Development of a gas chromatography-mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere

A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography–mass spectrometry (GC–MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1).Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5 ± 1%, a reproducibility of 13 ± 3% and detection limits of 0.05–0.18 pg m⁻³ for the particulate phase and 26–88 pg m⁻³ for the gaseous phase. Finally, the methodology was successfully applied to rural and agricultural samples in the Mediterranean area.     

Analysis of t-Butyldimethylsilyl Derivatives of Chlorophenols in the Atmosphere of Urban and Rural Areas in East of France

A method using GC-MS and derivatization with N-(t-butyldimethylsilyl)-N-ethyltrifluoroacetamide (MTBSTFA) was developed for the analysis of 19 chlorophenols compounds in atmospheric samples (gas and particles). Air sampling was carried out using a Hi-Vol sampler with glass fibre filter and XAD-2 resin at a flow rate of 60 m³ h⁻¹. The particle and gas phases were collected separately over a period of 4 h. Samples were Soxhlet extracted, evaporated to dryness under nitrogen and refilled with acetonitrile. 100 mL of these extracts were derivatized with 100 μL of MTBSTFA at 80 °C for 1 h under strong stirring. Sylylated chlorophenols were injected into a GC-MS in splitless mode and quantified as their TBDMS derivatives in the SIM mode. Mass spectral analysis of the derivatives of the 19 compounds studied indicates that the spectra are highly specific showing an ion at [M - 57]⁺ which is useful for structure confirmation or analysis at low levels using selected ion monitoring. Quantification limits varied between 5 μg L⁻¹ and 10 μg L⁻¹ which correspond to 20 pg m⁻³ and 40 pg m⁻³ for 250 m³ of air sampled. This method was successfully applied to atmospheric samples collected simultaneously in winter 2004 in an urban (Strasbourg) and rural (Erstein) areas in east of France.     

A new approach for determination of crustal and trace elements in airborne particulate matter

An ICP-OES procedure was developed for fast and accurate determination of various crustal (Al, Ca, Fe, Mg, Si) and trace elements (Ba, Cu, Mn, Na, K, Sr, Ti, Zn) in airborne particulate matter. The method is based on a preliminary treatment of the aerosol samples with a mixture of nitric acid and hydrogen peroxide at elevated temperature leading to a mineralization of the organic sampling substrate, dissolution of soluble material and homogeneous suspension of the remaining non-soluble fraction. After dilution the derived slurry solutions were measured using ICP-OES. The reproducibility of analysis given as the relative standard deviation (% RSD) varied between 3.2 and 6.8% for bulk constituents such as Al, Ca, Fe, Mg and Si whereas values ranging from 3.5 to 9.1% were obtained for trace metals present with distinctly lower abundance in PM10 (e.g. Ba, Cu, Mn, Sr, Zn). The limits of detection (LOD) calculated as three times the standard deviation (3σ) of the signal derived from filter blank samples ranged from approximately 1?ng?m^?3 (Sr) to 71?ng?m^?3(Ca). The developed procedure was evaluated by comparing the obtained results with the findings derived for the same set of aerosol samples analyzed using a microwave procedure for sample dissolution with subsequent ICP-OES analysis. Finally the developed procedure was applied for the analysis of crustal and trace elements in PM10 samples collected at an urban site (Getreidemarkt, Vienna) and a rural site (Hartberg, Styria), in Austria. The concentrations of the investigated crustal elements varied between some hundred ng?m^?3 and few µg?m^?3 with highest concentrations for Fe and Si, distinctly reduced concentrations ranging from some ng?m^?3 (Sr) to more than hundred ng?m^?3 (K) were found for trace elements. Observed PM10 concentrations were found to be in accordance to literature findings from urban sites in central Europe.     

Determination of diphenylamine in contaminated air of agricultural buildings using active sampling on solid sorbents

This paper reports the results of a study carried out with solid sorbents in order to establish the optimum procedure for sampling and determination of diphenylamine (DPA), the most widely used post-harvest chemical in apples, in the indoor air of apple storage buildings. Different sorbents (Amberlite XAD-2, Amberlite XAD-4, Supelpak 2, Florisil, and the octadecyl silica bonded sorbent, C-18) were evaluated for their capacity to efficiently retain DPA under different air sampling and storage conditions, whereas a desorption study of all sorbents tested was also performed to optimise a simple extraction procedure using low volumes of organic solvents. In general all sorbents produced acceptable results for DPA air sampling whereas DPA was recovered easily by the use of low volumes of both ethyl acetate and acetone from all sorbents studied thus making DPA a suitable analyte to be used in methods of indoor air analysis for multi-organic pollutants. However, the best results (analytical features, recovery results, and stability results during storage) were obtained by the use of Supelpak 2 as a sorbent for DPA active sampling. Limits of Quantification (LOQs) for the GC-NPD system ranged from 1.0 to 2.0?µg?m^?3 for 120 and 60?L air sampled, respectively. The developed air sampling procedure and analytical methodology was applied with success in the field to measure DPA residues in indoor air of two apple storage plants in Greece and results were further used to calculate the occupational inhalation exposure to DPA and consequently risk characterisation. Since DPA was detected in indoor air (at concentrations ranged from 1.6 to 580?µg?m^?3), there is no zero occupational risk for workers. However, the inhalation exposure of workers to DPA estimated in this study is far below the Acceptable Operator Exposure Level recently reviewed by the European Union and far below the critical exposure level for haematotoxicity systemic effect observed in carcinogenicity studies in rats for long-term inhalation exposure to DPA.     

Development of method for determination and preconcentration of uranium in water samples using XAD-4 resin loaded with Br-PADAP

In the present work, a minicolumn of XAD-4 loaded with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (Br-PADAP) is proposed as a preconcentration system for uranium determination in well, tap and mineral water samples by spectrophotometer using arsenazo III as the chromogenic reagent. Initially, a two-level (2³) full factorial design was used for the preliminary evaluation of three factors, involving the following variables: sampling flow rate, elution flow rate, and pH. This design has revealed that, for the studied levels, buffer concentration and pH were significant factors. When the experimental conditions established in the optimization step were pH = 8.6, and an elution flow rate of 8.6 mL min^?1 using 0.5% m/v ascorbic acid, this system has allowed for the determination of uranium with a detection limit (LOD) (3σ/S) of 0.05 μg L^?1 and a quantification limit (LOQ) (10σ/S) of 0.16 μg L^?1. The precision expressed as the relative standard deviation (R.S.D.) of 0.8% and 1.9% at 10.0 and 1.0 μg L^?1, respectively- and a preconcentration factor of 184.5 for a sample volume of 50.0 mL. Accuracy was confirmed by uranium determination in the standard reference material, NIST SRM 1566b trace element units in Oyster Tissue samples, and spike tests with recuperations ranging from 93.2 to 105%; the procedure were applied for uranium determination in tap water, well water, and drinking water samples collected from Caetité and Cruz das Almas Cities, Bahia, Brazil. Five water samples were analyzed the uranium concentrations varied from 0.50 to 2.07 μg L^?1     

Determination of Pyrethroid Pesticides in Environmental Waters Based on Magnetic Titanium Dioxide Nanoparticles Extraction Followed by HPLC Analysis

A simple and fast method based on magnetic separation for extraction of pyrethroid pesticides including beta-cyfluthrin, cyhalothrin and cyphenothrin from environmental water samples has been established. Magnetic titanium dioxide was used as sorbent, which was synthesized by coating TiO₂ on Fe₃O₄ in liquid-state co-precipitation method. The sorbent has been characterized by scanning electron microscopy and Fourier-transform infrared spectrometry, and the magnetic properties were investigated with physical property measurement system. Various parameters affecting the extraction efficiency were evaluated to achieve optimal condition and decrease ambiguous interactions. The analytes desorbed from the sorbent were detected by high performance liquid chromatography. Under the optimal condition, the linearity of the method is in the range of 25–2,500 ng L^?1. The detection limits and quantification limits of pyrethroid pesticides are in the range of 2.8–6.1 ng L^?1 and 9.3–20.3 ng L^?1, respectively. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2 % and from 3.6 to 9.1 % were obtained. In all three spiked levels (25, 250 and 2,500 ng L^?1), the recoveries of pyrethroid pesticides were in the range of 84.5–94.1 %. The proposed method was successfully applied to determine pyrethroids in three water samples. Cyphenothrin was found in one river water near farmlands, and its concentration was 52 ng L^?1.     

Multi-determination of organic pollutants in water by gas chromatography coupled to triple quadrupole mass spectrometry

A multi-determination method has been developed for the determination and confirmation of 68 organic pollutants in water samples by gas chromatography coupled to triple quadrupole mass spectrometry (GC-MS/MS). The following chemical families were determined in a chromatographic run of less than 26?min: polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenylethers (PBDEs), and pesticides (organochlorine, organophosphorus, triazine and others). The sample preparation involved a liquid-liquid extraction (LLE) procedure, obtaining recoveries ranging from 70 to 130% when dichloromethane was used as the extracting solvent. The detection limits of the proposed method were between 0.75 and 19.8?ng?L^?1. Samples from the Maipo River in central Chile were taken from 29 different points. Seven pesticides and two PAHs were detected in field collected samples with concentrations ranging from 10 to 95?ngL^?1. Concentrations of benzo[a]pyrene in environmental samples ranged from 25 to 33?ngL^?1 and were near the maximum levels established by the European Union Directives (50?ng?L^?1).     

Determination of some carbamate pesticides in watermelon and tomato samples by dispersive liquid–liquid microextraction combined with high performance liquid chromatography

A novel method for the determination of five carbamate pesticides (metolcarb, carbofuran, carbaryl, isoprocard and diethofencard) in watermelon and tomato samples was developed by dispersive liquid–liquid microextraction (DLLME) coupled with high performance liquid chromatography-diode array detection (HPLC-DAD). Some experimental parameters that influence the extraction efficiency were studied and optimised to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 10 to 1000?ng?g^?1 for all the five carbamate pesticides, with the correlation coefficients (r) varying from 0.9982 to 0.9992. Good enrichment factors were achieved ranging between 80 and 177, depending on the compound. The limits of detection (LODs) (S/N?=?3) were ranged from 0.5 to 1.5?ng?g^?1. The method has been successfully applied to the analysis of the pesticide residues in watermelon and tomato samples. The recoveries of the method fell in the range between 76.2% to 94.5% with RSDs less than 9.6%, indicating the feasibility of the DLLME method for the determination of the five carbamate pesticides in watermelon and tomato samples.     

Determination of the calibration factor for CR-39 based indoor radon detector

CR-39 based radon detectors are widely used in measuring indoor radon. In this regard, different groups have developed their own systems. However, before using any system for indoor radon measurements, it has, first, to be calibrated with a known source of radon. In the current study, CR-39 based NRPB type radon detector has been calibrated and presented. In this regard, about 200 holders for CR-39 were obtained from the Radiation Protection Division of the Health Protection Agency (former NRPB), UK and several thousand more similar detector holders, hereafter called NRPB type holders, were fabricated locally in Pakistan. Uranium ore samples of known grade were placed into the plastic containers of volume 5.4 × 10³ cm³ and CR-39 detectors were placed in the NRPB type holders and were then installed into the containers at a distance of 25 cm from the surface of the known grade ore samples. The containers were hermetically sealed and the detectors were allowed to expose to radon for 3 weeks. After 16 h etching in 25 % NaOH at 80 °C, the measured track densities were related to the radon concentration. The calibration factor of 2.563 tracks cm^?2 h^?1/kBq m^?3 was obtained.     

Investigation of radon and thoron concentrations in a landmark skyscraper in Tokyo

The temporal variation of the radon concentration, and the radon and thoron concentrations every 3 months for a year were measured using two types of devices in a landmark skyscraper, the Tokyo Metropolitan Government Daiichi Building. In the measurement of temporal variation of the radon concentration using a pulse type ionization chamber, the average radon concentration was 21 ± 13 Bq m^?3 (2–68 Bq m^?3). The measured indoor radon concentration had a strong relationship with the operation of the mechanical ventilation system and the activities of the office workers. The radon concentration also increased together with temperature. Other environmental parameters, such as air pressure and relative humidity, were not related to the radon concentration. In the long-term measurements using a passive radon and thoron discriminative monitor, no seasonal variation was observed. The annual average concentrations of radon and thoron were 16 ± 8 and 16 ± 7 Bq m^?3, respectively. There was also no relationship between the two concentrations. The annual average effective dose for office workers in this skyscraper was estimated to be 0.08 mSv y^?1 for 2000 working hours per year. When considering the indoor radon exposure received from their residential dwellings using the annual mean radon concentration indoors in Japan (15.5 Bq m^?3), the annual average effective dose was estimated to be 0.37 mSv y^?1. This value was 31 % of the worldwide average annual effective dose.     

Use of a Headspace Solid-Phase Microextraction-Based Methodology Followed by Gas Chromatography–Tandem Mass Spectrometry for Pesticide Multiresidue Determination in Teas

This study reports on the development of a fast and efficient method based on headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–tandem mass spectrometry (GC–MS/MS) for simultaneous analysis of 128 volatile or semi-volatile pesticide residues belonging to nine classes of pesticides. The important factors related to HS-SPME performance were optimized; these factors include fiber types, water volume, ion strength, extraction temperature, and extraction time. The best extraction conditions include a PDMS/DVB fiber, and analytes were extracted at 90 °C for 60 min from 1 g of tea added to 5 mL of 0.2 g mL^?1 NaCl solution. The methodology was validated using tea samples spiked with pesticides at three concentration levels (10, 50, and 100 μg kg^?1). In green tea, oolong tea, black tea, and puer tea, 82.8, 88.3, 79.7, and 84.3% of the targeted pesticides meet recoveries ranging from 70 to 120% with a relative standard deviation of?≤?20%, respectively, when spiked at a level of 10 μg kg^?1. Limits of quantification in this method for most of the pesticides were 1 or 5 μg kg^?1, which are far below their maximum residue limits prescribed by EU. The optimized method was employed to analyze 30 commercial samples obtained from local markets; 17 pesticide residues were detected at concentrations of 2–452 μg kg^?1. Chlorpyrifos was the most detected pesticide in 80% of the samples, and the highest concentration of dicofol (452 μg kg^?1) was found in a puer tea. This is the first time to find that the optimized extraction temperature for pesticide residues is 90 °C, which is much higher than other reported HS-SPME extraction conditions in tea samples. This developed method could be used to screen over one hundred volatile or semi-volatile pesticide residues which belong to multiple classes in tea samples, and it is an accurate and reliable technique.     

A multi-residue method for characterization and determination of atmospheric pesticides measured at two French urban and rural sampling sites

The extensive use of pesticides to protect agricultural crops can result in the transfer of these compounds into the atmosphere and their diffusion towards urban areas. Precise evaluation of the geographic impact of this type of pollution is important environmentally. In this paper, analytical methods for the sampling, characterization, and determination of agricultural pesticides in air were developed; the methods were then applied in the Paris and Champagne regions. Sixteen pesticides belonging to nine chemical families were monitored. Sampling was carried out in urban (Paris) and rural (Aube district) sites, utilizing either a high-volume pump (12.5 m³ h^–1) (urban site) or a low-volume pump (2.3 m³ h^–1) for the rural site. Quartz filters and polyurethane foams (PUF) were used for sampling in all cases. After extracting the samples and concentrating the recovered solutions, high-performance liquid chromatography (HPLC) analysis with UV detection was performed. Identification of the pesticides was confirmed by applying to the HPLC measurements a novel UV-detection procedure based on the normalized absorbance variation with wavelength (Noravawa procedure). The presence of metsulfuron methyl, isoproturon, linuron, deltamethrin (and/or malathion), and chlorophenoxy acids (2,4-D and MCPP) was found at the urban sampling site at levels ranging from about 1 to 1130 ng m^–3 of air, depending on the compound and sampling period. On the rural sampling site residues of isoproturon, deltamethrin (and/or malathion), MCPP, and 2,4-D were generally detected at higher levels (19–5130 ng m^–3) than on the urban site, as expected. The effects of the weather conditions and agricultural activity on the atmospheric concentrations of pesticides are discussed, as are long-range atmospheric transfer processes for these pesticides.     

FDU-15-Pt composites with different Pt loading and their electrocatalytic reduction to ultratrace nitroaromatic compounds

FDU-15 is a hexagonal mesoporous material with nanometer-sized, highly ordered arrays and large special surface area. In this work, FDU-15-Pt with 2.0%, 5.0% and 8.0% Pt loading were synthesised and used for electrochemical detection of trace nitroaromatic compounds (NACs). The FDU-15-Pt samples were characterised by CO Chemisorption, transmission electron microscopy (TEM) and X-ray diffraction (XRD). It has been demonstrated that FDU-15-Pt with 2.0% Pt loading has the smallest Pt particle size of 2.9?nm, highest Pt metal dispersion of 37.7% and largest Pt metal surface area of 21.36?m^2?g^?1. The FDU-15-Pt/PDDA modified electrode were assembled by electrostatic adsorption of Poly (diallyldimethylammonium chloride) (PDDA) and FDU-15-Pt. The 2.0% FDU-15-Pt modified sensor showed higher selectivity for NACs than those of 5.0% and 8.0% FDU-15-Pt, which were verified by electrochemical experiments. A linear response over TNT concentration ranging from 8.8?×?10^?9?M to 1.2?×?10^?5 M was exhibited with a low detection limit of 2.9?×?10^?9?M (S/N?=?3). Moreover, the proposed 2.0% FDU-15-Pt/PDDA modified sensor has been applied to the detection of NACs in spiked environmental water samples and shows promise for fast and accurate determination of trace NACs in real samples.     

Fixation of XAD-4 power on filter paper using methyl cellulose for the passive air sampling of semi-volatile organic compounds in indoor air

The sorption capacity of a substrate serving as sampling medium can be enhanced by adding another sorbent to its surface. This is usually achieved through an impregnation process by repeated dipping of the substrate in a slurry solution containing the powder of the sorbent. Because the impregnation process only deposits the sorbent powder on the surface of the substrate, the powder could detach and fall off during field deployment. In this study, a novel approach was explored to fix the added sorbent powder to the surface of the substrate. Methylcellulose (MC) in fine crystal form was selected as the fixing agent to secure the powder of polystyrene-divinyl benzene copolymer resin (XAD-4), with its high sorption capacity, to a cellulose filter paper (CFP). The process involved first mixing XAD-4 and MC in the presence of water to form a milky slurry solution that was then painted on to the surface of the paper and then allowed to dry. The painting technique resulted in a good reproducibility of the applied amount of XAD-MC mixture with a relative standard deviation (RSD) of 12% (n = 5). Scanning electron microscope (SEM) images showed that the XAD-4 powder was held to the surface of the filter paper. No free XAD powder was dislodged from the coated filter paper when coated paper was flicked with a finger. For use as an indoor passive air sampler (PAS), this new sampling medium was placed in a round housing made of electronically polished aluminium material and was tested for uptake of polybrominated diphenyl ethers and phthalic acid dialkylesters. Surface area specific uptake rates (ASUR) of PBDEs ranged from 1.14 to 2.82 m³/(dm²d), while ASUR of phthalates had a wider range from 2.74 to 5.66 m³/(dm²d).     

Application of Double-Phase Liquid Phase Microextraction in the Determination of Partition Coefficients and Analysis of Pesticides in Water Samples

A simple and solvent-minimized sample preparation technique based on two-phase hollow fiber-protected liquid-phase microextraction has been developed and used for the determination of partition coefficient and analysis of selected pesticides in environmental water samples. The analysis was performed by gas chromatography–electron capture detector. Three pesticides namely hexaconazole, quinalphos, and methidathion were considered as target analytes. Extraction conditions such as solvent identity, salt concentration, stirring speed, extraction time, length of the hollow fiber, and volume of donor phase were optimized. The analytes were extracted from a donor phase (water sample) through 3 μL of an organic solvent immobilized in the pores of a porous polypropylene hollow fiber and then into the acceptor phase present inside the hollow fiber. Excellent extractions of the analytes were achieved under the optimized conditions, with relative standard deviations of 4.6–7.9%, correlation coefficients (r ²) of 0.9954–0.9986 and limits of detection of 3–7 ng L^?1. The proposed method provided good average enrichment factors of up to 250-fold. The partition coefficients of the analytes determined were found to be directly correlated with the enrichment factor. The present methodology also confirms the robustness of microextraction for monitoring trace levels of pesticides in environmental water samples.     

Simultaneous Filtration and Solid-Phase Extraction Combined with Large-Volume Injection in GC/MS for Ultra-Trace Analysis of Polar Pesticides in Surface Water

A method combining simultaneous filtration and solid-phase extraction (SPE) with large-volume injection (LVI) in gas chromatography/mass spectrometry (GC/MS) was developed to determine 13 polar pesticides in surface water. The selected pesticides - 4 organophosphorus, 7 organonitrogens and 2 triazine degradation products - were extracted from 0.5-L samples of filtered and raw water using cartridges filled with a silica-bonded material (1 g of ISOLUTE triazine, C-18) and a depth filter. No obstruction was observed during the extraction of raw water drawn from the St. Lawrence River (concentration of suspended particulate matter (SPM) ranging from 2 to 58 mg L^?1). Overall percent recoveries were satisfactory for all the target pesticides (>60%) except desisopropyl-atrazine (more polar), which varied from 29 to 46% according to sample pH. The coefficient of variation was below 10% for the majority of the target pesticides and detection limits ranged from 0.1 to 0.8 ng L^?1. Applied to real samples drawn from the St. Lawrence River, this method allowed for the detection of atrazine, cyanazine, desethyl-atrazine (DEA), desisopropyl-atrazine (DIA), metolachlor and simazine, at concentrations of 6 to 91 ng L^?1. Using atrazine and metolachlor as examples, the correlation between filtered and raw water samples was more significant for the former (r = 0.87) than for the latter (r = 0.67). Temporal variations in atrazine and metolachlor in filtered water drawn from the St. Lawrence River, for example, were similar whether using the established method, based on liquid-liquid large-volume extraction (LVE) combined with GC/NPD analysis, or the one proposed herein. The latter method, however, systematically found atrazine concentrations 62% higher than those obtained by the older one, applied to the same field samples. Thus, the switch to the new analytical method will require the application of a correction factor to the atrazine concentration time series acquired with the previously used method.     

Simultaneous determination of nicotine and 3-vinylpyridine in single cigarette tobacco smoke and in indoor air using direct extraction to solid phase

The aim of the present study was to develop a new analytical method of chromatographic determination of two important markers of ETS exposure: nicotine and 3-vinylpyridine (3-ethenylpyridine, 3-EP) in mainstream (MS) and sidestream (SS) smoke of one single cigarette and in indoor air using direct solid phase extraction combined with gas chromatography. The method can be utilised for both nicotine and 3-EP determination in SS and MS of one single cigarette as well as it allows for a precise determination of compound distribution in indoor air. The application of the same analytical method for both kinds of samples allows anticipating indoor air distribution of both analysed compounds in a very precise way. The precision of the method (calculated as a relative standard deviation) was 9.78% for nicotine and 2.67% for 3-EP; whereas the accuracy (evaluated by a recovery study conducted at three different levels) was 70.1 and 87.3%, respectively. The limit of detection was 0.06 µg per cigarette for both nicotine and 3-EP. The method was evaluated by determining the compounds of interest in two commercially available brands of cigarettes as well as in the reference cigarettes 3R4F and also in indoor air polluted with tobacco smoke. Determined levels of compounds of interest in MS varied from 586 to 772 (nicotine) µg per cigarette and from 3.5 to 10.7 (3-EP) µg per cigarette. In SS smoke the level varied from 14,370 to 22,590 (nicotine) µg per cigarette and from 185 to 550 (3-EP) µg per cigarette, whereas levels in indoor air polluted with tobacco smoke varied from 50.1 to 157.3 (nicotine) µg m^?3and from 7.7 to 20.8 (3-EP) µg m^?3.     

A highly sensitive and rapid biological probe enhanced real-time immuno-polymerase chain reaction for detecting 2,2′,4,4′-tetrabromodiphenyl ether in indoor airborne particles

Polybrominated diphenyl ethers (PBDEs) are bromine flame retardants that are widely distributed in the environment. In this study, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) was used as a model PBDE compound. Based on the preparation of BDE-47 immunogen, coating antigen and polyclonal anti-BDE-47 antibody, a highly sensitive and rapid real-time immuno-polymerase chain reaction using biological probes (BP-IPCR) was developed to detect BDE-47 in indoor airborne particles. Several physiochemical factors that might influence the assay performance were optimised, such as OVA-BDE-47 and the biological probe concentration, primer concentration and annealing temperature. Under the optimal conditions, a standard curve was constructed with BDE-47 concentrations ranging from 5 pg L^?1 to 50 ng L^?1. The limit of detection was 1.32 pg L^?1. The BP-IPCR assay was highly selective, presenting low cross-reactivity values with BDE-47 analogues (below 5.26%). The recoveries of spiked samples were 92.6–107.9% and the coefficients of variation were 3.7–8.8%. The BP-IPCR data for the detection of BDE-47 in indoor airborne particles was consistent with gas chromatography-mass spectrometry findings (R² = 0.9849). This immunoassay is sensitive and reliable; it can be used for specific and sensitive batch detection of BDE-47 in environmental samples.     

High-volume sampling of airborne polychlorobiphenyls with amberlite xad-2 resin

Polyurethane foam, polyurethane foam coated with DC-200, Florisil, and Amberlite XAD-2 resin have been evaluated in a small-scale comparative study of their ability to sample airborne polychlorobiphenyls. XAD-2 resin has an excellent collection efficiency for tetrachlorobiphenyl at 1 l min^-1 flow rates and is also suitable for high-volume air sampling. A high-volume air sampler was modified to sample both particulate and vapor-phase polychlorobiphenyls by incorporating the XAD-2 resin behind a glass fiber filter. When the sampling system was operated at a flow rate of 0.7 m³ min^-1 for 24 h, the collection efficiencies for tetrachlorobiphenyl and Aroclor 1221 were 96.5% and 83.0%, respectively.     

The Nonreversibility of Adsorption-Desorption of Dieldrin and Lindane on Chitin in Seawater

Abstract

Adsorption and desorption of dieldrin and lindane on chitin were investigated in seawater batch tests as a function of chitin concentration, temperature, pH and salinity. For chitin concentrations ranging from 0.5 g l^?1 to 12.5 g l^?1, the pesticide concentrations were varied from 4 μgl^?1 to 65 μg^?1 for dieldrin and from 40 μl^?1 to 680 μg l^?1 for lindane. Both dieldrin and lindane show adsorption-desorption hysteresis at low chitin concentration. At high chitin concentrations (m > 6.25 g l^?1 for dieldrin and m > 10 gl^?1 for lindane) both pesticides exhibit reversible behaviour. However, only lindane adsorption is affected by chitin concentration. These types of behaviour remain fixed in prewashed chitin. However, an increase in the temperature and a decrease in the salinity made the process become reversible. A resistant-reversible two component model has been applied to account for these types of behaviour and provides a way to explain most of the observed effects by defining mass independent distribution coefficients.