Determination of phenol,cresols and xylenols in workplace air using XAD‐2 sorbent cartridges

A method for sampling and analysis of phenolic compounds in workplace atmospheres using Amberlite XAD‐2 sorbent tubes has been laboratory and field tested. After extraction of the adsorbed phenols with methylene chloride, the concentrated extract was analyzed by capillary column gas chromatography coupled with a flame ionization detector or a mass spectrometer. For a 3L air sample, the method has a detection limit for phenol, cresols, alkyl‐substituted phenols and xylenols of 0.3 mg/m³ using gas chromatography with flame ionization detection (GC/FID) analysis and 0.07 mg/m³ using gas chromatography mass spectroscopy/selected ion monitoring GC‐MS/SIM. Evaluation tests conducted in the laboratory indicated recoveries >85% for a wide range of phenols, cresols, xylenols and other alkyl‐substituted phenols and resorcinol. Sampling conditions were established to ensure that no breakthrough occurred for a predetermined sample volume of three (3) liters even in humid atmospheres. Stability tests indicated that for storage of up to 2 weeks at 4°C, only resorcinol showed a significant reduction in sample recovery. The proposed method and NIOSH Method 3502 were compared for the determination of phenol concentrations in air samples collected at a plant processing phenolic resins. Phenol was positively identified in the XAD sample using GC‐MS/SIM and was detected at concentrations of 40–50% of the total phenols detected using NIOSH Method 3502. This difference is attributed to the airborne paniculate matter which is known to contain bisphenols that will contribute to the total phenolic content sampled in Method 3502, but not on the XAD sample.     

超声波萃取—GC／MS测定大气颗粒物中的多环芳烃

采用超声波萃取大气颗粒物样品中的多环芳烃，样品不须纯化，直接可用于GC／MS分析，超声波萃取效率高，萃取时间短；采用MS的SIM方式对多环芳烃进行定性定量，回收率84.5%-108.5%，变异系数3.1%-14.5%。     

Determination of pentachlorophenol in human urine using solid phase extraction and GC‐MS analysis with stable isotope dilution

A method for the determination of pentachlorophenol (PCP) in human urine was developed. Urine samples were fortified with ¹³C₆‐IabeIed PCP and hydrolyzed with sulfuric acid prior to extraction. The urine samples were then passed through preconditioned solid phase extraction cartridges containing octadecylsilane adsorbent. The PCP was subsequently eluted from the cartridge with ethyl acetate and converted to pentachloroanisole prior to GC‐MS analysis. GC‐MS quantitation was performed using the technique of stable isotope dilution. Percent recoveries averaging 100, 97, and 111% were obtained for replicate urine samples fortified with approximately 2, 20, and 200 ng/mL of PCP, respectively. The method detection limit was estimated to be 0.2 ng/mL.     

Photochemical transformations of selected organic chemicals in two phase system

The photodegradation of some aromatic sulfur compounds dissolved in n‐hexane and spread as a thin liquid film on water was investigated. Dibenzothiophene and diphenylsulfide were found to be the most reactive towards photooxidation process among the compounds studied. The degraded compounds were investigated by HPLC and GC/MS.     

A new derivatization method for a determination of MX and related hydroxyfuranones in water

An extremely potent mutagen, 3‐chloro‐4(dichloromethyl)‐5‐hydroxy‐2(5/f)‐furanone (MX) is commonly present in chlorinated drinking water. Due to its high mutagenic activity and according to WHO guidelines its concentration should be controlled in drinking waters. Determination of MX is difficult due to ppt levels at which the compound usually exists in drinking waters. Derivatization with 2‐propanol is presented as a method which significantly lowers GC/MS detection level of MX. Suitability of 2‐propylation for derivatization of other hydroxyfuranones is also shown.     

Rapid liquid–liquid extraction for the reliable GC/MS analysis of volatile priority pollutants

Mass spectrometry is a powerful tool for the analysis of organic pollutants in the environment. Nevertheless, sample preparation for GC/MS analysis is often criticized for being too laborious and requiring expensive equipment. Thus, purge-and-trap or headspace devices are the most popular nowadays to investigate volatile organic pollutants. At the same time, modern commercial high-resolution mass spectrometers allow for the significant simplification of the sample preparation procedures due to better acquisition rate, accurate mass measurements, and improved sensitivity. Here, we used a time-of-flight high-resolution mass spectrometer Pegasus GC-HRT (LECO, USA) to identify and quantify 47 volatile priority organic pollutants in water. The developed accelerated water sample preparation approach requires just 1 mL of water and 1 mL of dichloromethane. The detection limits of the analytes are about 1 μg L^?1, while the quantification limits are approximately 5 μg L^?1. These limits correspond to those required by Method 8260C of the United States Environmental Protection Agency. Here, we demonstrate that sample preparation for the reliable and sensitive GC/MS analysis of volatile organic priority pollutants may be achieved in 5 min in 5-mL vials in the field or just prior to GC/MS analysis in the laboratory without the use of any expensive equipment.     

酵母基因报道系统检测环境二恶英类似物的污染

利用一套酵母基因报道检测系统，建立和标化了对二恶英类标准样品测定的方法，证明此系统可检测ng级的二恶英及其类似物，具有简单、快速的的特点．对广州市区工业和生活污水排放较为集中的水体进行的测定显示，二恶英及其类似物在部分地区超标，而各区经处理的自来水均无超标污染．对小鼠急性毒性实验的血清样品的测定同样证明系统能够测定未浓缩处理的复杂样本，具有一定的应用价值．图4参10     

Dioxins: Sources of environmental load and human exposure

Polychlorinated dibenzo‐p‐dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) represent a class of tricylic, almost planar, aromatic ethers with 1 to 8 chlorine atoms. Congeners with substituents in the positions 2, 3, 7, and 8 are of special concern due to their toxicity, stability, and persistence. These compounds have been identified in almost all environmental compartments and humans.

Dioxins are a potent carcinogen for animals and—at the moment—considered a probable carcinogen for humans. Actual toxicological risk assessment for humans are based on 2,3,7,8‐Cl4DD carcinogenicity studies on rodents. Tumorigenic effects were found for 2 strains of rats and 2 strains of mice. All dioxins and furans elicit common toxic and biological responses, starting with a specific binding to a protein receptor, but existing epidemiologic data do not provide definitive data on human health effects.

Toxicity equivalency factors (TEFs) have been developed by several agencies as a provisional method of risk assessment for complex mixtures of PCDD/PCDF.

Dioxins have never been produced intentionally and have never served any useful purpose. They are formed in trace amounts as by‐products in industrial processes; for instance within the chemical industry, of the pulp and paper industry, metallurgical processes, processes for reactivation of granular carbon, dry cleaning, and the manufacture of flame‐retarded plastics.

The main pathway for dioxins to enter the environment is via combustion processes. Incineration is of special importance since PCDD/PCDF are directly released to the atmosphere from either stationary sources, such as municipal, hazardous and hospital waste incinerators, the combustion of sewage sludge, and scrap metal recycling, or diffuse sources, e.g. automobile exhausts, private home heating with fossil fuels, forest fires, and cigarette smoking. Furthermore, fires with PCB and PVC have additionally contributed to the total dioxin load. The emission gases can undergo long‐range transport, so that dioxins have been found even in remote areas.

Besides the two primary sources (industrial processes and combustion processes) the release of dioxins from contaminated areas and waste dumps via the leachate and the application of sewage sludge for fertilization represents a third source of PCDD/PCDF.

After more than 10 years of dioxin research the most important sources of PCDD/PCDF have been identified and analytical methods have been developed for their quantification in trace levels and in complex matrices.

Various efforts have been undertaken to reduce the emission of dioxins: for example, optimization of combustion processes for municipal waste incineration, use of unleaded gasoline, ban of chemicals, such as polychlorinated biphenyls (PCBs) and pentachlorophenol (PCP). More detail is provided in the pulp and paper section where changes have been initiated to significantly reduce the sources of PCDD/PCDF.

However, relatively little is known about transport and transformation processes, so only rough estimates can be made. Photodegradation has been found to be the primary process for 2,3,7,8‐Cl4DD breakdown. A half‐life of 3–4 days has been estimated for photochemical degradation under oxidative conditions. Field studies on the fate of 2,3,7,8‐Cl4DD in soil gave a half‐life of 9.1 (Seveso) and 12 years (under special conditions: sand, erosion), respectively. Biodegradation seems to be negligible. Transfer factors soil‐plants for PCDD/PCDF have been determined—with a high degree of uncertainty—to be less than 0.1.

Human exposure primarily occurs via ingestion whereas inhalation is a minor pathway. Dermal absorption can be neglected although skin contact to polluted surfaces may occur. Due to the lipophilicity of PCDD/PCDF and their potential for accumulation, foods such as meat and especially dairy products contribute most to the dioxin body burden of humans.

Both national agencies and international organizations have recognized the significance of this problem and as a result have initiated regulations, recommendations and research programmes (1) to understand where and how PCDD/PCDF are formed, (2) to reduce their impact on the environment and to humans, and (3) to start remedial action on contaminated areas.     

Modified Edman degradation applied to hemoglobin for monitoring occupational exposure to alkylating agents

A method that can be used for the monitoring of exposure to alkylating agents in the environment is presented. It is based on the quantification of alkylated N‐terminal valines in hemoglobin, using a modified Edman degradation procedure. The detection limit (GC/electron capture detector or GC/MS) is increased by two magnitudes of ten when using pentafluorophenyl isothiocyanate instead of phenyl isothiocyanate in the derivatization step. As little as one nmole N‐(—2 hydroxyethyl)valine per gram hemoglobin can be detected under practical conditions.     

Thermodynamic investigation of the effect of oxygen and hydrogen chloride potential upon generation and decomposition behavior of dioxins

The thermodynamic equilibrium of the C‐H‐O‐Cl system has been calculated to elucidate the generation and decomposition behavior of dioxins, and is discussed from the viewpoint of the oxygen and hydrogen chloride potential. The dioxins behavior is greatly dependent on the oxygen potential, i.e. higher temperature and oxygen potential lead to the complete decomposition of dioxins, while low hydrogen chloride potential under insufficient oxygen condition leads to an increase of multi‐chlorine displacement of dioxins.     

PCBs,PCDDs and PCDFs in soil samples from uncontrolled burning of waste electrical material for metal reclamation

PCDDs, PCDFs and PCBs have been analysed in soil samples where waste electrical equipment has been burned directly on the ground in three locations of Burgos (Spain). High levels of PCDDs, PCDFs and PCBs were detected in the centre of combustion sites. The results show PCB levels between 0.824 and 1.240 μg/g, and PCDDs and PCDFs levels between 8.73–36.37 ng/g and 12.79–50.95 ng/g. The I‐TEF values between 2.96–9.15 for dioxins and furans indicate that these soils are heavily polluted and may represent a risk for human and animal health.     

Capacity estimation and preliminary strategy for reducing the release of dioxins in China

As a party of the Stockholm Convention on Persistent Organic Pollutants, China must submit its national implementation plan (NIP) for this convention. The strategy and action plan for reducing the release of dioxins in China are the most important components of the NIP. Three problems are key points for developing such strategy and action plan—what are the key sources for applying the best available technology/best environmental practice (BAT/BEP) to reduce the release of dioxins? How about the capacity for reducing the dioxins release from the key sources? Where are the areas of priority for applying BAT/BEP? This paper shows the efforts towards the solution of these problems. The list of key sources covering about half of the total dioxins release was determined considering four criteria. The capacity of key sources were estimated based on the difference between the emission factor corresponding to the actual situation in 2004 and that corresponding to the scenario that all key sources have been applied BAT/BEP to reduce the dioxins release. The priority analysis using the geographical information system (GIS) tool has revealed that castern provinces should be of high priority in the future reduction activities of dioxins release in China.     

Predicting the transportation tendency and potential reservoirs of dioxins by compartment distribution coefficient

We assessed the transportation tendency of dioxins and predict locations at high risk for dioxin pollution. A new parameter, the compartment distribution coefficient D_C, was created to account for the tendency of dioxins to preferentially accumulate in particular compartments. It was obtained by a model using levels of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) in four countries: Japan, the United States, the United Kingdom, and Australia. The comparison with the temporal and spatial variation of D_C indicated whether the location release or long-range transportation caused the changes. This study showed that PCDD/Fs have the greatest tendency to remain in soil among studied media. A higher D_C value in Australia may indicate that this location is a potential future reservoir source of dioxins.     

电子垃圾拆解对台州氯代/溴代二噁英浓度和组成的影响

电子垃圾拆解会导致有毒有害污染物向大气的排放,造成环境污染的产生。为了解电子垃圾拆解及废旧金属再生活动对拆解地及邻近地区空气质量的影响,对台州峰江金属再生园区附近及对照区路桥市区大气中(气态和颗粒态)氯代二噁英(PCDD/Fs)、溴代二噁英(PBDD/Fs)的含量、同系物组成及气/固分配规律进行了研究,通过相关性分析探讨了PCDD/Fs和PBDD/Fs的可能来源。结果显示,金属再生园区冬季采样期间17种2,3,7,8-PCDD/Fs和8种2,3,7,8-PBDD/Fs的平均浓度分别为212.2 pg·m-3和17.6 pg·m-3,夏季采样期间的平均浓度分别为84.5 pg·m-3和5.4 pg·m-3,均显著高于对照点。夏季采样期间对照点处于再生园区的下风向,其二噁英浓度高于冬季,说明其受到了金属再生园区的明显影响。基于相关性分析的结果,塑料焚烧是金属再生活动中氯代和溴代二噁英的主要来源。初步的暴露风险评价表明,金属再生园区附近居民每日摄入的二噁英含量远远超过世界卫生组织规定的人体每日耐受量(1~4 pg W-TEQ·kg-1·d-1)。上述研究结果为规范电子垃圾拆解活动提供了基础数据。     

Mechanistic aspects of the thermal formation of halogenated organic compounds including polychlorinated dibenzo‐p‐dioxins. Part V†: Hypotheses and summary

The hypotheses on the de novo syntheses of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo‐p‐dioxins (PCDDs), based on known literature, are presented. Polychlorinated benzenes and polychlorinated phenols are probably key intermediates.

In the present article, hypotheses that may account for the presence of polychlorinated dibenzofurans (PCDFs) and dibenzo‐p‐dioxins (PCDDs) in the effluents from municipal and industrial incinerators are put forward. These hypotheses are based on the previously surveyed literature (Ref. 203–206) and experimental results on laboratory scale and thermodynamic calculations are considered. The interconnections of various reaction steps are speculative and no technological information was added to account for conditions in real incinerators. Conclusion of the discussions on the related subject matter, presented in the Parts I‐IV (Ref. 203–206), are also described in this paper.     

煤飞灰环境标准参考物中PAHs的表征

本文采用不同提取方法以及不同溶剂对煤飞灰环境标准参考物质样品中PAHs的提取效率进行了考察.采用HPLC,毛细管GC以及GC-MS对飞灰样品中的PAHs进行了分析表征,并对前两种分析方法的精密度、准确性和所得结果的一致性进行了研究.     

Environmental degradation of atrazine,linuron and fenitrothion in soil samples

The persistence of atrazine, linuron and fenitrothion in soil samples from an estuarine area (Ebro delta, Tarragona, Spain) has been studied. Soil samples from the top surface (10 cm) were collected during 1989–91, freeze‐dried, sieved through 200 μm, Soxhlet extracted with methanol, cleaned‐up with Florisil and analysed either by gas chromatography‐nitrogen phosphorus detection (GC‐NPD), in the case of atrazine and fenitrothion, or by liquid chromatography with diode array detection (LC‐DAD), for linuron. Confirmation of the samples analysed by GC‐NPD was carried out using GC‐mass spectrometric detection (MS) in the electron impact mode. The soil half lives obtained under the real environmental conditions have been calculated and the values obtained have been correlated with the physicochemical properties of each pesticide and the soil type. Degradation was affected by volatilization since temperatures in the area of study are relatively high, ca. 30°C, in the summer period. In the case of atrazine it has been shown that deethylatrazine is formed in all the samples studied..     

Temporal limitations in the use of potassium dichromate as a blood preservative for the analysis of organohalogenated contaminants including polybrominated diphenyl ethers,dioxins and PCBs

Previous studies described the use of potassium dichromate (K₂Cr₂O₇) to successfully preserve whole blood for up to 34 days at room temperature (20–22°C) for analysis of chlorinated dioxins, dibenzofurans and PCBs. Potassium dichromate has been successfully employed as a preservative for cows’ milk and in a World Health Organization study of human milk. The use of two 100?mg tablets in 40 to 100?mL of whole blood in anticoagulant was found to provide almost identical levels of dioxins, dibenzofurans, PCBs and lipids as found in frozen comparison blood at??70°C which is generally regarded as the gold standard for blood preservation. Potassium dichromate was found to be preferable to 20 and 40% ethyl alcohol for this preservation. This finding opens opportunities for preservation under field conditions in developing countries where neither electricity nor dry ice is available. Not having to use dry ice for shipping also allows more flexibility in the choice of commercial carriers for transporting blood to an analytical laboratory. It is recommended considering a number of compounds in addition to those studied in our first report and extending the time beyond 34 days in order to determine if longer storage might also be feasible. Data on polybrominated diphenyl ethers (PBDEs), as well as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and selected polychlorinated biphenyls (PCBs) are reported. For the present study 3 and 6 months were chosen in potassium dichromate at room temperature compared to freezing at ?70°C. Data indicate that these times exceed the limits of efficacy of potassium dichromate for whole blood preservation. This was attributed to degradation of the lipid component of the blood. Since dioxins and closely related structural analogues are traditionally reported as lipid normalized blood levels, this degradation of lipids provides erroneous results. Therefore, potassium dichromate is not recommended for long-term storage beyond 34 days at room temperature. It is planned to study the time period between one and three months and higher temperature preservation for shorter time periods, simulating conditions in tropical countries, to attempt to extend further the ease and convenience of chemical preservation of blood.     

Photochemical reactions of musk ketone

The photolysis of musk ketone in cyclohexane and methanol afforded several cyclization products while the product spectrum in cyclohexene and squalene was characterized by an amino derivative and a ring expansion product, respectively. On cellulose stearate layers the photochemical reactions of musk ketone proceeded readily both under sun simulator and in natural sunlight and several photoproducts identified in solvent experiments were detected. Photoproducts were isolated by preparative HPLC and TLC and analyzed by means of HPLC, GC/MS, MS, LC/MS, ¹H‐ and ¹³C‐NMR.     

Occupational exposure to airborne aromatic amines in rubber manufacturing: Determination by gas chromatography‐mass spectrometry

Aromatic amines (AAs) are used in a variety of chemical industries and consequently they are the object of great attention in occupational hygiene owing to the carcinogenic effects that many of them have shown. This work outlines a procedure for the determination of occupational exposure to airborne AAs in the rubber industry and the application of this method in a tyre manufacturing plant using p‐phenylenediamines as antiozonants. Samples were collected on a glass fibre filter followed by a silica gel tube and analyzed by GC‐MS/SIM using a capillary column coated with methyl silicone. p‐Phenylendiamines and other AAs probably formed as thermodegradation products were found in concentrations of up to 10 μg/m³ during rubber vulcanization.