尼龙6纳米纤维膜固相膜萃取-高效液相色谱法测定塑料瓶装矿泉水中双酚A

采用静电纺丝法制备尼龙6纳米纤维膜,结合固相膜萃取-高效液相色谱法测定了矿泉水中的双酚A。对洗脱溶剂及其体积、进样速度、样品体积、样品pH值、尼龙6纳米纤维膜的用量、及其活化方式和使用次数等影响因素进行了研究。结果表明:10mL样品调至pH8.0后,以3mL/min流速通过1.5mg尼龙6纳米纤维膜,300μL甲醇即可将膜上吸附的双酚A完全洗脱,每张膜至少可重复使用6次。在此最优化条件下,方法的线性范围为0.20～20.0μg/L;检出限为0.15μg/L,膜内和膜间的相对标准偏差均小于4.5%(n=6)。本方法应用于6种不同品牌的矿泉水中双酚A的分析测定,在1.0μg/L加标水平下,测得回收率为95.0%,双酚A测得浓度低于0.30μg/L。与固相萃取方法相比,本方法高效、环保,表明尼龙6纳米纤维膜是极具潜力的萃取介质     

Simultaneous Determination of Cyanazine, Chlorotoluron and Chlorbenzuron in Environmental Water Samples with SPE Multiwalled Carbon Nanotubes and LC

In this paper, a new method based on solid-phase extraction with multiwalled carbon nanotubes as the packed materials for sensitive determination of cyanazine, chlorotoluron and chlorbenzuron in environmental water samples was demonstrated. Related parameters that may influence the enrichment efficiency of multiwalled carbon nanotubes such as the kind and volume of elute, sample flow rate, sample pH, and volume of the water samples were investigated. Under the optimum conditions, the detection limits of cyanazine, chlorbenzuron and chlorotoluron were 0.015, 0.012, 0.034 ng mL⁻¹, respectively. The experimental results indicated a good linearity (R ² > 0.9947) over the concentration range of 0.4–40 ng mL⁻¹ for cyanazine and chlorotoluron, and 0.8–80 ng mL⁻¹ for chlorbenzuron. The relative standard deviations of the three analytes were 3.54, 1.55 and 1.38%, respectively. The established method also was applied to the analysis of the real-world water samples and excellent achievements were obtained with average spiked recoveries from 87.8 to 110.1%. All the results indicated that this procedure could allow the simultaneous determination of these three compounds in environmental water samples at trace levels.     

Use of Multiwalled Carbon Nanotubes as a SPE Adsorbent for Analysis of Carfentrazone-Ethyl in Water

Solid-phase extraction and gas chromatography with electron-capture detection has been used for sensitive, simple, and reliable analysis of carfentrazone-ethyl residues in water. Carfentrazone-ethyl was enriched by use of multiwalled carbon nanotubes (MWCNT), a new adsorptive material. Several conditions affecting recovery of the analyte, for example polarity and volume of eluents, pH of water samples, and sample volume, were studied. Recovery from fortified samples, linear range, and limit of detection were evaluated. The results showed that MWCNT are an efficient SPE adsorbent for preconcentration of carfentrazone-ethyl in water. Under the optimized SPE conditions, recovery of carfentrazone-ethyl from fortified water was 81.49–91.08%, with RSD from 1.66 to 8.21%. The limits of detection and quantification were 0.01 and 0.03 µg L^?1, which were lower than the MRL stipulated by the EU for individual pesticides in water (0.1 µg L^?1). Finally, the method was applied to tap water and river water; the results showed that the method was suitable for detection of carfentrazone-ethyl 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.     

Supported Liquid Membrane Enrichment Studies of Natural Water Samples Applied to Liquid Chromatographic Determination of Triazine Herbicides

Abstract

A method for sample work-up and enrichment using Supported Liquid Membrane (SLM) and liquid chromatographic determination of triazine herbicides in natural waters was investigated. A porous PTFE membrane was impregnated with a water immiscible organic solvent, forming a barrier between two aqueous phases. With a flowing donor and a stagnant acceptor solution, an enrichment of the triazines was obtained. The various factors that influence the extraction efficiency and selectivity of the extraction procedure were experimentally studied. The obtained results were in good agreement with the developed theoretical model. The pH of the acceptor solution was found to be the critical limiting factor in obtaining higher extraction efficiencies and led to an extraction efficiency decrease with an increase in enrichment time. By increasing both the trapping capacity of the acceptor solution and the donor flow rate, the method detection limit of the triazines ranged from 0.03 to 0.16 μgL^?1 in natural waters with 20 minutes extraction time.     

Oxidized Multi-Walled Carbon Nanotubes as SPE Sorbent for Determination of Mefenacet and Its Degradation Products Residues in Water Samples by RRLC-UV-ESI-MS

A new method was developed for the analysis of herbicide mefenacet (MN) and its three photolysis degradation products namely hydroxylbenzothiazole (HBT), N-methylaniline (N-MA) and 2-benzothiazoloxyacetic acid (2-BAA) in water samples by rapid resolution liquid chromatography coupled with UV detection and electrospray ionization mass spectrometry. In the SPE pre-concentration step, the adsorptive potential of oxidized multi-walled carbon nanotubes for the extraction of these four target analytes was investigated for the first time. Parameters influencing the extraction efficiency, such as sample flow-rate, eluent volume and sample volume, were examined. The mean recoveries were between 85.6 and 101.4% and relative standard deviations were between 3.0 and 9.2%. The limits of detection obtained were 0.02 μg L^?1 for MN and 2-BAA and 0.04 μg L^?1 for HBT and N-MA. The proposed method was applied to monitor the residual concentrations of these four target analytes in 39 real water samples collected from April to July of 2009.     

SPE Preconcentration and TLC Determination of Alachlor,Atrazine and α-Cypermethrin in Water Samples

JPC – Journal of Planar Chromatography – Modern TLC - Quantitative determination of the pesticides alachlor, atrazine and α-cypermethrin in aquatic samples is reported. The method...     

酚类环境雌激素的色谱分析方法

综述了近年来酚类环境雌激素的色谱分析研究进展,包括气相色谱和气质联用,高效液相色谱和各种检测器联用技术。比较了使用气相色谱和液相色谱两种方法的优缺点,并对环境雌激素样品预处理作了介绍。     

Graphene as Solid-Phase Extraction Adsorbent for CZE Determination of Sulfonamide Residues in Meat Samples

A solid-phase extraction (SPE) using graphene as adsorbent coupled with capillary zone electrophoresis method was developed for the determination of four sulfonamide residues (sulfadimidine, sulfadimethoxine, sulfathiazole and sulfadiazine) in meat sample. Several condition parameters, such as elution solvents and volumes, sample pH and sample volume were optimized to obtain high SPE recoveries and extraction efficiency. Intra-day precisions of sulfonamides were in the range of 2.5–2.6 % and the inter-day precisions of sulfonamides were in the range of 2.6–3.4 %. Recoveries were 60.9–66.6 % for sulfadiazine and 86.1–111.4 % for other three sulfonamides in spiked meat sample. The developed method was successfully applied for the determination of sulfonamides in meat samples.     

On-Line SPE on Restricted Access Adsorbent for HPLC-MS/MS Analysis of Felodipine in Plasma Samples

Direct plasma loading on a LiChrospher ADS C18 cartridge on-line coupled to an analytical Zorbax XDB C18 column was used to analyze felodipine by means of positive atmospheric pressure chemical ionization (APCI) tandem mass spectrometric (MS/MS) detection. Appropriate sensitivity, accuracy, and precision were obtained using an ion trap mass analyzer operated in a multiple reaction monitoring (MRM) mode. Diethyl-4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate) was used as an internal standard. The method was fully validated. The method was successfully applied to a pilot bioequivalence study made on extended release oral dosage forms containing 10 mg of felodipine, under fed and fasting conditions.     

Application of SPE Using Multi-Walled Carbon Nanotubes as Adsorbent and Rapid Resolution LC-MS-MS for the Simultaneous Determination of 11 Triazine Herbicides Residues in River Water

A method for the simultaneous determination of 11 triazine herbicides residues in river water has been developed. It involves solid-phase extraction (SPE) pretreatment step and rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS-MS). In the SPE pretreatment step, the adsorptive performance of MWCNTs material as SPE adsorbent and the elution capability of five kinds of solvents were investigated; in the LC separation step, a rapid resolution high throughput LC column, was used and the gradient elution mode adopted. The linear correlation coefficients (r ²) of the method for 11 target analytes varied between 0.9930 and 0.9980, the mean recoveries were in the range of 73.0 and 98.0% with relative standard deviations (RSD) 2.6 ~ 4.2%, the method detection limits (MDL) were all below 0.1 ng L^?1. An expanded uncertainty of not more than 20% was estimated for each analyte at the spiked concentration of 4.0 μg L^?1. The proposed method was applied to the determination of the residue concentrations of 11 pollutants in Songhuajiang River water.     

A New Spectrophotometry Method for the Determination of Aniline in Environmental Water Samples

ABSTRACT

A new spectrophotometric method has been established to determine trace aniline in water samples. A mixture solution of N-chlorosuccinimide and 8-hydroxyquinaldine in N, N-dimethylformamide (DMF) was used to react with the aniline in water at room temperature (20°C). When the solution was adjusted to pH 10-11 by adding 3 mol/L NaOH, a clear and blue-colored dye formed immediately with the maximum absorption wavelength at 615 nm. Molar absorptivity and detection limit were found to be 1.0×10⁴ L mol^?1 cm ^?1 and 30 μg/L, respectively. Linearity was excellent in the concentration range of 0.2 to 15 mg/L aniline in water sample. The proposed method has been used to analyze aniline in surface and sewage water samples with the recoveries 96-103% and relative standard deviation less than 3%. It's a promising method to be applied for routine analysis of aniline in water.     

极谱法检测水体中的孔雀石绿

基于荧光素(SF)在pH=7.0的B-R缓冲溶液中可以产生一灵敏的还原峰,而孔雀石绿(MG)可以与荧光素络合而抑制荧光素的峰电流,建立了一种检测水体中孔雀石绿含量的极谱新方法。最佳测定体系为:1.2×10-5 mol/L的荧光素-9.0mL B-R缓冲溶液(pH=7.0)。在此体系中,于起始电位-0.40V,峰电位-0.85V,孔雀石绿含量在20~100μg/L范围内与峰电流呈线性关系,检出限为7.5μg/L。该方法用于环境水样中孔雀石绿的检测,回收率为90.5%~105.6%。     

分子印迹固相萃取技术检测江水、尿液及牛奶中雌激素残留

以β-雌二醇和炔雌醇的分子印迹聚合物为填料制备固相萃取小柱,选择60%(V/V)甲醇-水溶液作为雌激素的淋洗液,甲醇-乙酸(9:1,V/V)为洗脱液,洗脱两次可彻底洗脱固相萃取小柱中目标分子.以建立的萃取条件对上海黄浦江水、尿液、牛奶中雌激素进行富集,结合高效液相色谱法,建立了基于分子印迹固相萃取技术检测上述实际样品中...     

顺序注射荧光分析方法测定环境水中的镁

1引言镁是动物体内所必需的元素之一。研究灵敏、快速、准确的测量环境中镁离子方法,对于了解地理环境与生命体动态平衡有重要意义。以镁离子在弱碱性条件下与8-羟基喹啉-5-磺酸形成1∶1的络合物为基础,结合顺序注射进样技术,建立了顺序注射荧光光度分析环境水中镁离子的方法。     

磁性微孔聚合物富集/表面增强拉曼光谱法测定水与土壤中多环芳烃

建立了磁性聚亚苯基共轭微孔聚合物富集/表面增强拉曼光谱法测定水样和土壤中4种多环芳烃的分析方法。待测物经磁性聚亚苯基共轭微孔聚合物吸附萃取,甲醇洗脱后进行SERS检测。结果表明,蒽、芘、荧蒽和苯[α]芘在0.1~10μg/L范围内与其SERS特征峰峰强呈良好的线性关系,检出限为0.03μg/L,回收率为71.6%~115.8%,相对标准偏差不大于13.7%。该分析方法灵敏度高,能够满足实际水样和土壤中4种多环芳烃同时检测的要求。     

线性扫描极谱法检测环境水样中四环素

基于四环素在pH=5.5的柠檬酸-柠檬酸钠缓冲溶液中可产生一灵敏的还原峰,建立了一种测定四环素的极谱新方法。在优化条件下,于起始电位-0.9 V(vs.SCE),峰电位-1.4V(vs.SCE),四环素浓度分别在0.1~30、30~90μg/mL范围内与峰电流呈现良好的线性关系,检出限为0.0024μg/mL。该方法直接用于环境水样中四环素的检测,回收率为97.8%~102.9%。用线性扫描极谱法研究了检测体系的电化学行为,证明了极谱波为不可逆还原吸附波,并讨论了电极反应机理。     

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。     

利用炭石灰固相萃取测定水中的有机氯农药

研究利用炭石灰作为反相固定相,萃取水中12种有机氯农药,并用GC／ECD检测。实验表明,炭石灰萃取水中有机氯的效果与商品柱的萃取效果相当,对于200mL添加40ng有机氯农药混合标准溶液水样,其目标化合物的回收率为70％～122％,检出限为0．023～0．124μg／L,多次重复实验测定的相对标准偏差为3．40％～12．9％（n=5）。