Headspace solid phase microextraction (HSSPME) for the determination of volatile and semivolatile pollutants in soils

We have investigated the use of headspace solid phase microextraction (HSSPME) as a sample concentration and preparation technique for the analysis of volatile and semivolatile pollutants in soil samples. Soil samples were suspended in solvent and the SPME fibre suspended in the headspace above the slurry. Finally, the fibre was desorbed in the Gas Chromatograph (GC) injection port and the analysis of the samples was carried out. Since the transfer of contaminants from the soil to the SPME fibre involves four separate phases (soil-solvent-headspace and fibre coating), parameters affecting the distribution of the analytes were investigated. Using a well-aged artificially spiked garden soil, different solvents (both organic and aqueous) were used to enhance the release of the contaminants from the solid matrix to the headspace. It was found that simple addition of water is adequate for the purpose of analysing the target volatile organic chemicals (VOCs) in soil. The addition of 1 ml of water to 1 g of soil yielded maximum response. Without water addition, the target VOCs were almost not released from the matrix and a poor response was observed. The effect of headspace volume on response as well as the addition of salt were also investigated. Comparison studies between conventional static headspace (HS) at high temperature (95 degrees C) and the new technology HSSPME at room temperature ( approximately 20 degrees C) were performed. The results obtained with both techniques were in good agreement. HSSPME precision and linearity were found to be better than automated headspace method and HSSPME also produced a significant enhancement in response. The detection and quantification limits for the target VOCs in soils were in the sub-ng g(-1) level. Finally, we tried to extend the applicability of the method to the analysis of semivolatiles. For these studies, two natural soils contaminated with diesel fuel and wood preservative, as well as a standard urban dust contaminated with polyaromatic hydrocarbons (PAHs) were tested. Discrimination in the response for the heaviest compounds studied was clearly observed, due to the poor partition in the headspace and to the slow kinetics of all the processes involved in HSSPME.     

Determination of persistent organochlorine compounds in blood by solid phase micro extraction and GC-ECD

Biomonitoring of persistent organochlorine compounds in blood using the solid phase microextraction technique (SPME) and gas chromatography with electron capture detection (GC-ECD) is described. Polar substances as tri-, tetra- and penta-chlorophenols are analyzed simultaneously with less polar compounds such as hexachlorobenzene (HCB), α-, β-, and γ-hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its derivatives and with some important congeners of the polychlorinated biphenyls (PCB). No derivatization is needed for the determination of the phenolic compounds. The results show a good reproducibility down to the lower μg/L-region. The method is very fast and of low cost compared to the classic extraction and determination procedures. Received: 7 July 1997 / Revised: 6 October 1997 / Accepted: 21 October 1997     

Determination of persistent organochlorine compounds in blood by solid phase micro extraction and GC-ECD

Biomonitoring of persistent organochlorine compounds in blood using the solid phase microextraction technique (SPME) and gas chromatography with electron capture detection (GC-ECD) is described. Polar substances as tri-, tetra- and penta-chlorophenols are analyzed simultaneously with less polar compounds such as hexachlorobenzene (HCB), α-, β-, and γ-hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its derivatives and with some important congeners of the polychlorinated biphenyls (PCB). No derivatization is needed for the determination of the phenolic compounds. The results show a good reproducibility down to the lower μg/L-region. The method is very fast and of low cost compared to the classic extraction and determination procedures.     

The determination of volatile organic compounds in soils using solid phase microextraction with gas chromatography-mass spectrometry

Solid phase microextraction (SPME) was applied in the development of a protocol for the analysis of a number of target organic compounds in landfill site samples. The selected analytes, including aromatic hydrocarbons, chlorinated hydrocarbous, and unsaturated compounds, were absorbed directly from a headspace sample above a soil layer onto a fused silica fiber. Following exposure, the fiber was thermally desorbed in the injection port of the gas chromatograph and eluted compounds were detected using a mass selective detector. The stability and sensitivity of the extraction technique were examined at five temperatures (22–60°C) using a 100μm polydimethylsiloxane fiber. Calibrations, using soil samples spiked with selected solvents (0.5–30 μg/g), were linear; trichloroethene (r² = 0.992) and benzene (r² = 0.998). SPME was applied to the examination of a municipal landfill where 8 sites were sampled, at three depths, resulting in the detection of xylene (maximum 2.8 μg/g) and a number of other non-target organic contaminants.     

Environmental analysis of organic compounds in water using solid phase micro extraction

Solid Phase Micro Extraction (SPME) involves exposing a fused silica fiber coated with stationary phase to a contaminated water sample. The organic analytes become partitioned between the stationary phase and the water and when equilibrium is reached the fiber is removed from the solution and the analytes are thermally desorbed in the injector of a gas chromatograph. The fiber is contained in a syringe to facilitate handling. Factors which affect linear range, limit of detection, and total analysis time are discussed with regard to the development of a method for analysis of volatile compounds in environmental water samples. The sensitivity of the method was determined by the thickness of the film of stationary phase; the equilibration time, however, increased with the film thickness, although it can be minimized by use of a cross-shaped stirrer bar. Increasing the thickness of stationary phase in the analytical column enables the cryofocusing temperature to be increased from ?40 to ?15°C. With an ion trap mass spectrometer, detection limits required by the US Environmental Protection Agency are met for all compounds except chloromethane and chloroethane. The method has been applied to environmental water samples.     

Application of solid phase micro extraction for the rapid analysis of chlorinated organics in breast milk

The method presented here allows the monitoring of persistent organochlorine compounds in breast milk using the solid phase microextraction technique (SPME) and gas chromatography with electron capture detection (GC-ECD). It describes the determination of hexachlorobenzene (HCB), α-, β-, and γ-hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its derivatives, and some important congeners of the polychlorinated biphenyls (PCB). Also included are more polar substances such as tri-, tetra- and penta-chlorophenols, which can be analyzed simultaneously with the afore-mentioned less polar compounds without the need of a derivatization for the determination of the phenolic compounds. The reproducibility of the results is very good down to the lower μg/L-region. The method is very fast and of low cost compared to the classic extraction and determination procedures.     

Application of solid phase micro extraction for the rapid analysis of chlorinated organics in breast milk

The method presented here allows the monitoring of persistent organochlorine compounds in breast milk using the solid phase microextraction technique (SPME) and gas chromatography with electron capture detection (GC-ECD). It describes the determination of hexachlorobenzene (HCB), alpha-, beta-, and gamma-hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its derivatives, and some important congeners of the polychlorinated biphenyls (PCB). Also included are more polar substances such as tri-, tetra- and penta-chlorophenols, which can be analyzed simultaneously with the afore-mentioned less polar compounds without the need of a derivatization for the determination of the phenolic compounds. The reproducibility of the results is very good down to the lower microg/L-region. The method is very fast and of low cost compared to the classic extraction and determination procedures.     

Rapid determination of volatile organic compounds in environmentally hazardous wastewaters using solid phase microextraction

Solid phase micro-extraction (SPME) was applied to the determination of volatile organic compounds (VOC) in wastewater discharges. Environmentally significant samples, typical of those subject to regulatory control, were examined and included discharges from pharmaceutical, petrochemical and municipal sewerage treatment plants. Analysis was performed using gas chromatography – mass spectrometry (GC-MS) following sampling using headspace or immersion SPME. Fused silica fibres, coated with either poly(dimethylsiloxane) or poly(acrylate), were examined to determine VOC which included chloroform, saturated carboxylic acids, alkylbenzenes, phenol, benzonitrile and benzofuran. Detection limits varied from 10 to 170 ng/ml and satisfactory relative standard deviations (%RSD < 10) were obtained. For most samples, headspace sampling was preferred to immersion. SPME was found to be a useful technique for the rapid screening of wastewaters for VOC.     

Estimating uncertainty in matrix solid phase extraction methodology for the determination of chlorinated compounds in fish

In this study, a detailed process of uncertainty estimation associated with matrix solid phase dispersion method (MSPD) for the extraction of organochlorinated compounds from fish coupled with gas chromatography is given. The evaluation of uncertainty arising from trueness using fully nested experimental designs is presented by estimating proportional bias, in terms of recovery. The uncertainty of measurements associated with the actual chromatographic process was also estimated. The methodology was applied for the determination of selected organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in real fish samples, from selected study locations in Western Greece (Mesologgi lagoon and Trichonida lake), based on chromatographic techniques. The sources of uncertainty are presented along with the calculated combined uncertainty terms derived from the analytical procedure and chromatographic process. The estimation of uncertainty was included in the presentation of final determinations.     

In-tube extraction for enrichment of volatile organic hydrocarbons from aqueous samples

In-tube extraction (ITEX) is a novel solventless extraction technique in which a headspace syringe with a needle body filled with a sorbent (here: Tenax TA) is used. The analytes are extracted from sample headspace by dynamic extraction. The needle body is surrounded by a separate heater, which is used for thermal desorption of analytes into the injection port of a GC system. We report here for the first time the optimization and evaluation of a fully automated analytical method based on ITEX. As target analytes, 19 common groundwater contaminants such as halogenated volatiles and monoaromatic compounds have been chosen. Method related parameters such as extraction temperature, number of extraction cycles, extraction and desorption volume as well as extraction and desorption flow rates were investigated in detail. The linear dynamic range of the ITEX method ranged over six orders of magnitude between 0.028 microg/L and 1218 microg/L with linear correlation coefficients between 0.990 and 0.998 for the investigated compounds. Method detection limits for monoaromatic compounds were between 28 ng/L (ethylbenzene) and 68 ng/L (1,2,4-trimethylbenzene). For halogenated volatile organic compounds, method detection limits between 48 ng/L (chloroform) and 799 ng/L (dichloromethane) were obtained. The precision of the method with external calibration was between 3.1% (chloroform ethylbenzene) and 7.4% (1,2,3-trimethylbenzene).     

Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction

In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography–mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-μm film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons. Figure SPDE Principle     

Trends of volatile chlorinated hydrocarbons and trihalomethanes in Antarctica

In order to understand behaviour and environmental fate of manmade chemicals in remote and cold areas, during the XXVII Italian Expedition carried out in Antarctica throughout the austral summer 2011/2012, superficial snow and lake water were sampled along the Ross Sea's South coast and their content of some low-molecular weight volatile halogenated hydrocarbons was evaluated. In consideration of their important role in stratospheric ozone chemistry, some volatile chlorinated hydrocarbons (VCHCs) and trihalomethanes (THMs) were investigated. The analyses were realised with a dedicated system composed by a purge-and-trap injector coupled to a gas chromatograph with a mass spectrometer (PTI-GC-MS) operating in SIM mode. The investigated VCHCs (chloroform; 1,1,1-trichloroethane; tetrachloromethane; trichloroethylene and tetrachloroethylene) were present in all analysed samples, and concentration levels ranged from units to hundreds of ng L^?1 according to considered matrix. For the first time, THMs (bromoform; dibromochloromethane; bromodichloromethane), were measured in Antarctic lake waters and freshly deposited snow; their concentration levels ranged from units to tens of ng L^?1. In order to assess eventual temporal variations, VCHC content in aqueous Antarctic matrices was compared with levels occurring in the past Italian Antarctic expeditions: for some banned substances, a decrease in concentration was observed, probably due to worldwide use restrictions. Finally, current Antarctic and Italian VCHC and THM levels in snow and lake water samples were compared and were found to be quite similar, differing at most by one order of magnitude, corroborating the hypothesis of an accumulation of halogenated compounds in Antarctic aqueous matrices.     

A novel porous carbon and its perspectives for the solid phase extraction of volatile organic compounds

A porous carbon sorbent prepared by controlled pyrolysis of saccharose in a matrix of silica gel was tested for the preconcentration of a variety of compounds differing in polarity and volatility (hydrocarbons, halocarbons, oxygenated compounds) in simulated and real air samples. The trapped components were desorbed off-line by liquid-(carbon disulphide and carbon disulphide with 1% methanol) and on-line by thermo-desorption in combination with HRCGC. Adsorption-desorption properties of the sorbent were evaluated according to the determined recovery values, whereby physicochemical interactions of both the sorbent and solute were taken into consideration. With oxygenated compounds recovery data indicate the presence of active sites on the surface of the sorbent.Dedicated to Professor Dr. Dr. h.c. mult. J. F. K. Huber on the occasion of his 70th birthday     

固相萃取光度法测定烟草中的挥发酚

研究了用Waters Sep-Park-C18固相萃取小柱萃取测定烟草样品中的挥发酚的方法。用自动水蒸汽蒸馏仪蒸馏出烟草样品中的挥发酚，4-氨基安替比林显色，显色产物可用Waters Sep-Park-C18固相萃取小柱萃取，以乙醇洗脱后用分光光度法测定，该方法可用于烟草样品中挥发酚的测定。     

On-site solid phase extraction and coupled-column high-performance liquid chromatographic determination of six polycyclic aromatic hydrocarbons in water

A high-performance liquid chromatographic method for the determination of fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene in water is presented. The analytical procedure consists of on-site solid-phase extraction of the analytes on a selective sample column using a new device, transport and integration of the loaded sample column into a HPLC-system and coupled-column HPLC-analysis. The method allows reliable quantification of the PAHs at the low ng/l-level in particle-free as well as in particle-containing surface water.Dedicated to Professor Dr. Dr. h.c. mult. J. F. K. Huber on the occasion of his 70th birthday     

Rapid determination of chlorinated pesticides using CN-bonded cartridges followed by GC-ECD

Summary Gas chromatography of chlorinated pesticides in water is carried out after adsorption of a 50 mL sample using a cartridge containing 100 mg CN-bonded porous silica and extraction with 500 L pentane. The average recovery for eight organochloride pesticides at 1 ppb was >95%. The procedure described is simple, selective and reproducible.     

Rapid cleanup of natural organic extracts for the recovery of plyacyclic aromatic hydrocarbons by solid phase extraction

A rapid cleanup procedure has been tested and applied routinely in our laboratory to petroleum and sediment extracts for the recovery of polycyclic aromatic hydrocarbons. Solid-phase extractsion (SPE) on Florisil cartridges yields a fast and good recovery of neutral aromatic compounds which has been checked by normal-phase high performance liquid chromatographic (HPLC) analysis with UV-absorption detection.     

在线固相萃取-液相色谱法直接测定水中超痕量多环芳烃

建立了在线固相萃取-液相色谱直接测定水体中16种超痕量多环芳烃（PAHs）的方法。水样经高速离心后，加入适量甲醇，配制成40%（体积分数）甲醇水溶液，直接进样2 mL至在线固相萃取流路，进行萃取富集，再通过阀切换将洗脱的PAHs转移至分析流路进行分离检测。16种PAHs在各自范围内线性关系良好，相关系数均大于0.996；方法的检出限为0.14~12.50 ng/L，其中苯并[a]芘（B（a）P）的检出限为0.38 ng/L。实际水样在10、40和200 ng/L加标水平下的加标回收率为76.1%~134.9%，RSD为0.3%~16.6%。B（a）P在1 ng/L加标水平下的回收率为71.8%~92.7%，RSD为3.9%。结果表明，该方法操作简单，灵敏度高，溶剂消耗量少，可满足水样中PAHs，尤其是B（a）P的超痕量分析要求。     

Simultaneous extraction and determination of fluoroquinolones,tetracyclines and sulfonamides antibiotics in soils using optimised solid phase extraction chromatography-tandem mass spectrometry

An analytical method was developed for the simultaneous extraction and determination of 18 fluoroquinolones (FQs), tetracyclines (TCs) and sulfonamides (SAs) antibiotics from soils using solid phase extraction and liquid chromatography-tandem mass spectrometry. The soils were extracted by different solvents with the help of mechanical shaking and ultrasonic treatment at 59?kHz, followed by a strong anion exchange (SAX) cartridge to clean up soil samples and a hydrophilic lipophilic balance (HLB) cartridge as enrichment. The method was evaluated by testing the following variables: extraction solvents, the type of SPE cartridges, solvent volumes, initial spiking levels and soil types (silty clay loam and clay loam soils). The soil extraction method was validated using these two types of soils, representing two typical agricultural soils in northern China. For 2?g soil, the extraction steps with the mixture of potassium phosphate buffer and acetonitrile (ACN) (1/1, v/v, pH 3.2) provided satisfactory recoveries. In the clay loam soil, the recoveries of all the compounds were from 56% to 89% at the spiking level of 50?µg?kg^?1 soil, and from 69% to 97% at the spiking level of 200?µg?kg^?1 soil, respectively. Recoveries in silty clay loam soil were similar to that in clay loam. The method was successfully employed using soil samples collected from a farmland and afforestion area irrigated with sewage in northern China. The result indicates that trace antibiotics in sewage may accumulate in soil irrigated by river water containing sewage.