danger to ground water by waste materials. These requirements can be fulfilled by used of solid phase extraction on enrichment columns, and fluorescence or UV/VIS diode array detection.

Trace enrichment and HPLC analysis of polycyclic aromatic hydrocarbons in environmental samples, using solid phase extraction in connection with UV/VIS diode-array and fluorescence detection

For the title compounds 4,4′-DADPM, MOCA, 3,3′-DCB, 4-ADP and 4-ADPA listing on the EPA priority pollutant list, an analytical practicable, reliable, reproducible and sensitive procedure is required. Therefore a new method has been developed for the routine determination of these toxic aromatic amines in urine at the ppb level. The quantitative determination of amines is a suitable procedure of occupationally exposed persons. Urine sample preparation is done using simple liquid-liquid extraction followed by a precolumn enrichment (PRP1-material; Hamilton). Breakthrough measurements were done using an enrichment column packed with PRP1 material. The capacities of the studied amines ranged from 21.9mg/g to 96.6mg/g, while influent concentrations differed from 28.3mg/l to 332.0mg/l. The advantages of electrochemical detection regarding to selectivity and sensitivity are clearly indicated in this paper. Separation has been achieved applying reversed-phase-high-performance-liquid chromatography (LiChrosorb RP 18/5μm) followed by electrochemical or UV-detection. The detection limits employing an electrochemical detector at a potential of 1 V range from 2.2ng to 12.1ng. UV detection at 254 nm and 280 nm is about 10–100 times less sensitive. Recoveries from spiked water samples at the 5ppb levels were 75% to 96% respectively. The standard deviation of the developed procedure varies from 5.3% to 14%. Day-to-day repeatability is good.

Trace analysis of selected benzidine and diaminodiphenylmethane derivates in urine by means of liquid chromatography using precolumn sample preconcentration, UV and electrochemical detection

Two different anthryl-modified silica packings were investigated for the separation of PAHs and nitro-PAHs. Plots of k′ versus mobile phase composition show distinct selectivity both with acetonitrile/water and with methanol/water. PAHs are separated by π-π-interactions, whereas the corresponding nitrosubstituted compounds are longer retained on both stationary phases due to charge-transfer interactions being possible.

Comparison of two anthryl-modified silica stationary phases for the HPLC separation of PAHs and nitro-PAHs

A number of 11 triazine herbicides and 7 of their corresponding metabolites were separated in a single HPLC run. The separation was achieved on a reversed-phase column using gradient elution with acetonitrile/buffer. Detection was by UV absorption at a wave-length of 220 nm.

High-performance-liquid chromatographic separation of 1,3,5-trizine herbicides

One possible method of characterizing chemicall-modified stationary phases is to describe their chromatographic properties. In this study we investigated several chemically-modifiedpolystyrene-divinylbenzene packings for the separation of nitroarenes, polycyclic aromatic hydrocarbons and aminosubstituted aromatic hydrocarbons. Chromatography was carried out on commercially available polymer stationary phases, for example C-18 or vinylpyridine modified polystyrene. In addition, a chemically-immobilized polymer packing was prepared by introducing nitrogroups, which were established by elemental analysis and infrared spectroscopy.

A. Kettrup

Papers

Trace enrichment and HPLC analysis of polycyclic aromatic hydrocarbons in environmental samples, using solid phase extraction in connection with UV/VIS diode-array and fluorescence detection

Trace analysis of selected benzidine and diaminodiphenylmethane derivates in urine by means of liquid chromatography using precolumn sample preconcentration, UV and electrochemical detection

Comparison of two anthryl-modified silica stationary phases for the HPLC separation of PAHs and nitro-PAHs

High-performance-liquid chromatographic separation of 1,3,5-trizine herbicides

Modified polystyrene, stationary phases for the separation of different aromatic hydrocarbon types by HPLC