离子液体键合固相微萃取涂层用于水样中五氯酚的测定

合成了1-甲基-3-三乙氧基硅基丙基咪唑二(三氟甲基磺酸酰)亚胺盐([TPMIM][NTf2])离子液体, 其热稳定性可达480 ℃, 并用其通过溶胶-凝胶法制备了一种含键合离子液体的固相微萃取(SPME)涂层. 该涂层的使用温度可达340 ℃. 优化了萃取温度、萃取时间、溶液的pH、盐效应、解析温度以及解析时间. 在最优条件下, 采用顶空固相微萃取结合GC/FID的方法测定水样中五氯酚(PCP)的检出限为1 ng/L, 线性范围为10-3~102 μg/L, 线性相关系数为0.9994, 相对标准偏差(RSD, n=5)为3.5%, 加标回收率为84.5%.     

自制离子液体固相微萃取涂层分析人体尿液中的五氯酚

建立了顶空固相微萃取与气相色谱法（HS-SPME-GC）测定人体尿液中五氯酚（PCP）的新方法。 采用溶胶-凝胶法,加入自制的离子液体键合固相微萃取涂层,优化了萃取温度、萃取时间、pH值、离子强度及解吸时间。 结果表明,样品中加入3 g NaCl,溶液的pH值为2,并以一定速度搅拌的条件下,在80 ℃顶空萃取50 min,300 ℃下解吸5 min,方法的检测限为5.0 ng/L,线性范围为0.05～100 μg/L,相对标准偏差(RSD)为5.9%,加标回收率为106.6%。     

离子液体和苯基双功能基键合固相微萃取涂层用于水样中多环芳烃的测定

以含离子液体基团的三烷氧基硅烷和二苯基二甲氧基硅烷为前体,通过溶胶-凝胶法制备了一种含键合离子液体和苯基双功能基的SPME涂层,该涂层的使用温度可达340℃。优化了萃取温度和时间、盐效应以及解析温度和时间,确定NaCl为4 g、80℃平衡50 min、300℃解吸5 min为最优条件,并在该条件下采用顶空固相微萃取结合GC/FID的方法测定水样中5种多环芳烃的检出限为0.002～0.083μg/L,其线性相关系数的平方均大于0.9973。东湖水样中5种痕量的PAHs的回收率介于71.4%～107.0%,相对标准偏差(RSD,n=5)为1.5%～5.3%。     

固相微萃取涂层制备方法研究进展

涂层是固相微萃取技术的核心,近年来出现的各种新型涂层材料和制备技术,进一步拓宽了固相微萃取技术的应用范围.该文介绍了各种新型固相微萃取介质的发展,并综述了各种新型固相微萃取涂层的制备方法,包括直接制备、溶胶-凝胶技术、化学键合与聚合、分子印迹技术、树脂固载技术、电化学沉积等.     

选择性固相微萃取涂层的研究进展

固相微萃取装置的核心部分是它的涂层,涂层的种类和厚度是影响分析灵敏度和选择性的最重要因素。具选择性的涂层可增强固相微萃取的分离能力,扩展它的应用范围。本文介绍了固相微萃取的类型,综述了近年来选择性固相微萃取涂层的研究进展,包括溶胶-凝胶涂层、限进介质涂层、分子印迹涂层等涂层的研制及应用。     

纳米碳纤维涂层固相微萃取探头的制备及性能分析

采用纳米碳纤维(CNF)作为固相涂层制备了固相微萃取探头(SPME)并进行了评价.该涂层对苯系物(BTX)富集能力强,最高使用温度可达260℃,250℃解析条件下使用50次以上涂层无脱落现象.与活性碳涂层相比,尽管萃取量略小,但其解析时间仅为活性炭的60%,具有更高的精密度和准确度.对BrIX固相微萃取.气相色谱分析结果表明,样品质量浓度在0.1～38.7μg/L范围内与色谱峰面积呈良好线性关系(r=0.9891～0.9940),相对标准偏差为3.9%～5.3%,方法的检出限为2.5×10~(-3)μg/L.     

固相微萃取-气相色谱法测定红葡萄酒中残留的有机磷农药

采用溶胶-凝胶包埋技术制备了耐高温固相微萃取头(SPME),用该萃取头与气相色谱-热离子化检测器联用对红葡萄酒中的12种有机磷农药残留进行了测定。实验中对搅拌速度、萃取时间、盐浓度等条件进行了优化。结果表明,在样品用量25 mL,搅拌速度1250 r/min,盐浓度 150 g/L,萃取时间30 min的条件下,绝大多数组分峰面积的相对标准偏差（RSD）在5%以下,各种有机磷农药的检测限为5 ng/L到0.38 μg/L。     

固相微萃取涂层及其形貌特征研究

采用物理涂渍、溶胶-凝胶技术(sol-gel)制备了固相微萃取(SPME)固相涂层：),γ-Al2O3涂层、聚丙烯酸树脂涂层、聚酰亚胺-二氧化硅溶胶凝胶涂层、聚酰亚胺-二氧化钛涂层。通过扫描电镜显示涂层表面形貌,并比较了萃取容量与涂层形貌间的关系.证明涂层的微观形态结构对涂层性能具有一定的影响,可以通过微观形态分析,了解不同微观结构对宏观性质的影响。     

固相微萃取-气相色谱-质谱法同时测定天然饮用水中39种有机污染物

提出了固相微萃取-气相色谱-质谱法测定天然饮用水中39种有机污染物含量的方法。为使固相微萃取达到更高的效率,选用60μm PDMS/DVB作为固相萃取头的涂层,萃取温度及时间为90℃和30min,解析温度及时间为270℃和10min。用J&W DB-35 MS毛细管色谱柱分离,电子轰击离子源选择离子监测模式检测。39种有机污染物的质量浓度均在0.10～50.0μg.L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.002～2μg.L-1之间。方法的回收率在82.0%～110%之间,测定值的相对标准偏差(n=6)在2.0%～13%之间。     

顶空固相微萃取/气相色谱-质谱法测定液态化妆品中8种增塑剂

建立了顶空固相微萃取(HS-SPME)/气相色谱-质谱(GC-MS)同时测定液态化妆品中8种邻苯二甲酸酯类增塑剂(PAEs)的分析方法,并对萃取涂层、萃取温度、搅拌速率、盐浓度等参数进行了优化。最终采用65μm聚二甲基硅氧烷/二乙烯基苯(PDMS/DVB)固相微萃取纤维头,调节待萃取液盐浓度为360 g.L-1,在搅拌速率600 r/min及萃取温度90℃条件下萃取60 min,在250℃进样口解吸4 min后供GC-MS分析。结果表明,该方法对除邻苯二甲酸二苯酯(DPhP)外的7种目标化合物的线性范围为10～2 000μg.kg-1,检出限为0.7～13.6μg.kg-1,回收率为83%～97%,相对标准偏差(RSD)为2.5%～10.0%;由于DPhP在萃取涂层上的保留较弱,其回收率为70%,检出限为75μg.kg-1,RSD为13.9%。该方法能很好地富集基体中的目标化合物,满足液态化妆品中多种PAEs的分析要求。     

Solid‐phase microextraction Arrow for the volatile organic compounds in soy sauce

A novel solid‐phase microextraction Arrow was used to separate volatile organic compounds from soy sauce, and the results were verified by using gas chromatography with mass spectrometry. Solid‐phase microextraction Arrow was optimized in terms of three extraction conditions: type of fiber used (polydimethylsiloxane, polyacrylate, carbon wide range/polydimethylsiloxane, and divinylbenzene/polydimethylsiloxane), extraction temperature (40, 50, and 60°C), and extraction time (10, 30, and 60 min). The optimal solid‐phase microextraction Arrow conditions were as follows: type of fiber = polyacrylate, extraction time = 60 min, and extraction temperature = 50°C. Under the optimized conditions, the solid‐phase microextraction Arrow was compared with conventional solid‐phase microextraction to determine extraction yields. The solid‐phase microextraction Arrow yielded 6–42‐fold higher levels than in solid‐phase microextraction for all 21 volatile organic compounds detected in soy sauce due to the larger sorption phase volume. The findings of this study can provide practical guidelines for solid‐phase microextraction Arrow applications in food matrixes by providing analytical methods for volatile organic compounds.     

Comparison and application of two microextractions based on syringe membrane filter

Two proposed syringe membrane filter solid phase microextraction and syringe membrane filter liquid/solid phase microextraction, coupled separately with high performance liquid chromatography, were developed for simultaneous enrichment and determination of the trace level of flavonoids in traditional Chinese medicine. In syringe membrane filter solid phase microextraction, the membrane of syringe membrane filter was served as a solid adsorption film to adsorb target analytes. And in syringe membrane filter liquid/solid phase microextraction, the membrane of syringe membrane filter was used as not only an adsorption phase, but also as a holder of extraction solvent to realize liquid‐solid synergistic extraction. The simple operation, rapid extraction, and little or no organic solvent consumption make the two approaches very interesting. To evaluate the two proposed approaches, the crucial parameters affecting the enrichment factors of target analytes were investigated and optimized, and the two microextractions were intercompared. Moreover, their microextraction mechanisms were analyzed and described. Under the optimized conditions, both the new approaches achieved good linearities, accuracies, precisions, and low limits of detection, and the two methods were successfully applied for concentration of the flavonoids in traditional Chinese medicines.     

Electromembrane‐surrounded solid‐phase microextraction coupled to ion mobility spectrometry for the determination of nonsteroidal anti‐inflammatory drugs: A rapid screening method in complicated matrices

A new robust method of electromembrane‐surrounded solid‐phase microextraction coupled to ion mobility mass spectrometry was applied for nonsteroidal anti‐inflammatory drugs determination in complex matrices. This is the first time that a graphene/polyaniline composite coating is applied in electromembrane‐surrounded solid‐phase microextraction method. The homemade graphene/polyaniline composite is characterized by a high electrical conductivity and thermal stability. The variables affecting electromembrane‐surrounded solid‐phase microextraction, including extraction time; applied voltage and pH were optimized through chemometric methods, central composite design, and response surface methodology. Under the optimized conditions, limits of detection of 0.04 and 0.05 ng/mL were obtained for mefenamic acid and ibuprofen, respectively. The feasibility of electromembrane‐surrounded solid‐phase microextraction followed by ion mobility mass spectrometry was successfully confirmed by the extraction and determination of low levels of ibuprofen and mefenamic acid in human urine and plasma samples and satisfactory results were obtained.     

中空纤维膜液相微萃取-高效液相色谱联用技术测定尿液中痕量己烯雌酚

采用中空纤维液相微萃取与高效液相色谱联用技术测定了尿液样品中的痕量己烯雌酚;考察了样品相酸度、中间相种类、接收相浓度、搅拌速度、萃取时间等对液-液-液三相微萃取效率的影响,进而确定了最佳萃取条件.结果表明,当样品相pH为2.5,中间相为甲苯,接收相为3μL 0.25mol/L氢氧化钠溶液,搅拌速度为800r/min,萃取时间为50min时,萃取效率最佳.在最佳萃取条件下,样品的回收率为76.4%,相对标准偏差为3.8%.     

Comparison of two ultrasound‐enhanced microextractions combined with HPLC for determining acaricides in water

An ultrasound‐enhanced in situ solvent formation microextraction has been developed first time and compared with ultrasound‐enhanced ionic‐liquid‐assisted dispersive liquid–liquid microextraction for the HPLC analysis of acaricides in environmental water samples. A ionic liquid ([C₈MIM][PF₆]) was used as the green extraction solvent through two pathways. The experimental parameters, such as the type and volume of both of the extraction solvent disperser solvent, ultrasonication time, and salt addition, were investigated and optimized. The analytical performance using the optimized conditions proved the feasibility of the developed methods for the quantitation of trace levels of acaricides by obtaining limits of detection that range from 0.54 to 3.68 μg/L. The in situ solvent formation microextraction method possesses more positive characteristics than the ionic‐liquid‐assisted dispersive liquid–liquid microextraction method (except for spirodiclofen determination) when comparing the validation parameters. Both methods were successfully applied to determining acaricides in real water samples.     

Direct synthesis of nitrogen-doped graphene on platinum wire as a new fiber coating method for the solid-phase microextraction of BXes in water samples: Comparison of headspace and cold-fiber headspace modes

In this work, a new solid-phase microextraction fiber was prepared based on nitrogen-doped graphene (N-doped G). Moreover, a new strategy was proposed to solve problems dealt in direct coating of N-doped G. For this purpose, first, Graphene oxide (GO) was coated on Pt wire by electrophoretic deposition method. Then, chemical reduction of coated GO to N-doped G was accomplished by hydrazine and NH₃. The prepared fiber showed good mechanical and thermal stabilities. The obtained fiber was used in two different modes (conventional headspace solid-phase microextraction and cold-fiber headspace solid-phase microextraction (CF-HS-SPME)). Both modes were optimized and applied for the extraction of benzene and xylenes from different aqueous samples. All effective parameters including extraction time, salt content, stirring rate, and desorption time were optimized. The optimized CF-HS-SPME combined with GC-FID showed good limit of detections (LODs) (0.3–2.3 μg/L), limit of quantifications (LOQs) (1.0–7.0 μg/L) and linear ranges (1.0–5000 μg/L). The developed method was applied for the analysis of benzene and xylenes in rainwater and some wastewater samples.     

Determination of phthalate esters in bottled water using dispersive liquid–liquid microextraction coupled with GC–MS

Dispersive liquid–liquid microextraction method was developed for the determination of the amount of phthalate esters in bottled drinking water samples and dispersive liquid–liquid microextraction samples were analyzed by GC–MS. Various experimental conditions influencing the extraction were optimized. Under the optimized conditions, very good linearity was observed for all analytes in a range between 0.05 and 150 μg/L with coefficient of determination (R²) between 0.995 and 0.999. The LODs based on S/N = 3 were 0.005–0.22 μg/L. The reproducibility of dispersive liquid–liquid microextraction was evaluated. The RSDs were 1.3–5.2% (n = 3). The concentrations of phthalates were determined in bottled samples available in half shell. To understand the leaching profile of these phthalates from bottled water, bottles were exposed to direct sunlight during summer (temperature from 34–57°C) and sampled at different intervals. Result showed that the proposed dispersive liquid–liquid microextraction is suitable for rapid determination of phthalates in bottled water and di‐n‐butyl, butyl benzyl, and bis‐2‐ethylhexyl phthalate compounds leaching from bottles up to 36 h. Thereafter, degradation of phthalates was observed.     

Accelerated solvent extraction combined with dispersive liquid–liquid microextraction before gas chromatography with mass spectrometry for the sensitive determination of phenols in soil samples

A method combining accelerated solvent extraction with dispersive liquid–liquid microextraction was developed for the first time as a sample pretreatment for the rapid analysis of phenols (including phenol, m‐cresol, 2,4‐dichlorophenol, and 2,4,6‐trichlorophenol) in soil samples. In the accelerated solvent extraction procedure, water was used as an extraction solvent, and phenols were extracted from soil samples into water. The dispersive liquid–liquid microextraction technique was then performed on the obtained aqueous solution. Important accelerated solvent extraction and dispersive liquid–liquid microextraction parameters were investigated and optimized. Under optimized conditions, the new method provided wide linearity (6.1–3080 ng/g), low limits of detection (0.06–1.83 ng/g), and excellent reproducibility (<10%) for phenols. Four real soil samples were analyzed by the proposed method to assess its applicability. Experimental results showed that the soil samples were free of our target compounds, and average recoveries were in the range of 87.9–110%. These findings indicate that accelerated solvent extraction with dispersive liquid–liquid microextraction as a sample pretreatment procedure coupled with gas chromatography and mass spectrometry is an excellent method for the rapid analysis of trace levels of phenols in environmental soil samples.     

Determination of volatile organic acids in tobacco by single‐drop microextraction with in‐syringe derivatization followed by GC‐MS

In this work, the novel technique based on headspace single‐drop microextraction with in‐syringe derivatization followed by GC‐MS was established to determine the volatile organic acids in tobacco. The parameters for headspace single‐drop microextraction and in‐syringe derivatization were optimized, including extraction time, and volume of derivatization reagent and in‐syringe derivatization time. The method validations including linearity, precision, recovery and LOD were also studied. The obtained results illustrated that the optimized technique was easy, highly efficient and sensitive. Finally, the proposed method was successfully applied to the analyses of volatile organic acids in tobacco samples with seven different brands. It was further demonstrated that the present technique developed in this study does offer a simple and fast approach to determine volatile organic acids in tobacco.     

Ultrasound‐assisted magnetic dispersive solid‐phase microextraction: A novel approach for the rapid and efficient microextraction of naproxen and ibuprofen employing experimental design with high‐performance liquid chromatography

A simple, rapid, and sensitive method for the determination of naproxen and ibuprofen in complex biological and water matrices (cow milk, human urine, river, and well water samples) has been developed using ultrasound‐assisted magnetic dispersive solid‐phase microextraction. Magnetic ethylendiamine‐functionalized graphene oxide nanocomposite was synthesized and used as a novel adsorbent for the microextraction process and showed great adsorptive ability toward these analytes. Different parameters affecting the microextraction were optimized with the aid of the experimental design approach. A Plackett–Burman screening design was used to study the main variables affecting the microextraction process, and the Box–Behnken optimization design was used to optimize the previously selected variables for extraction of naproxen and ibuprofen. The optimized technique provides good repeatability (relative standard deviations of the intraday precision 3.1 and 3.3, interday precision of 5.6 and 6.1%), linearity (0.1–500 and 0.3–650 ng/mL), low limits of detection (0.03 and 0.1 ng/mL), and a high enrichment factor (168 and 146) for naproxen and ibuprofen, respectively. The proposed method can be successfully applied in routine analysis for determination of naproxen and ibuprofen in cow milk, human urine, and real water samples.