A novel method for the determination of a PCB sum value by enzyme immunoassay to overcome the cross-reactivity problem

Many attempts have been made to detect polychlorinated biphenyls (PCBs) by enzyme immunoassay (ELISA). All known ELISAs to PCBs show characteristic cross-reactivity problems. Without any prior information about the composition of the sample, no quantification of the total PCB content is possible. A chemical approach is shown to solve the cross-reactivity problem by the quantitative dechlorination of all PCB congeners to the single compound biphenyl. For the reductive dechlorination palladium on barium sulfate and ammonium formate were used. The dechlorination procedure was optimized to be performed at room temperature in methanol without the exclusion of oxygen or water. For the development of polyclonal biphenyl-antibodies the synthesis of the hapten biphenylhexanoic acid via Grignard cross-coupling is described and an immunization protocol is given. The purity of the used immunological reagents proved to be very crucial. The whole procedure was tested with spiked soil samples. The detection limit for PCBs (Clophen A50) in soil was 1 mg/kg (3.1 μmol/kg). This corresponds to a biphenyl concentration in methanol of 0.1 mg/L (0.6 μmol/L). Received: 25 September 1998 / Revised: 1 December 1998 / Accepted: 4 December 1998     

Randomly Methylated β-Cyclodextrins (RAMEB) Enhance the Aerobic Biodegradation of Polychlorinated Biphenyl in Aged-Contaminated Soils

The biological removal of polychlorinated biphenyls (PCBs) from contaminatedsoils is adversely affected by the poor bioavailability of these pollutants. Twodifferent aged-contaminated soils containing about 890 and 8500 mg/kg of PCBswere supplemented with biphenyl and treated in slurry- and solid-phase aerobic0.5 litre-microcosms in the presence of RAMEB at 0, 0.5, 1.0, 3.0% (w/w). RAMEB,which was non-toxic and slowly biodegraded by the soil microorganisms, significantlyenhanced the bioavailability (from 30 to 50%) and the biological degradation (from 15to 55%) and dechlorination of PCBs in both soils and treatment conditions. RAMEBeffects were dependent on the concentration at which it was applied, the soil featuresand the treatment conditions. RAMEB enhanced PCB biodegradation by increasingboth the PCB bioavailability and the availability of biodegrading bacteria in themicrocosms. RAMEB appears a promising bioavailability enhancing agent for thetreatment of PCB-contaminated soils, not only for its positive effects on the PCBsbiodegradation, but also for its biodegradability, non-toxicity and relatively low cost.     

Catalytic dechlorination of Aroclor 1242 by Ni/Fe bimetallic nanoparticles

Ni/Fe bimetallic nanoparticles were synthesized for treatment of Aroclor 1242, in order to evaluate their applicability for in situ remediation of groundwater and soil contaminated by polychlorinated biphenyls (PCBs). Our experimental results indicate that the total PCB concentration changed during the reduction of 3,5-dichlorobiphenyl (PCB 14), and biphenyl was produced as the final product. Initially, the concentration of 3-chlorobiphenyl (PCB 2) was increased in the prophase reaction and then slowly decreased, suggesting that Aroclor 1242 was first adsorbed by Ni/Fe nanoparticles, and then, the higher chlorinated congeners were converted gradually to the lower chlorinated congeners, and finally to biphenyl. The dechlorination efficiency of Aroclor 1242 reached approximately 80% at 25°C in just 5h, then 95.6% and 95.8% in 10h and 24h, respectively. The study revealed that high Ni/Fe nanoparticle dosage and high Ni content in Ni/Fe nanoparticles favor the catalytic dechlorination reaction. Moreover, a comparison of different types of catalysts on the dechlorination of Aroclor 1242 indicated that Ni/Mg and Mg powders showed a greater reactivity than Ni/Fe and Fe nanoparticles, respectively.     

A new advanced method for heterogeneous catalysed dechlorination of polychlorinated biphenyls (PCBs) in hydrocarbon solvent

The dechlorination of PCBs with solid hydrazine hydrochloride catalysed by palladium, in an organic solvent, yields biphenyl in short reaction times. The catalyst system can be efficiently reused for several cycles. Ultrasonication of the heterogeneous catalysed reaction increases the dechlorination rate remarkably. The reactivity of the C---Cl bond on the PCB ring are in the order meta>paraortho.     

Pd修饰Ti电极对水相中2,4,5-PCB还原脱氯的研究

实验研究了Pd修饰Ti电极对甲醇/水相中十六烷基三甲基溴化铵(CTAB)增溶的2,4,5-PCB(PCB: 多氯联苯)的电化学还原脱氯作用. 采用两室流通式电解池, 考察了Pd负载量、电极结构、电场条件和溶液流速对2,4,5-PCB的去除效率的影响. 优化条件是: Pd负载量为3 mg•cm-2, 阴极为3层电极极板, 电极电位为－1.10 V(vs SCE); 溶液流速对脱氯效率的影响不明显. 在该条件下经过9 h电解, 2,4,5-PCB的去除率达96.2%, 脱氯产物未完全生成联苯, 其产率为89.6%, 电流效率介于11.3%~33.0%之间.     

Application of C-labelled polychlorinated biphenyl congener 153 as internal standard in the gas chromatographic-mass spectrometric analysis of polychlorinated biphenyls

We developed a method of qualitative and quantitative GC-MS analysis of polychlorinated biphenyls (PCBs) in soil samples, to be able to determine the biodegradation efficiency for individual PCBs. ¹³C₁₂-Substituted PCB 153 was used as internal standard. The analyses were performed on a DB-5 capillary column. The identification procedure was based on the correlation analysis of the measured and published relative retention r₁₂ data using [¹³C₁₂]PCB 153 instead of octachloronaphthalene (OCN). [¹³C]PCB 153 was also used for quantification of individual PCBs in soil samples.     

Optimized method for the determination of 25 polychlorinated biphenyls in water samples using stir bar sorptive extraction followed by thermodesorption-gas chromatography/mass spectrometry

An optimized method using stir bar sorptive extraction (SBSE) for the determination of 25 polychlorinated biphenyls (PCBs) from water samples among them three of the most toxic coplanar PCBs (PCB 77, PCB 126 and PCB 169) was developed. Since the investigated PCBs comprise all steps of chlorination (from PCB 1 as monochlorobiphenyl to PCB 209 as decachlorobiphenyl) the results should be representative for the total class of the 209 PCB congeners. For 8 ml spiked water samples with 2 ml methanol addition and 2 h exposure time of stir bars recoveries between 28% (PCB 209) and 93% (PCB 1, PCB 52, PCB 77) were found. Detection limits between 0.05 ng/l and 0.15 ng/l were calculated for the combination of SBSE and thermodesorption-GC/MS. The procedure was applied to the investigation of groundwater and river water samples from the industrial region of Bitterfeld northern Leipzig, Germany.     

Dispersive liquid-liquid microextraction followed by gas chromatography–electron capture detection for determination of polychlorinated biphenyls in fish

A new method of dispersive liquid-liquid microextraction (DLLME) combined with GC-electron capture detection (GC-ECD) was proposed for the extraction and determination of four polychlorinated biphenyls (PCBs) congeners in fish samples. Acetone was used as extraction solvent for the extraction of PCBs from fish samples. The target analytes in the acetone solvent were rapidly transferred to chlorobenzene, which was used as extraction solvent in DLLME procedures. Under the optimum conditions, linearity was obtained in the concentration range from 1.25 to 1250 μg/kg for PCB 52, and 0.25 to 250 μg/kg for PCB 101, 138 and 153. Coefficients of correlation (r²) ranged from 0.9993 to 0.9999. The repeatability was tested by spiking fish samples at 10 μg/kg PCBs, and RSD% (n = 8) varied between 2.2 and 8.4%. The LODs were between 0.12 and 0.35 μg/kg. The enrichment factors of PCBs were from 87 to 123. The relative recoveries of the four PCB congeners for the perch, pomfret and yellow-fin tuna at spiking levels of 10, 20 and 50 μg/kg were in the range of 81.20–100.6%, 85.00–102.7% and 87.80–108.4%, respectively. The results demonstrated that DLLME combined with GC-ECD was a simple, rapid, and efficient technique for the extraction and determination of PCBs in fish samples.     

Fast Gas Chromatographic Assessment of Polychlorobiphenyl Levels in Wall Plaster Coats

Abstract

Sampling (“scrape test”) and analytical procedures were defined to determine PCBs in sorbing solid surfaces such as wall plaster. After sampling, samples were extracted by means of a mechanical device. Following steps included clean-up on a multilayer chromatographic column and assessment with macrobore capillary gas chromatography equipped with an electron capture detector. Mean recovery yields were ≧75% for PCB levels from 2.00 to 7000μg/m² (0.550–1940 μg/kg). Intralaboratory tests performed by two independent operators yielded: (a) maximum deviation from expected value, 25%; (b) maximum deviation between operators, 17%; and (c) maximum variation coefficient, 20%. Background PCB levels in wall surface layer samples were ≧2.9μg/m² (≧0.81 μg/kg). The analytical procedure tested with agricultural topsoil samples provided mean recovery yields >65% for PCB levels ≧500 μg/ kg (≧ 50 mg/m²).     

Analysis of 60 PCB congeners in drinkable water samples at 10–50 pg/L level

In this paper, an analytical method used to determine the presence of 60 polychlorinated biphenyl (PCB) congeners in water as a means to evaluate the quality of drinking water from public wells in the Brescia area is presented and discussed. In this area, PCBs were produced until 1984 leading to contamination of air, irrigation water, surrounding lands and consequently soil products, animals and fish. As contamination of the environment is still present in several sites, it appeared advisable to check the purity of drinking water. The limits of detection for the various congeners vary from 10 to 20 pg/L, for lower chlorinated congeners, up to 50 pg/L, for the higher chlorinated ones. To reach these limits, it is critical to minimize the blank sample contributions. This goal was achieved by checking all the solvents used in the procedure and by washing the glassware. The water used for the blank was pre-extracted. The action and the procedure used, respectively, to compensate and flag the incidence of the blank for each analytical result are also presented.     

Enantiomer separation of polychlorinated biphenyl atropisomers and polychlorinated biphenyl retention behavior on modified cyclodextrin capillary gas chromatography columns

Seven commercially-available chiral capillary gas chromatography columns containing modified cyclodextrins were evaluated for their ability to separate enantiomers of the 19 stable chiral polychlorinated biphenyl (PCB) atropisomers, and for their ability to separate these enantiomers from achiral congeners, necessary for trace environmental analysis of chiral PCBs. The enantiomers of each of the 19 chiral PCBs were at least partially separated on one or more of these columns. Enantiomeric ratios of eleven atropisomers could also be quantified on six columns as they did not coelute with any other congener containing the same number of chlorine atoms, so could be quantified using gas chromatography-mass spectrometry. Analysis of a lake sediment heavily contaminated with PCBs showed enantioselective occurrence of PCB 91, proof positive of enantioselective in situ reductive dechlorination at the sampling site.     

Polychlorinated biphenyls,dibenzo-p-dioxins and dibenzofurans in soil samples from airport areas of Croatia

Levels and patterns of polychlorinated biphenyls (PCBs) were studied in surface soil samples collected in the coastal part of Croatia within and surrounding four different airports and in the vicinity of two partially devastated electrical transformer stations. The compounds accumulated from air-dried soil samples by multiple ultrasonic extraction with an n-hexane?:?acetone 1?:?1 mixture were analysed by capillary gas chromatography with electron capture and ion-trap detection. PCBs were quantified against a standard Aroclor 1242/Aroclor 1260 mixture and a standard mixture of 17 individual PCB congeners (IUPAC No.: 28, 52, 60, 74, 101, 105, 114, 118, 123, 138, 153, 156, 157, 167, 170, 180, and 189). The mass fractions of total PCBs in 18 soil samples collected within the airport premises ranged from 3 to 41?327?µg/kg dry weight (dw) (median: 533?µg/kg?dw), and those in 21 samples collected at a distance ranging from several metres to 5?km away from the airport fence, from <1 to 39?µg/kg?dw (median: 5?µg/kg?dw). The highest PCB levels were determined in soils along the airport aprons where the aircrafts were serviced and refuelled. The PCB pattern was very similar to technical Aroclor 1260 in all airport soils. The PCB pattern in 22 soils collected in the vicinity of electrical transformer stations was dominated by congeners contained in Aroclor 1242. These soils contained 7 to >400?µg/kg?dw of total PCBs. One highly PCB-contaminated airport soil sample was analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). With an international toxic equivalent (I-TEQ) of 9.7?ng/kg?dw, the airport soil contamination was within values typical for urban and rural areas, and the congener patterns gave no clear indication for PCBs as the only source of PCDDs/PCDFs.     

PCBs的超(亚)临界水催化氧化及还原裂解

简要分析了多氯联苯(PCBs)的来源及其对环境构成的危害,介绍了PCBs在超（亚）临界水中的反应及其处理效果。分别从超临界水氧化、超临界水裂解及亚临界水还原三个方面阐明了超临界反应过程中PCBs降解的反应路径和降解效率,解释了共溶剂（甲醇、苯）、碱催化剂（Na₂CO₃、NaOH）、氧化剂（NaNO₃、NaNO₂）等对PCBs脱氯和分解的增效作用机理。发现在超临界水氧化与超临界水裂解条件下CH3OH对PCBs降解反应的促进机制有所不同,碱催化剂通过中和反应过程中产生的HCl生成NaCl沉淀导致体系中Cl的含量降低,从而促进脱氯反应的进行。对反应器防腐、处理的经济性方面略作讨论,在总结上述研究工作的基础上提出了PCBs的超临界反应处理技术未来发展的若干研究方向。     

Bio Availability of Polychlorinated Biphenyl Congeners in the Soil to Earthworm (L. rubellus) System

Abstract

The earthworm's (Lumbricus rubellus) uptake of polychlorinated biphenyls (PCBs) from a soil contaminated with a commercial PCB formulation (Askarel at 150 μg g^?1) and their elimination of PCBs into a low contaminated soil (15 μg g^?1) has been studied. 17 individual congeners were monitored. The uptake and the elimination rate were similar for all PCB congeners notwithstanding their different chloro-substitution pattern which suggested that bioaccumulation of PCBs in earthworms is governed by passive, possibly diffusion controlled processes. The equilibrium state in the three-phase system, soil/soil water/earthworm was reached with a half-time around 3–4 days. The soil to earthworm bioconcentration factor ranged from 4 to 20 for tetra- to octa-chlorinated biphenyls and was weakly depending on the octanol-water partition coefficient: BCF = ?(1.3?1.8) × K _OW ^(0.35?0.40).     

Determination of polychlorinated biphenyls by liquid chromatography–atmospheric pressure photoionization–mass spectrometry

This study presents the atmospheric pressure photoionization (APPI) of high‐chlorinated (five or more chlorine atoms) polychlorinated biphenyls (PCBs) using toluene as dopant, after liquid chromatographic separation. Mass spectra of PCB 101, 118, 138, 153, 180, 199, 206 and 209 were recorded by using liquid chromatography‐APPI‐tandem mass spectrometry (LC‐APPI‐MS/MS) in negative ion full scan mode. Intense peaks appeared at m/z that correspond to [M ? Cl + O]^? ions, where M is the analyte molecule. Furthermore, a detailed strategy, which includes designs of experiments, for the development and optimization of LC‐APPI‐MS/MS methods is described. Following this strategy, a sensitive and accurate method with low instrumental limits of detection, ranging from 0.29 pg for PCB 209 to 8.3 pg for PCB 101 on column, was developed. For the separation of the analytes, a Waters XSELECT HSS T3 (100 mm × 2.1 mm, 2.5 µm) column was used with methanol/water as elution system. This method was applied for the determination of the above PCBs in water samples (surface water, tap water and treated wastewater). For the extraction of PCBs from water samples, a simple liquid–liquid extraction with dichloromethane was used. Method limits of quantification, ranged from 4.8 ng l^?1, for PCB 199, to 9.4 ng l^?1, for PCB 180, and the recoveries ranged from 73%, for PCB 101, to 96%, for PCB 199. The estimated analytical figures were appropriate for trace analysis of high‐chlorinated PCBs in real samples. Copyright © 2014 John Wiley & Sons, Ltd.     

Ultrasound‐assisted magnetic SPE based on Fe3O4‐grafted graphene for the determination of polychlorinated biphenyls in water samples

An ultrasound‐assisted magnetic SPE procedure with an Fe₃O₄‐grafted graphene nanocomposite as the magnetic adsorbent has been developed to determine seven polychlorinated biphenyls (PCBs; PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) simultaneously in 200 mL environmental water samples, in combination with GC–MS/MS. Several factors related to magnetic SPE efficiencies, such as the superparamagnetic intensity and amount of adsorbent, extraction time, sample pH, and desorption conditions were investigated. With the assistance of ultrasound, the extraction achieved the maximum within only 20 s, attributed to the powerful adsorptive ability of the magnetic adsorbent toward the PCBs. Under the optimized conditions, an excellent linearity was observed in the range of 0.1–100 ng/L for PCB28, 0.2–100 ng/L for PCB52, and 0.5–100 ng/L for the other five PCBs with the correlation coefficients ranging from 0.9988 to 0.9996. The mean recoveries at spiked levels of 5.0 and 10.0 ng/L were 84.9–108.5%, the coefficients of variations were <6.5%. With convenient magnetic separation, the synthesized magnetic adsorbent could be recycled more than ten times. The proposed method was demonstrated to be feasible, simple, rapid, and easy to operate for the trace analysis of the PCBs in environmental water samples.     

气相色谱-三重四极杆质谱同位素内标法测定鱼样中20种多氯联苯

建立了一种气相色谱-三重四极杆质谱结合双稳定性同位素内标检测鱼样中多氯联苯的方法。采用自动索氏提取器提取样品中的多氯联苯,经一根复合净化柱净化后,采用质谱多反应监测模式检测,选取两个独立的离子对。分析了20种多氯联苯,包含7种指示性多氯联苯,从三氯联苯到八氯联苯每族3个化合物,九氯联苯和十氯联苯各一个,每族使用一个相同氯代程度的¹³C₁₂标记多氯联苯作为定量内标、2种回收内标。20种多氯联苯在33 min内流出,分离良好,线性范围为0.05~10 μg/L,相关系数r均在0.99以上,低、中、高3种水平的加标回收率均在80.3%~117.6%之间,相对标准偏差（RSD,n=6）在5.09%~18.5%之间,方法检出限为0.01~0.02 μg/kg。20种多氯联苯总量在1.2~8.8 μg/kg（湿重）范围内,7个指示性多氯联苯总量在0.68~6.4 μg/kg（湿重）范围内。该方法缩短了分析时间,减少了有机溶剂的使用量,适合鱼样中多氯联苯的测定。     

Simultaneous determination of total polychlorinated biphenyl and dichlorodiphenyltrichloroethane (DDT) by dechlorination with Fe/Pd and Mg/Pd bimetallic particles and flame ionization detection gas chromatography

Simultaneous measurement of total dichlorodiphenyltrichloroethane (DDT, technical mixture) and polychlorinated biphenyl (PCB-Aroclors 1248 and 1260) is facilitated by quantitative dechlorination to diphenylethane and biphenyl. The two-stage dechlorination reaction utilizes a palladium catalyst deposited onto iron and magnesium particles. The treatment has the advantage of converting the complex chromatographic pattern that arises from the multiple congeners and degradation products of PCB and DDT into peaks corresponding to their representative hydrocarbon skeletons. The limit for quantitative measurement (LOQ) using this treatment and GC-FID analysis is 40 parts-per-billion (ppb, μg/l) for Aroclor 1260 and 100 ppb for DDT with a linear response extending to 100 times the LOQ. The calibration was successfully tested with triplicate water samples fortified at 15 (DDT) and 10 (Aroclor 1260) times the LOQ. Accuracy (mean percent) and precision (percent relative standard deviation) were 92% and 6.2% for DDT and 96% and 5.2% for Aroclor 1260. Accuracy and RSD for 35 ppm triplicate spiked soil samples were 76% and 18% for Aroclor 1260 and 68% and 26% for DDT. These results are comparable to the published single laboratory results for EPA method 8082 ‘Polychlorinated Biphenyls by Gas Chromatography’. However, the single laboratory results for EPA method 8081A ‘Organohalide Pesticides by Gas Chromatography,’ failed to resolve DDT and therefore could not be compared with this method.     

Diol sep-pak cartridges for enrichment of polychlorobiphenyls and chlorinated pesticides from water samples; determination by GC-ECD

Summary Gas chromatography of polychlorinated biphenyls and chlorinated pesticides in water samples has been performed after adsorption from a 20–200-mL sample on to a cartridge containing 100 mg diol-bonded porous silica. The PCBs are desorbed with 500 μL ethyl acetate, which is concentrated and analysed by gas chromatography with electron-capture detection (GC-ECD). The average recovery of 0.1 ng mL⁻¹ PCB congeners from distilled water and from Aniene river water is≥95% (standard deviation≤2.8). Average recoveries of 25 ng mL⁻¹ Aroclor 1254 from distilled water and from Aniene river water were, respectively, 94.4% and 92.5% (standard deviation 5.8). In the separation of PCB congeners from the chlorinated pesticides only the aldrin (40%) was eluted with the PCBs from the diol Sep-Pak cartridge by aqueous methanol. The method described is simple and reproducible.