新一代萃取分离技术──固相微萃取

介绍了一种新型样品制备法——固相做萃取（SPME）的原理及其应用。与其它样品制备技术相比,SPME法具有操作时间短、样品量小、无需萃取溶剂、适于分析挥发性与非挥发性物质、重视性好等优点。     

新型无溶剂样品制备方法—固相微萃取法

固相微萃取法（SPME）是在固相萃取（SPE）的基础上结合顶空分析（Headspace)建立起来的一种新型样品制备方法,具有简便,经济、不使用溶剂等优点,并且能做到提取、净化、浓缩和仪器分析同步完成,文中对固相微萃取的装置,原理、萃取条件等、特点,应用及SPME法今后可能发展的方向作以介绍和进行初步探讨。     

溶胶-凝胶固相微萃取涂层及其在农药残留分析中的应用

利用溶胶-凝胶(sol-gel)技术制备固相微萃取(SPME)涂层材料.通过硅醇盐前驱体与涂层聚合物羟基硅油(OH-TSO)的水解共聚的方法,成功地制备了聚二甲基硅氧烷sol-gel 涂层的SPME 萃取头,并以农药的混合标准水溶液为研究对象,用直接-固相微萃取-气相色谱法(GC)对涂层的性能进行考察,制成的萃取头适用于多种农药残留的萃取分离分析.     

固相微萃取的涂层进展

 对固相微萃取 (SPME)的固定相涂层的发展进行了综述。阐述了商品化和非商品化涂层的各自特点 ,并对涂层的选择性和SPME技术作了简单的介绍。     

采用溶胶-凝胶技术涂层的新型固相微萃取方法及其应用

将溶胶-凝胶技术应用于SPME固相涂层的制备,涂制的端羟基-聚二甲基硅氧烷固相涂层热稳定性好,萃取时间和解吸时间短,对极性化合物及非极性化合物均有较强的萃取富集能力。扫描电镜图显示涂层表面为多孔结构。采用该涂层的SPME方法在对环境样品的分析中获得了令人满意的效果。     

固相微萃取技术在滥用药物分析中的应用进展

固相微萃取技术(Solid phase microextraction,SPME)是将少量吸附材料通过物理或化学的方法固定于不锈钢丝或光纤等材质表面制备成萃取纤维,再将萃取纤维暴露于样品体系中,对待测物进行萃取、富集、进样和解析的一种适用于实验室和现场样品的新型前处理技术。由于SPME及其联用技术具有快速、简便、灵敏、绿色等优点,已经在滥用药物检验鉴定领域被成功应用,并成为此类药物定性定量分析的最佳方法之一。本文综述了近年来SPME技术在滥用药物分析中的研究进展。     

Nafion涂层固相微萃取探头的制备

采用Nafion作为固相涂层在不锈钢丝上涂制了固相微萃取 (SPME)探头 ,研究了它的特性 ,并与类似商品探头作了比较。该探头具有萃取量大、可比商品探头 (SPME)的富集率高 1个数量级 ,灵敏度高、寿命长、且不易折断等特性。由于Nafion有很强的极性 ,因此它对极性化合物有很强的萃取能力 ,适合萃取醇等物质。用该探头测定了醇类物质 ,检出限达 2 0～ 60ng·ml-1,相对标准偏差RSD <5 %。     

新型固相微萃取涂层的研究进展*

作为一种样品前处理方法的固相微萃取(solid phase microextraction, SPME)技术,具有操作方便,快速,灵敏和无需大量有机溶剂的优点,因此在分离分析方面得到了广泛的应用。涂层是SPME技术的核心部分,其性能决定了SPME的性能和应用范围,因此发展新型涂层一直是SPME研究和应用工作的重点。近年来随着涂层材料制备技术的发展,出现了一些新型涂层。这些新型涂层的出现进一步拓宽SPME技术的应用范围。本文综述了近三年来SPME涂层的研究进展,并着重介绍新型涂层的制备方法和性质。     

聚苯乙烯-丙烯酸乙酯新型固相微萃取吸附质的研究与应用

固相微萃取(SPME)是90年代兴起的新型无溶剂样品前处理技术,基本的固相微萃取是通过石英纤维头表面涂渍的高分子层对样品中的有机分子进行萃取和预富集,然后进行色谱分析,使预处理过程大为简化,提高了分析速度及灵敏度。目前,商品SPME．GC联用装置是由美国Supclco公司生产的涂有PDMS、PA、PEG20M3种单一吸附质及4种部分交联的复合固相材料。涂层极性决定了其应用范围。     

顶空固相微萃取-气相法测定酒中的甲醇和杂醇油

 采用环氧树脂作为固相涂层制作固相微萃取 (SPME)装置 ,建立了顶空固相微萃取 气相法 (HS SPME GC)测定酒精饮料中甲醇和杂醇油的方法 ,并对萃取条件和条件进行了优化。方法的检出限为 0 0 2mg/L～0 0 4mg/L ,相对标准偏差为 1 4 %～ 4 1% ;与顶空气相法相比 ,灵敏度可提高 2 0倍～ 30 0倍。将该法用于啤酒、葡萄酒和保健酒中的甲醇和杂醇油的测定 ,加标回收率为 80 8%～ 110 3% ;与顶空气相法 (国家标准方法 )进行了比较 ,相对误差不大于 7 3%。该法简便、快速、灵敏、精密度好 ,拓宽了SPME的应用范围。     

Automated multiple solid phase micro extraction. An approach to enhance the limit of detection for the determination of pesticides in water

A method was developed to decrease the limit of detection (LOD) for pesticide residue analysis in water using multiple SPME. To enhance the absolute amount transferred to the GC column an enrichment step is integrated in the SPME/GC-analysis. A series of several extraction and desorption steps are performed and the analytes are trapped at the front of the cold GC column before the GC analysis is started. The parameters mainly influencing this enrichment are the equilibrium time, the slope of the adsorption time/peak area profile at its start, the number and the duration of the extraction steps. The role of these parameters was investigated.     

Automated multiple solid phase micro extraction. An approach to enhance the limit of detection for the determination of pesticides in water

A method was developed to decrease the limit of detection (LOD) for pesticide residue analysis in water using multiple SPME. To enhance the absolute amount transferred to the GC column an enrichment step is integrated in the SPME/GC-analysis. A series of several extraction and desorption steps are performed and the analytes are trapped at the front of the cold GC column before the GC analysis is started. The parameters mainly influencing this enrichment are the equilibrium time, the slope of the adsorption time/peak area profile at its start, the number and the duration of the extraction steps. The role of these parameters was investigated.     

Determination of polycyclic aromatic hydrocarbons in aqueous samples by microwave assisted headspace solid-phase microextraction and gas chromatography/flame ionization detection

The novel pretreatment technique, microwave-assisted heating coupled to headspace solid-phase microextraction (MA-HS-SPME) has been studied for one-step in situ sample preparation for polycyclic aromatic hydrocarbons (PAHs) in aqueous samples before gas chromatography/flame ionization detection (GC/FID). The PAHs evaporated into headspace with the water by microwave irradiation, and absorbed directly on a SPME fiber in the headspace. After being desorbed from the SPME fiber in the GC injection port, PAHs were analyzed by GC/FID. Parameters affecting extraction efficiency, such as SPME fiber coating, adsorption temperature, microwave power and irradiation time, and desorption conditions were investigated.Experimental results indicated that extraction of 20 mL aqueous sample containing PAHs at optional pH, by microwave irradiation with effective power 145 W for 30 min (the same as the extraction time), and collection with a 65 μm PDMS/DVB fiber at 20 °C circular cooling water to control sampling temperature, resulted in the best extraction efficiency. Optimum desorption of PAHs from the SPME fiber in the GC hot injection port was achieved at 290 °C for 5 min. The method was developed using spiked water sample such as field water with a range of 0.1-200 μg/L PAHs. Detection limits varied from 0.03 to 1.0 μg/L for different PAHs based on S/N = 3 and the relative standard deviations for repeatability were <13%. A real sample was collected from the scrubber water of an incineration system. PAHs of two to three rings were measured with concentrations varied from 0.35 to 7.53 μg/L. Recovery was more than 88% and R.S.D. was less than 17%. The proposed method is a simple, rapid, and organic solvent-free procedure for determination of PAHs in wastewater.     

Analysis of anaesthetics and analgesics in human urine by headspace SPME and GC

The determination of widely used anaesthetic and analgesic drugs in biological fluids is of major clinical importance. Typical methods used for sample preparation employ liquid–liquid extraction protocols which are complex, costly, not handy and not amenable to automation. In the present communication, we report the development of a methodology that employs headspace solid‐phase microextraction (HS‐SPME) for the determination of four anaesthetic (lidocaine, midazolam, diazepam and ketamine) and three analgesic drugs (fentanyl, remifentanyl and codeine) in human urine. Important parameters controlling SPME were studied: selection of SPME fibre, type and amount of salt added, preheating and extraction time, extraction temperature, sample volume and desorption time. GC with nitrogen phosphorus detection (GC‐NPD) facilitates sensitive and selective detection of the anaesthetics. The developed method renders an efficient tool for the precise and sensitive determination of the anaesthetics and analgesics in human urine (RSDs ranged from 7.7 to 12.6%, whereas LODs ranged from 0.01 to 1.5 ng/mL). The method was applied to the determination of the anaesthetics and analgesics in human urine from patients that had undergone coronary by‐pass surgery operations. The proposed protocol can function as an attractive alternative for clinical acute intoxications and medico‐legal cases.     

Selected ion storage versus tandem MS/MS for organochlorine pesticides determination in drinking waters with SPME and GC-MS

The use of two modes for mass spectrometry (MS) detection with an ion trap instrument, selected ion storage (SIS) and tandem mass spectrometry (MS/MS), are compared for the solid-phase microextraction (SPME)–gas chromatography (GC) coupled to mass spectrometry (GC-MS) determination of 16 priority organochlorine pesticides (OCPs) in drinking water samples at the ultratrace levels (ng?L^?1) required by official guidelines in the European legislation. Experimental parameters investigated for the SPME sample preparation were: the type of coating (100?µm polydimethylsiloxane, PDMS, and 65?µm poly(dimethylsiloxane)–divinylbenzene, PDMS/DVB), SPME modality, extraction and desorption times and desorption temperature and the methanol percentage in the SPME working solution. Under the calculated optimal conditions two methodologies were developed, one for SIS and the other for MS/MS modes. The detection limits, precision and accuracy were evaluated for both alternatives and were appropriate to the official guidelines requirements. The SPME–GC-MS(SIS) methodology offered LODs from 0.2–6.6?ng?L^?1, precision below 13% and recoveries between 83 and 110%. The SPME–GC–MS/MS methodology provided limits of detection (LODs) ranging from 0.3 to 7.6 ng?L^?1, % RSD were ≤14% and recoveries of 79–108% were achieved. After the results observed within an Interlaboratory Exercise, the latest MS methodology was selected for the pursued analysis in real drinking water samples. Also, the good results in this round-robin exercise validate the proposed SPME–GC–MS/MS methodology.     

Fast field analysis of short-chain aliphatic amines in water using solid-phase microextraction and a portable gas chromatograph

A novel method is firstly presented for field and rapid analysis of short-chain aliphatic amines in water as their pentafluorobenzaldehyde (PFBAY) derivative using solid-phase microextraction (SPME) and portable GC. In the proposed method, short-chain aliphatic amines in water rapidly reacted with PFBAY, and then were headspace extracted and concentrated by SPME. The formed amines derivatives were analyzed by portable GC. The SPME parameters of fiber selection, extraction temperature, extraction time, and stirring rate were studied. The method validations including LOD, recovery, precision, and linearity were studied. It was found that the proposed method required the whole analysis time 22 min, and provided low LOD of 1.2-4.6 ng/mL, good recovery of 91-106%, good precision of RSD value 3.5-9.3%, and linear range 20.0-500 ng/mL (r(2) >0.99). The obtained results demonstrated that the SPME-portable GC is a simple, rapid, and efficient method for the field analysis of short-chain aliphatic amines. Finally, the proposed method was further applied to the quantification of ethylamine, propylamine, and butylamine in environmental water.     

Determination of Herbicides in Natural Waters Using Solid Phase Microextraction (SPME) and Gas Chromatography Coupled with Flame Thermionic and Mass Spectrometric Detection

Abstract

This study develops a method for solid phase microextraction (SPME) of ten widespread herbicides from water. The selected herbicides belong to different chemical groups are EPTC, molinate, propachlor, trifluralin, atrazine, propazine, terbuthylazine, prometryne, alachlor. Their determination was carried out by gas chromatography with flame thermionic and mass spectrometric detection. To perform the SPME, two types of fibre have been assayed: Carbowax-divinylbenzene (CW-DVB) of 65 μm thickness and polydimethylsiloxane-divinylbenzene (PDMS-DVB) of 65 μm thickness. The main factors affecting the SPME process such as pH, ionic strength, methanol content, memory effect, stirring rate and adsorption-time profile were studied. The method was applied to spiked natural waters such as ground water, sea water, lake water and river water in a concentration range of 0.1 to 10 μg/L. Limits of detection with each of the detectors were determined to be 1 – 20 ng/L in PDMS-DVB and 2–20 ng/L CW-DVB fibres. The recoveries of herbicides compared to distilled water were in relatively high levels 78.3–127.3 % and the average r² values of the calibration curves were above 0.99 for all the analytes. The SPME conditions were finally optimized in order to obtain maximum sensitivity and samples were applied for the trace-level determination in river water samples originating from Ioannina region (Greece).     

Determination of aniline in silica gel sorbent by one-step in situ microwave-assisted desorption coupled to headspace solid-phase microextraction and GC-FID

Microwave-assisted desorption (MAD) coupled to in situ headspace solid-phase microextraction (HS-SPME) was first proposed as a possible alternative pretreatment of samples in absorbent collected from workplace monitoring. Aniline collected on silica gel was investigated. Under microwave irradiation, the aniline was desorbed from silica gel and directly absorbed onto the SPME fiber in the headspace. Having been sampled on the SPME fiber, and desorbed in the GC injection port, aniline was analyzed using a GC-FID system. Parameters that affect the proposed extraction efficiency, including the extraction media and its pH, the microwave irradiation power and the irradiation time as well as desorption parameters of the GC injector, were investigated. Experimental results revealed that the extraction of a 150-mg silica gel sample using a 0.8-ml aqueous solution (pH 12) and a PDMS/DVB fiber under medium-high-powered irradiation (345 W) for 3 min maximized the efficiency of extraction. Desorption of aniline from the SPME fiber was optimal at 230 °C held for 3 min. The detection limit was 0.09 ng. The proposed method provided a simple, fast, and organic solvent-free procedure to analyze aniline from a silica gel matrix.     

固相微萃取/气相色谱/质谱联用测定水中的2,4-二硝基苯酚

研究了水中痕量2,4-二硝基苯酚的固相微萃取（SPME）方法,得到了2,4-二硝基苯酚的SPME最佳萃取条件：水溶液调pH2,并用NaCl他和,在室温下直接萃取30min,气相色谱／质谱分析时,纤维探针在270℃下脱附3min。所建立的方法适于快速、方便地测定水中2,4-二硝基苯酚,不需浓缩和预处理。     

Preparation of ionic liquid based solid-phase microextraction fiber and its application to forensic determination of methamphetamine and amphetamine in human urine

A new solid-phase microextraction (SPME) procedure using an ionic liquid (IL) has been developed. Reusable IL-based SPME fiber was prepared for the first time by fixing IL through cross-linkage of IL impregnated silicone elastomer on the surface of a fused silica fiber. 1-Ethoxyethyl-3-methylimidazloium bis(trifluoromethane) sulfonylimide ([EeMim][NTf₂]) ionic liquid was employed as a demonstration and the prepared fiber was applied to the forensic headspace determination of methamphetamine (MAP) and amphetamine (AP) in human urine samples. Important extraction parameters including the concentration of salt and base in sample matrix, extraction temperature and extraction time were investigated and optimized. Combined with gas chromatography/mass spectrometry (GC/MS) working in selected ion monitoring (SIM) mode, the new method showed good linearity in the range of 20–1500 μg L⁻¹, good repeatability (RSD < 7.5% for MAP, and <11.5% for AP, n = 6), and low detection limits (0.1 μg L⁻¹ for MAP and 0.5 μg L⁻¹ for AP). Feasibility of the method was evaluated by analyzing human urine samples. Although IL-based SPME is still at the beginning of its development stage, the results obtained by this work showed that it is a promising simple, fast and sensitive sample preparation method.