Article

A headspace SPME-GC-ECD method suitable for determination of chlorophenols in water samples.

Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, Porto, Portugal.
Analytical and Bioanalytical Chemistry (Impact Factor: 3.66). 03/2011; 399(7):2531-8. DOI: 10.1007/s00216-010-4610-y
Source: PubMed

ABSTRACT A headspace solid phase microextraction coupled to gas chromatography with electron capture detector (HS-SPME-GC-ECD) method was optimized for the determination of seven chlorophenols (CPs) with different levels of chlorination. This is the first time that HS-SPME-GC-ECD with acetylation of the analytes is used for the simultaneous determination of CPs in water samples. The influence of fibre type, derivatization conditions, salt addition, temperature and time of extraction and temperature of desorption was checked. Possible sources of contamination and analyte losses were considered. The best results were obtained with the polydimethylsiloxane/divinylbenzene fibre, derivatization by acetylation using 100 μL of acetic anhydride and 0.1 g of anhydrous sodium carbonate per 10 mL of sample, salt addition of 100 g L(-1) sodium chloride, extraction at 70 °C for 60 min and desorption in the GC injector at 260 °C for 6 min. The limits of detection (LOD) for monochlorophenols were 12 and 122 ng L(-1) for 2-chlorophenol and 4-chlorophenol, respectively. For polychlorinated CPs, the LODs were lower than 6 ng L(-1), values similar to the existing methods that use SPME with derivatization for CPs determination in water samples. The method is suitable for the determination of CPs in most environmental aqueous samples. Repeatability and reproducibility were less than 16.8% and 11.7%, respectively. The optimized method was successfully applied for the analysis of waters with complex matrices such as river and estuarine water samples.

0 Bookmarks
 · 
138 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Chlorophenols (CPs) as persistent toxic compounds are of worldwide environmental concern. Usage of chlorinated phenols, especially pentachlorophenol (PCP), has been restricted or widely banned in many countries due to their possible adverse health effects even at low concentrations. Ion mobility spectrometry (IMS) has received increasing interest in environmental applications due to its unique characteristics, such as portability and speed of analysis. A range of sample introduction methods combined with IMS enable analysis from different environmental matrices. This study utilised headspace solid phase microextraction IMS (HS-SPME-IMS) in the determination of CPs from water samples. The extraction conditions were examined and the method was applied to real water samples. The developed method is suitable to detect CPs at milligram per liter level in water. Based on the results, SPME-IMS setup is feasible as an early warning system for water monitoring of pollutants present in drinking or surface water in case of environmental accidents or leakages.
    Talanta 09/2013; 114:176-82. · 3.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pentachlorophenol (PCP) effects on a strain of the cyanobacterium Microcystis aeruginosa were investigated at laboratory scale. This is the first systematic ecotoxicity study of the effects of PCP on an aquatic cyanobacterium. The microalga Chlorella vulgaris was studied in the same conditions as the cyanobacterium, in order to compare the PCP toxicity and its removal by the species. The cells were exposed to environmental levels of PCP during 10 days, in Fraquil culture medium, at nominal concentrations from 0.01 to 1000 μg L(-1), to the cyanobacterium, and 0.01 to 5000 μg L(-1), to the microalga. Growth was assessed by area under growth curve (AUC, optical density vs time) and chlorophyll a content (chla). The toxicity profiles of the two species were very different. The calculated effective concentrations EC20 and EC50 were much lower to M. aeruginosa, and its growth inhibition expressed by chla was concentration-dependent while by AUC was not concentration-dependent. The cells might continue to divide even with lower levels of chla. The number of C. vulgaris cells decreased with the PCP concentration without major impact on the chla. The effect of PCP on M. aeruginosa is hormetic: every concentration studied was toxic except 1 μg L(-1), which promoted its growth. The legal limit of PCP set by the European Union for surface waters (1 μg L(-1)) should be reconsidered since a toxic cyanobacteria bloom might occur. The study of the removal of PCP from the culture medium by the two species is an additional novelty of this work. M. aeruginosa could remove part of the PCP from the medium, at concentrations where toxic effects were observed, while C. vulgaris stabilized it.
    Water Research 01/2014; 52C:63-72. · 4.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pentachlorophenol (PCP) is a priority pollutant due to its persistence and high toxicity. For the first time, PCP effects were investigated at laboratory scale on co-cultures of two ubiquitous freshwater phytoplankton species: the cyanobacterium Microcystis aeruginosa and the microalga Chlorella vulgaris. The cells were exposed to environmental levels of PCP for 10 days in Fraquil culture medium, at nominal concentrations from 0.1 to 10000 μg L−1. Growth was assessed by area under growth curve (cell count vs time). The phytoplankton community structure can be changed as a consequence of a PCP contamination. Low μg L−1 levels of PCP are advantageous to M. aeruginosa. This is the first report of the promoting effect of PCP on the growth of aquatic cyanobacteria, using mixtures with microalgae. As a result of the direct toxic effects of high PCP concentrations on M. aeruginosa, C. vulgaris cell count increased given that in biological controls M. aeruginosa inhibited the C. vulgaris growth. At 16.7 mg L−1, PCP already had direct toxic effects also on the microalga. The pH of culture medium tended to decrease with increasing PCP concentrations, which was mostly related to the growth inhibition of cyanobacterium caused by PCP. The PCP concentration was stable in the co-cultures, which differed from what has been observed in monocultures of the same two species. Short-term laboratory assays with two phytoplankton species gives important information on the species interactions, namely possible direct and indirect effects of a toxicant, and must be considered in ecotoxicity studies regarding environmental extrapolations.
    Aquatic Toxicology 05/2014; 150:159-164. · 3.73 Impact Factor