Determination of Short-Chain Chlorinated Paraffins by Carbon Skeleton Gas Chromatography

Short-Chain Chlorinated Paraffins (SCCPs) are highly complex technical mixtures of polychlorinated n-alkanes with a chlorination degree between 50 and 70 % by mass, and a linear carbon chain length from C10 to C13, constituted by thousands of homologues, diastereomers and enantiomers. They have been used in many different applications, such as extreme pressure additives in lubricants and cutting fluids, plasticizers in PVC, and flame retardants in paints, adhesives and sealants. SCCPs are toxic towards aquatic organisms, bioaccumulative and persistent, and therefore the concern about this class of pollutants has increased in the last few years. In 2000 the European Union has included SCCPs in the list of priority substances in the field of water policy, amending the Water Framework Directive (WFD) 2000/60/EC. The implementation of the directive requires that laboratories should be able to measure such substances reliably at the level of the environmental quality standard (EQS). Unfortunately, this is not the case for SCCPs. The analytical tools currently available for the analysis of this class of compounds are scarce and no methodology has been fully validated. This is due to the complexity of their mixtures, and the lack of pure solutions for calibrations as well as matrix-matched reference materials. No routine method for monitoring purposes exists and a poor comparability of results was demonstrated. At present determination of SCCPs is mostly performed by mass spectrometry (MS) in the Electron Capture Negative Ionisation (ECNI) mode. The quantification relies on the monitoring of [M-Cl]- ions of specific mass to charge (m/z) ratio for each SCCP group according to the method developed by Tomy et al. This approach is prone to interferences from other chlorinated compounds and from medium chain chlorinated paraffins, therefore a thorough clean-up of the sample and a careful selection of the ions to be detected are necessary. The method is also affected by a strong dependence on the degree of chlorination of the standard used for calibration. Errors of up to 1100 % have been reported when the calibrant does not match the chlorination degree of the sample. An alternative approach for SCCPs determination is the carbon skeleton gas chromatography (GC)-MS in which chlorinated paraffins are catalytic hydrodechlorinated to the corresponding n-alkanes (see Figure 1). Information on the chlorination degree is lost, but accurate quantification is possible. In this paper the two approaches are compared, and some preliminary results in the determination of SCCPs in water samples with the carbon skeleton method are presented.JRC.DG.D.2-Reference material

Certified Reference Materials for Marine Monitoring

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Metodi chimici e biochimici per misurare le concentrazioni e la tossicità di sostanze inquinanti in matrici ambientali

In questo lavoro di ricerca è stato misurato il grado di contaminazione originato da diverse classi di composti organici in sedimenti e biota della Laguna di Venezia ed è stato utilizzato un biomarker per stimare uno dei possibili effetti biologici generati da questi composti sugli organismi. E' stato valutato l'andamento temporale e spaziale della contaminazione dei sedimenti superficiali da PCB, IPA e Pesticidi Organoclorurati nel corso di quindici anni, dal 1987 al 1998, in 25 stazioni uniformemente distribuite nella porzione centrale della Laguna di Venezia, I risultati mettono in evidenza una diminuzione statisticamente significativa dal 1987 al 1998 per PCB e pesticidi organoclorurati con percentuali di abbattimento in prossimità della zona industriale ài Porto Marghera fino all'80 e 90 %. Al contrario, la contaminazione da IPA non è significativamente diminuita nell'intervallo di tempo considerato, anzi in alcune zone in prossimità del centro storico veneziano sembra essere in aumento per il continuo apporto di questi composti in Laguna. . . Inoltre, è stata valutata la contamina none da Composti Organostannici, sia butilici che fenilici (TBT e TPhT e i relativi metaboliti, DBT, MBT, DPhT e MPhT), rilasciati principalmente dalle vernici antivegetative applicate sugli scafi delle barche. L'analisi in diversi comparti ambientali ha rilevato la presenza di concentrazioni significativamente superiori nel biota piuttosto che nel sedimento e una forte tendenza al bioaccumulo nei molluschi. La specie di mollusco gasteropode Hexaplex trunculus, in particolare, è stata analizzata, oltre che per il contenuto di composti organostannici nei tessuti (viscere e resto del corpo molle), anche per il grado di imposex. Questo fenomeno consiste nell'imposizione di caratteristiche sessuali maschili (pene e vaso deferente) nelle femmine e. può portare, allo stadio più acuto, alla sterilità e quindi impedire la riproduzione. Il grado di imposex nelle popolazioni di H. trunculus analizzate in questo studio si è rivelato abbastanza elevato e nessuna delle femmine ispezionate morfologicamente è risultata priva di modificazioni anatomiche. La lunghezza del pene delle femmine è stata messa in relazione sia con il contenuto di TBT sia con la somma di composti organostannici nell'intero organismo, ottenendo buone correlazioni nella forma di una curva dose-risposta in entrambi i casi (rispettivamente r=0.917 e r=0.982 per n=l 1; p<0.05). Al fine di verifìcare il possibile ruolo antagonista o sinergico giocato nello sviluppo dell'imposex da altri composti in grado di perturbare il sistema endocrino, allo stesso modo del TBT, gli stessi organismi di H. trunculus sono stati analizzati anche per il contenuto di PCB, Pesticidi Organoclorurati e EPA. E' stato applicato il metodo PLS (Partial Least squares regression in latent variables) per mettere in relazione la risposta biologica (imposex) con le concentrazioni delle quattro classi di composti organici determinate nei tessuti del mollusco. Il modello chemiometrico mostra, con una buona capacità predittiva della variabile dipendente, che le concentrazioni di PCB e Pesticidi Organoclorurati contribuiscono positivamente a spiegare l' imposex, mentre gli IPA sono caratterizzati da un effetto opposto ai Composti Organostannici, ai PCB e ai Pesticidi Organolorurati. The level of pollution derived from different classes of organic compounds was estimated in sediments and biota of the Lagoon of Venice and a biomarker was used to estimate one of the possible biological effect of these compounds. Temporal and spatial trends of the contamination by PCBs, PAHs and organochlorine compounds in superficial sediments were evaluated at 25 stations uniformly distributed in the central portion of the Lagoon in the period from 1987 to 1998. The results highlight a statistically significant difference between 1987 and 1998 as regard PCBs and pesticides concentrations, with a reduction up to 80 and 90% at areas close to the industrial zone of Porto Marghera. On the contrary, PAH contamination has not significantly decreased in the period considered and near the historical centre it seems rather to be increased for the continuous input of these compounds to the Lagoon. Moreover, the contamination by organotin compounds, both butyltins and phenyltins (TBT and TPhT and the relative metabolites, DBT, MBT, DPhT and MPhT), mainly released from the antifouling paints applied on the ship hulls, was measured. The analysis in different compartments of the environment has pointed out significantly higher concentrations in the biota, rather than in the sediments. Among the different species of biota analysed, molluscs are the ones that tend to accumulate organotin compounds more than the others. The species of gastropod Hexaplex trimculus, in addition to the content of organotin compounds in the tissues (visceral coil and rest of the soft body), was analysed even for the degree of imposex. This phenomenon consists of the imposition of male sexual characters (namely a penis and a vas deferens) on females and at its acute stage can lead to sterility and prevent the reproduction. The level of imposex in the H. trunculus populations analysed in this study was shown to be relatively high. No one of the morphologically inspected females was free from abnormalities. Female penis length was related to the content of TBT and also to the sum of butyltins and phenyltins in the entire organism, achieving a good correlation in the form of a dose-response curve in both cases (r=0.917 and r=0.982 respectively, n=ll; p<0.05). In order to verify the possible antagonistic or synergistic role of other endocrine disrupters in the development of imposex, the same organisms of H. trunculus were also analysed for the content of PCBs, pesticides and PAHs. The PLS method (Partial Least squares regression in latent variables) was applied to relate the imposex response (Y) to the concentrations of the four classes of compounds (X block) analysed in this study. The chemometric model shows, with a good predictive capacity of the dependent variable, that the concentrations of PCBs and pesticides positively contribute to the explanation of the imposex effect. On the contrary, a negative effect seems to characterise PAHs in respect to PCBs, pesticides and OTCs

Validation of a Method for the Determination of Short-Chain Chlorinated Paraffins in Soil and Sediments

A new method for the reliable quantification of short-chain chlorinated paraffins (SCCPs) in sediments and soil, based on carbon skeleton gass chromatography is presented in this paper. The use of this procedure as a standard method coupled to the definition of a method-defined parameter overcomes some of the main difficulties encountered so far in the analysis of SCCPs. The uncertainty budget estimations show that with this approach the expanded uncertainty is reduced to acceptable values. In-house development and full validation of the method on sediment and soil samples, are presented in this paper.JRC.D.2-Reference material

Butyltins and phenyltins in biota and sediments from the Lagoon of Venice

Sediments and organisms were sampled to determine organotin contents - butyltins (BTs) and phenyltins (PhTs) - at 12 locations in an estuarine ecosystem, the Lagoon of Venice, characterised by varying contamination impacts. The results showed that organotin contamination in sediments is at lower levels, ranging from 2.5 &#177; 0.1 to 84 &#177; 1 ng g^-1 (d.w.) for SigmaBTs and from 0.8 &#177; 0.2 to 7 &#177; 1 ng g^-1 (d.w.), for SigmaPHTs, than in organisms, where the highest concentrations were found infilter feeders like mussels - from 60 &#177; 3 to 7632 &#177; 148 ng g^-1 (d.w.) for SigmaBTs and from 0.80 &#177; 0.01 to 4005 &#177; 121 ng g^-1 (d.w.) for SigmaPHTs. The possible risk to human health was assessed on the basis of the consumption of edible species sampled in some areas of the lagoon

Certification of the Mass Fractions of Various Polybrominated Diphenyl Ethers (PBDEs), Decabrominated Biphenyl and Total Br and Total Sb in Two Polymer Reference Materials, ERM-EC590 and ERM-EC591

This report describes the preparation and certification of the polymer certified reference materials (CRM) ERM-EC590 and ERM-EC591. The CRMs have been certified by the European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Geel, Belgium. The CRMs were prepared from a low-density polyethylene granulate and polypropylene granulate spiked with technical mixtures of brominated diphenylethers (BDEs) and brominated biphenyls (BB). Technical Penta-BDE, Deca-BDE and Deca-BB were added. Certification of the CRM included testing of the homogeneity and stability of the material as well as the characterisation using an intercomparison approach. The CRMs have been certified for their content of Br as well as for several BDE congeners and decabrominated biphenyl (BB-209). Indicative values have been established for Sb. Additional information about several BDE-congeners is given. These CRMs are intended for use in quality assurance of measurements of BDEs. BB-209 and elements in polymers and related matrices. Uncertainties are expanded uncertainties estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) with a coverage factor of k=2, corresponding to a level of confidence of about 95 %.JRC.D.2-Reference material

Laboratory Intercomparison Study on the Analysis of Short-Chain Chlorinated Paraffins in an Extract of Industrial Soil

Short-chain chlorinated paraffins (SCCPs) are a class of organic pollutants used in many industrial applications, and released into the environment , whose analytical determination is very challenging. Although at present there is no fully validated measurement procedure which might be applied in routine monitoring, the European Water Framework Directive (WFD) requires regular monitoring of this class of compounds at river basin scale starting from 2007. to assess the status quo in the analysis of SCCPs in relation to the requirements posed by the WFD, an interlaboratory comparison on the quantification of SCCPs in an extract of an industrial soil has been organised. Six laboratories participated in the present exercise using three different techniques, gas chromatography (GC) coupled to mass spectrometry (MS) in the electron capture negative ionization (ECNI) mode, GC with atomic emission detection (AED), and carbon skeleton GC-MS. the reported result ranged from 8.5 mg L-1 to 3200 mg L-1. This confirms that reliable quantification of SCCPs is still very difficult to achieve and that comparability of SCCP data reported to the European Commission is at least questionable.JRC.D.2-Reference material

New implications in the use of imposex as a suitable tool for Tributyltin contamination: experimental induction in Hexaplex trunculus (Gastropoda, Muricidae) with different stressors

Imposex, i.e. the development of additional male sex organs (penis and/or vas deferens), in females of gonochorist marine and freshwater gastropods, is known to be caused by tributyltin (TBT), and it has been widely used as a biomonitoring tool in environmental surveys for TBT pollution assessment. In this study, we experimentally tested the potential to induce imposex by another endocrine disruptor (polychlorinated biphenyls [PCBs] mixture—Aroclor 1260). Adults of Hexaplex trunculus with low imposex level, coming from an Italian Marine Protected Area, were injected separately with different doses of tributyltin chloride (TBTCl) and Aroclor 1260. The compounds were dissolved in ethanol and the organisms were narcotised by immersion in MgCl2 solution before injection. Before and after the experiment, butyltin compounds (BuTs) and PCB tissue concentrations were determined. A significant increase in imposex with respect to non-treated organisms was observed in all treatments, including artefact controls. No clear correlation was observed between BuTs and PCB tissue concentrations and indices of imposex incidence. Based on these results, no assumption can be formulated about PCB effect on imposex development. Nevertheless, they suggest that the imposex level increase, at least in H. trunculus, in laboratory conditions might not be caused by TBT only, but it would rather be a non-specific response to different stress stimuli