悬浮固化分散液相微萃取-高效液相色谱/串联质谱法测定环境水样品中6种雌激素

本文建立了悬浮固化分散液相微萃取(DLLME-SFO)高效液相色谱-串联质谱法(HPLC-MS/MS)测定环境水样品中壬基雌酚、双酚A、己烯雌酚、雌酮、雌二醇、炔雌醇6种雌激素的分析方法。萃取的最优条件为:以90μL 1-十二醇为萃取剂,250μL0.025mol/L Triton X-100为分散剂,调节pH至7.0,超声3min,在室温条件下萃取环境水样中的雌激素残留。最优条件下,该方法在三个浓度水平下的平均加标回收率为93.4%~108.6%,相对标准偏差为1.3%~8.7%,检出限为0.001~0.05μg/L。将该方法应用于环境水样中雌激素残留分析,获得了较好的回收率。     

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。     

基于碳纳米管的固相萃取-分散液液微萃取测定水中多种痕量环境雌激素

建立了基于碳纳米管的固相萃取-分散液液微萃取/ 上浮溶剂固化-高效液相色谱/荧光法测定水体中痕量雌激素雌三醇(E3)、 双酚A(BPA)、 17α-乙炔基雌二醇(EE2)及17β-雌二醇(E2)的方法. 利用中心复合实验设计分别对固相萃取和分散液液微萃取条件进行了优化, 通过响应曲面法得到的最佳萃取条件为碳纳米管用量30 mg, 水样体积210 mL, 流速2.0 mL/min, 萃取剂(十二醇)体积50 μL, 分散剂(甲醇)体积0.2 mL以及不添加盐. 在优化的实验条件下, E3, BPA, EE2和E2测定的线性范围分别为0.05~100, 0.05~100, 0.05~50和0.05~50 μg/L, 相关系数为0.9993~0.9999, 检出限分别为48.4, 3.3, 8.1和6.0 ng/L. 对不同加标浓度(0.40和4.00 μg/L)的实验室自来水、 排水沟污水及市售矿泉水3种实际水样进行了分析: E3, BPA, EE2和E2的加标回收率依次为107.5%~120.8%, 92.5%~108.3%, 103.5%~121.0%和102.5%~132.5%, 相对偏差分别为2.47%~13.28%, 1.73%~11.94%, 1.72%~8.36%和3.54%~11.95%, 富集因子平均值分别为461, 1075, 2074和949. 实际水样分析结果表明, 本方法可用于不同基质水样中雌激素的测定. 与其它方法相比, 本方法虽然固相萃取时间长及水样量大, 但检出限低、 富集因子高、 操作简便及费用低, 仍可作为一种可普及的水中痕量雌激素检测方法.     

固相萃取-超高效液相色谱-串联质谱法测定农田回用再生水中的9种雌激素

建立了水体中9种雌激素的固相萃取-超高效液相色谱-串联质谱检测方法。利用HLB固相萃取柱富集水体中的痕量雌激素,以0.05%氨水/甲醇为流动相,经C18色谱柱分离,采用电喷雾离子源、质谱多反应监测和负离子扫描模式,实现了水体中9种雌激素的同时检测,方法分析速度为6 min,RSD在4.7%~9.5%之间,回收率范围为73%~116%,检出限在0.001~0.024μg/L之间。利用该方法对北京市某再生水灌区出水口、灌溉渠、农田灌溉点的再生水中雌激素进行了检测分析,未检出天然雌激素(雌酮、雌二醇、雌三醇)和人工合成雌激素(炔雌醇、己烷雌酚、己烯雌酚)等,但检出了壬基酚、辛基酚和双酚A等3种类环境雌激素,浓度范围为31~748 ng/L。     

SPE–ICP–AES法测定环境水样中Cr(Ⅲ)

建立固相萃取与电感耦合等离子体原子发射光谱法(ICP–AES)测定环境水样中Cr(Ⅲ)含量的方法。合成了功能化铁氧体磁性材料作为固相萃取剂,优化了固相萃取条件。当样品溶液的p H值为2.5时,固相萃取剂能在5 min内完成Cr(Ⅲ)的富集。使用1 mol/L HNO3在3 min内即可解吸附分离Cr(Ⅲ),饱和吸附容量为15.2μg/mg,研究了共存离子的影响。Cr(Ⅲ)含量在1~50μg/L范围内与发射光谱强度呈良好的线性关系,线性相关系数为0.999 9,检出限为0.09μg/L,测定结果的相对标准偏差为2.2%(n=8),回收率为97.7%~104.8%。该方法高效、快速,测定结果准确可靠,可用于测定环境水样品中的痕量Cr(Ⅲ)。     

磁性氧化石墨烯的制备及其在环境水样中7种内分泌干扰物检测中的应用

制备了十二胺修饰的磁性氧化石墨烯纳米材料并将其用于磁固相萃取。在对磁固相萃取材料合成与萃取条件以及液相色谱分离等条件进行优化的基础上,建立了磁固相萃取与高效液相色谱-紫外检测对环境水样中7种内分泌干扰物的分析方法。该方法对雌酮、雌二醇、雌三醇、双酚A、17α-乙炔基雌二醇、己烷雌酚和雄烯二酮7种内分泌干扰物的检出限在0.10~0.23 nmol/L之间。将该方法分别应用于废水样品和湖水样品的加标回收试验,回收率在73.9%~112.9%和74.9%~114.7%之间。该方法操作简便,分析成本较低,可为环境水体中内分泌干扰物的分析提供技术支持。     

气相色谱-质谱法同时测定饲料中6种雌激素类药物

建立了固相萃取/气相色谱-质谱法(GC-MS)同时测定饲料中己烷雌酚、己烯雌酚、双烯雌酚、雌酮、17β-雌二醇、雌三醇的检测方法。饲料样品经乙醚提取后,HLB固相萃取柱净化、衍生化后用气相色谱-质谱仪进行检测,外标法定量。结果表明,己烷雌酚在2.5~250 ng/m L,其它5种雌激素类药物在5~500ng/m L范围内具有良好的线性关系,相关系数不小于0.99,检出限为3~8μg/kg,样品的平均加标回收率为75.9%~96.3%。该方法检出限低,能够准确进行定性和定量测定,可同时测定饲料中的6种雌激素类药物。     

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。     

高效液相色谱法对环境样品中甲基托布津与甲霜灵残留的测定

建立了自动固相萃取/高效液相色谱法测定地表水和土壤中甲基托布津和甲霜灵残留的方法。地表水采用C18固相萃取小柱进行富集、净化及浓缩;土壤采用丙酮-二氯甲烷(体积比3∶7)溶液振荡萃取,弗罗里硅土小柱净化和浓缩;以乙腈和水为流动相,于230 nm波长处对样品进行高效液相色谱检测。甲基托布津和甲霜灵在水中的检出限分别为0.36、3.49μg/L,在土壤中的检出限分别为0.03、0.18 mg/kg;在优化实验条件下,甲基托布津和甲霜灵在水样和土壤样品中的添加回收率为77%~105%,精密度为1.2%~8.5%。方法可用于环境样品中甲霜灵和甲基托布津残留量的测定。     

亚胺连接的多孔共价有机骨架材料结合固相萃取-液相色谱-串联质谱检测蜂蜜中雌激素

以亚胺连接的多孔共价有机骨架材料(IL-COF-1)作为固相萃取的吸附剂,建立了液相色谱-串联质谱快速检测蜂蜜样品中痕量雌激素的方法。该研究选择雌二醇、己烯雌酚、雌三醇、β-雌二醇和炔雌醇5种雌激素作为目标分析物。在蜂蜜样品中添加雌激素,采用单因素优化法对影响萃取效果的重要因素进行优化,获得最佳条件:IL-COF-1用量为30 mg,样品流速为3 mL/min,样品溶液pH值为7,以5 mL的1%(v/v)氨水-甲醇溶液进行洗脱,流速为0.4 mL/min,萃取过程中不添加NaCl。采用高效液相色谱-三重四极杆质谱联用技术对提取物中的雌激素进行定量分析。以乙腈和5 mmol/L的乙酸铵溶液作为流动相进行梯度洗脱,经C18色谱柱分离,采用电喷雾离子源、质谱多反应监测和负离子扫描模式,实现了蜂蜜样品中5种雌激素的快速定性定量分析。在最佳条件下,方法验证结果中雌三醇、β-雌二醇和炔雌醇的线性范围为1~500 ng/g,雌二醇和己烯雌酚的线性范围为0.1~100 ng/g,相关系数(r)为0.9934~0.9972。检出限(S/N=3)为0.01~0.30 ng/g,定量限(S/N=10)为0.05~0.95 ng/g。添加50 ng/g 5种雌激素进行重复性实验,日内精密度相对标准偏差(RSD)为3.2%~6.6%,日间精密度RSD为4.2%~7.9%。基于IL-COF-1的固相萃取-液相色谱-串联质谱法具有快速准确、灵敏度高等特点,适用于蜂蜜中雌激素的分析和检测。将该方法应用于4个实际蜂蜜样品中雌激素的检测,均未检出目标物;在低中高3个水平下,5种雌激素的加标回收率为80.1%~115.2%,结果令人满意。     

多壁纳米碳管固相萃取测定水中的有机氯农药

对于水样中的有机氯农药的净化方法主要是采用传统的液液分配的方法,缺点是溶剂使用量和前处理复杂。近年来固相萃取及固相微萃取等技术被应用到水样中的有机污染物的测定。如利用键合在硅胶上的非极性(C18,LC18等)或极性物质(LC-CN,LC-NH2)对水中有机物进行富集,用GDX或XAD自填的固相柱的报道也很多。纳米技术和纳米材料的发展为开发固相萃取材料带来新契机。纳米材料是指尺寸大小在从1～100m之间物质。与普通的块体材料相比,纳米材料具有较大的比表面,因而有可能具有较大吸附容量。纳米材料在环境有机污染物分离富集方面的应用研究才刚刚开始。本文主要就纳米碳管对水样中的有机氯农药进行研究,优化固相萃取条件。     

Facile preparation of magnetic graphene oxide/nanoscale zerovalent iron adsorbent for magnetic solid‐phase extraction of ultra‐trace quinolones in milk samples

A simple pH‐responsive magnetic solid‐phase extraction method was developed using graphene oxide–coated nanoscale zerovalent iron nanoparticles as an efficient adsorbent prior to high‐performance liquid chromatography‐tandem mass spectrometry for determination of ultra‐trace quinolones in milk samples. Various parameters affecting maghemite synthesis and separation such as pH of sample solution, amount of magnetic adsorbent, eluent type, and volume were optimized. The limits of detection are from 3.1 to 13.3 ng/L. The intra‐ and interprecision values are in the range of 2.9–6.9% and 7.6–15.1%, respectively. Recoveries are from 82.4 to 103.9%. Therefore, this simple and sensitive method is suitable for detecting ultra‐trace quinolone residues in milk.     

Polyaniline-coated Fe(3) O(4) nanoparticles: An anion exchange magnetic sorbent for solid-phase extraction

In this study, the capability of the prepared polyaniline-coated Fe(3) O(4) nanoparticles for magnetic solid-phase extraction of three parabens from environmental wastewater, cream, and toothpaste samples is presented. Synthesized Fe(3) O(4) nanoparticles were coated with sulfate-doped polyaniline via polymerization of aniline in the presence of Fe(3) O(4) nanoparticles and sulfuric acid. Here, polyaniline-coated Fe(3) O(4) nanoparticles are presented as anion exchange sorbent, which extract anionic form of parabens via anion exchange with dopant of polyaniline. The experimental conditions affecting extraction efficiency were further studied and optimized. The experimental results showed that maximum extraction efficiency can be obtained at 70 mL sample solution of pH 8, extraction and desorption times of 2 and 1 min, respectively, 100 μL of 3% (v/v) acetic acid in acetonitrile as eluent, and 100 mg of the adsorbent. Under these conditions, the linear dynamic ranges were 0.5-100 μg/L with good correlation coefficients (0.998-0.999). The detection limits were in the range of 0.3-0.4 μg/L and the relative standard deviations were less than 2.4 (n = 5) for the three parabens. Finally, this fast and efficient method was further employed for determination of target analytes in cream, toothpaste, and environmental wastewater samples and satisfactory results were obtained.     

Solid-phase extraction and sample stacking-capillary electrophoresis for the determination of quaternary ammonium herbicides in drinking water

Conditions for the simultaneous determination of paraquat, diquat and difenzoquat by capillary zone electrophoresis were established by combining two preconcentration procedures. Off-line solid-phase extraction was used for the isolation and preconcentration of quats in drinking water. Quats were then analysed by capillary electrophoresis using sample stacking with matrix removal as on-column preconcentration procedure. Two different porous graphitic carbon cartridges were compared. The breakthrough volumes of the three herbicides were calculated and the loading capacity of the sorbents was compared. Recoveries higher than 80% for difenzoquat and around 40% for paraquat and diquat were obtained when a sample volume of 250 ml was percolated. For the stacking-capillary electrophoresis analysis of quats, 50 mM acetic acid-ammonium acetate (pH 4.0), 0.8 mM cetyltrimethylammonium bromide with 5% (v/v) methanol as carrier electrolyte was used. Detection limits, based on a signal-to-noise ratio of 3:1, were lower than 0.3 microg l(-1) for standards in Milli-Q water, and lower than 2.2 microg l(-1) for drinking water samples. Run-to-run and day-to-day precision of the method were established. The two preconcentration procedures used together was successfully applied to the analysis of the three herbicides in spiked drinking water at concentrations below the maximum admissible US Environmental Protection Agency levels.     

Determination of pesticide residues and related compounds in water and industrial effluent by solid-phase extraction and gas chromatography coupled to triple quadrupole mass spectrometry

Pollution of drinking water supplies from industrial waste is a result of several industrial processes and disposal practices, and the establishment of analytical methods for monitoring organic compounds related to environmental and health problems is very important. In this work, a method using solid-phase extraction (SPE) and gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS) was developed and validated for the simultaneous determination of pesticide residues and related compounds in drinking and surface water as well as in industrial effluent. Optimization of the method was achieved by using a central composite design approach on parameters such as the sample pH and SPE eluent composition. A single SPE consisting of the loading on a polymeric sorbent of 100 mL of sample adjusted to pH 3 and elution with methanol/methylene chloride (10:90, v/v) permitted the obtaining of acceptable recoveries in most cases. The concentration factor associated with sensitivity of the chromatographic analysis permitted the achievement of the method limit of detection values between 0.01 and 0.25 μg L^?1. Recovery assays presented mean recoveries between 70 and 120 % for most of the compounds with very good precision, despite the different chemical nature of the compounds analyzed. The selectivity of the method, evaluated through the relative intensity of quantification and qualification ions obtained by GC-QqQ-MS/MS, was considered adequate. The developed method was finally applied to the determination of target analytes in real samples. River water and treated industrial effluent samples presented residues of some compounds, but no detectable residues were found in the drinking water samples evaluated.     

A new molecularly imprinted polymer for selective extraction and pre‐concentration of guaifenesin in different samples: Adsorption studies and kinetic modeling

This paper describes the synthesis of a molecularly imprinted polymer by chemical oxidation of pyrrole as the functional monomer, and at the presence of guaifenesin as the template. The prepared polymer was used as adsorbent in molecularly imprinted solid‐phase extraction followed by spectrophotometric determination. Different parameters in the solid‐phase extraction including sample pH, adsorbent weight, washing solution, and elution solvent were studied to determine optimum conditions for isolation and enrichment of guaifenesin. The results showed guaifenesin was quantitatively adsorbed on the molecularly imprinted polymer at pH 6.0 and completely eluted with an ethanol–water solution (50% v/v). An enrichment factor of four with satisfactory recoveries (87.0–95.0%) was obtained. The solid‐phase extraction columns could be used for up to six consecutive elution‐loading cycles without significant decreases in the analyte recoveries. The method had a dynamic range of 3.0 × 10^?6–1.5 × 10^?4 mol/L with a limit of detection and limit of quantification of 1.4×10^?6 and 4.5×10^?6 mol/L, respectively. The proposed procedure was used for the extraction and determination of guaifenesin in different pharmaceutical formulations, with satisfying results being achieved.     

Pipette‐tip solid‐phase extraction using cetyltrimethylammonium bromide enhanced molybdenum disulfide nanosheets as an efficient adsorbent for the extraction of sulfonamides in environmental water samples

Surfactant cetyltrimethylammonium bromide enhanced molybdenum disulfide was used as an adsorbent in pipette‐tip solid‐phase extraction for the pretreatment of sulfonamides in environmental water samples. The factors affecting the extraction recoveries of the analytes, including the sample pH value, amount of sorbent, type and volume of eluent solution, and salt concentration were optimized. This pipette‐tip solid‐phase extraction method demonstrated good linearity (0.05–10.0 µg/L) with a coefficient of determination of 0.9984–0.9996, limit of detection (0.2–0.4 ng/L) and limit of quantitation (0.5–1.0 ng/L), good analyte recoveries (76–91), and acceptable limit of quantitation (<10%) under the optimized conditions. These results indicated that the proposed method was a good tool for monitoring sulfonamides in environmental water samples.     

Bamboo Charcoal as Solid-Phase Extraction Adsorbent for the Determination of Organophosphorus Pesticides in Water Samples by High-Performance Liquid Chromatography

In this paper, bamboo charcoal was successfully developed for the solid-phase extraction adsorbent for the determination of six organophosphorus pesticides in water samples. After the bamboo charcoal was pretreated and packed in the solid-phase extraction cartridge, the organophosphorus pesticides in water samples were carried out the solid-phase extraction. To establish a perfect solid-phase extraction procedure, the experimental conditions including the eluent, eluent volume, pH of the sample, flow rate of the sample, and loading volume of the sample were all investigated. When 100 mL water samples in the pH range of 6–7 were loaded with the flow rate of 2.5 mL · min^?1 and then eluted with 10 mL acetonitrile, the proposed extraction method was validated by the recovery, correlation coefficient (R²), repeatability (RSD, n = 7) and LODs, which were 69.6–93.4%, 0.9982–0.9998, 2.9–5.6%, and 0.08–1.04 µg · L^?1, respectively. Furthermore, the analysis of the tap, snow, and river water samples demonstrated the feasibility of the proposed SPE method for real water samples. Based on the aforementioned factors, it could be concluded that bamboo charcoal was a good solid-phase extraction adsorbent, and this proposed solid-phase extraction method was suitable for the effective enrichment and determination of the organophosphorus pesticides in water samples.