上海农村及郊区土壤中PCBs污染特征及来源研究

2007年3月采集上海市农村及郊区36个表层土壤样品,采用气相色谱法对土壤中的多氯联苯（PCBs）残留进行了分析,揭示了土壤中PCBs的残留水平、分布、组成特征及来源。结果表明,试区土壤中共检出62种PCB,总浓度最高2530ng·kg-1,最低71.7ng·kg-1,平均含量534ng·kg-1。较高污染浓度主要是编号为BS2、SJ6、JS4和FX4的土壤样品,但从整体采样区域来看,其污染可能主要来源于城区污染导致的区域大气沉降或是全球大气传输所致。上海农村及郊区土壤PCBs污染物以Tri-CBs和Tetra-CBs为主,主要以工业Aroclor1242来源为主。相关性分析显示,土壤中PCBs与TOC具有显著相关性,尤其是对于挥发性较强的低氯代PCBs,表明TOC是影响上海市土壤中PCBs持留的重要因素之一。聚类分析显示,部分采样点PCBs污染与工业品使用有关,但可能还存在其他来源。     

PCB concentrations in stream sunfish (Lepomis Auritus and L. Macrocmirus) in relation to proximity to chronic point sources

Sunfish (Lepomis auritus and L. macrochirus) were used to monitor polychlorinated biphenyl (PCB) contamination in a group of small streams flowing into a larger stream/reservoir system. Mean PCB concentrations in sunfish appeared to reflect exposure conditions at the site of capture. Fish from uncontaminated sites 1 to 2 km distant from PCB-contaminated sites did not exhibit PCB contamination, and PCB concentrations in fish downstream from a discrete source decreased at a rate greater than or equal to downstream dilution of the point source. Mean PCB concentrations in fish near the source exhibited relatively large (-40%) fluctuations between semi-annual sampling periods, suggesting that PCB concentrations in sunfish populations may respond rapidly to changes in exposure. Sunfish were not sensitive enough indicators of contamination to use in assessing whether or not problematic levels of contamination may occur in other species. Although the presence of PCB contamination in sunfish can be used to infer that PCBs are elevated in other species, the absence of PCB contamination in sunfish cannot be used to infer that older, fattier fish higher up the food chain are uncontaminated.     

Enzyme-linked immunosorbent assay with monoclonal and single-chain variable fragment antibodies selective to coplanar polychlorinated biphenyls

Coplanar polychlorinated biphenyls (Co-PCBs) consisting of non-ortho and mono-ortho-chlorinated PCBs are dioxin-like compounds and cause wide contamination in the environment. To monitor Co-PCB residues, it was attempted to establish an enzyme-linked immunosorbent assay (ELISA) with monoclonal and recombinant antibodies selective to Co-PCBs. When 3,3',5,5'-tetrachlorobiphenoxybutyric acid (PCBH)-keyhole limpet hemocyanin conjugate was immunized into mice, two monoclonal antibodies, Mab-0217 and Mab-4444, were obtained. 3,3',5,5'-Tetrachlorobiphenyl (PCB80) was determined with an IC(50) value of 2.6 and 0.46 ng mL(-1) in ELISA based on Mab-0217 and Mab-4444, respectively. Mab-4444 cross-reacted with Co-PCB congeners, except for PCB77 and PCB81. Mab-0217 reacted with PCB80 and cross-reacted with PCB111. A single-chain variable fragment (scFv) antibody derived from Mab-4444 was produced in recombinant Escherichia coli cells. The scFv antibody showed nearly the same sensitivity toward PCBH as the parent monoclonal antibody in ELISA. These results clearly suggested that Mab-4444 and its scFv antibodies were suitable for monitoring the representative congeners of Co-PCBs.     

金华城区土壤中7种指示性多氯联苯（PCBs）的分布特征和来源分析

采用气相色谱串联质谱测定了金华城区20份土壤样品中的7种指示性PCBs（PCB28,PCB52,PCB101,PCB118,PCB138,PCB153,PCB180）,并分析了其分布特征和来源。结果显示金华城区PCBs残留总量在0.111～2.688μg.kg-（1干重）之间,相比国内外其他城市污染程度较轻。和我国其他地区相类似,PCBs的构成中主要以低氯代的三氯联苯和四氯联苯为主,即可能的污染源是我国历史上生产和使用较多的1号PCB,但个别点也显示2号PCB或进口PCBs污染的存在。PCBs污染程度为工业园区〉农田〉公园,说明城市中PCBs的污染源仍是工业园区,其他区域的污染可能来自于大气传播。农田土壤在作物采收后直接暴露在空气污染中,可能是导致其PCBs含量高于公园土壤的主要原因。     

Effect of sublethal chlorinated discharges on PCB accumulation in transplanted Asiatic clams (Corbicula fluminea)

From 1987–1990, uncontaminated Asiatic clams (Corbicula fluminea) were placed in cages and transplanted into two streams receiving industrial discharges to help identify and quantify polychlorinated biphenyl (PCB) contamination to the streams. Clams accumulated substantial PCB residues at most sites monitored, with the exception of the sites closest to chlorinated discharges. Clams placed nearest to the chlorinated stream reaches consistently underestimated PCB contamination, based on the amount of PCBs found in fish and sediment at those sites. In a separate experiment, clams exposed in stream-side tanks to untreated (total residual chlorine ranged from 0.02–0.07 mg^?1 L daily) and dechlorinated stream water exhibited differing degrees of valve movement, growth, and PCB accumulation after a four-week exposure to the two treatments. Clams exposed to untreated (chlorinated) stream water closed their shells more often, exhibited less growth, and accumulated substantially lower PCB concentrations than clams exposed to dechlorinated stream water. Clams apparently close their shells to avoid chlorine exposure, thus isolating clam tissues from PCBs found in the stream water and in the clams' food. Because chlorine and PCBs occur together in many industrial discharges, this finding is a significant consideration for monitoring programs that utilize clams to assess PCB bioavailability.     

Phytoremediation of a PCB-contaminated soil by alfalfa and tall fescue single and mixed plants cultivation

Purpose

Two plant species (tall fescue and alfalfa) grown alone and in combination was investigated to evaluate phytoremediation of polychlorinated biphenyl (PCB)-contaminated soil and the impact on the catabolic genes and soil enzyme activities in the rhizosphere.

Materials and methods

Surface soil was collected from Xiaoshan (a PCB-containing capacitors and transformers storage site). The phytoremediation experiment was carried out in an agricultural greenhouse experiment station at Huajiachi campus, Zhejiang University. Soil dressing method and fertilizers were applied to improve soil quality for the pot experiment. Soil dehydrogenase activity was measured spectrophotometrically by the reduction of 2, 3, 5-triphenylterazolium chloride (TTC) to triphenyl formazane (TPF) and catalase activity was determined by back-titrating residual H₂O₂ with KMnO₄. Quantitative real-time PCR using SYBR green I was employed with the individual primer sets to determine the relative abundance of the biphenyl dioxygenase genes. Total bacterial numbers were determined by CFU counting and amplification of 16S rDNA.

Results and discussion

Planting treatment significantly enhanced bacterial numbers and PCB removal. The copy numbers of the bphA, bphD.1.B, bphD.2.A, and bphD.2.A/B genes, total bacteria counts, and dehydrogenase activity were the highest in mixed cropping soil, which indicated that tall fescue (forage grass) and alfalfa (legume) mixed cropping was most beneficial to soil bacteria, the potential PCB degraders, and enzyme activity. However, the highest removal of PCBs was found in tall fescue single plant cultivation, followed by combined plant cultivation, probably because tall fescue had greater biomass and could extract more PCBs from soil. Compared with nutrients amended unplanted control, the removals of tri-, tetra-, and penta-CBs in tall fescue single-planted and tri-CBs in combined planted soils were significantly enhanced (p?<?0.01).

Conclusions

The presence of vegetation significantly promoted the dissipation of PCBs and growth of total bacteria and the potential PCBs degraders in soils. Tall fescue and alfalfa mixed cropping was most beneficial to soil bacteria and enzyme activity. Tall fescue showed highest ability for remediation of PCBs in a poor quality soil.     

Authenticity assessment of gamma- and delta-decalactone from prunus fruits by gas chromatography combustion/pyrolysis isotope ratio mass spectrometry (GC-C/P-IRMS)

Authenticity assessment of gamma-decalactone (1) and delta-decalactone (2) from peach (Prunus persica var. persica), apricot (Prunus armeniaca), and nectarine (Prunus persica var. nectarina) was performed using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) in the combustion (C) and pyrolysis (P) mode. In addition, commercially available synthetic (nature-identical) 1 and 2 as well as biotechnologically produced samples (declared to be "natural") were characterized by their delta(2)H(V)(-)(SMOW) and delta(13)C(V)(-)(PDB) values. For the Prunus fruits under study, rather narrow ranges of delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data of 1, varying from - 34.6 per thousand to - 38.4 per thousand and -160 per thousand to -206 per thousand, respectively, were obtained. Synthetic references of 1 showed delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data ranging from -27.4 per thousand to -28.3 per thousand and -151 per thousand to -184 per thousand, respectively. Samples of 1 declared to be "natural" exhibited ranges from -28.1 per thousand to -29.2 per thousand and -192 per thousand to -286 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively. For 2 from peach, apricot, and nectarine, delta(13)C(V)(-)(PDB) values ranging from -34.0 per thousand to -37.9 per thousand were determined; the delta(2)H(V)(-)(SMOW) values ranged from -171 per thousand to -228 per thousand. The delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data for synthetic 2 were -28.2 per thousand and -171 per thousand, respectively, that is, similar to those of 2 from "natural" origin, ranging from -27.7 per thousand to -30.1 per thousand and -185 per thousand to -230 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively. GC-C/P-IRMS allowed clear-cut analytical differentiation of the synthetic and "ex-plant" origin of 1 and 2, whereas narrow ranges of delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data were found for samples of synthetic and "natural" origin.     

珠江三角洲典型地区表层农田土壤中多氯联苯残留状况

采集了珠江三角洲典型区域384个表层农田土壤样品,分析了其中常见6种土壤多氯联苯(PCB28、PCB52、PCB101、PCB138、PCB 153与PCB180)的残留状况.研究结果表明:6种多氯联苯总量(Σ6PCBs)的检出率为78.13％,其平均值为0.42 μg/kg. PCB138的检出率与含量高于其他5种PCBs;土壤中6种多氯联苯的残留状况存在很大的差异;PCB101的检出率最低,仅为10.16％,但其平均值(0.11 μg/kg)较高,主要源于某点位PCB101高达32.44 μg/kg,土壤受到了严重污染.线性相关关系分析结果表明:土壤有机质、黏粒含量则与PCB52存在显著正相关关系.总体而言,低氯代的PCBs含量与土壤理化性质具有一定的相关性,高氯代的PCBs呈现典型的点位污染且在点位土壤中其含量显著高于低氯代同系物.     

Polychlorinated biphenyls (PCBs) in bulk soil and particle size separates of soils in a rural community

In a rural community (Stephanskirchen, Southern Germany) situated near a waste incineration plant six A horizons were sampled to determine 14 polychlorinated biphenyls (PCBs) in bulk soil and particle size separates (clay, silt, fine and coarse sand) and to test the suitability of alkaline saponification for PCB extraction. The PCB concentrations were higher in alkaline saponification extracts than in Soxhlet extracts. However, the extraction efficiency of up to fourfold chlorinated PCBs was lower and more than sevenfold chlorinated PCBs were destroyed. Nevertheless, alkaline saponification was suitable to determine the indicator congeners 28, 52, 101, 138, 152, and 180. The sum of the PCB concentrations ranged from 8.4 to 59.5 μg kg^?1 which was as high as in soils of big cities. However, the concentrations did not reach the threshold value for agricultural purposes of 200 μg kg^?1 as proposed in literature for the sum of the six indicator congeners. The hexachlorinated PCBs 138 and 153 were the most abundant (together > 50% in all samples) whereas PCB 1 could not be detected in any sample. On the average, PCB concentrations increased as particle size decreased. When normalized to C_org, however, the fine sand fraction had the highest PCB concentrations. A slight decrease of lower chlorinated PCBs as particle size decreased indicated an increasing state of degradation. The PCB compositions in the emissions of a comparable waste incineration plant (Bamberg, Bavaria) and in Stephanskirchen soils differed markedly. Therefore, we did not get any indications that waste incineration was a main source of PCBs in the examined soils. Instead, higher chlorinated technical PCB mixtures such as Clophen A 60 or Aroclor 1260 may be the most important sources.     

东平湖表层沉积物中多氯联苯的污染特征

[目的]查明东平湖表层沉积物多氯联苯(PCBs)的污染特征,为东平湖沉积物的污染控制及风险评价提供科学依据。[方法]于2015年7月对东平湖16个不同点位的表层沉积物进行采样,使用GC-ECD检测了PCBs(PCB28,PCB52,PCB101,PCB118,PCB153,PCB138,PCB180)的含量,对东平湖PCBs的空间分布进行分析。运用EPA法对东平湖表层沉积物中多氯联苯进行生态风险评价。[结果]东平湖表层沉积PCBs总的含量范围为nd～605.9ng/kg,均值为126ng/kg,标准差为153。在空间分布上,湖区中部(184.5ng/kg)入湖口(149.9ng/kg)湖区西南部(101.4ng/kg)湖区北部(46.7ng/kg)。研究区PCBs同系物组成以七氯联苯为主,占总量的66.72%。与其他地区的沉积物相比较,东平湖表层沉积物中PCBs处于较低水平,风险评价表明该研究区域生物毒性效应概率远远小于10%。[结论]由于水文因素的影响,东平湖表层沉积物中多氯联苯(PCBs)呈现出由大汶河入湖口向西北方向递减的空间分布趋势;东平湖表层沉积物中的多氯联苯属于轻微污染水平,未对水体环境安全造成严重影响,沉积物中PCBs的浓度水平对大多数底栖生物无毒性影响。     

Composition of PCBs and PAHs in the Montreal Urban Community Wastewater and in the Surface Water of the St. Lawrence River (Canada)

Samples of treated wastewater drawn from the effluent of the Montreal Urban Community (MUC), Canada, and surface water samples from the St. Lawrence River were collected in 1993 and 1994 and analysed for PCBs and PAHs. The average concentrations of Σ13 PCBs and Σ14 PAHs in the effluent were 1.34 ± 0.71 ng L-1 and 326 ± 229 ng L-1, respectively. PCB concentrations in the effluent did not show any clear seasonal pattern in the effluent but PAH concentrations increased during the winter period. In the effluent plume, both PCB and PAH concentrations increased significantly between the upstream control site and the effluent outfall, and subsequently decreased. The profiles of PCB congeners were similar within the effluent plume and also among water masses of the St. Lawrence River. PAH profiles were also similar within the effluent plume, but were different across the two water masses of the St. Lawrence River. Based on the composition of PCB congeners, atmospheric inputs appear to represent the major source of PCBs in the St. Lawrence River. The sources of PAHs in the MUC effluent and in the St. Lawrence River water would appear to be, respectively, petroleum products and combustion-derived products.     

Flavor authentication studies of alpha-ionone, beta-ionone, and alpha-ionol from various sources

In addition to the already available information on the authenticity of alpha- (1) and beta-ionone (2) from plant tissues, there is an interest in the stable isotope data of 1 and 2 available by synthesis from citral and acetone, as European Union regulations, in contrast to the United States and other countries, do not allow a product to be declared as 'natural' that has been chemically synthesized (e.g., by using a natural catalyst) from natural educts. Analyses performed by on-line capillary gas chromatography-isotope ratio mass spectrometry in the combustion and pyrolysis modes (HRGC-C/P-IRMS) as well as by elemental analyzers (EA-C/P-IRMS) measuring delta(13)C(V)-PDB and delta(2)H(V)-SMOW values provide for the first time isotope data of such 'natural' 1 and 2 as well as of synthetic and 'ex plant' alpha-ionol (3). The isotope data recorded for synthesized 1 and 2 reflected the influence of the origin of the used citral, whereas that of acetone was less remarkable. For instance, 'natural' 1 ex citral from lemongrass showed, as expected for a C4 plant, an enriched delta(13)C(V)-PDB value of -18.5 per thousand. In addition, the use of synthetic citral resulted in an enriched delta(2)H(V)-SMOW value of -43 per thousand, whereas with citral ex Litsea cubeba and ex lemongrass values of -242 and -232 per thousand, respectively, were recorded. IRMS analyses of 'natural' 2 revealed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values that were nearly identical to that recorded for 'natural' 1. As to both 1 and 2, variations of synthesis conditions led to distinct changes in the delta(13)C(V)-PDB but not the delta(2)H(V)-SMOW values. Synthetic 3 showed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values of -24.5 and -184 per thousand, respectively. These data differed from those found in raspberry fruit under study (n = 8), that is, ranging from -33.6 to -36.6 per thousand for delta(13)C(V)-PDB and from -200 to -225 per thousand for delta(2)H(V)-SMOW. The values determined additionally for 1 and 2 in raspberry fruit samples ranged from -30.3 to -35.1 per thousand and from -176 to -221 per thousand for delta(13)C(V)-PDB and delta(2)H(V)-SMOW, respectively, and thus corresponded to the already known literature information.     

Optimization of large-volume injection for the determination of polychlorinated biphenyls in children's fast-food menus by low-resolution mass spectrometry

This study includes the determination of five indicator polychlorinated biphenyls (PCBs) (52, 101, 153, 138, and 180), six non-ortho PCBs (35, 80, 81, 77, 126, and 169), and two mono-ortho PCBs (28 and 118) in fast food for children. A freeze-dried sample of 10 g is extracted by using pressurized n-hexane in two 5 min cycles at 120 degrees C and 100 mbar. Fatty extracts were cleaned up by means of acetonitrile/n-hexane partitioning and gel-permeation chromatography. The fractionation of non-ortho, mono-ortho, and indicator PCBs was made on graphitized carbon solid-phase extraction cartridges by using n-hexane, n-hexane/toluene (99:1, v/v), and toluene as elution solvents. Gas chromatography coupled to tandem mass spectrometry and large-volume injections with a programmed-temperature vaporizer (PTV-LV) were used to increase sensitivity and selectivity of the PCB determination. The PTV-LV injection settings, that is, vaporizing temperature, vaporizing time, and purge flow, were optimized by using a central composite design. A 15-40 times increased sensitivity was reached as compared with that obtained with the conventional 1 microL splitless injection. The limits of detection achieved were between 0.3 and 1.2 pg/g, and repeatability data, as relative standard deviation varied, ranged from 2 to 9% for the 0.05 ng/mL PCB level.     

Comparison of Various Phosphate Stabilisation Agents for the Immobilisation of Ni and Zn in Sewage Sludge

This paper reports the results of the treatment of polychlorinatedbiphenyl (PCB) contaminated sandy soils (100 mg kg^-1 Aroclor 1242) with the Fenton advanced oxidation process (AOP). The results obtained in the various assays permitted the optimization of conditions as follows: 5% H₂O₂; 100 ppm of Fe³⁺; and a ratio of sandy soil mass/volume of oxidizing solution (m/V) of 1/3 g mL^-1. In addition, these tests established the need for agitation and dispensed with the need for heat. The results obtained confirm that the oxidation process occurs in solid phase (on the PCBs adsorbed to soil particles), producing 98% elimination of the original PCB structure and 82% dechlorination, all within a reaction time of 72 hr. The degree of elimination was found to be dependent on the level of congener chlorination and the process displays a pseudo first order kinetics. In addition, the Fenton chemical oxidation process may be complemented by subsequent aerobic biological degradation which, after 15 days, produces 72% mineralization of the products generated during the chemical oxidation process.     

兰州地区PCBs的长距离传输潜力及其总持久性模拟研究

运用TaPL3（version3.00）模型计算了7种PCBs同系物在兰州地区通过大气和水体的特征迁移距离（CTD）及其总持久性（Po）v,讨论了其长距离传输潜力（LRTP）和Pov之间的关系,并以PCB28为例,应用灵敏度分析方法对模型的不确定性进行了研究。结果显示,兰州地区PCB28、PCB52、PCB77、PCB101、PCB138、PCB153和PCB180通过大气的CTDair在250～2500km之间,Pov在500～33000d之间,PCB138、PCB153和PCB180对源区影响较大;通过水体的CTDwater在6500～61000km之间,Pov在850～36000d之间,PCB28、PCB52、PCB77和PCB101对源区影响较大。7种PCBs的同系物LRTP和Pov之间没有直接的联系,就排放到大气中的PCBs而言,对Pov和CTD影响最大的参数都是理化参数;就排放到水体中的PCBs而言,Pov比CTD更依赖于PCBs的理化性质,而CTD比Pov更依赖于环境条件。同国外的研究相比,兰州地区PCB28通过大气的CTDair偏低,通过水体的CTDwater偏高,PCB28通过大气和水体的Pov都偏高。     

Polychlorinated biphenyls (PCBs) detection in food samples using an electrochemical immunosensor

In this work, a disposable electrochemical immunosensor, based on a competitive assay scheme, was applied to detect polychlorinated biphenyls (PCBs) in food. For this purpose, antibodies against PCBs were directly immobilized onto the carbon surface of a disposable screen-printed electrode. A competition between the PCBs present in the sample and a fixed concentration of an enzyme-labeled PCB was realized and evaluated by electrochemical detection. Alkaline phosphatase was used as the enzyme label, coupled with differential pulse voltammetry (DPV) as the electrochemical technique. The immunosensor was tested on aroclor mixture detection (1242 and 1248) and then on some typologies of food samples to evaluate the possible application for real sample analysis. Samples analyzed were from different matrixes, such as sheep milk, bovine adipose tissue, and bovine muscle. Results obtained were compared with the accredited results according to ISO 17025 methods for PCB detection (HRGC-LRMS) as a confirmatory analysis. Preliminary results show the possibility to use this device as a screening method in food sample analysis. The negligible matrix effect observed may lead to a simplified extraction procedure, and considerable time and consumable savings are the immediate benefits given by the proposed method.     

Remediation of polychlorinated biphenyl-contaminated soil by soil washing and subsequent TiO2 photocatalytic degradation

Purpose

An efficient method was developed for treating polychlorinated biphenyl (PCB)-contaminated soil by soil washing and subsequent TiO₂ photocatalytic degradation, and the photocatalytic degradation mechanism of PCBs was explored.

Materials and methods

Hydroxypropyl-??-cyclodextrin (HP??CD) and polyoxyethylene lauryl ether (Brij35) were used to extract PCBs from contaminated soil at first, and then the degradation of PCBs in the soil extracts was performed by TiO₂ photocatalysis under UV irradiation.

Results and discussion

Washing conditions including washing time, the concentration of HP??CD/Brij35, and the ratio of soil mass to solution volume for extracting 2,4,4??-trichlorobiphenyl (PCB28) from a PCB28-spiked soil were investigated at first. The results indicated that both HP??CD and Brij35 exhibited good performance. The intermediates of photocatalytic degradation of PCB28 were from its dechlorination and hydroxylation in the HPCD and aqueous solutions, respectively. A field PCB-contaminated soil from e-waste recycling sites was treated by this method. The results showed that the extracting percentage was significantly affected by the chlorination degree of PCBs, and HP??CD slowed down the photocatalytic degradation efficiency of overall PCBs.

Conclusions

Soil washing and subsequent TiO₂ photocatalytic degradation was successfully applied for treating PCB-contaminated soil, and HP??CD strongly altered the pathways of the photocatalytic degradation of PCBs.     

Tillage effects on the accumulation of polychlorinated biphenyls in biosolid‐amended soils

Soil tillage along with the application of organic waste probably affects the concentrations of organic carbon and the enrichment of introduced polychlorinated biphenyls (PCBs). In a three‐year experiment the PCB status of soils from three different field sites (silty clay loam, silt loam, sandy loam) which were long‐term differently tilled (NT = no‐tillage, CT = conventional plough tillage) and amended with two different organic wastes such as sewage sludge and compost (biosolids) was examined. No significant alteration in soil‐PCB quality and quantity with biosolid application could be proven within the course of the experiments. This indicates soil‐air exchange of PCBs dominates their concentrations in soil. Organic carbon in soil was significantly tillage‐dependent and determined the fate of PCBs resulting in a generally elevated PCB‐level in the non tilled soils. Linear regression of PCB load and organic matter content of all investigated untreated soils was highly significant (R² = 0.73). Due to already elevated PCB levels in non tilled soils with a maximum of 65 μg kg^—1 in the superficial layer of the silt loam control plot, any additional potential input, i. e. through the amendment with organic wastes, should therefore be avoided.     

Determination of 2H/1H and 13C/12C isotope ratios of (E)-methyl cinnamate from different sources using isotope ratio mass spectrometry

For the authenticity assessment of (E)-methyl cinnamate from different origins, combustion/pyrolysis-isotope ratio mass spectrometry (C/P-IRMS) was used by an elemental analyzer (EA) and on-line capillary gas chromatography coupling (HRGC-C/P-IRMS). For that reason, (E)-methyl cinnamate self-prepared from synthetic, natural, and semisynthetic educts was analyzed in comparison to the commercial synthetic and natural ester. In addition, (E)-methyl cinnamate from basil extract and a number of commercial natural aromas was investigated. The data of self-synthesized synthetic (E)-methyl cinnamate, i.e., delta(13)C(V)(-)(PDB) = -33.8 per thousand and delta(2)H(V)(-)(SMOW) = +349 per thousand, corresponded with that found for the commercial synthetic samples (-29.5 to -31.4 per thousand and +328 to +360 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively). The ester produced from natural educts by acid as well as Candida antarctica catalysis revealed delta(13)C(V)(-)(PDB) = -25.6 and -30.1 per thousand as well as delta(2)H(V)(-)(SMOW) = -162 and -169 per thousand, respectively. Acid-catalyzed semisynthetic products differed in their delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) values depending on the origin of their educts. For the ester from synthetic methanol and natural cinnamic acid, -27.3 and -126 per thousand were determined for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively, whereas for the ester produced from natural methanol and synthetic acid delta(13)C(V)(-)(PDB) = -30.6 per thousand and delta(2)H(V)(-)(SMOW) = +287 per thousand were found. Basil extract showed -28.9 and -133 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively. Commercial aromas declared to be natural revealed delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data ranging from -25.7 to -28.5 per thousand as well as -85 to -191 per thousand, respectively, indicating, in part, incorrect declaration.     

Polychlorinated biphenyls in soils of Belarus: Sources,contamination levels,and problems of study

Polychlorinated biphenyls (PCBs) in soils of Belarus were studied. The PCB concentrations in reference soils were determined. High accumulation levels of PCBs were found at the working and storage sites of PCB-containing electrical equipment. Soil contamination under PCB leakage from damaged capacitors and transformers was analyzed. Contamination of the Lakokraska plant site and adjacent areas (Grodno oblast) because of the long-term use of the Sovol was revealed. The structure of the PCB isomers in the soils was described depending on the contamination source.