Analysis of trace levels of pesticides in rainwater using SPME and GC–tandem mass spectrometry

Modified DLLME-GC-TQMS determination of pesticide residues in Gomti River, Lucknow, India: ecological risk assessment and multivariate statistical approach

This research article aims to establish an easy and well-defined analytical method for detection and quantification of multiclass pesticides in Gomti river water samples because the increased agricultural activities, industrialization, and urbanization had increased the presence of pesticides in the ecosystem which causes the depletion of water quality making it a global concern. The analytical method, vortex-assisted ultrasonication-based dispersive liquid-liquid microextraction-solidification of floating organic droplets (VAUS-DLLME-SFO) was optimized using one parameter at a time approach which gave the recovery between 69.45 and 114.15%, limit of detection (LOD), and limit of quantification (LOQ) 0.0011-0.0111 µg/L and 0.0033-0.0368 µg/L, respectively, and RSD in the range of 0.75-1.29 which shows sensitivity and accuracy better than earlier reported methods. The data obtained were subjected to measurement uncertainty, risk assessment, and multivariate statistical analysis to establish the robustness of the developed analytical method. The measurement uncertainty found was concluded to be in the acceptable range for analytical results. Furthermore, the real samples were analyzed and the associated value of the risk quotient was found to be less than 1, except for aquatic invertebrates, establishing the fact that the current concentration of pesticides has no such negative threat to flora and fauna. The possible source of pesticides in the Gomti river system was established by multivariate analysis. It was thus concluded that anthropogenic activity is responsible for the variable concentration of pesticides found in the sample.

Utilization of long duration high-volume sampling coupled to SPME-GC-MS/MS for the assessment of airborne pesticides variability in an urban area (Strasbourg, France) during agricultural application

Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used in maize crops (acetochlor, benoxacor, dicamba, s-metolachlor, pendimethalin, and bromoxynil), in cereal crops (benoxacor, chlorothalonil, fenpropimorph, and propiconazole), in vineyards (tebuconazole), and as herbicides for orchards, meadows of green spaces (2,4-MCPA, trichlopyr). This is in accordance with the diversity of crops found in the Alsace region and trends observed are in accordance with the period of application of these pesticides. Variations observed permit also to demonstrate that the long time sampling duration used in this study is efficient to visualize temporal variations of airborne pesticides concentrations. Then, long time high-volume sampling could be a simple method permitting atmospheric survey of atmospheric contamination without any long analysis time and consequently low cost.

Partitioning of the pesticide trifluralin between dissolved organic matter and water using automated SPME-GC/MS

Solid-phase microextraction (SPME) was used to determine the equilibrium association constant for a pesticide, trifluralin (TFR), with dissolved organic matter (DOM). After optimization of the SPME method for the analysis of TFR, partition coefficients (K DOM) with three different sources of DOM were determined in buffered solutions at pH 7. Commercial humic acids and DOM fractions isolated from two surface waters were used. The values of log K DOM varied from 4.3 to 5.8, depending on the nature of the organic material. A good correlation was established between log K DOM and DOM properties (as measured with the H/O atomic ratio and UV absorbance), in agreement with literature data. This is consistent with the effect of polarity and aromaticity for governing DOM-pollutant associations, regardless of the origin of DOM. This association phenomenon is relevant to better understand the behavior of pesticides in the environment since it controls part of pesticide leaching and fate in aquatic systems.

Application of XAD-2 resin-based passive samplers and SPME-GC-MS/MS analysis for the monitoring of spatial and temporal variations of atmospheric pesticides in Luxembourg

Passive air sampling has been shown to be a very interesting alternative to high-volume sampling by overcoming its disadvantages (size, weight, expensiveness). However, to date, only limited data is available about passive air sampling of current-use pesticides. In order to test if passive samplers allow monitoring of spatial and temporal variations of atmospheric pesticide concentrations, five XAD-2-resin based passive air samplers were deployed at five locations in Luxembourg. Samplers were analyzed using accelerated solvent extraction coupled to solid-phase microextraction and gas chromatography with tandem mass spectrometry. Collected data was used to study the spatial and temporal variations of the concentrations of the compounds. Twenty two pesticides were detected between March and October, while no pesticides were detected from November to February. Highest concentrations were measured on the rural sites, suggesting that the used XAD-2 resin-based passive samplers allow the simultaneous monitoring of multiple current-use pesticides and identifying spatial and temporal variations.

Uso de agrotóxicos na produção de soja do estado do Mato Grosso: um estudo preliminar de riscos ocupacionais e ambientais

OBJETIVO: identificar e discutir alguns dos principais riscos associados ao uso de agrotóxicos na produção de soja do estado de Mato Grosso. MÉTODO: estudo exploratório descritivo, de caráter preliminar, realizado entre 2008 e 2009 e baseado em triangulação metodológica que incluiu: análise de banco de dados agrícola; análise de indicadores biológicos da exposição a agrotóxicos; e análise da contaminação de água de chuva por esses agentes químicos. RESULTADOS: a análise dos dados de consumo mostra um elevado e crescente uso de agrotóxicos, em particular o do herbicida glifosato. A análise da água de chuva mostrou presença de resíduos de diferentes agrotóxicos, ampliando o risco para além do ambiente de trabalho. Essa exposição ambiental foi detectada pela análise de indicadores biológicos de exposição a agrotóxicos junto a trabalhadores e moradores de áreas próximas às zonas de plantio. CONCLUSÃO: os dados do estudo apontam para a necessidade de um monitoramento ambiental e de saúde permanente em áreas produtoras de soja como parte das estratégias de vigilância em saúde do trabalhador e ambiental.

Determination of farm workers' exposure to pesticides by hair analysis

In the present work, a highly sensitive method based on solid phase microextraction and gas chromatography tandem (triple quadrupole) mass spectrometry was used to test hair samples for 50 pesticides including 39 molecules from different chemical families currently used in agriculture and 11 organochlorines. The population investigated was composed of 18 farm workers who provided hair samples repeatedly collected during the entire treatment period (from March to November 2009). Among the 62 hair samples that were collected, 33 different target molecules were detected. The most frequently detected agricultural pesticides were Diflufenican and Pyrimethanil, two herbicides which were detected in 13 subjects. The concentration in volunteers' hair matched with agricultural activity and the highest concentration was observed for Cyprodinil (1161pg/mg), an anilinopyrimidine used as a fungicide. For organochlorines, p,p'-DDE and γ-HCH were the most frequently detected molecules as they were present in at least one of the hair samples provided by each of the 18 volunteers. The highest concentrations detected for these chemicals reached 21.0pg/mg for p,p'-DDE and 23.5pg/mg for γ-HCH, but the highest concentration of organochlorine was observed for β-endosulfan (105pg/mg). The results suggest that farm workers have a weak, though constant exposure to organochlorine pesticides, especially to p,p'-DDE and γ-HCH, while exposure to currently used pesticides is strongly associated with occupation. Observations also suggest that spraying work would not necessarily be the only source of exposure to agricultural pesticides and that worker not directly involved in spraying can also be submitted to significant level of exposure.

Preconcentration and determination of pyrethroid insecticides in with ionic liquid dispersive liquid-phase microextraction in combination with high performance liquid chromatography

This paper developed a new method with temperature controlled ionic liquid dispersive liquid-phase microextraction for the determination of pyrethroid insecticides such as fenpropathrin, fenvalerate and bifenthrin in water samples. The effect of alkyl chain length of ionic liquid 1-alkyl-3-methylimidazolium hexafluorophosphate and other parameters such as sample pH, temperature, salting-out effect and sample volume on the extraction efficiency were investigated in detail. Four different alkyl chain length ionic liquids ([CnMIM][PF6], n = 4, 6, 7, 8) were tested. The experimental results demonstrated that the alkyl chain length of ionic liquids (ILs) did have an important role on the extraction efficiency. The experimental results indicated that the longer alkyl chain length of ILs resulted in better extraction efficiency. Among the four ILs, 1-octyl-3-methylimidazolium hexafluorophosphate [C8MIM] [PF6] was the best one for extraction of the target analytes. Under the optimized conditions, three pyrethroid insecticides had limits of detection (LOD, S/N = 3) in the range of 0.34∼0.48 μg L-1. The precisions of the proposed method (RSDs, n = 6) with a spiked concentration of 20 μg L-1 were in the range of 2.0∼3.4%. The proposed method was evaluated with real water samples spiked at a concentration of 10 ng mL-1 and good spiked recoveries over the range of 89.2∼102.7% were obtained.

Multi-residual GC-MS determination of personal care products in waters using solid-phase microextraction

A multi-residual method is described for the simultaneous determination of 23 personal care products (PCPs), which display a wide range of physicochemical properties, present at trace levels in water samples. A one-step procedure was developed based on solid-phase microextraction (SPME) coupled with GC-MS analysis. A chemometric approach consisting of an experimental design (design of experiments) was applied to systematically investigate how four operating parameters--extraction temperature and time and desorption temperature and time--affect extraction recovery of PCPs in water. The optimum SPME procedure operating conditions, those yielding the highest extraction recovery for all the compounds, were determined; they correspond to an extraction time of 90 min and temperature of 80 °C and a desorption time of 11 min and temperature of 260 °C. Under these optimized conditions, the SPME procedure shows good analytical performance characterized by high reproducibility (RSD% intra-day accuracy varying in the 0.01-1.3% range) as well as good linearity and low detection limits (LODs lower than 2 ppb for most of the investigated PCPs).

Temporal variations of concentrations of currently used pesticides in the atmosphere of Strasbourg, France

Atmospheric samples have been collected in Strasbourg between April 18 and May 29, 2007 and were analyzed for 71 current-use pesticides, of which 38 were detected. Average concentrations ranged from 0.09 ng m(-3) for Fenarimol to 110.42 ng m(-3) for Dimethachlor, which was slightly higher than the concentrations reported from other, comparable agricultural regions. Significant temporal variations were observed for 30 pesticides, and for most of them it could be shown that these were linked to time, temperature or atmospheric pressure. In several cases this helped to identify pesticide application just before or at the beginning of the sampling period, or ongoing treatment. Humidity, in contrast to previous reports, could not be linked to these variations. For the other 8 pesticides, only very little temporal variations were observed. Generally, these concentrations were low (less than 1 ng m(-3)), and it was assumed that they are not in use in Alsace at present.

Determination of trace levels of aquaculture chemotherapeutants in seawater samples by SPME-GC-MS/MS

A sensitive and efficient solid-phase microextraction (SPME) method for the determination of organophosphorous (OPPs) and pyrethroid pesticides (Pyrs) in aquaculture-seawater samples by using GC with MS/MS (GC-MS/MS) was developed. Dichlorvos and chlorpyrifos (OPPs); permethrin, alpha-cypermethrin and deltamethrin (Pyrs) were selected according to their use as chemotherapeutants in the aquaculture industry. Different parameters affecting extraction efficiency such as fibre coating, agitation, pH and extraction time profiles were investigated. An experimental central composite design (alpha = 1) and desirability functions were used for the simultaneous optimization of extraction temperature and sample volume. Finally, a method based on direct SPME in 40 min at 75 degrees C using 100-microm-thick poly(dimethyl)siloxane (PDMS) fibre and 20 mL of sample volume is proposed. The method was validated, exhibiting good linearity, precision and accuracy parameters with picogram per millilitre LODs. The proposed methodology was applied to determine the ultratrace levels of OPPs and Pyrs in aquaculture-seawater samples by the standard addition approach, which proved to be reliable and sensitive, in addition to requiring only small amounts of sample.

Needs for reliable analytical methods for monitoring chemical pollutants in surface water under the European Water Framework Directive

The state of the art in monitoring chemical pollutants to assess water quality status according to Water Framework Directive (WFD) and the challenges associated with it have been reviewed. The article includes information on environmental quality standards (EQSs) proposed to protect the aquatic environment and humans against hazardous substances and the resulting monitoring requirements. Furthermore, minimum performance criteria for analytical methods and quality assurance issues have been discussed. The result of a survey of existing standard methods with a focus on European (EN) and international standards (ISO) for the analysis of chemical pollutants in water is reported and the applicability of those methods for the purpose of compliance checking with EQSs is examined. Approximately 75% of the 41 hazardous substances for which Europe-wide EQSs have been proposed can be reliably monitored in water with acceptable uncertainty when applying existing standardised methods. Monitoring in water encounters difficulties for some substances, e.g., short-chain chlorinated paraffins (SCCPs), polybrominated diphenyl ethers (PBDEs), tributyltin compounds, certain organochlorine pesticides and six-ring PAHs, mainly due to a lack of validated, sufficiently sensitive methods that are applicable in routine laboratory conditions. As WFD requires monitoring of unfiltered samples for organic contaminants more attention needs to be paid to the distribution of chemical pollutants between suspended particulate matter and the liquid phase. Methods allowing complete extraction of organic contaminants from whole water samples are required. From a quality assurance point of view, there is a need to organise interlaboratory comparisons specifically designed to the requirements of WFD (concentrations around EQSs, representative water samples) as well as field trials to compare sampling methodologies. Additional analytical challenges may arise when Member States have identified their river basin specific pollutants and after revision of the list of priority substances.

Current trends in solid-phase-based extraction techniques for the determination of pesticides in food and environment

Solid-phase extraction (SPE) procedures for pesticide residues in food and environment are reviewed and discussed. The use of these procedures, which include several approaches such as: matrix solid-phase dispersion (MSPD), solid-phase micro-extraction (SPME) and stir-bar sorptive extraction (SBSE), represents an opportunity to reduce analysis time, solvent consumption, and overall cost. SPE techniques differ from solvent extraction depending on the interactions between a sorbent and the pesticide. This interaction may be specific for a particular pesticide, as in the interaction with an immunosorbent, or non-specific, as in the way a number of different pesticides are adsorbed on apolar or polar materials. A variety of applications were classified according to the method applied: conventional SPE, SPME, hollow-fiber micro-extraction (HFME), MSPD and SBSE. Emphasis is placed on the multiresidue analysis of liquid and solid samples.