Fractionation of halogenated organic matter present in rain and snow

Chlorine cycling and the fate of Cl in terrestrial environments

Chlorine (Cl) in the terrestrial environment is of interest from multiple perspectives, including the use of chloride as a tracer for water flow and contaminant transport, organochlorine pollutants, Cl cycling, radioactive waste (radioecology; 36Cl is of large concern) and plant science (Cl as essential element for living plants). During the past decades, there has been a rapid development towards improved understanding of the terrestrial Cl cycle. There is a ubiquitous and extensive natural chlorination of organic matter in terrestrial ecosystems where naturally formed chlorinated organic compounds (Clorg) in soil frequently exceed the abundance of chloride. Chloride dominates import and export from terrestrial ecosystems while soil Clorg and biomass Cl can dominate the standing stock Cl. This has important implications for Cl transport, as chloride will enter the Cl pools resulting in prolonged residence times. Clearly, these pools must be considered separately in future monitoring programs addressing Cl cycling. Moreover, there are indications that (1) large amounts of Cl can accumulate in biomass, in some cases representing the main Cl pool; (2) emissions of volatile organic chlorines could be a significant export pathway of Cl and (3) that there is a production of Clorg in tissues of, e.g. plants and animals and that Cl can accumulate as, e.g. chlorinated fatty acids in organisms. Yet, data focusing on ecosystem perspectives and combined spatiotemporal variability regarding various Cl pools are still scarce, and the processes and ecological roles of the extensive biological Cl cycling are still poorly understood.

Simultaneous Determination of Chlorinated and Brominated Acetic Acids in Various Environmental Water Matrixes by High-Performance Liquid Chromatography-Inductively Coupled Plasma Tandem Mass Spectrometry without Sample Preparation

The halogenated acetic acids (HAAs) are generally considered as environmental contaminants and are suspected to pose a major public health concern. The inductively coupled plasma mass spectrometry (ICPMS) has been improved by coupling with the tandem mass spectrometry technology (ICPMS/MS), enabling ultratrace determination of heteroatoms. There have been few reports about the determination of chlorine-containing analytes by high-performance liquid chromatography (HPLC)-ICPMS/MS but none about utilizing this technique for the speciation analysis of organic halogenated compounds in environmental matrixes. We report a rapid method for the simultaneous determination of up to nine chlorinated and brominated acetic acids by HPLC-ICPMS/MS in Austrian surface, ground, and tap water. The chromatographic separation of the main five regulated haloacetic acids (so-called HAA5: chloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, and dibromoacetic acid) could be achieved in <6 min with limits of detection of 1.4-1.6 μg Cl L-1 and 0.8-1.5 μg Br L-1 for the chlorinated and brominated acetic acids, respectively. The method was validated through recovery experiments at four concentration levels (10-500 μg L-1) as well as by analyzing the U.S. Environmental Protection Agency (EPA) 552.2 CRM (certified reference material) in pure water and in three different water matrixes (tap, river, and groundwater), and thereby validated for repeatability (RSD% 1-10%), accuracy (±1.0-15%), and linearity (r2 = 0.9996-0.9999). The method fulfills the regulatory concentration limits by the EPA for HAA5 [maximum contaminant level (MCL) 60 μg L-1] and the limits currently being reviewed by the European Union for HAA9 (80 μg L-1) and demonstrates the advantages of HPLC-ICPMS/MS for the analysis of environmental water samples for halogen-tagged contaminants.

Spectroscopic characterization of dissolved organic matter isolated from rainwater

Rainwater is a matrix containing extremely low concentrations (in the range of muM C) of dissolved organic carbon (DOC) and for its characterization, an efficient extraction procedure is essential. A recently developed procedure based on adsorption onto XAD-8 and XAD-4 resins in series was used in this work for the extraction and isolation of rainwater dissolved organic matter (DOM). Prior to the isolation and fractionation of DOM, and to obtain sufficient mass for the spectroscopic analyses, individual rainwater samples were batched together according to similar meteorological conditions on a total of three composed samples. The results of the isolation procedure indicated that the resin tandem procedure is not applicable for rainwater DOM since the XAD-4 resin caused samples contamination. On the other hand, the XAD-8 resin allowed DOM recoveries of 39.9-50.5% of the DOC of the original combined samples. This recovered organic fraction was characterized by UV-visible, molecular fluorescence, FTIR-ATR and 1H NMR spectroscopies. The chemical characterization of the rainwater DOM showed that the three samples consist mostly of hydroxylated and carboxylic acids with a predominantly aliphatic character, containing a minor component of aromatic structures. The obtained results suggest that the DOM in rainwater, and consequently in the precursor atmospheric particles, may have a secondary origin via the oxidation of volatile organic compounds from different origins.

Organic composition in the dry season rainwater of Guangzhou, China

This paper reports the results from a study of the organic composition of rainwater collected at Tianhe district of Guangzhou city, P.R. China, during the dry season. Several special setups of a pyrex bottle with a glass funnel were used for the collection of the rainwater. Three fractions (aliphatics, PAHs and fatty acids) were separated from the total extracted organic compounds and identified with GC-MS. The molecular diagnostic ratios were utilized for the source reconciliation. The aliphatic hydrocarbon and the biomarkers (triterpanes and steranes) distribution show a characteristic of the petrochemical source in the rainwater samples. The PAHs diagnostic ratios [e.g. MP/P, MPI, Fl/ (Fl + Py)] indicated vehicular emissions. The fatty acids ratios (e.g. C(18:1)/C(18:0) and C(18:2)/C(18:0)) reflect the contribution of cooking emissions, while the higher plant waxes play little part. Moreover, the values of MP/P, MPI, BaA/(BaA + CT) and BeP/(BeP + BaP) reflected the origin of the long-distance transportation to some extent. On the whole, for the dry season rainwater, all molecular diagnostic ratios indicated the complexity of the organic composition of the rain, which have the characteristics of both a local emission contribution and a long-distance transportation contribution.

Adsorbable organic halogens (AOXs) in solid residues from hazardous and clinical waste incineration

Trace concentrations of a variety of chemicals remain in solid residues following combustion even in properly designed and operated incinerators. In the present study, the adsorbable organic halogen (AOX) levels of the solid residues, i.e., bottom ash, fly ash, and filter cake, were investigated during a 82-day of continuous operation of a Hazardous and Clinical Waste Incinerator. The distribution of halogens in the waste input prior to the incineration was also determined. The AOX levels measured in bottom ash, fly ash and filter cake were in the range of 0.014-1.879, 0.012-0.263, and 0.004-0.062 mg-Cl(-)/kg, respectively. The AOX levels are significantly low in the fly ash and filter cake due to the post-combustion process in the incinerator. At the end of the 82 days, the total AOX output in the bottom ash, fly ash, and filter cake were 571, 3.71, and 6.26 g, respectively. The partitioning of the total AOX in solid residues was 98.28, 0.64, and 1.08% for the bottom ash, fly ash and filter cake, respectively. This shows that the bottom ash is more contaminated with AOX than the other two residues.

Organohalogenated compounds in pine needles from Beijing city, China

Pine needles collected from 22 sites of six areas in Beijing city, China, were analyzed by instrumental neutron activation analysis (INAA) combined with organic extraction for extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX). The concentrations of EOX (EOX = ECl + EOBr + EOI) were in the order of EOCl >> EOBr > EOI. About 1.6-34% of EOCl remained as extractable persistent organochlorine (EPOCl) after treatment with concentrated sulfuric acid, which suggested that major fractions of EOCl in pine needles were an acid-liable or acid-soluble fraction. The fact that pine needle contained higher EOCl contents in chemical industrial and traffic hub areas indicated that chemical industries and exhaust emission from vehicle were the main sources of organochlorines in the Beijing's air. The relative proportions of the known organochlorines (such as HCHs, DDTs, chlordanes, HCB and PCBs) to total EOCl and EPOCl were 0.32-0.76% and 2.5-11.4%, respectively, which implied that a major portion of the EOCl and EPOCl measured in pine needles was unknown. The organochlorinated pesticides (OCPs) and PCBs concentrations in six areas were as follows: sigma HCH (sigma HCH = alpha- + beta- + gamma- + delta-HCH), 11.7-20.8 ng/g; sigma DDT (p,p'-DDT + p,p'-DDE + p,p'-DDD), 12.5-113.3 ng/g; hexachlorobenzene (HCB), 1.1-5.3 ng/g; sigma chlordane (cis-chlordane + trans-chlordane + heptachlor), 1.7-9.5 ng/g, sigma PCB, 41.8-270.5 ng/g, on dry weight basis. The samples from chemical industrial area and residential area nearby chemical industries contained the highest concentrations of sigma DDT, HCB, sigma chlordane and sigma PCB, while the contamination levels of most OCPs and PCBs in iron-steel industrial area were the lowest. The ratios of alpha/gamma-HCH (ranged from 0.9-1.5) and p,p'-DDT/DDTs (ranged from 72.1% to 91.0%) revealed the presence of the recent use of lindane and DDTs or impure dicofol in Beijing.

State-of-the art of selective detection and identification of I-, Br-, Cl-, and F-containing compounds in gas chromatography and liquid chromatography

This review article presents an overview of halogen-specific detection in gas chromatography (GC) and liquid chromatography (LC). Attention is primarily focused on the use of plasma emission spectroscopy and plasma mass spectrometry as detectors, but other halogen-selective detection principles are also mentioned. Different instrumental configurations are discussed both with respect to technical set-up and performance, the principal reasons for halogen-selective detection are highlighted, and recent applications are reviewed from areas such as environmental chemistry, petroleum characterization, and drug analysis.

Levels of extractable organohalogens in pine needles in China

Pine needles can accumulate organohalogens from the ambient air, which are, hence, able to serve as a biomonitor to evaluate the levels of organochlorinated contaminants in the atmospheric environment. Extractable organochlorine (EOCl), the most abundant of the extractable organohalogens (EOX) in environmental samples, has received much attention as a parameter for evaluation of total contamination levels of organochlorinated compounds (OCs). However, few data concerning EOCl in vegetation are available. In this study, we selected pine needles from 17 different areas in China as a sampling matrix to reflectthe regional distribution of OCs. EOX (EOX = EOCl + EOBr + EOI) were measured by instrument neutron activation analysis for their concentrations and distribution in pine needles. The concentrations of EOX were on the order of EOCl >> EOBr > EOI. About 5-38% of EOCl remained as sulfuric acid-resistant organochlorine (EPOCl). The relatively high concentrations of EPOCl in pine needles from remote areas suggested that EPOCl mainly originated from long-range atmospheric transport and contaminated soil. The relative proportions of the known organochlorines (such as HCHs, DDTs, aldrin, heptachlor, and chlordanes) to total EOCl and EPOCl were 0.3-5.2% and 1.4-19.8%, respectively, which implied that a major portion of the EPOCl measured in pine needles was unknown. The EPOX accumulation rates were preliminarily estimated under the natural condition, which suggested that the "young" needle accumulated EPOX more quickly than the "old" and more than 94% of EPOX was accumulated at the first year of pine needles.