Multi-component trace analysis of organic xenobiotics in surface water containing suspended particular matter by solid phase extraction/gas chromatography–mass spectrometry

Pollution of water in Africa: a review of contaminants and fish as biomonitors and analytical methodologies-the case of Senegal

Environmental pollution is one of the major problems facing human health, ecosystems, and biodiversity. This is particularly the case for water quality in Senegal. Fish can be used as a biomonitor of pollution by accumulating pollutants from the environment through their tissues. Fish is an indispensable element in the assessment of the quality of the environment due to the diversity of biological cycles and their position in the food chain. Fish, which is very sensitive to chemical and bacterial pollution, concentrates pollutants and is a good indicator of water quality. This review presents water pollution in Senegal and the possibility of using fish as an ideal monitoring matrix for marine environments, to detect the concentration of heavy metals and organic pollutants. The different extraction and analytical techniques used for fish biomonitoring will be also described.

Spatial distribution of organochlorine and organophosphorus pesticides in soil-groundwater systems and their associated risks in the middle reaches of the Yangtze River Basin

Soil and groundwater samples were collected from paddy fields in the middle reaches of the Yangtze River Basin to study the occurrence and the risks associated with organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) in soil and groundwater. Results showed that OCPs and OPPs were widely distributed throughout the study area. The levels of OCPs and OPPs in the soil were much lower than those specified by soil quality standards. However, the levels of four OCPs (heptachlors, aldrin, dieldrin, and γ-hexachlorocyclohexane) in groundwater were higher than those permitted by drinking water standards. The health risk assessment method suggested by the US Environment Protection Agency was used to evaluate the regional risks from selected pesticides. Results showed that there were low health risks from OCPs and OPPs in soil at the regional scale, but high risks from heptachlor, aldrin, and endrin in groundwater, suggesting an urgent need for groundwater protection. There are widespread concerns on dichlorodiphenyltrichloroethane and hexachlorocyclohexane, but little focus on other pesticides in China. However, our results suggest that the presence of, and risks from, other pesticides in groundwater should be a focus from the region aspect.

Chemical monitoring of Swedish coastal waters indicates common exceedances of environmental thresholds, both for individual substances as well as their mixtures

Chemical pollution was monitored and assessed along the Swedish west coast. 62 of 172 analyzed organic chemicals were detected in the water phase of at least one of five monitored sites. A Concentration Addition based screening-level risk assessment indicates that all sites are put at risk from chemical contamination, with total risk quotients between 2 and 9. Only at one site did none of the individual chemicals exceeded its corresponding environmental threshold (PNEC, EQS). The monitoring data thus demonstrate a widespread blanket of diffuse pollution, with no clear trends among sites. Further issues critical for the environmental chemical risk assessment include the challenges to achieve sufficiently low levels of detection, especially for hormones and cypermethrin (a pyrethroid insecticide), the appropriate consideration of non-detects and the limited availability of reliable PNECs and EQS values.

Influence of the drying step within disk-based solid-phase extraction both on the recovery and the limit of quantification of organochlorine pesticides in surface waters including suspended particulate matter

In this study, 21 organochlorine pesticides (OCPs) were determined based on sample preparation using solid-phase extraction disks (SPE disks) coupled with programmable temperature vaporizer (PTV)-large-volume injection gas-chromatography mass spectrometry (LVI-GC-MS). The work includes a comprehensive testing scheme on the suitability of the method for routine analysis of surface and drinking water including suspended particulate matter (SPM) with regard to requirements derived from the European Water Framework Directive (WFD, Directive 2000/60/EC). SPM is an important reservoir for OCPs, which contributes to the transport of these compounds in the aquatic environment. To achieve the detection limits required by the WFD, a high pre-concentration factor during sample preparation is necessary, which was achieved by disk SPE in this study. The performance of disk SPE is strongly influenced by the drying step, which could be significantly improved by effective elimination of the residual water by combination of a high vacuum pump and a low humidity atmosphere. Detection limits of the WFD in the ng/L range were achieved by large volume injection of 100μL sample extract. The recoveries ranged from 82% to 117% with an RSD smaller than 13%. The applicability of this method to natural samples was tested for instrumental qualification and system suitability evaluation. Successful participation in an interlaboratory comparison proved the suitability of the method for routine analysis.

Potential reference measurement procedures for PBDE in surface water at levels required by the EU Water Frame Directive

Polybrominated diphenylethers (PBDE), used as flame retardants, are named as priority substances in the Directive 2000/60/EC of the European parliament and of the council establishing a framework for Community action in the field of water policy. An annual average environmental quality standard (EQS) for inland surface waters of 0.0005 µg/L (0.0002 µg/L for other surface waters) for PBDE congeners involved in the technical penta-PBDE mixtures containing PBDE with five bromine atoms has been established. The directives focus especially on the congeners PBDE 28, 47, 99, 100, 153 and 154 contained in the penta-PBDE mixture. Up to now, no reference measurement procedures have been established reaching the limits of quantification (LOQs) and the associated uncertainties as defined in the directives with results traceable to the SI. Within a recent European project on metrology, different approaches for the traceable quantification of PBDE, based on liquid/liquid or solid phase extraction followed by the detection with gas chromatography coupled to either inductively coupled plasma mass spectrometry or triple quadrupole mass spectrometry, were investigated and the related LOQs and expanded uncertainties of the results were compared. A complete uncertainty budget for each method was estimated according to the Guide to the Expression of Uncertainty in Measurement (GUM). All presented analytical procedures can serve as reference measurement procedures regarding the LOQs and their associated expanded uncertainties for monitoring the six priority PBDEs named above. LOQs as low as 0.026 ng/kg with an associated expanded uncertainty of 0.002 ng/kg could be achieved.

Yangtze Three Gorges Reservoir, China: A holistic assessment of organic pollution, mutagenic effects of sediments and genotoxic impacts on fish

Besides obvious benefits, the Three Gorges Dam's construction resulted in new pollution scenarios with the potentials to threaten the Three Gorges Reservoir (TGR) ecosystem. In order to record organic contamination, to find links to ecotoxicological impacts and to serve as reference for ensuing monitoring, several sites in the TGR area were screened applying the triad approach with additional lines-of-evidence as a holistic assessment method. Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011 and 2012 to determine organic pollution levels, mutagenic potentials and genotoxic impacts. Two regional hot-spots near the cities of Chongqing and Kaixian were identified and further investigated in 2013. Only polycyclic aromatic hydrocarbons (PAHs) could be detected in sediments in 2011 (165-1653ng/g), emphasizing their roles as key pollutants of the area. Their ubiquity was confirmed at Chongqing (150-433ng/g) and Kaixian (127-590ng/g) in 2013. Concentrations were comparable to other major Chinese and German rivers. However, the immense sediment influx suggested a deposition of 216-636kgPAH/day (0.2-0.6mgPAH/(m(2)·day)), indicating an ecotoxicological risk. PAH source analysis highlighted primary impacts of combustion sources on the more industrialized upper TGR section, whereas petrogenic sources dominated the mid-low section. Furthermore, sediment extracts from several sites exhibited significant activities of frameshift promutagens in the Ames fluctuation assay. Additionally, significant genotoxic impairments in erythrocytes of P. vachellii were detected (Chongqing/Kaixian), demonstrating the relevance of genotoxicity as an important mode of action in the TGR's fish. PAHs, their derivatives and non-target compounds are considered as main causative agents.

Monitoring of selected priority and emerging contaminants in the Guadalquivir River and other related surface waters in the province of Jaén, South East Spain

The province of Jaén counts with four natural parks, numerous rivers, reservoirs and wetlands; moreover, it is probably the region with higher olive oil production in the world, which makes this zone a proper target to be studied based on the European Water Framework Directive 2000/60/CE. The aim of this survey is to monitor a total number of 373 compounds belonging to different families (pesticides, PAHs, nitrosamines, drugs of abuse, pharmaceuticals and life-style compounds) in surface waters located at different points of the province of Jaén. Among these compounds some priority organic substances (regulated by the EU Directive 2008/105/EC) and pollutants of emerging concern (not regulated yet) can be found. A liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) method covering 340 compounds was developed and applied, together with a gas chromatography triple-quadrupole mass spectrometry (GC-MS/MS) method which enabled the analysis of 63 organic contaminants (30 of these compounds are analyzed by LC-TOFMS as well). From April 2009 to November 2010 a total of 83 surface water samples were collected (rivers, reservoirs and wetlands). In this period numerous organic contaminants were detected, most of them at the ng L(-1) level. The most frequently priority substances found were chlorpyrifos ethyl, diuron and hexachlorobenzene. Within the other groups, the most frequently detected compounds were: terbuthylazine, oxyfluorfen, desethyl terbuthylazine, diphenylamine (pesticide family); fluorene, phenanthrene, pyrene (PAHs group), codeine, paracetamol (pharmaceuticals compounds) and caffeine, nicotine (life-style compounds). As is could be expected, the total concentration of emerging contaminants is distinctly larger than that of priority pollutants, highlighting the importance of continuing with the study of their presence, fate and effects in aquatic environments. However, concentration levels (at the ng per liter level) are low in general for both kinds of contaminants which minimizes the possible harmful effect on the environment.