金属-有机纳米管分散固相萃取-气相色谱-串联质谱高灵敏分析环境水样中痕量多氯联苯

采用含铅金属-有机纳米管为吸附剂,基于分散固相萃取和气相色谱-串联质谱建立了一种高灵敏分析环境水样中痕量多氯联苯的方法.采用正交设计响应面法对影响萃取效果的重要因素(如离子强度、萃取时间和吸附剂用量等)进行了优化.获得的最优条件为:离子强度4.92 %(w/V)NaCl,萃取时间4.5 min,正己烷为解吸剂,吸附剂用量62.5 mg.在优化条件下,方法的线性范围为2~1000 ng/L,检出限为0.26~0.82 ng/L. 日内和日间相对标准偏差分别为0.8%~5.5% (200 ng/L, n=6)和2.7%~7.4% (200 ng/L, n=6).将本方法应用于实际环境水样中多氯联苯的分析,回收率为78.9%~113.3%,结果满意.     

磁性石墨烯纳米粒子固相萃取与气相色谱-质谱相结合测定环境水样中的三嗪类除草剂

将磁性石墨烯作为磁性固相萃取的吸附剂与气相色谱-质谱(GC-MS)相结合建立了环境水样中7种三嗪类除草剂残留的测定新方法。对影响萃取效率的一些因素如吸附剂用量、萃取时间、样品溶液的pH值、离子强度和解吸条件等进行了优化。在优化的实验条件下,7种三嗪类除草剂的富集倍数在574~968之间。测定西玛津、扑灭津、嗪草酮、西草净、氰草津的线性范围为0.01~10.0μg/L,莠去津的线性范围为0.05~10.0μg/L,扑灭净的线性范围为0.01~8.0μg/L。线性相关系数为0.996 8~0.999 8,检出限(S/N=3)为1.0~5.0ng/L。将本方法应用于井水、自来水和湖水等实际水样的分析,在0.5μg/L和2.0μg/L下的加标回收率为79.8%~118.3%,相对标准偏差为3.6%~10.5%。该法操作简单、富集倍数高,可满足水样中三嗪类除草剂残留的检测要求。     

衍生-分散液相微萃取/气相色谱-质谱法测定纺织品中的含氯酚及邻苯基苯酚

建立了衍生、分散液相微萃取(DLLME)与气相色谱-质谱(GC-MS)联用测定纺织品中5种含氯酚(PCPs)和邻苯基苯酚(OPP)的方法。对影响萃取和富集效率的因素,萃取剂种类及用量、分散剂种类及用量、碳酸钾溶液浓度等条件进行了优化。确定最佳实验条件为:纺织样品用0.15 mol/L的碳酸钾溶液超声提取后定容,取5 mL溶液,加入0.1 mL乙酸酐进行衍生处理2 min后,经0.2 mL四氯化碳(萃取剂)与0.6mL异丙醇(分散剂)混合溶液分散萃取,在4 000 r/min下离心3 min,取下层有机相进行GC-MS分析。在优化实验条件下,5种含氯酚和邻苯基苯酚的线性范围为0.001~1 mg/L,相关系数为0.999 1~0.999 9,检出限(S/N=3)为0.5~5μg/kg,样品加标回收率为87.2%~103.7%,相对标准偏差为2.5%~4.8%。方法简单、灵敏,回收率和重复性良好,可用于纺织品中5种含氯酚和邻苯基苯酚的测定。     

固相萃取-气相色谱质谱法测定水体中氯代多环芳烃

本研究建立了固相萃取-气相色谱质谱联用测定水体中6种Cl-PAHs的分析方法。采用poly-sery HLB固相萃取小柱对水样进行富集浓缩,用大体积采样器以2 mL/min的流速过柱,用6 mL的正己烷-二氯甲烷(4∶1,V/V)洗脱,气相色谱-质谱联用、选择离子扫描方式进行定性和定量分析,并采用内标定量法。在对应Cl-PAHs线性范围内的线性相关系数为0.9952~0.9997,检出限与定量限分别为0.013~0.592 ng/L和0.051~0.257 ng/L。除9-Cl Flu(加标回收率为34.4%~45.6%)外,其它Cl-PAHs的加标回收率为77.8%~105.4%。将本方法用于测定南京工业园区及周边水体中Cl-PAHs分析,测得其总浓度为23.594~106.374 ng/L。     

固相萃取-气相色谱法检测血清中有机氯农药残留的研究

建立了血清中DDTs和BHCs共8种有机氯农药残留的固相萃取-气相色谱检测方法。样品经超声酸化沉淀蛋白后,采用正己烷-丙酮(9∶1)经Cleanert ODS C18N固相萃取小柱提取,Florisil固相萃取小柱净化,氮气吹干,以500μL正己烷定容,气相色谱-电子捕获检测器(GC-ECD)进行定量分析。结果表明,方法的线性范围2~200 ng/m L,相关系数(r)为0.996 4~0.999 0,检出限(LOD)为0.1~0.9 ng/m L,定量下限(LOQ)为0.4~3.0 ng/m L。8种农药的回收率为80.5%~112.7%,相对标准偏差(RSD)为2.1%~7.9%。该方法具有较高的准确度和精密度,适用于血清样品中痕量有机氯农药的检测。     

搅拌棒吸附萃取-热脱附-气相色谱-质谱法测定水中3种烷基酚

应用搅拌棒吸附萃取富集及热解吸进样与气相色谱-质谱相结合测定了水样中3种烷基酚(即正辛基酚、叔辛基酚和正壬基酚)的含量。将水样预先用盐酸调节其酸度至pH 3,分取10.00mL置于顶空瓶中,放入搅拌棒进行吸附萃取。取出搅拌棒,置于热脱附管上解吸并通过程序升温进样系统进样,用DB-5MS柱进行色谱分离。质谱分析条件:电子轰击正离子源,全扫描模式(定性分析)和选择离子扫描模式(定量分析)。3种烷基酚的质量浓度均在5~200ng·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在1.2~2.5ng·L-1之间。以实际水样为基体进行加标回收试验,测得回收率在95.0%~118%之间,测定值的相对标准偏差(n=5)在0.90%~10%之间。     

石墨烯/Fe3O4磁性纳米材料分散固相萃取环境水样中的己烯雌酚

合成了石墨烯/Fe3O4磁性纳米材料(G/Fe3O4),并以此作为吸附剂,建立了分散固相萃取环境水样中己烯雌酚(DES)的新方法.通过红外光谱(FT-IR)、X射线衍射仪对吸附剂进行表征.考察了pH值、吸附时间、盐类等对吸附性能的影响.结果表明,最佳吸附pH值为7.0,吸附时间为20 min,吸附率最高可达88.2％.无水乙醇可有效洗脱吸附在石墨烯/Fe3O4磁性纳米材料表面的己烯雌酚,回收后的吸附剂可再利用.石墨烯/Fe3O4磁性纳米材料对己烯雌酚的等温吸附符合Langmuir模型,其最大吸附容量为79.6 mg/g,Langmuir吸附平衡常数为5.39 mL/μg.     

顶空固相微萃取气相色谱法测定浓海水中的氯酚

建立浓海水中氯酚的顶空固相微萃取气相色谱法检测方法。采用顶空固相微萃取对海水淡化排放的浓海水样品中2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)进行分离富集,气相色谱-电子捕获检测器(μECD)测定浓海水样品中2,4,6-TCP和PCP的含量。讨论了萃取时间、萃取温度、水样盐度等实验条件对富集效率的影响,确定了萃取时间为40 min,萃取温度为60℃。2,4,6-TCP,PCP的质量浓度在0.500~20.0μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数均大于0.999,2,4,6-TCP和PCP的检出限(2S/N)分别为0.055,0.128μg/L,测定结果的相对标准偏差为3.65%~11.4%(n=6),加标回收率为73.5%~119.0%。该方法快速,灵敏度高,适合于浓海水中氯酚的分析。     

气相色谱-质谱法测定地下水中多氯萘

建立了地下水中1-氯萘、2-氯萘、1,4-二氯萘、1,2,3,4-四氯萘、1,3,5,7-四氯萘、1,2,3,5,7-五氯萘、1,2,3,5,6,7-六氯萘、1,2,3,4,5,6,7-七氯萘和八氯萘9种多氯萘(PCNs)的气相色谱-质谱(GC-MS)分析方法。对比研究了液液萃取(LLE)和固相萃取(SPE)萃取地下水中PCNs的提取效率,优选二氯甲烷-液液萃取为PCNs检测的前处理方法。在优化条件下,9种PCNs的线性范围为5~100μg/L,各组分的相关系数(r)大于0.995,方法检出限(S/N=3)为4.21~7.41 ng/L,地下水的平均加标回收率为70.7%~112%,相对标准偏差(RSD,n=5)均小于9.9%。该方法已用于地下水样中多氯萘的检测。     

分散液液微萃取-反相液液微萃取-扫集-胶束电动色谱法测定红酒中的3种氯酚类物质

建立了分散液液微萃取(DLLME)-反相液液微萃取(RP-LLME)-扫集-胶束电动色谱富集模型,并用于红酒中五氯酚(PCP)、2,4,6-三氯酚(TCP)和2,4-二氯酚(DCP)3种氯酚的测定。实验考察了两步微萃取的萃取参数对氯酚萃取率的影响和样品分离富集的电泳条件。最佳萃取条件DLLME为:3.5 mL红酒(pH3.0,120 g/L NaCl),300μL正己烷(萃取剂);RP-LLME为:25μL 0.16 mol/L NaOH(萃取剂)。最佳电泳条件:25 mmol/L NaH2PO4,100 mmol/L十二烷基硫酸钠(SDS),30%(v/v)乙腈,pH2.3;分离电压-15 kV;样品基质为80mmol/L NaH2PO4;压力进样20 s×20.67 kPa(3 psi)。PCP和TCP的线性范围为0.5~100μg/L(r≥0.991 0),DCP的线性范围为1.5~80μg/L(r=0.985 1)。3种分析物的检出限(S/N=3)为0.035~0.114μg/L,加标回收率为75.2%~104.7%,相对标准偏差≤6.17%。该方法富集倍数高、灵敏度高、重现性好、分析速度快,可为不同样品基质中痕量氯酚污染物及某些弱酸性有机污染物测定提供参考。     

The use of graphene-based magnetic nanoparticles as adsorbent for the extraction of triazole fungicides from environmental water

A graphene-based magnetic nanocomposite (graphene-ferriferrous oxide; G-Fe(3) O(4) ) was synthesized and used as an effective adsorbent for the preconcentration of some triazole fungicides (myclobutanil, tebuconazole, and hexaconazole) in environmental water samples prior to high-performance liquid chromatography-ultraviolet detection. The method, which takes the advantages of both nanoparticle adsorption and magnetic phase separation from the sample solution, could avoid the time-consuming experimental procedures commonly involved in the traditional solid phase extraction such as centrifugation and filtrations. Various experimental parameters affecting the extraction efficiencies such as the amount of the magnetic nanocomposite, extraction time, the pH values of the sample solution, salt concentration, and desorption conditions were investigated. Under the optimum conditions, the enrichment factors of the method for the three analytes were 5824, 3600, and 4761, respectively. A good linearity was observed in the range of 0.1-50 ng/mL for tebuconazole and 0.05-50 ng/mL for myclobutanil and hexaconazole, respectively, with the correlation coefficients ranging from 0.9992 to 0.9996. The limits of detection (S/N = 3) of the method were between 0.005 and 0.01 ng/mL. The results indicated that as a magnetic solid-phase extraction adsorbent, the graphene-ferriferrous oxide (G-Fe(3) O(4) ) has a great potential for the preconcentration of some compounds from liquid samples.     

Determination of triazine herbicides in environmental water samples by high-performance liquid chromatography using graphene-coated magnetic nanoparticles as adsorbent

In this paper, a graphene-based Fe(3)O(4) magnetic nanoparticles (G-Fe(3)O(4) MNPs) was used as the adsorbent for the magnetic solid-phase extraction of some triazine herbicides (atrazine, prometon, propazine and prometryn) in environmental water samples followed by high performance liquid chromatography-diode array detection (HPLC-DAD). After the extraction, the adsorbent can be conveniently separated from the aqueous samples by an external magnet. The main factors influencing the extraction efficiency including the amount of the MNPs, the extraction time, the pH of sample solution, and desorption conditions were studied and optimized. Under the optimized experimental conditions, a good linearity was observed in the range of 0.1-50.0 ng mL(-1) for all the analytes, with the correlation coefficients (r) ranging from 0.9996 to 0.9999. The limits of detection of the method ranged between 0.025 and 0.040 ng mL(-1). Good reproducibility was obtained with the relative standard deviations below 5.2%. The developed method was applied to the analysis of the triazine herbicides in different water samples (lake, river and reservoir). The recoveries of the method were in the range between 89.0% and 96.2%.     

Dispersive Solid Phase Extraction with an Ionic Liquid Modified Polymer for Determination of Cyanazine and Atrazine in Tomatoes

A novel ionic liquid modified polymer was employed as an adsorbent for dispersive solid phase extraction for the determination of cyanazine and atrazine in tomatoes. This polymer was advantageous over conventional solid phase extraction in terms of the operational simplicity, speed, handling of large sample volumes, and recovery. Extraction parameters, such as the adsorbent amount, adsorbent time, elution solvent, elution time, and pH of aqueous samples were optimized. The optimized extraction conditions included 50 mg of 1-ethyl-3-methylimidazolium bromide modified polymer as the adsorbent, dichloromethane as the eluent, and 6 min as the adsorption time. Under the optimized conditions, the recovery from tomato samples ranged from 72.0 to 95.1%, which was comparable to tomato juice. The limits of detection for cyanazine and triazine were 0.51 ng/mL and 0.35 ng/mL, respectively.     

Preparation of a magnetic porous carbon with hierarchical structures from waste biomass for the extraction of some carbamates

In this study, corn stalk was used to synthesize a magnetic adsorbent by pyrolysis together with KHCO₃ as the chemical activator and iron(III) salt as the magnetic reagent. The characterization by scanning electron microscopy, transmission electron microscopy and N₂ adsorption–desorption analysis showed that the magnetic carbon adsorbent had a structure of hierarchical pores with a high specific surface area. To evaluate its adsorption performance, the adsorbent was used for the extraction of carbamates pesticides (propoxur, isoprocarb and fenobucarb) from water and zucchini samples before high‐performance liquid chromatography analysis. The result showed that the adsorbent had a good adsorption capability for the analytes. Under the optimized conditions, a good linearity for the analytes existed in the range of 0.1–100.0 ng/mL for water samples and 0.5–100.0 ng/g for zucchini samples with the correlation coefficients of 0.9992–0.9998. The limits of detection for the analytes at a signal to noise ratio of 3 were 0.03 ng/mL for water samples and 0.20–0.50 ng/g for zucchini samples.     

Magnetic solid‐phase extraction of polycyclic aromatic hydrocarbons in water samples by Fe3O4@polypyrrole/carbon nanotubes

A magnetic solid‐phase extraction method coupled with gas chromatography was proposed for the determination of polycyclic aromatic hydrocarbons in the environmental water samples. The magnetic adsorbent was prepared by incorporating Fe₃O₄ nanoparticles, multi‐walled carbon nanotubes, and polypyrrole. The main factors affecting the extraction efficiency including the amount of the sorbents, desorption conditions, extraction time, salt concentration, and sample solution pH were investigated and optimized. Under the optimum conditions, good linearity was obtained within the range of 0.03?100 ng/mL for all analytes, with correlation coefficients ranging from 0.9942 to 0.9973. The method detection limits (S/N = 3) were in the range of 0.01–0.04 ng/mL and the limits of quantification (S/N = 10) were 0.03–0.1 ng/mL. Repeatability of the method was assessed through five consecutive extractions of independently prepared solutions at concentrations of 0.1, 10, and 100 ng/mL of the compounds. The observed repeatability ranged 3.4–10.9% depending of the compound considered. The proposed method was successfully applied in the analysis of PAHs in environmental samples (tap, well, river, and wastewater). The recoveries of the method ranged between 93.4 and 99.0%. The procedure proved to be efficient and environmentally friendly.     

Preparation of silica-magnetite nanoparticle mixed hemimicelle sorbents for extraction of several typical phenolic compounds from environmental water samples

A novel type of superparamagnetic silica-coated (Fe3O4/SiO2 core/shell) magnetite nanoparticle modified by surfactants has been successfully synthesized and was applied as an effective sorbent material for the pre-concentration of several typical phenolic compounds (bisphenol A (BPA), 4-tert-octylphenol (4-OP) and 4-n-nonylphenol (4-NP)) from environmental water samples. Compared with pure magnetic particles, a thin and dense silica layer would protect the iron oxide core from leaching out in acidic conditions. In order to enhance their adsorptive tendency towards organic compounds, cetylpyridinium chloride (CPC) or cetyltrimethylammonium bromide (CTAB) were added, which adsorbed on the surface of the Fe3O4/SiO2 nanoparticles (Fe3O4/SiO2 NPs) and formed mixed hemimicelles. Main factors affecting the adsolubilization of analytes were optimized and comparative study on the use of CPC and CTAB-coated Fe3O4/SiO2 NPs mixed hemimicelles-based SPE was also carried out. CPC-coated Fe3O4/SiO2 NPs system was selected due to lower elution volume required and more effective adsorption of the target compounds. Under selected conditions, concentration factor of 1600 was achieved by using this method to extract 800 mL of different environmental water samples. The detection limits obtained for BPA, 4-OP and 4-NP with HPLC-FLD were 7, 14, and 20 ng/L, respectively.     

Rapid magnetic solid phase extraction with in situ derivatization of methylmercury in seawater by Fe3O4/polyaniline nanoparticle

A new Fe(3)O(4)/polyaniline nanoparticle (PANI) material has been successfully developed as magnetic solid-phase extraction sorbent in dispersion mode for the determination of methylmercury (MeHg) in aqueous samples, via quantification by gas chromatography/mass spectrometry (GC-MS). The resultant core-shell magnetic solid-phase extraction nanoparticle (MSPE-NP) sorbent was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS) and Fourier transform-infrared (FTIR) spectroscopy. Fe(3)O(4)/PANI composites showed fibrous structure with diameters between 50 and 100 nm for fibers. The MSPE-NP process involved the dispersion of the Fe(3)O(4)/PANI nanoparticles in water samples with sonication, followed by magnetic aided retrieval of the sorbent and then, solvent (hexane) desorption of extracted MeHg for GC-MS analysis. The extraction, derivatization and adsorption conditions were optimized by selecting the appropriate extraction parameters including the amount of sorbent, extraction time, derivatizing reagent volume and extraction solvent. The calibration graph was linear in the concentration range of 0.5-300 ng mL(-1) (R(2)>0.993) with detection limit of 0.1 ng mL(-1) (n=3), while the repeatability was 4.1% (n=5). Enrichment factor was obtained as 91. Seawater sample was analyzed as real sample and good recoveries (>98%) were obtained at different spiked values.     

Modifying the surface of Fe3O4/SiO2 magnetic nanoparticles with C18/NH2 mixed group to get an efficient sorbent for anionic organic pollutants

In this article, C(18)/NH(2) mixed group modified Fe(3)O(4)/SiO(2) magnetic nanoparticles (Fe(3)O(4)/SiO(2)/C(18)+NH(2) MNPs) were successfully synthesized and used for the extraction of perfluorinated compounds (PFCs) from large volume of water solution. The Fe(3)O(4)/SiO(2)/C(18)+NH(2) MNPs, about 25 nm in diameter, possess high extraction ability to the anionic organic pollutants due to the dual function of hydrophobic octadecyl group and cationic aminopropyl groups at low pH. More than 90% of the targets can be extracted from 500 mL of water solution with 0.1g of the MNP sorbent at pH 3. Twenty min is sufficient to reach adsorption equilibrium, and the targets can be desorbed from the sorbent readily with 12 mL of alkalized methanol after magnetic separation. Simplified extraction procedure could be achieved because of the superparamagnetism and high saturation magnetization of the sorbent (44 emu g(-1)). Therefore, preconcentration of trace level of PFCs from water solution can be performed by using this Fe(3)O(4)/SiO(2)/C(18)+NH(2) MNP sorbent which are stable for multiple reuses.     

磁性氧化石墨烯固相萃取/高效液相色谱-串联质谱法测定环境水样中6种三嗪类除草剂残留

采用一步合成法制备磁性氧化石墨烯材料(GO-Fe_3O_4),将其用作磁性固相吸附剂对环境水样中的6种三嗪类除草剂进行萃取和富集,并与高效液相色谱-串联质谱法相结合进行测定。以扫描电镜和傅立叶红外光谱对合成材料进行了表征,并考察了GO-Fe_3O_4用量、萃取时间、水样的pH值及离子强度和解吸条件等因素对萃取效率的影响。6种三嗪类除草剂的检出限为0.1~1.0 ng/L,富集倍数可达616~902倍。将方法应用于苏州地区太湖水、运河水和护城河水等实际水样的分析,加标回收率为85.4%~117.6%,相对标准偏差为1.2%~10.0%。该方法操作简单快速,富集倍数较高,检出限低,可用于水样中痕量三嗪类除草剂残留的检测。     

Magnetic retrieval of graphene: extraction of sulfonamide antibiotics from environmental water samples

A new technique of retrieving graphene from aqueous dispersion was proposed in the present study. Two-dimensional planar graphene sheets were immobilized onto silica-coated magnetic microspheres by simple adsorption. The graphene sheets were used as adsorbent material to extract six sulfonamide antibiotics (SAs) from water samples. After extraction, they were conveniently separated from the aqueous dispersion by an external magnetic field. Under the optimal conditions, a rapid and effective determination of SAs in environmental water samples was achieved. The limits of detection for six SAs ranged from 0.09 to 0.16 ng/mL. Good reproducibility was obtained. The relative standard deviations of intra- and inter-day analysis were less than 10.7% and 9.8%, respectively.