纳米SiO2膜新型萃取头固相微萃取测定蔬菜中5种农药残留量的研究

建立了以纳米SiO2膜为萃取头涂层的固相微萃取(SPME)-气相色谱(GC)联用测定蔬菜中5种农药残留 (p,p′-DDD, p,p′-DDE, o,p′-DDT, p,p′-DDT, 联苯菊酯)的新方法. 探讨并优化了萃取时间、萃取温度和转子转速等参数.     

微波辅助萃取-固相微萃取-气相色谱法同时测定茶叶中的有机氯和拟除虫菊酯农药残留

建立了微波辅助萃取-固相微萃取-气相色谱(MAE-SPME-GC)同时测定茶叶中六六六(α-BHC,β-BHC,γ-BHC,δ-BHC 4种异构体)、滴滴涕类(DDD,DDE,o,p′-DDT,p,p′-DDT)、氯氰菊酯(cypermethrin)和氰戊菊酯(fenvalerate)等10种农药残留的方法。采用外标法定量,除氰戊菊酯外,农药的质量浓度与其色谱峰面积在一定范围内有较好的线性关系,相关系数为0.9705～0.9984。10种组分的加标回收率为64%～121%,相对标准偏差为10.4%～22.9%,检测限为1～50 ng/L。应用该方法测定了市场上3种茶叶中上述农药残留的含量。     

单羟基七元瓜环的固相微萃取纤维对环境水样中苯酚类物质的分析检测

以单羟基七元瓜环(Q[7]-OH)和端羟基聚二甲基硅氧烷(OH-PDMS)为固定相,利用溶胶-凝胶方法制备了PDMS/Q[7]-OH的固相微萃取纤维(SPME fiber).建立了PDMS/Q[7]-OH SPME纤维-气相色谱(GC)/氢火焰离子化检测器(FID)对环境水样中5种苯酚类化合物同时检测的分析方法.实验结...     

非平衡固相微萃取联用气相色谱测定蔬菜中残留有机磷

建立了非平衡固相微萃取与气相色谱联用测定蔬菜中残留有机磷农药的方法。探讨了影响SPME萃取效果的纤维涂层、搅拌类型、离子强度、萃取时间等因素,并对蔬菜样品的预处理进行了研究。该方法检出限分别为乙硫磷7.5 ng/g;甲拌磷2.5 ng/g;二嗪农5.0 ng/g;异硫磷5.0 ng/g;对硫磷8.3 ng/g。线性范围为0.005~1μg/mL(相关系数r=0.9968);回收率为77.6%~91.6%;相对标准偏差(RSD)为0.97%~9.0%。     

镍钛合金表面离子液体掺杂聚苯基吡咯纤维涂层的制备及其对多氯联苯的高效固相微萃取

采用水热法和电沉积法在镍钛(NiTi)合金表面构筑1-丁基-3-甲基咪唑六氟磷酸盐离子液体(IL)掺杂聚苯基吡咯(PPPy)纤维涂层,成功制备了新型IL@PPPy-TiO_2/NiOCNSs固相微萃取(SPME)纤维。将该新型纤维与高效液相色谱(HPLC)联用,以多氯联苯(PCBs)、邻苯二甲酸酯(PAEs)、多环芳烃(PAHs)和紫外线(UV)吸收剂为模型分析物评价其萃取性能。结果显示,该纤维对PCBs有较强的萃取选择性和较高的萃取效率。在优化条件下,5种PCBs在一定质量浓度范围内呈良好线性,相关系数r≥0.998 6,检出限(LOD)为0.015～0.11μg/L。采用单支纤维在同日和隔日对50μg/L PCBs混合标准溶液进行萃取测定,相对标准偏差(RSD)分别为4.7%～6.1%和5.4%～7.0%,相同方法制备的5支纤维测定的RSD为6.5%～7.7%。实际水样的加标回收率为83.0%～104%,RSD不大于8.6%。所建立的SPME/HPLC法适用于不同环境水样中痕量PCBs的快速萃取和高效测定。     

快速制备金属基固相微萃取金涂层用于环境水样中痕量苯并[a]芘的测定

本文以刻蚀不锈钢丝作为固相微萃取(SPME)纤维基体,用化学沉积技术快速制备了亚微米金颗粒涂层,与高效液相色谱(HPLC)联用,用苯并[a]芘(B[a]p)评价了SPME金涂层的萃取分离性能,优化了实验条件。实验结果表明,该金涂层与基体结合牢固、稳定性好、寿命长、制备简单。所建立的金涂层SPME-HPLC法测定B[a]p线性范围为25~5 000ng/L,检出限(S/N=3)为12.50ng/L;对于4μg/L的B[a]p溶液,制备的单一金涂层SPME-HPLC分析结果的相对标准偏差(RSD)为4.86%(n=6),重复制备的金涂层SPME-HPLC分析结果的RSD为7.81%(n=6)。实际水样中B[a]p的加标回收率在94.25%~110.9%之间,RSD为2.67%~10.24%。     

刻蚀不锈钢丝固相微萃取-高效液相色谱联用测定环境水样中痕量苯并[a]芘

用化学刻蚀法制作了不锈钢丝固相微萃取(SPME)纤维头,与高效液相色谱(HPLC)联用测定了环境水样中的痕量苯并[a]芘(B[a]p),考察了影响SPME的实验参数如萃取时间、解吸时间、萃取温度、搅拌速率和离子强度对萃取效率的影响,建立了测定水样中痕量B[a]p的SPME-HPLC方法。方法的线性范围0.10～4.00 ng/mL,相对标准偏差为7.5%(n=6),检出限为0.04 ng/mL,实际水样的加标回收率90.0%～105.0%。微萃取头机械强度高、寿命长、制作成本低,方法适用于测定环境水样中的痕量B[a]p。     

石墨烯/聚二甲基硅氧烷涂层顶空固相微萃取与气相色谱联用测定环境水和果汁中菊酯农药残留

建立了石墨烯/聚二甲基硅氧烷涂层顶空固相微萃取与气相色谱在线联用测定环境水和果汁样品中6种菊酯类农药的检测方法。该涂层的萃取性能优于商用聚二甲基硅氧烷(PDMS,Polydimethylsilane)及聚丙烯(PA,Polypropylene)涂层。对影响萃取性能的因素(如萃取温度、离子强度、萃取时间及解吸时间)依次进行了优化。在最优条件下,丙烯菊酯与联苯菊酯的线性范围为0.02~5μg/L,甲氰菊酯、氯氰菊酯、氰戊菊酯的线性范围为0.1~20μg/L,溴氰菊酯的线性范围为0.2~20μg/L,其相关系数均高于0.99,检出限为6.8~58.2 ng/L,定量下限为18.2~154.9 ng/L。同一涂层的相对标准偏差(RSD,n=5)不高于9.2%,3根涂层之间的RSD为6.7%~10.8%。将该方法用于河水、鱼塘水、苹果汁和橙汁中6种菊酯残留的分析,加标回收率分别为81.6%~92.9%,82.3%~96.1%,78.2%~92.8%和79.9%~91.7%。方法简便、灵敏,能够满足环境水样及浓缩果汁样品中痕量农药残留的分析要求。     

固相微萃取-气相色谱联用测定饮料中残留的10种可挥发性卤代烃

建立了固相微萃取(SPME)与气相色谱(GC)联用测定饮料中残留的可挥发性卤代烃(VHH)的检测方法.探讨了影响SPME萃取效果的纤维涂层、离子强度、萃取时间等因素,并对饮料样品的预处理进行了研究.方法的检出限0.3μg/L,线性范围3～90μg/L,回收率在79.5%～104.3%之间,RSD在1.3%～12%之间.     

石墨烯固相微萃取纤维的制备及对多氯联苯的检测

采用溶胶-凝胶方法合成了石墨烯复合材料,将其均匀地涂在铜丝表面制备了石墨烯固相微萃取纤维,结合固相微萃取-气相色谱-电子捕获检测器(SPME-GC-ECD)技术,建立了对环境中类二英多氯联苯(DL-PCBs)的直接测定方法。实验优化了萃取温度、萃取时间、pH值和离子强度等固相微萃取条件。在优化条件下,石墨烯固相微萃取纤维较商品化纤维(100μm PDMS、75μm CAR/PDMS、85μm PA)的萃取效率平均高2倍。对于DL-PCBs分析,该方法在0.05～3.5μg.L-1范围内呈良好线性(除PCB169外,r2均高于0.99),检出限为4.7～8.8 ng.L-1,单个纤维间及纤维与纤维间的相对标准偏差分别为1.4%～8.1%和2.4%～12.8%。该纤维对12种环境样品中DL-PCBs加标0.5μg.L-1和2 ng.g-1的回收率为87%～120%。方法简单、快速、灵敏,可实现对多氯联苯的痕量检测。     

Development of polymethylphenylsiloxane-coated fiber for solid-phase microextraction and its analytical application of qualitative and semi-quantitative of organochlorine and pyrethroid pesticides in vegetables

An approach to the synthesis of hydroxyl-terminated polymethylphenylsiloxane (PMPS-OH) was proposed and the synthesized PMPS-OH was successfully applied as a precursor to prepare a novel coating for solid-phase microextraction (SPME) via the sol-gel process. The thickness and length of the prepared coating was 70 μm and 1.5 cm, respectively. The extraction efficiency of the PMPS-coated fiber for selected pesticides was higher than that of commercial fibers including 100 μm polydimethylsiloxane (PDMS), 85 μm polyacrylate (PA) and 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB). The influence of the extraction process, extraction temperature, extraction time, stirring rate, ionic strength, GC inlet conditions, desorption temperature and time for PMPS-coated fiber application was studied and optimized. Several experiments were carried out to evaluate the analytical characteristics of the proposed SPME-GC-ECD method under optimized conditions. The linearity was from 0.5 to 100 ng g⁻¹ for p,p′-DDE, p,p′-DDD and bifenthrin, and from 2 to 100 ng g⁻¹ for o,p′-DDT, p,p′-DDT, fenpropathrin, beta-cyfluthrin and cyhalothrin. The detection limits of these pesticides were between 0.13 and 1.45 ng g⁻¹. The recovery of the pesticides spiked in various vegetables at 4 ng g⁻¹ ranged from 42.9% to 105.3%, and the relative standard deviations were less than 16.2%.     

Automated solid phase dynamic extraction – Extraction of organics using a wall coated syringe needle

Extractions of liquid samples were carried out using wall coated needles prepared from stainless steel capillary columns instead of syringe needles. This micro extraction technique was applied to the analysis of pesticides in water. Important parameters influencing the extraction such as sample velocity, extraction time and also the desorption parameters were investigated and optimized. Automation of this technique was realized using a conventional automatic sampler. Limits of detection were improved using the multiple extraction / desorption technique. Chromatographic data and limits of detection were compared with those obtained by solid phase micro extraction (SPME). Using a needle with a 7 μm film yielded limits of detection varying from 0.001–0.1 μg/L and were in the same range as those resulting from the extraction using a 100 μm polydimethylsiloxane (PDMS) SPME fiber. The main advantages of the needle extraction technique were the significantly higher extraction speed and the practical aspects of a stable steel needle compared to those of a fragile fiber. The extraction speed using a needle with a ¶7 μm film was up to five times higher than the speed of SPME using a 100 μm PDMS fiber. The steel needle could be stressed mechanically in a higher extent than a SPME fiber. Sample volumes and aliquots of liquid media could be handled and moved from one bottle to another using the automatic sampler.     

Application of polyphenylmethylsiloxane coated fiber for solid-phase microextraction combined with microwave-assisted extraction for the determination of organochlorine pesticides in Chinese teas

Polyphenylmethylsiloxane (PPMS) as a novel coating for solid-phase microextraction (SPME) combined with microwave-assisted extraction (MAE) has been applied to determine the concentrations of organochlorine pesticides (OCPs) in Chinese teas. The characteristics of PPMS fiber, the extraction modes of SPME, the extraction time, temperature, and salt effects were investigated. Microwave irradiation time and power were also studied. Compared with commercial polydimethylsiloxane (PDMS) fiber and homemade sol-gel polymethylsiloxane (PMS) fiber, the novel porous sol-gel PPMS fiber exhibited high sensitivity and selectivity for OCPs compounds, higher thermal stability (to 350 degrees C) and long service life (more than 150 times). The recoveries of MAE is compared with that of ultrasonic extraction (USE), MAE-SPME-gas chromatography (GC)/electron-capture detection (ECD) methods showed better results for Chinese teas. Linear ranges of OCPs in the blank green tea was 0.1-10(3) ng/l. Detection limits of this method are below 0.081 ng/l. Recoveries of this method are between 39.05 and 94.35%. The repeatability of the technique was less than 16% relative standard deviation (R.S.D.). The tested pesticides in three Chinese teas were at the ng/g level.     

Analysis of trace levels of pesticides in rainwater using SPME and GC–tandem mass spectrometry

A multiresidue method using gas chromatography coupled to ion trap tandem mass spectrometry (GC–ITD–MS/MS) associated with solid phase microextraction (SPME) was developed for the analysis of 20 pesticides commonly used in the Alsace region in rainwater samples. Since the pesticides were expected to be present at very low concentrations and in complex matrices, the analytical method used was both highly selective and sensitive. Therefore, fibers coated with polyacrylate (PA), polydimethylsiloxane (PDMS) and polydimethylsiloxane-divinylbenzene (PDMS-DVB) were tested, and the parameters affecting the precision and accuracy of the SPME method were investigated and optimized. These parameters include the type of fiber, the adsorption time, the effect of salt, and the extraction temperature. The PDMS fiber was the most polyvalent for the extractions of the different pesticides studied. Detection limits of between 5 and 500 ng L⁻¹, depending on the compounds under study (except for those which could not be analyzed: captan and mevinphos), were obtained with this analytical procedure. This method was applied to the analysis of rainwater samples collected simultaneously on a weekly basis at one rural and one urban site between March 2002 and July 2003. While some of the 20 pesticides analyzed were constantly detected (such as lindane and atrazine), a strong temporal variability was observed for some of the others (including alachlor, metolachlor, atrazine).     

Automated solid phase dynamic extraction--extraction of organics using a wall coated syringe needle

Extractions of liquid samples were carried out using wall coated needles prepared from stainless steel capillary columns instead of syringe needles. This micro extraction technique was applied to the analysis of pesticides in water. Important parameters influencing the extraction such as sample velocity, extraction time and also the desorption parameters were investigated and optimized. Automation of this technique was realized using a conventional automatic sampler. Limits of detection were improved using the multiple extraction/desorption technique. Chromatographic data and limits of detection were compared with those obtained by solid phase micro extraction (SPME). Using a needle with a 7 microns film yielded limits of detection varying from 0.001-0.1 microgram/L and were in the same range as those resulting from the extraction using a 100 microns polydimethylsiloxane (PDMS) SPME fiber. The main advantages of the needle extraction technique were the significantly higher extraction speed and the practical aspects of a stable steel needle compared to those of a fragile fiber. The extraction speed using a needle with a 7 microns film was up to five times higher than the speed of SPME using a 100 microns PDMS fiber. The steel needle could be stressed mechanically in a higher extent than a SPME fiber. Sample volumes and aliquots of liquid media could be handled and moved from one bottle to another using the automatic sampler.     

Solid Phase Microextraction Fibers Coated with Sol-gel Aminopropylsilica/polydimethylsiloxane: Development and Its Application to Screening of Beer Headspace

The preparation and applicability of solid phase microextraction (SPME) fibers coated with a sol-gel organically modified silica based on 3-aminopropyltrimethoxysilane and polydimethylsiloxane (APTMS/PDMS) are described here. Micrographs of the coated fibers revealed a rugous surface; the thickness of the coating was estimated to be less than 30 microm. The APTMS/PDMS fibers were tested with synthetic samples and compared to commercial fibers for headspace SPME analysis of beer. Extraction and desorption using the APTMS/PDMS fibers were faster, which is typical for sol-gel SPME fibers. For polar and semi-polar compounds on beer headspace, the extraction efficiencies of the APTMS/PDMS fiber were superior to those of conventional fibers. The APTMS/PDMS fiber was found to be capable of extracting a broad range of analytes, including highly polar acidic species such as organic acids.     

固相微萃取气相色谱法测定水相中邻苯二甲酸二酯

 采用m(聚硅氧烷 (OV 1) )∶m (富勒烯聚二甲基硅氧烷 (PSO C60 ) ) =4∶1的混合固定相自制萃取头 ,利用顶空固相微萃取与气相色谱联用技术 (HS SPME GC)分析了水中 5种邻苯二甲酸二酯。考察了萃取温度、离子强度、吸附和热解吸时间等因素对该方法灵敏度的影响。结果表明该萃取头萃取选择性优于商用PDMS萃取头。方法的检出限为 0 331ng/L～ 12 5 μg/L ;除邻苯二甲酸二正壬酯外 ,相对标准偏差均在 12 %以下。     

Physically incorporated extraction phase of solid-phase microextraction by sol-gel technology

A sol-gel method for the preparation of solid-phase microextraction (SPME) fiber was described and evaluated. The extraction phase of poly(dimethysiloxane) (PDMS) containing 3% vinyl group was physically incorporated into the sol-gel network without chemical bonding. The extraction phase itself is then partly crosslinked at 320 degrees C, forming an independent polymer network and can withstand desorption temperature of 290 degrees C. The headspace extraction of BTX by the fiber SPME was evaluated and the detection limit of o-xylene was down to 0.26 ng/l. Extraction and determination of organophosphorus pesticides (OPPs) in water, orange juice and red wine by the SPME-GC thermionic specified detector (TSD) was validated. Limits of detection of the method for OPPs were below 10 ng/l except methidathion. Relative standard deviations (RSDs) were in the range of 1-20% for pesticides being tested.     

加压溶剂萃取-气相色谱法测定荞麦中残留的有机氯农药

用所研制的24位全自动加压溶剂萃取仪(APLE),以丙酮-正己烷(体积比为1∶1)为溶剂,在100 ℃和10 MPa条件下,对荞麦样品中残留的7种有机氯农药进行了萃取,并通过气相色谱对萃取液进行定量分析。萃取的绝对回收率为68%～126%,相对标准偏差为1.2% ～14.7%,检测下限为0.051～0.18 ng/g。与索氏提取法对比,相对提取回收率为116%～148%,表明萃取收率高于索氏提取法。     

固相萃取-毛细管气相色谱法测定枇杷花中有机氯农药残留量

建立了枇杷花中有机氯类农药残留量的固相萃取-毛细管气相色谱(SPE-CGC)分析方法。对采自福建蒲田等12地的枇杷花中六六六(4种异构体)、滴滴涕(4种异构体)、五氯硝基苯共9种有机氯农药的残留量进行了测定。样品采用丙酮超声波提取,浓缩后过Florisil固相萃取小柱净化,洗脱剂为V(正己烷)∶V(丙酮)100∶1。用DB-1701弹性石英毛细管气相色谱柱分离样品,微电子捕获检测器进行检测。9种有机氯农药的峰面积与其质量浓度均有良好的线性关系,相关系数均大于0.999,最低检测限为0.016~0.125μg/L,样品的加标回收率为85.4%~106.9%,相对标准偏差为1.8%~9.8%。该方法能够满足农药残留检测的要求。