Anna Kotrikla

Determination of two antifouling booster biocides and their degradation products in marine sediments by high performance liquid chromatography-diode array detection

A method for the simultaneous determination of two antifouling booster biocides, diuron [1-(3,4-dichlorophenyl)-3,3-dimethylurea] and irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) and their degradation products, DCPMU [1-(3,4-dichlorophenyl)3-methylurea], DCPU [1-(3,4-dichlorophenyl) urea], DCA [3,4-dichloroaniline] and M1 (2-methylthio-4-tert-butylamino-s-triazine), in marine sediments by high performance liquid chromatography–diode array detection (HPLC–DAD) was developed. The extraction of these compounds from sediment was achieved by means of methanolic ultrasonic extraction. The optimization of the extraction procedure included the variation of the volume of the extraction solvent, the amount of the extracted sediment, the duration and the temperature of sonication. C18 solid phase extraction (SPE) cartridges were used for the cleaning of the extracts. The relative standard deviations (R.S.Ds) of the developed procedure was <10% for all the tested compounds, except for DCA, where R.S.Ds up to 15% were obtained. Satisfactory recoveries were obtained (higher than 80% for all substances), except for DCA, which gave a recovery in the range of 35–50%. The limits of detection (LODs) of the substances varied between 1.7 (DCPU) and 4.0 (DCPMU) ng g −1 of dry sediment.

Monitoring of triazine and phenylurea herbicides in the surface waters of Greece.

A large-scale study was implemented to monitor triazine and phenylurea herbicides in the main surface water bodies of continental Greece from October 1998 to September 1999. Samples from 10 rivers and 7 lakes were analyzed for the presence of five triazine (atrazine, cyanazine, prometryne, simazine, terbuthylazine) and five phenylurea (chlorotoluron, diuron, linuron, metobromuron, monolinuron) herbicides. The samples were extracted with C18 cartridges and analyzed by high-performance liquid chromatography–diode array detection (HPLC-DAD). The most frequently detected herbicides were atrazine, followed by prometryne, cyanazine, and simazine. The concentrations of the compounds were generally low (< 0.78 μ g/L) and are not considered harmful for the freshwater ecosystem. Most of the positive samples were taken from the water bodies of northern Greece where agricultural activity is more intense.

Monitoring priority substances of directives 76/464/EEC and 2000/60/EC in Greek water bodies.

The priority substances of List I, 76/464/EEC Directive, some of which belong to the new Water Framework Directive 2000/60/EC, have been monitored in the surface waters of Greece through the developed network of 53 sampling stations. The analytical methods used for the determination of these substances included Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds, Gas Chromatography-Electron Capture Detection for organochlorine insecticides, High Performance Liquid Chromatography for pentachlorophenol and Atomic Absorption Spectrometry for metals. The results have shown the presence of several priority substances in Greek surface waters, in most cases at concentrations well below the regulatory limits. However, non-compliance was observed for a limited number of compounds. The monitoring network and the analytical determinations have to be expanded to more water bodies and more priority substances, in order to safeguard the quality of Greek surface waters.

Determination of the priority substances regulated by 2000/60/EC and 2008/105/EC Directives in the surface waters supplying water treatment plants of Athens, Greece

ABSTRACT An investigation into the occurrence of priority substances regulated by 2000/60/EC Water Framework Directive and 2008/105/EC Directive was conducted for a period of one year in the surface water sources supplying the water treatment plants (WTPs) of Athens and in the raw water of WTPs. Samples from four reservoirs and four water treatment plants of Athens were taken seasonally. The substances are divided into seven specific groups, including eight volatile organic compounds (VOCs), diethylhexylphthalate, four organochlorine pesticides (OCPs), three organophosphorus/organonitrogen pesticides (OPPs/ONPs), four triazines and phenylurea herbicides, pentachlorophenol, and four metals. The aforementioned substances belong to different chemical categories, and different analytical methods were performed for their determination. The results showed that the surface waters that feed the WTPs of Athens are not burdened with significant levels of toxic substances identified as European Union (EU) priority substances. Atrazine, hexachlorocyclohexane, endosulfan, trifluralin, anthracene and 4-nonylphenol were occasionally observed at very low concentrations. Their presence in a limited number of cases could be attributed to waste disposal, agricultural activities, and to a limited industrial activity in the area nearby the water bodies.

The influence of mercury(II) on the extraction efficiency of herbicides from water

In this work, the effect of Hg(II) on the extraction efficiency of triazine and phenylurea herbicides from water samples was tested. The results showed that in the presence of Hg(II), the recoveries of the s-triazine herbicides (except hexazinon) from styrene divinylbenzene (SDVB) cartridges were significantly reduced using acetonitrile as the elution solvent, whereas acidified methanol quantitatively eluted all the herbicides. Consequently, the loss in the recoveries was not due to degradation of the compounds but rather due to irreversible adsorption onto the resin. The adsorption is probably due to ternary complex formation between the compounds, Hg(II) and the polymeric resin. The chemical structure and the basicity of the compounds affected their interaction with Hg(II). When using octadecyl (C18) cartridges, only atraton was affected. Mercury did not affect the liquid–liquid extraction of the herbicides. The findings suggest that acidic methanol is a suitable elution solvent of s-triazines from mercury-loaded water samples.