Trace Amounts Of Polycyclic Aromatic Hydrocarbons Research Articles

Rapid screening and quantitation of PAHs in water and complex sample matrices by solid-phase microextraction coupled to capillary atmospheric pressure photoionization-mass spectrometry.

A capillary atmospheric pressure photoionization (cAPPI) source was used to analyze polycyclic aromatic hydrocarbons (PAHs) in complex matrices like grilled meat extract and urban dust reference material, as well as screening for PAHs in aqueous samples such as tap and lake water. A high-throughput workflow was developed that allowed rapid screening of unknown samples by direct solid-phase microextraction (SPME) coupled with cAPPI-MS, with confirmatory gas chromatography performed only for samples containing trace amounts of PAHs. Extraction times were as low as 15 s, with a total analysis time of 2 min per sample for screening. Limits of detections were in the low pg/ml range and in the subpg/ml range for the direct and chromatographic approach, respectively, with a linear dynamic range between two and three orders of magnitude, as determined for 15 model PAHs. This rapid approach represents an attractive way to screen samples containing nonpolar compounds using an ambient ionization source.

DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL SAMPLES USING ULTRASONIC PROBE AND SALT-ASSISTED LIQUID-LIQUID EXTRACTION COUPLED WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Background : Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals which have 2 to 7 fused aromatic rings. It is demonstrated that even trace amounts of PAHs are carcinogens, mutagens, and teratogens which can lead to serious risk to the health of humans. According to these facts, determination of PAHs in environmental samples is essential. Methods : In this study, ultrasonic in combination with salt-assisted liquid-liquid extraction was used efficiently for the extraction of PAHs from soil and water samples. In order to evaluate the performance of the proposed method three PAHs, naphthalene, anthracene and pyrene were selected as model analytes. Influential parameters on the extraction efficiency of analytes such as extraction solvent and its volume, salting-out agent and its concentration, ultrasonic time, ultrasonic amplitude and pulse were investigated and optimized. Results : The optimum conditions were as follow; extracting solvent; tetrahydofuran, extracting solvent volume; 3 mL, salting-out agent; sodium acetate, salting-out agent concentration; 20 %w/v, ultrasonic time; 10 s, ultrasonic amplitude; 60% and ultrasonic pulse; 0.5 s. The limits of quantitation for pyrene, naphthalene and anthracene were 1.0, 1.0 and 0.7 ng g-1, respectively. Under the optimum conditions, obtained recoveries in different matrices were in the range of 80.0 to 100.0% with a relative standard deviation better than 7.5%. Conclusions : In the proposed method, after the UAE, sample was exposed to SALLE without need of solid residue removal from the sample. Therefore, extraction steps such as filtration and centrifuge were removed which lead to time saving.

Polycylic Aromatic Hydrocarbons in Rape Seeds with Relation to their Growing Site and Thermal Treatment

A significant source of polycyclic aromatic hydrocarbons (PAH) in human diet is vegetable oils, especially those produced from plants grown in regions where the soil and the atmosphere are contaminated with these chemicals. Contamination with PAH of vegetable oils may also occur in the process of plant material drying with smoke or exhaust fumes, or in the course of extraction of that material with solvents containing trace amounts of PAH. The objective of this study was to determine the relationship between the levels of PAH present in rape seeds and the occurrence of these compounds in cultivation region and the relationship of the levels of PAH in rape seeds to thermal treatment after harvest. Rape seeds and pods from experimental fields and rape seeds subjected to thermal treatment in dryers obtained from suppliers of the raw material were examined and compared. Cleanup of extracts was performed with high-resolution size exclusion chromatography (SEC) and final determinations were by Trace Ultra/PolarisQ gas chromatography–mass spectroscopy (GC-MS). The results obtained indicated that during thermal treatment of rape seeds the concentration of PAH increased, but the levels of benzo[a]pyrene did not exceed threshold permissible levels. Data demonstrate that rapeseed cultivation in the presence of PAH results in higher levels of contaminants; however, the PAH levels still did not exceed the maximal allowable levels in Poland.

Mutagenicity and clastogenicity of gas stove emissions in bacterial and plant tests

The aim of this research was to study the gaseous and particulate emissions of genotoxic substances during cooking with two types of methane stoves (a new one and an old one). The particulates were sampled both with a cascade impactor air sampler and an impinger with ice trap and analyzed by two bacterial mutagenicity tests (Ames and Kado tests) and by HPLC for polycyclic aromatic hydrocarbons (PAH). Gaseous emissions were studied in situ using the Ames test, a clastogenicity plant test (Tradescantia-micronucleus test), and in an automated system for chemical analyses. Clear indirect mutagenicity was found only with the Kado test (TA98-S9) in extracts of particulates emitted from the old methane stove and collected with the impinger. Similar mutagenicity (TA98+S9) was also found for the finest fraction of particulates (<0.5 um) collected from both stoves. Gaseous emissions of both stoves caused clastogenicity in the in situ experiments with the Tradescantia-micronucleus test. The physico-chemical analyses of the emissions showed also the presence of very fine particulates and trace amounts of PAH. The exposure of these genotoxins could be particularly important for occupationally exposed individuals in homes and businesses and for susceptible subjects living indoors for long periods (infants, children, the sick, and the elderly).

Polycyclic Aromatic Hydrocarbons in Soil at Groundwater Level Near an Earthen Pit for Produced Water in the Duncan Oil Field

Abstract Hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and alkylated PAH with two to four rings were found in soil at groundwater level down-gradient from an earthen waste disposal pit for produced water, in the Duncan Oil Field of NW New Mexico. Depth to groundwater was only 1 to 1.5m in this flood plain of the San Yuan River. Complex mixtures of hydrocarbons with carbons numbers from 12 to 30 were detected in solvent extracts of soil samples collected 25m and 50m down-gradient from the waste pit. The concentration of total extracted organic mass was as large as 500 ppm at 25m, but a reduction in concentration of 90 to 100% was seen for samples at 50m on the same axes. No similar contamination was found in soil samples located on axes drawn up-gradient from the waste pit. Concentrations for total PAH in soil at 25m distance from the waste pit were as large as 4900 ppb and 37 ppb at 50m on the same axis. Detectable but trace amounts of PAH in samples up-gradient from the pit may be evidence for a ...

Mutagenic/carcinogenic hazards in a cold-rolling steel plant exposed to mineral oils: environmental monitoring phase.

A survey was carried out in a cold-rolling steel plant exposed to mineral oils to study the mutagenic/carcinogenic hazards, following a coupled environmental/biological monitoring. The present paper deals only with the environmental phase by determining polycyclic aromatic hydrocarbons (PAH) and applying a mutagenicity test (Ames test), and includes the following steps: (a) work process and environment study; (b) sampling and analysing mineral oils before and after use (PAH determination and mutagenicity analysis); (c) sampling and analysing oil mist (TWA determination, PAH determination and mutagenicity analysis). The results showed that: (1) both unused and used (recycled) mineral oils contained only trace amounts of PAH and were not mutagenic; (2) the TWA concentrations of oil mists were lower than the TLV (less than 5 mg/m3); (3) oil mists contained only trace amounts of PAH and were not mutagenic. The authors suggest that these results could be due to the moderate temperature of the oil during the work process and that there is a relationship between low PAH content and absence of mutagenicity in the oils and air samples.