Solid-phase extraction with C30 bonded silica for analysis of polycyclic aromatic hydrocarbons in airborne particulate matters by gas chromatography-mass spectrometry

A solid-phase extraction (SPE) method using triacontyl bonded silica (C30) as sorbent was developed for the determination of 16 US Environmental Protection Agency polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matters quantitatively by gas chromatography-mass spectrometry (GC-MS). Optimization experiments were conducted using spiked standard aqueous solution of PAHs and real airborne particulates samples aiming to obtain highest SPE recoveries and extraction efficiency. Factors were studied in SPE procedures including the concentration of organic modifier, flow rate of sample loading and elution solvents. The ultrasonication time and solvents were also investigated. Recoveries were in the range of 68-107% for standard PAHs aqueous solution and 61-116% for real spiked sample. Limits of detection (LODs) and limits of quantification (LOQs) with standard solution were in the range of 0.0070-0.21 microgL(-1) and 0.022-0.67 microgL(-1), respectively. The optimized method was successfully applied to the determination of 16 PAHs in real airborne particulate matters.     

Polycyclic aromatic hydrocarbon analysis in different matrices of the marine environment

Polycyclic aromatic hydrocarbons (PAHs) were determined in marine samples of various types, i.e. seawater, sediment and mussel homogenate samples. The samples were spiked with standard PAH mixtures in both polar (acetonitrile) and non-polar (i-octane) solvents, then extracted. Extraction from seawater was performed by liquid/liquid extraction to hexane (LLE) and with solid phase extraction (SPE) discs. The water samples were filtered and unfiltered seawater, and redistilled water for comparison. The discs with PAHs adsorbed from water samples, and also the sediment and mussel homogenate samples, were extracted with acetonitrile by sonication. PAHs in the disc extracts and from the LLE were cleaned-up using TLC and next determined by GC/MS/IT (with ion-trap) and HPLC-DAD/UV. The analytical procedures were verified with deuterated PAH standard mixtures. The large differences in PAH recoveries (from 12 to 86% for sum, and from 3 to 135% for particular PAHs) do not depend solely on the type of matrix and analytical procedure applied (e.g. standard solvent, volume of evaporated sample), but also on the concentration and molecular structure of the analyte. Usually, only a fraction of each PAH content in the matrix is determined, depending on the particulate matter in seawater and the sorption properties of the solid matrix. The recoveries of deuterated PAHs are higher than those of non-deuterated compounds.     

Bamboo charcoal as adsorbent for SPE coupled with monolithic column-HPLC for rapid determination of 16 polycyclic aromatic hydrocarbons in water samples

The coupling of solid-phase extraction (SPE) using bamboo charcoal (BC) as an adsorbent with a monolithic column-high performance liquid chromatography (MC-HPLC) method was developed for the high-efficiency enrichment and rapid determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water. Key influence factors, such as the type and the volume of the elution solvent, and the flow rate and the volume of the sample loading, were optimized to obtain a high SPE recovery and extraction efficiency. BC as an SPE adsorbent presented a high extraction efficiency due to its large specific surface area and high adsorption capacity; MC as an HPLC column accelerated the separation within 8 min because of its high porosity, fast mass transfer, and low-pressure resistance. The calibration curves for the PAHs extracted were linear in the range of 0.2-15 μg/L, with the correlation coefficients (r(2)) between 0.9970-0.9999. This method attained good precisions (relative standard deviation, RSD) from 3.5 to 10.9% for the standard PAHs I aqueous solutions at 5 μg/L; the method recoveries ranged in 52.6-121.6% for real spiked river water samples with 0.4 and 4 μg/L. The limits of detection (LODs, S/N = 3) of the method were determined from 11 and 87 ng/L. The developed method was demonstrated to be applicable for the rapid and sensitive determination of 16 PAHs in real environmental water samples.     

Porous metal membranes for solid-phase extraction of polycyclic aromatic hydrocarbons

Solid-phase extraction (SPE) is one of the most important techniques for sample preparation, purification, concentration and cleanup. Membranes made from synthetic organic polymers, cellulose, or glass fibers are used for sample pretreatment. In this work, we report that a porous metal membrane, the metal filter in HPLC, was used as a novel kind of solid-phase extraction adsorbent material. To evaluate the performance of the porous metal membrane for the SPE, naphthalene, fluorene, anthracene, phenanthrene, fluoranthene, pyrene, chrysene, perylene and benzo(a)pyrene were selected as analytes. Several parameters that affected the extraction efficiency such as the extraction time, the concentration of NaCl, the extraction temperature and the agitation speed were optimized. The experimental result indicates that the porous metal membrane possesses high adsorption ability to the tested polycyclic aromatic hydrocarbons (PAHs). Under the optimum conditions, the detection limits of the developed method were in the range of 0.03-0.082 μg L(-1) (S/N = 5), and excellent linear correlations between peak area and concentration of PAHs were found over the range of 0.1-60 μg L(-1). The precisions (RSD) for five replicate extractions of the PAHs from sample solutions were in the range of 2.6-5.0%. The recoveries of the PAHs from tap water and river water samples spiked with 9 PAHs (20 μg L(-1) of each individual PAH) ranged from 83.0% to 112.5%. The porous metal membrane is durable, simple, inexpensive, reproducible and has a high adsorption ability for use in SPE of PAHs.     

ASE-SPE/GC-MS测定土壤中16种PAHs质量控制研究

优化了土壤中16种优控多环芳烃( PAHs)的分析方法,建立了一套完备的质量控制体系,解决了PAHs分析中常见的技术难点,如苯并(a)芘(BaP)回收率低,基质复杂的样品净化效果不理想,萘(Nap)和菲(Phe)挥发损失和环境本底影响等.样品经加速溶剂提取(ASE),固相萃取(SPE)净化,逐级减压浓缩,气相色谱质谱( GC - MS)测定,并以氘代苯并a芘(BaP - d12)作回收率指示物.实验比较了3种正相SPE吸附剂的效果,发现弗罗里硅土对BaP存在明显的降解现象,BaP的定量应使用同位素稀释法,以降低其分析不确定度;氧化铝对PAHs的吸附性过强,不利于样品净化;硅胶最为理想.PAHs的仪器检出限为0.26～5.7 pg,方法检出限为0.067 ～0.97 ng/g(干重),土壤基质加标回收率为71％～ 122％,相对标准偏差为1.6％～8.3％.将该法用于7个电子废物焚烧区域农田土壤样品的测定,PAHs含量在28～ 283 ng/g(干重)之间,样品中BaP-d12的回收率为90％～124％,各项质控指标符合检测要求.     

Focused microwave aqueous extraction of chlorophenols from solid matrices and their analysis by chromatographic techniques

Open-vessel focused microwave (FMW) extraction with a purely aqueous carbonate solution was used for the extraction of chlorophenols from various solid matrices. After SPE on C18-bonded silica, the analytes were determined as such by LC-UV or, as their acetyl derivatives, by GC-ECD. The FMW aqueous extraction is efficient and rapid and no organic solvents are used. PCP was detected in several solid samples, with recoveries of 101-115% (RSD, 2-4%) relative to Soxhlet extraction. Similar recoveries were obtained for the other chlorophenols for spiked samples.     

Surface water preparation procedure for chromatographic determination of polycyclic aromatic hydrocarbons and polychlorinated biphenyls

A new sample preparation procedure for the analysis of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in water containing suspended particulate matter (SPM) has been developed. A specially designed filtration vessel coupled directly to an SPE cartridge was used for this purpose. SPM separation and analyte isolation/concentration were carried out in a single step. Both the SPE cartridge and the suspended matter collected on the filter were solvent extracted, and analyte recoveries were determined. Analyte recoveries from the filtrate ranged from 64 to 100% of the spiked amount for PAHs with the highest aqueous solubilities, and did not exceed 20% for those with the lowest solubilities. Total recoveries of PAHs from surface water containing 21 mg l(-1) SPM ranged from 65 to 121%. PCB recoveries from the particulate matter reached over 10% of the spiked amount, while those from the filtrate ranged from 20 to 57%. Total PCBs recoveries ranged from 34 to 69%.     

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。     

Trace Determination of Benzalkonium Chlorides in River and Wastewater by Capillary Electrophoresis following Solid‐Phase Extraction Coupled with Salting‐Out Extraction

Trace levels analysisbenzalkonium chlorides (BAKs) in river water and wastewater treatment plants (WWTP) effluents were determined by capillary electrophoresis (CE) following solid‐phase extraction (SPE) and salting‐out extraction. Salting‐out extraction using an appropriate ratio of sodium chloride (NaCl) and acetonitrile (ACN) mixed with concentrated SPE elutant was capable of providing more than 500‐fold enhancement in detection sensitivity. The ratios of ACN and NaCl for salting‐out extraction were investigated and optimized. Matrix interference was eliminated by salting‐out extraction. Limits of quantitation of BAK homologues were achieved at 0.1 μg/L in 250 mL water samples. Recoveries of BAKs in various spiked water samples ranged from 70% to 84% with relative standard deviation (RSD) less than 9%. Trace amounts of total BAKs were detected in river water and WWTP effluent samples ranging from 27 to 145 μg/L at the first time by CE.     

Determination of polynuclear aromatic hydrocarbons in aerosol by solid-phase extraction and gas chromatography-mass spectrum

The optimum procedures for clean up aerosols in silica solid-phase extraction (SPE) cartridge prior to the analysis of polynuclear aromatic hydrocarbons (PAHs) by gas chromatography–mass spectrum (GC–MS) in selected ion monitoring detection mode have been investigated. The silica SPE cartridge is activated by dichloromethane and hexane, and then dried up by vacuum in SPE instrument for about 5 min. The sample volume loaded on the cartridge is 3 ml and after loading the sample the cartridge was dried in vacuum for 5 min. The PAHs were eluted from the cartridge by 3 ml 20% dichloromethane in hexane. The flow-rate of sample loading and eluting was controlled in about 1 ml min⁻¹. The aerosols collected on the campus of Beijing Normal University from August 2001 to July 2002 have been processed with these optimum procedures and 16 EPA priority pollution PAHs in the aerosols have been quantitatively determined.     

Solid-phase extraction clean-up procedure for the analysis of PAHs in lichens

A clean-up procedure based on a solid-phase extraction column was optimized for determination of polycyclic aromatic hydrocarbons (PAHs) in lichen extracts to remove co-extracted compounds from the matrix in the final extract. Several kinds of solid phases were evaluated: normal phase (-NH₂ and alumina), strong anion exchange and reversed phase. The -NH₂ columns were the most effective by using a packed solid bed of 500?mg. The lichen raw extract was loaded on the column previously conditioned with dichloromethane and hexane. Hexane (0.5?mL) was used as rinsing solvent, and PAHs were quantitatively eluted (80–97%) using 2?mL of hexane–dichloromethane (65–35) as eluting solvent. In these conditions, even the heaviest PAHs were quantitatively eluted. The optimized SPE method provides a short time and low-solvent-consumption sample clean-up compared with other conventional methods based on column chromatography. The analytical procedure, dynamic sonication-assisted extraction, followed by the optimized solid-phase extraction clean-up, was used to determine the 16 EPA priority PAHs from native lichens collected from the Aragon valley in central Pyrenees. The PAH concentrations in lichen samples ranged from 352 to 1654?ng?g^?1, and the minimum concentration value was established as the regional reference PAH levels in the area.     

Determination of 16 polycyclic aromatic hydrocarbons in environmental water samples by solid-phase extraction using multi-walled carbon nanotubes as adsorbent coupled with gas chromatography–mass spectrometry

A solid-phase extraction (SPE) using multi-walled carbon nanotubes (MWCNTs) as adsorbent coupled with gas chromatography–mass spectrometry (GC–MS) method was developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Several condition parameters, such as extraction adsorbents, elution solvents and volumes, and sample loading flow rate and volume were optimized to obtain high SPE recoveries and extraction efficiency. 150 mg MWCNTs as sorbent presented high extraction efficiency of 16 PAHs due to the large specific surface area and high adsorption capacity of MWCNTs compared with the commercial C18 column (250 mg/2 mL). The calibration curves of 16 PAHs extracted were linear in the range of 20–5000 ng L⁻¹, with the correlation coefficients (r²) between 0.9848 and 0.9991. The method attained good precisions (relative standard deviation, RSD) from 1.2% to 12.1% for standard PAHs aqueous solutions; method recoveries ranged in 76.0–125.5%, 74.5–127.0%, and 70.0–122.0% for real spiked samples from river water, tap water and seawater, respectively. Limits of detection (LODs, S/N = 3) of the method were determined from 2.0 to 8.5 ng L⁻¹. The optimized method was successfully applied to the determination of 16 PAHs in real environmental water samples.     

GC-MS determination of polycyclic aromatic hydrocarbons evolved from pyrolysis of biomass

A method for the determination of polycyclic aromatic hydrocarbons (PAHs) in liquid pyrolysate of biomass (bio-oil) was developed with attention to greenness along with accuracy. Bio-oil obtained from preparative pyrolysis at 500 °C of poplar wood as representative biomass matrix was dissolved into acetonitrile (ACN). An aliquot of the ACN solution (0.1 mg bio-oil) was added with water (20% v/v) and spiked with perdeuterated standards, then PAHs were extracted with n-hexane and separated from phenolic interferents by silica gel solid-phase extraction (SPE). All 16 priority PAHs were detected at concentrations between 7.7 μg g⁻¹ (naphthalene) and 0.1 μg g⁻¹ (benz[a]anthracene) with RSD in the 6–23% range. Recovery of perdeuterated acenaphthene, phenanthrene and chrysene was 84, 93 and 90%, respectively. Results obtained from the analysis of bio-oil were used to evaluate the performance of analytical pyrolysis conducted with a heated platinum filament in off-line configuration. Two sampling procedures were compared: (1) sorption onto silica gel followed by elution with n-hexane (Py-SPE), (2) dynamic solid-phase micro-extraction followed by fibre cleanup with aqueous ammonia (Py-SPME). Emission levels of priority PAHs could be determined by Py-SPE with RSD in the 13–45% range, while Py-SPME was unsatisfactory for quantitation. Emission levels determined by Py-SPE fell in the 6.4–0.1 μg g⁻¹ range slightly higher than those calculated from bio-oil analysis. Both Py methods were adequate for screening purposes to assess the effect of catalysts on PAH formation. In particular, they agreed to show that the content of PAHs expected in bio-oil increased dramatically when pyrolysis was conducted over HZSM-5 zeolite.     

高效液相色谱法测定黄浦江表层沉积物中的痕量多环芳烃

建立了高效液相色谱-二极管阵列检测器(PDA)测定上海市黄浦江表层沉积物中16种多环芳烃(PAHs)的方法。在保留时间定性分析的基础上,利用PDA获取的紫外扫描光谱图对目标组分进行了准确的定性,并通过异构体紫外光谱图中特征峰的差异有效地识别了样品中的4种异构体,即苯并［b］荧蒽、 苯并［k］荧蒽、 苯并［a］芘和苯并［e］芘。通过检测波长的优化,减少了干扰物的影响,提高了检测灵敏度;针对分离度较差的两种目标组分(苯并［b］荧蒽和苯并［k］荧蒽)的定量进行了分析讨论。该方法对16种PAHs的检出限(以干基计)介于1.1～18.3 ng/g之间,具有较高的方法灵敏度。黄浦江表层沉积物测定结果表明,除二氢苊外的15种PAHs都被检出,含量为10.1～253.0 ng/g。     

Pyrrole-based conductive polymer as the solid-phase extraction medium for the preconcentration of environmental pollutants in water samples followed by gas chromatography with flame ionization and mass spectrometry detection

A pyrrole-based polymer was synthesized and applied as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Polypyrrole (PPy) was synthesized by chemical oxidation of the monomer in nonaqueous solution. SPE of selected phenols, pesticides, and polyaromatic hydrocarbons (PAHs) from aqueous samples were performed using 200 mg PPy. The determination was subsequently carried out by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The polymer showed much higher recoveries for aromatic compounds than aliphatics. Preconcentration of sample volumes up 11 led to acceptable recoveries for aromatic and other tested polar compounds. The R.S.D. for a river water sample spiked with phenols, pesticides and PAHs at sub-ppb level was lower than 10% (n = 3) and limits of detection for these compounds were between 15 and 120 ng l(-1).     

Trace Determination of Rhodamine B and Rhodamine 6G Dyes in Aqueous Samples by Solid‐phase Extraction and High‐performance Liquid Chromatography Coupled with Fluorescence Detection

A simple and reliable method was developed to detect two basic synthetic dyes, rhodamine B (RB) and rhodamine 6G (R6G), in wastewater and surface water samples by high performance liquid chromatography with fluorescence detection (HPLC‐FLD). These dyes have been reported to be both mutagenic and carcinogenic in various organisms. The contents of these two dyes in water samples were extracted by Oasis HLB solid‐phase extraction (HLB‐SPE), and were then determined by an isocratic HPLC using an Atlantis® T3‐C18 column. Water samples at various pH conditions and the compositions of eluents for SPE were evaluated. The results indicate that the proposed method is precise and sensitive in analyzing these two basic synthetic dyes, and the limits of quantitation were 1.5 ng/L for RB and 0.3 ng/L for R6G in 100 mL of water samples. The recovery of analytes in spiked surface water and municipal wastewater treatment plant (WWTP) effluent samples ranged from 61 to 90% with the precision (RSD) ranging from 2 to 12%. The concentrations of analytes were detected in various water samples ranging from 0.7 to 81 ng/L.     

全二维气相色谱-飞行时间质谱测定地下水中低环多环芳烃及其衍生物

建立了地下水中低环多环芳烃及其衍生物的全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)检测方法。对比研究了液液萃取(LLE)和固相萃取(SPE)对地下水中低环多环芳烃及其衍生物的提取效率,优选液液萃取为前处理方法。在优化条件下,除1,2,3,4-四氢萘(r=0.987 2)和联苯(r=0.989 9)外,其它目标物在0.1~1 000μg/L范围内具有良好的线性关系,相关系数(r)均大于0.99。地下水的平均加标回收率为63.3%~111%,除喹啉的相对标准偏差(RSD,n=6)为24.9%外,其余目标物的RSD均小于9.5%,方法检出限在1.63~14.7 ng/L之间。该方法用于河北地区6个地下水样中低环多环芳烃及其衍生物的检测,4个样品有检出,最高浓度达353 ng/L。     

Simultaneous determination of tetrabromobisphenol A, tetrachlorobisphenol A, bisphenol A and other halogenated analogues in sediment and sludge by high performance liquid chromatography-electrospray tandem mass spectrometry

A high performance liquid chromatography-electrospray (negative) ionization-tandem mass spectrometry (HPLC-ESI(-)-MS-MS) based method has been developed for simultaneous determination of bisphenol A (BPA), tetrachlorobisphenol A (TCBPA), and tetrabromobisphenol A (TBBPA), as well as lower brominated BPA analogues in sediment and sludge samples. Samples were extracted with MTBE, target compounds were partitioned by aqueous solution of sodium hydroxide. The solution was subsequently acidified, and the enrichment and desalting were performed via solid phase extraction (SPE). After cleanup the target compounds were determined by HPLC-ESI(-)-MS-MS. The method limits of quantification (MLOQs) from sediment and sludge for BPA, monobromo-bisphenol A (mono-BBPA), dibromo-bisphenol A (di-BBPA), tribromo-bisphenol A (tri-BBPA), TBBPA and TCBPA were 0.15, 0.02, 0.02, 0.04, 0.05, and 0.03 ng/g (dry weight), respectively. Mean recovery of the analytes from spiked samples ranged from 70 to 105%, and the relative standard deviation ranged from 4.9 to 13.1%. The method was successfully applied to sediment and sludge samples analysis.     

Polycyclic aromatic hydrocarbons in waste waters and sewage sludge: Extraction and clean-up for HPLC analysis with fluorescence detection

Summary A modified solid-phase extraction technique using sonication of the adsorbent material instead of the elution normally applied has been compared with two conventional liquid-liquid extraction procedures for the determination of the 16 EPA PAHs in municipal waste waters by means of HPLC coupled with fluorescence detection. Liquid-liquid extraction with cyclohexane proved to be the most efficient and simplest procedure. Clean-up of the waste-water extracts was not considered necessary, because of the high chromatographic resolution of the column and the selectivity of the fluorescence detector. Different organic solvents were also compared for ultrasonic extraction of PAHs from sewage sludge. The best results were obtained by use of acetonitrile. Clean-up of sewage-sludge extracts was not found necessary for accurate quantification of the major PAH components with fluorescence detection. The precision of the whole analytical procedure from extraction to the final determination of PAHs was satisfactory for both waste-water and sewage-sludge samples.     

beta-Cyclodextrin-bonded silica particles as the solid-phase extraction medium for the determination of phenol compounds in water samples followed by gas chromatography with flame ionization and mass spectrometry detection

A new absorbent for solid-phase extraction (SPE) was prepared by a beta-cyclodextrin bonded silica stationary phase (CDS) has been applied to determine the concentrations of phenol compounds in water samples. SPE of selected phenolic compounds from aqueous samples were performed using 250 mg CDS. The determination was subsequently carried out by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Compared with available SPE, the CDS showed high sensitivity and fast velocity of mass transfer for phenolic compound because of its porous structure of beta-cyclodextrin. The relative standard deviation (RSD) for river water sample spiked with phenolic compounds at sub-ppb level was lower than 10% and limit of detection (LOD) for these compounds were between 10 and 100 ng l(-1).