Determination of Polychlorinated Biphenyls and Chlorinated Pesticides in Environmental Biological Samples Using Focused Microwave-assisted Extraction

Abstract

Organochlorine compounds such as polychlorinated biphenyls (PCBs) and chlorinated pesticides have been analysed in environmental biological samples using focused microwave-assisted extraction (FMW). The analytical procedure is presented and the results for two Standard Reference Materials, a cod liver oil and a freeze-dried mussel tissue, are reported. The average recoveries for the sum of the PCBs are between 93% and 106%, and for the sum of the chlorinated pesticides are between 109 to 115% for all the certified compounds analysed. The developped analytical procedure is highly reproducible with an average standard deviation of 8% for the sum of the PCBs and 9.7% for the sum of the chlorinated pesticides in the two matrices.     

气相色谱-负化学电离源质谱法测定鱼油中16种多氯联苯

建立了气相色谱-负化学电离源质谱(GC-NCI-MS)同时测定鱼油中16种多氯联苯(PCBs)的方法。鱼油样品经正己烷提取和浓硫酸净化,在选择离子监测模式下进行GC-NCI-MS检测。所检测的PCBs在0.01~10 μg/L范围内呈现良好的线性关系(r>0.99),定量限(S/N=10)在3~67 pg/g之间。基质加标回收率为62.3%~121.8%,相对标准偏差(n=3)≤12%。相比传统的多种填料固相萃取前处理法,本方法样品处理简单快速,有机溶剂使用量少,具有较好的抗基质干扰能力和较高的灵敏度,适用于鱼油中痕量共平面多氯联苯及常见指示性多氯联苯等的同时检测。     

Decomposition of PCBs in transformer oil using an electron beam accelerator

Decomposition of PCBs in commercially used transformer oil used for more than 30 years has been carried out at normal temperature and pressure without any additives using an electron beam accelerator. The experiments were carried out in two ways: batch and continuous pilot plant with 1.5 MeV of energy, a 50 mA current, and 75 kW of power in a commercial scale accelerator.The electron beam irradiation seemed to transform large molecular weight compounds into lower ones, but the impact was considered too small on the physical properties of oil. Residual concentrations of PCBs after irradiation depend on the absorption dose of the electron beam energy, but aliphatic chloride compounds were produced at higher doses of irradiation. As the results from FT-NMR, chloride ions decomposed from the PCBs are likely to react with aliphatic hydro carbon compounds rather than existing as free radical ions in the transformer oil. Since this is a dry process, treated oil can be used as cutting oil or machine oil for heavy equipment without any additional treatments.     

Utilisation of certified reference materials in monitoring common environmental pollutants (PAHs, Nitro-PAHs, PCBs)

Summary Monitoring of the concentration levels of certain environmental organic pollutants which pose potential health hazards is examined. The use of reference materials in the quantitative measurement of common pollutants such as polycyclic aromatic hydrocarbons (PAHs), polycyclic heteroaromatic compounds, nitro-polycyclic aromatic hydrocarbons, and polychlorinated biphenyls (PCBs) is reviewed within the context of achieving optimum precision sand accuracy of the measurements.

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Verwendung zertifizierter Referenzmaterialien bei der Messung von Umweltverunreinigungen (PAHs, Nitro-PAHs, PCBs)

     

Column Chromatographic Procedure for the Determination of Polychlorinated Biphenyls in Certain Industrial Oils

Abstract

Certain oils cause considerable interference in the determination of PCBs by gas chromatography with electron capture detection, requiring time-consuming sample clean-up procedures. Column chromatography, using small, radially-compressed silica columns, is used to isolate PCBs in various oil matrices, thus permitting quantitative analysis. Pure mineral oil, phosphate ester, glycol-base, and sulfonated mineral oils were studied.     

双重净化-气相色谱法测定植物油中指示性多氯联苯

为了考察食用油中7种指示性多氯联苯(PCBs)的残留情况,建立了食用油中痕量多氯联苯测定的双重净化-气相色谱法。以乙腈提取样品,提取液浓缩至干后用正己烷溶解,经浓硫酸、硅胶分散固相萃取双重净化后进行气相色谱分析,外标法定量。优化的色谱条件为:HP-5石英毛细管柱(30 m×0.32 mm×0.25 μm)程序升温分离,流速0.8 mL/min,进样量1.00 μL,电子捕获检测器检测。结果表明:在优化的条件下,7种多氯联苯在10~500 μg/L范围内线性良好,相关系数大于0.999,不同基质中的检出限(S/N=3)范围为1.8~8.9 μg/kg,定量限(S/N=10)范围为5.9~29.8 μg/kg。在橄榄油、花生油和棕榈油空白样品中添加10、20、100 μg/kg 3个水平的7种多氯联苯,其加标回收率范围为71.0%~105.5%,相对标准偏差(RSD)范围为4.0%~11.3%。该方法具有操作简便、快速、准确的特点,可用于植物油中指示性多氯联苯残留量的日常检测。     

Analysis of PCBs in Biotic Matrices by Two-Dimensional GC-ECD

Abstract

The suitability of three GC-ECD systems for the separation of a model mixture containing various congeners of PCBs together with persistent chlorinated aromatics (pesticides and their metabolites, industrial chemicals) was tested. Analyses were performed on two parallel capillaries, the stationary phase of one of them was always in routine practice very common 5% phenyl-methylpolysiloxane, the second one was either 50% phenylmethylpolysiloxane or 7% phenyl-7% cyanopropyl-methylpolysiloxane. The number of unresolved (coeluted) analytes was significantly reduced in these systems and thus unbiased quantitation of PCBs and other components used for regulation was possible. The utilization of this type of multidimensional chromatography for rapid and reliable analysis of real samples (fish oil, human fat) was documented.     

GC-MS analysis of the PCB substitute Ugilec 141 and its occurrence in waste mineral oils

After the restrictions on production and use of PCBs, Ugilec 141, a technical mixture of dichlorobenzyldichlorotoluenes (DBDTs), has been used as a PCB substitute in hydraulic systems. In the Netherlands, the production, import and use of Ugilec 141 has been forbidden since 1988. A method has been developed for the analysis of Ugilec 141 in waste mineral oils to control waste oil import and processing. The method development was based on modification of procedures for the analysis of PCBs in oil and dioxins in fatty matrices and analysis was performed with gas chromatography with mass spectrometry. For sample clean-up, several combinations of column chromatography with activated carbon, alumina, and silica gel have been tested to obtain extracts free from matrix interferences. An internal standard of ¹³C-labeled DBDT was examined to check recoveries from the clean-up procedures. Quantification was performed by comparison with the six most abundant peaks of an external Ugilec 141 standard mixture. Validation experiments showed a linear range from 0.25 to 60 mg Ugilec 141 kg^?1 oil, a reproducibility of 3% and a limit of determination of 0.25 mg Ugilec 141 kg^?1 waste oil. The method was applied in a survey of 70 samples of waste mineral oils from producers all over the Netherlands; this revealed levels below the limit of determination and one positive sample with a concentration of 5.7±0.1 mg Ugilec 141 kg^?1 oil. In an inspection inquiry, one contaminated oil was found containing 116 ± 9 g Ugilec 141 kg^?1 oil.     

Interference of Transformer oil Matrices to the Internal Standards on PCB Quantification

Abstract

Polychlorinated biphenyls (PCBs) are toxic, perssstent, global environmental contaminants which were formulated as complex mixtures of congeners. Many methods have been developed in the past to analyze PCB in transformer oil samples for regulatory purposes. The most important consideration in the cleanup procedure is the ability to remove the oil from the sample matrix, since trace amount of oil will interfere with the subsequent GC-MS analysis. Electron capture detection (ECD) has been the most common method for gas chromatographic analysis of PCBs because of its high sensitivity toward halogenated compounds. ECD can also respond to some non-PCB compound resulting in biased concentrations of PCB. In this work, a two-stage cleanup method, using DMSO liquid/liquid extraction and HPLC column chromatography. has been applied to two types of transformer oil. Five internal standards have been selected to show their performance in the presence of different oil matrices. The comparison of the PCB quantification at different conditions for GC-MS and GC-ECD will be demonstrated.     

The Effect of Temperature on GPC for the Separation of PCBs from Transformer Oil and Subsequent Analysis by GC-MSD

Abstract

The analysis of PCBs often involves lengthy and expensive cleanup procedures to remove interferences associated with environmental sample matrices. Gel permeation chromatography (GPC) has proven to be a useful tool in removing many of these interferences from environmental samples, especially from difficult matrices such as oils, lipids and sediments. This paper describes the effect of temperature upon the GPC column in separating PCBs from transformer oil and its implication on GC-MS analysis.     

Development of a high-performance liquid chromatography carbon column based method for the fractionation of dioxin-like polychlorinated biphenyls

A method to separate polychlorinated biphenyls (PCBs) by using high-performance liquid chromatography (HPLC) was developed. The HPLC column was packed with Amoco PX-21 activated carbon dispersed on octadecylsilane (ODS). The separation was carried out by gradient elution with n-hexane-dichloromethane and toluene in the forward direction followed by reversed elution with toluene. The results show that this HPLC method is useful for the separation of PCBs according to the number of substituted ortho chlorine atoms attached to the biphenyl structure. Average recoveries for a number of individual di-ortho PCBs, mono-ortho PCBs, and non-ortho PCBs in three selected elution windows were 97, 92, and 96%, respectively. Clophen A50, a herring sample, and a cod liver oil sample were fractionated on the column and the analytical results are compared with data from the literature. The method presented here is useful for quantitative separations of mono-ortho PCBs as well as non-ortho PCBs which have been assigned toxic equivalency factors by the World Health Organisation.     

Analytical quality control for the determination of polychlorobiphenyls in environmental matrices

Analytical quality control procedures for ensuring reliable data in the determination of PCBs in environmental matrices are described. Several extraction procedures of PCBs from sediment samples are critically compared and recovery and reproducibility for PCBs determination in sediment and cod liver oil samples are evaluated. Extraction by 1:1n-hexane/acetone mixture in an ultrasonic bath and by supercritical fluids generally give a quantitative recovery and a coefficient of variation lower than 15%, while extraction by a Soxhlet system does not give such good results and requires much longer extraction times. Certified reference materials available from three international organizations, namely the Standards, Measurements and Testing programme of the European Union, the USA National Institute of Standards and Technology and the National Research Council of Canada were used. Finally, the on-going European Union QUASIMEME programme aimed at improving the analytical quality of marine pollution monitoring measurements of European laboratories is addressed.     

Rapid and simultaneous determination of polychlorinated biphenyls and their main metabolites (hydroxylated and methyl sulfonyl) by gas chromatography coupled to mass spectrometry: Comparison of different ionisation modes

Instrumental methods based on gas chromatography coupled to mass spectrometry (GC–MS) have been developed and compared using two different MS ionisation modes, electron impact (EI) and electron capture negative ionisation (ECNI), for the fast, quantitative and simultaneous determination of polychlorinated biphenyls (PCBs) and their main metabolites (hydroxylated PCBs, OH-PCBs, and methyl sulfone PCBs, MeSO₂-PCBs). Parameters affecting chromatographic separation and MS detection were evaluated in order to achieve the highest selectivity and sensitivity for both operation modes. The analytical characteristics of the developed methods were studied and compared in terms of linear range, limits of detection (LODs), limits of quantification (LOQs), and instrumental precision (repeatability and intermediate precision). Both ionisation methods showed similar precision, being relative standard deviations (RSD, %) lower than 9% and 14% for repeatability and intermediate precision, respectively. However, better LODs (from 0.01 to 0.14 pg injected for the three families of congeners studied) were achieved using ECNI-MS as ionisation mode. The suitability of the developed method was demonstrated through their application to fish liver oil samples.     

PAH and PCB determination of the concentration gradient in moss Pleurozium schreberi near a highway,and seasonal variability at the background reference site

Moss (Pleurozium schreberi) was investigated as biomonitor of atmospheric polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Samples were collected at a distance of 10, 50 and 100 m from a highway and were seasonally collected in a forest stand near a regional background air pollution station situated approximately 30 km from the highway. The samples from the background area were dried using two different techniques in parallel, air-drying and freeze-drying. Simultaneous pressurised liquid extraction of PAHs and PCBs was performed, followed by purification using gel permeation chromatography of the crude extract. The concentration of the 15 most important Environmental Protection Agency (EPA) PAHs was determined by gas chromatography coupled with ion-trap mass spectrometry with a selected ion storage acquisition programme, and the PCB concentrations were determined using a mass spectrometer operated in tandem mass spectrometry (MS/MS) mode. Acceptable recoveries and quality parameters for PAHs and PCBs were achieved with the use of pressurised liquid extraction followed by gel permeation chromatography. The detection limit was <0.76 ng g^?1 for PAHs and <0.04 ng g^?1 for PCBs. Possible contamination of the moss samples by 3-ring PAHs and PCBs in the atmosphere was found during air drying. Increased PAH and PCB concentrations caused by car engine exhausts and by asphalt and oil evaporation were found near the highway. Generally, the PAH and PCB concentrations in moss decreased exponentially with distance from the highway. The organic compound concentrations close to the background station showed seasonal fluctuations corresponding to the fluctuations in the local air temperature and particle concentration.     

Analysis of polychlorinated biphenyls in transformer oils by automated on-line coupling reversed phase liquid chromatography-gas chromatography using the through oven transfer adsorption desorption (TOTAD) Interface

An automated method for the direct analysis of polychlorinated biphenyls (PCBs) in transformer oil is presented. The proposed method uses the TOTAD (through oven transfer adsorption desorption) interface for the on-line coupling of reversed phase liquid chromatography and gas chromatography (RPLC-GC). In this fully automated system, the oil is injected directly with no sample pre-treatment step other than dilution with n-propanol and filtration. In the LC step, PCBs are separated from other components of the oils using methanol/water (90:10 v/v) as mobile phase, at a flow rate of 1?mL?min^?1. The LC fraction containing the PCBs is automatically transferred to the GC by the TOTAD interface and GC analysis enables the separation of the PCB congeners. The proposed method is compared with two other methods: the European Norm (UNE-EN-61619) and that of the American Society for Testing and Materials (ASTM) (D4059-00). The proposed method practically eliminates the time-consuming sample preparation step and avoids errors caused by sample manipulation. The total PCB concentrations obtained with the three methods are similar.     

Determination of fat-soluble chlorinated compounds in fish

Summary The level of chlorinated non-polar compounds in samples of sprat (Clupea sprattus) has been determined. The total amounts of chlorine, bromine and iodine in the lipid phase were determined by neutron activation analysis prior to and after treatment of the lipid phase with concentrated sulfuric acid. In sprat samples from a contaminated area the following chlorinated hydrocarbons have been identified and quantified by means of gas chromatography and mass spectrometry: pentachlorobenzene, hexachlorobenzene, heptachlorostyrene and octachlorostyrene. In addition, the following compounds have been detected by gas chromatography using standards: dichlorobenzene, trichlorobenzene, tetrachlorobenzene and polychlorinated biphenyls. A gradual reduction of the level of individual components and total level of chemically persistent chlorinated hydrocarbons in the samples is observed with increasing distance from the source of contamination (Frierfjorden). The same tendency is not seen for the PCB. It has been found that highly chlorinated compounds are distinctly enriched in the sprat oil relative to compounds with lower contents of chlorine.

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Bestimmung von fettlöslichen chlorierten Verbindungen in Fisch

Zusammenfassung Chlorierte unpolare Verbindungen wurden in Fischproben (Sprotten, Clupea sprattus) bestimmt. Der Gesamtgehalt an Chlor, Brom und Jod in der Fettphase wurde vor und nach deren Behandlung mit konz. Schwefelsäure mit Hilfe der Neutronenaktivierungsanalyse erfaßt. In Proben aus einem kontaminierten Gebiet wurden folgende Verbindungen durch Gas-Chromatographie/ Massenspektrometrie identifiziert und quantitativ bestimmt: Pentachlorbenzol, Hexachlorbenzol, Heptachlorstyrol und Octachlorstyrol. Zusätzlich wurden die folgenden Verbindungen durch GC mit Hilfe von Standards erfaßt: Dichlorbenzol, Trichlorbenzol, Tetrachlorbenzol, polychlorierte Biphenyle. Eine allmähliche Abnahme des Gehaltes an einzelnen Verbindungen sowie des Gesamtgehaltes an beständigen chlorierten Kohlenwasserstoffen wurde mit zunehmender Entfernung vom Ursprung der Verschmutzung (Frierfjorden) beobachtet. Dies konnte jedoch im Falle von PCBs nicht festgestellt werden. Hochchlorierte Verbindungen werden im Sprottenöl im Gegensatz zu solchen mit niederen Chlorgehalten deutlich angereichert.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria.     

The determination of trace elements in oils

Summary A heavy oil distillate from an oil containing high sulphur (2.58% w/w) and nitrogen (0.36% w/w) and a high amount of vanadium, nickel, and iron (125.6 ppm) was examined. It had a relatively high content of the asphaltenes (5% w/w) and resins (28% w/w). Trace metals were determined by AAS. The oil was divided into three fractions and a residue by vacuum distillation. The relationship between the N, S, V, Ni and Fe content of the fractions and the boiling-temperature range of the fractions was investigated. The heavy oil distillate was demetallized, and oils before and after the demetallization process were compared in terms of V, Ni, Fe, asphaltenes and resins content.

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Bestimmung der Spurenelemente in Ölen

Zusammenfassung Das zur Untersuchung herangezogene Schweröl war durch einen hohen Gehalt an Schwefel (2,58 Gew.-%) und Stickstoff (0,36 Gew.-%) sowie an metallischen Elementen (V, Ni und Fe; insgesamt 125,6 Gew.-%) gekennzeichnet. Ein so hoher Gehalt an den genannten Elementen ist mit einem hohen Gehalt an Asphaltbestandteilen (5 Gew.-%) und Harz (28 Gew.-%) verbunden. Die Spurenelemente wurden mit AAS bestimmt. Das Öl wurde durch Vakuumdestillation in drei Fraktionen und den Rückstand geteilt. Die Abhängigkeit des Siedepunktes der Fraktionen von dem Gehalt an N, S, V, Ni und Fe wurde untersucht. Der Gehalt an V, Ni, Fe, Asphaltbestandteilen und Harz wurde dem Schweröl entzogen.

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Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980.     

Analysis of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in vegetable oil samples by gas chromatography-ion trap tandem mass spectrometry

Gas chromatography coupled to ion trap tandem mass spectrometry (CG-MS-MS) has been evaluated for the analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in vegetable oil samples containing different concentration levels (0.2-6 pg WHO-TEQ g(-1) for both PCDD/Fs and dl-PCBs) of the 29 toxic congeners of PCDD/F and dioxin-like PCBs. The effect of potential interfering compounds such as polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs) and polychlorinated diphenylethers (PCDEs) on the quantification of mono-ortho PCBs has been investigated. In addition, the influence of the clean-up procedure on the final determination by CG-MS-MS was studied, showing that the quality of the results depends to a great extent on this analytical step. Quality parameters have been established and good precisions (CV: 3-19%) and low limits of detection for PCDD/Fs (0.04-0.20 pg g(-1) oil) and dl-PCBs (0.08-0.64 pg g(-1) oil) were obtained. The method was validated by a comparison of the CG-MS-MS results with those obtained by GC-HRMS.     

Reversed phase liquid chromatography of PCBs as a basis for the calculation of water solubility and log Kow for polychlorobiphenyls

Summary Water solubility (S _w) and log K _ow values have been determined for 154 possible polychlorobiphenyls using the retention indices obtained by RP-HPLC and structurally selected PCB congeners with known log K _ow values for the regression lines. The water solubility data are melting point corrected.

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Umkehrphasen-Flüssig-Chromatographie von PCBs als Grundlage zur Berechnung der Wasserlöslichkeit und des log K _ow für Polychlorbiphenyle

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Dedicated to Prof. Dr. W. Fresenius on the occasion of his 75th birthday     

Separation of polychlorinated biphenyls from chlorinated pesticides using aminopropyl bonded-phase cartridge and determination by GC-ECD

Summary Gas chromatography of polychlorinated biphenyls and chlorinated pesticides in water samples is carried out after adsorption from a 25–500 mL sample, on a cartridge containing 100 mg aminopropyl-bonded porous silica. The clean-up step in which the PCBs and chlorinated pesticides are separated in different eluates is achieved by passing 25 mL of 40% aqueous methanol through the NH₂ Sep-Pak cartridge. The PCBs are desorbed with 500 μL ethylacetate, which is concentrated and analysis by GC-ECD. The average recovery, at 1 ppb is >97% with a standard deviation <2. The limits of detection are 0.1 ng μL⁻¹ and 5 pg μL⁻¹ respectively for Cl₃-PCB and Cl₈-PCB congeners. In the separation of PCBs from the chlorinated pesticides tested in this work, only the Aldrin is adsorbed for 60% with the PCBs by the NH₂ Sep-Pak cartridge. The method described is rapid, simple and reproducible.