Development and optimisation of a GC-MS method for the evaluation of oestrogens and persistent pollutants in river and seawater samples

This paper describes the development and validation of a GC-MS method which allows the simultaneous quantification of 11 endocrine disrupting compounds (EDCs) in surface water samples from both estuary and sea. The analysed EDCs are oestrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), 4-tert-octylphenol, 4-n-octylphenol, 4-nonylphenol, bisphenol A and finally, mono and diethoxylates of 4-nonylphenol and 4-octylphenol. The method includes the pre-concentration of water samples, 1000-fold factor, in OASIS HLB cartridges by solid phase extraction, the derivatisation of all EDCs by N,O-bis(trimethylsilyl)trifluoroacetamide added with 1% trimethylchlorosilane and pyridine (at 65°C for 30?min) and, finally the stabilisation of the EDCs-silylated derivatives, in hexane, for 72?h. The validation parameters revealed that this method was highly specific for all target compounds using real samples. The linearity of the calibration curves (r ²) showed correlation factors higher than 0.990. The detection limits ranged from 0.10 to 1.45?ng?L^?1, depending on each analysed compound, and recoveries were satisfactory for most of the assayed EDCs (>60%). Analysis of samples from four polluted areas of Douro River estuary and from two points of the Atlantic Ocean (Portugal) showed high amounts of E1 (up to 1.96?ng?L^?1), E2 (up to 14.36?ng?L^?1) and EE2 (up to 2.76?ng?L^?1).     

分散液液微萃取-衍生化高效液相色谱-荧光检测法测定环境水样中4种酚类内分泌干扰物

为实现小体积环境水样中酚类化合物的准确、快速、高灵敏测定,通过分散液液微萃取(DLLME)和荧光衍生化的结合,建立了高效液相色谱-荧光检测(HPLC-FLD)双酚A、壬基酚、辛基酚和对特辛基酚的分析方法。考察并优化了DLLME和衍生化条件,结果表明,最优的DLLME条件为萃取剂氯仿用量70μL,分散剂乙腈用量400μL,漩涡振荡3 min,高速离心2 min。以2-[2-(7 H-二苯并[a,g]咔唑-乙氧基)]-乙基氯甲酸酯(DBCEC-Cl)为柱前衍生试剂,在pH10.5的Na2CO3-NaHCO3缓冲液/乙腈溶液、50℃下衍生反应3 min得到稳定的衍生产物,于10min内实现了4种酚衍生物的分离。方法的检出限为0.9~1.6 ng/L,定量限为3.8~7.1 ng/L,具有良好的线性、精密度和回收率,与以往报道的方法相比具有一定的优势和实用性,可用于造纸厂废水、湖水、生活废水、自来水中4种酚类内分泌干扰物的测定。     

分散液-液微萃取-高效液相色谱法测定环境水样中的多环芳烃

建立了简便、快速、有效的分散液-液微萃取-高效液相色谱-荧光检测(DLLME-HPLC-FLD)测定环境水样中15种多环芳烃(PAHs)的方法。重点探讨了萃取剂的种类和用量、分散剂的种类和用量以及萃取时间等对PAHs萃取效率的影响。在优化的条件下,评价了方法的可靠性。15种PAHs在0.01～10 μg/L范围内呈良好的线性关系,相关系数r均不小于0.9913,峰面积的相对标准偏差(RSD)在2.3%～4.7%之间(n=6)。在优化条件下,富集因子和萃取回收率良好,分别为674～1032和67.4%～103.2%,15种PAHs的检出限(S/N=3)在0.0003～0.002 μg/L之间。建立的方法应用于敖江水样中PAHs的检测,平均加标回收率在79.5%～92.3%之间,RSD在4.3%～6.7%范围内(n=5)。该方法适用于环境水样中痕量PAHs的分析。     

Poly (methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary for in-tube solid phase microextraction coupled to high performance liquid chromatography and its application to determination of basic drugs in human serum

A poly (methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column was prepared for in-tube solid-phase microextraction. Comparing with the commonly used open tubular extraction capillary, which cannot provide sufficient extraction efficiency since the ratio of its coating volume to that of the capillary void volume is relatively small, the monolithic column with greater phase ratio combined with convective mass transfer provides the possibility to improve the extraction efficiency with shorter capillary. As to poly (methacrylic acid-ethylene glycol dimethacrylate), its hydrophobic main chains and acidic pendant groups make it a superior material for extraction of basic analytes from aqueous matrix.An on-line monolithic capillary column solid phase microextraction (SPME) method was developed for determination of theobromine, theophylline and caffeine in serum samples. The high extraction efficiency was obtained for all the three analytes, yielding the detection limits of 12, 8 and 6.5 ng/mL by UV detection, respectively. Excellent method reproducibility (R.S.D. < 2.9%) was found over a linear dynamic range of 0.05-2 μg/mL in serum sample. The monolithic capillary column was proved to be reusable in coping with serum samples, which would facilitate practical determination of basic drugs.     

A new high-speed hollow fiber based liquid phase microextraction method using volatile organic solvent for determination of aromatic amines in environmental water samples prior to high-performance liquid chromatography

A new and fast hollow fiber based liquid phase microextraction (HF-LPME) method using volatile organic solvents coupled with high-performance liquid chromatography (HPLC) was developed for determination of aromatic amines in the environmental water samples. Analytes including 3-nitroaniline, 3-chloroaniline and 4-bromoaniline were extracted from 6 mL basic aqueous sample solution (donor phase, NaOH 1 mol L⁻¹) into the thin film of organic solvent that surrounded and impregnated the pores of the polypropylene hollow fiber wall (toluene, 20 μL), then back-extracted into the 6 μL acidified aqueous solution (acceptor phase, HCl 0.5 mol L⁻¹) in the lumen of the two-end sealed hollow fiber. After the extraction, 5 μL of the acceptor phase was withdrawn into the syringe and injected directly into the HPLC system for the analysis. The parameters influencing the extraction efficiency including the kind of organic solvent and its volume, composition of donor and acceptor phases and the volume ratio between them, extraction time, stirring rate, salt addition and the effect of the analyte complexation with 18-crown-6 ether were investigated and optimized. Under the optimal conditions (donor phase: 6 mL of 1 mol L⁻¹ NaOH with 10% NaCl; organic phase: 20 μL of toluene; acceptor phase: 6 μL of 0.5 mol L⁻¹ HCl and 600 m mol L⁻¹ 18-crown-6 ether; pre-extraction and back-extraction times: 75 s and 10 min, respectively; stirring rate: 800 rpm), the obtained EFs were between 259 and 674, dynamic linear ranges were 0.1-1000 μg L⁻¹ (R > 0.9991), and also the limits of detection were in the range of 0.01-0.1 μg L⁻¹. The proposed procedure worked very well for real environmental water samples with microgram per liter level of the analytes, and good relative recoveries (91-102%) were obtained for the spiked sample solutions.     

超声辅助分散液液微萃取-高效液相色谱测定水样中的4种邻苯二甲酸酯类增塑剂

建立了采用超声辅助分散液液微萃取技术结合高效液相色谱法(UA-DLLME-HPLC)对4种邻苯二甲酸酯(PAEs)进行富集、检测的方法,并成功应用于实际水样分析。实验中采用富集因子来评价萃取效率,考察并优化了影响萃取效率的主要因素,包括萃取剂类型和用量、分散剂类型和用量、超声时间、离子强度、萃取时间和pH值等。结果表明: 在最佳萃取条件下,该法对4种PAEs（邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯和邻苯二甲酸二正辛酯）具有较高的富集能力,富集因子分别为71、144、169和159;检出限分别为3.78、1.77、3.07和3.30 μg/L。对实验室自来水、某品牌矿泉水以及湖水分别加标50、200及500 μg/L的回收率为82.99%～114.47%,相对标准偏差为1.93%～8.31%。该法简便、快速、环保,可以用于测定实际水样中的PAEs类增塑剂。     

分子印迹固相萃取-高效液相色谱法测定饲料中莱克多巴胺

以莱克多巴胺为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了对莱克多巴胺具有高选择性的分子印迹聚合物。考察了甲醇、乙腈、丙酮和氯仿-甲醇与三乙胺构成致孔剂合成的聚合物性能及其形貌特征。通过正交试验优化的聚合反应配方为: 1.0 mmol莱克多巴胺,4.0 mmol丙烯酰胺,20.0 mmol乙二醇二甲基丙烯酸酯,6.0 mL乙腈-三乙胺(30:1, v/v), 50.0 mg偶氮二异丁腈。建立的基于分子印迹固相萃取-高效液相色谱测定饲料试样中莱克多巴胺的方法,在0.50～100 mg/L质量浓度范围内有良好的线性关系(r=0.9994);饲料试样中1.0、10及100 mg/kg 3个添加水平的莱克多巴胺平均回收率大于80%;批内、批间测定的相对标准偏差小于10%;检出限(信噪比为3)达到0.1 mg/kg。该方法灵敏、可靠,用于饲料等复杂基质中莱克多巴胺检测的效果优于相关标准分析方法。     

Optimisation of solid-phase microextraction coupled to HPLC-UV for the determination of organochlorine pesticides and their metabolites in environmental liquid samples

A solid-phase microextraction (SPME) procedure using two commercial fibers coupled with high-performance liquid chromatography (HPLC) is presented for the extraction and determination of organochlorine pesticides in water samples. We have evaluated the extraction efficiency of this kind of compound using two different fibers: 60-μm polydimethylsiloxane–divinylbenzene (PDMS-DVB) and Carbowax/TPR-100 (CW/TPR). Parameters involved in the extraction and desorption procedures (e.g. extraction time, ionic strength, extraction temperature, desorption and soaking time) were studied and optimized to achieve the maximum efficiency. Results indicate that both PDMS-DVB and CW/TPR fibers are suitable for the extraction of this type of compound, and a simple calibration curve method based on simple aqueous standards can be used. All the correlation coefficients were better than 0.9950, and the RSDs ranged from 7% to 13% for 60-μm PDMS-DVB fiber and from 3% to 10% for CW/TPR fiber. Optimized procedures were applied to the determination of a mixture of six organochlorine pesticides in environmental liquid samples (sea, sewage and ground waters), employing HPLC with UV-diode array detector.     

固相萃取-超高压液相色谱-串联质谱同时分析环境水样中四环素类和喹诺酮类抗生素

应用固相萃取及超高压液相色谱-质谱联用技术,建立了环境水样中4种四环素类和6种喹诺酮类抗生素的同时分析方法。样品经HLB固相萃取柱富集、净化后用甲醇洗脱,以超高压液相色谱-串联质谱仪多反应监测(MRM)离子模式定性、定量分析。以河水和海水为基质,卡巴氧为替代物进行回收率评价,4种四环素类抗生素在加标质量浓度分别为20.0 ng/L和100.0 ng/L时的回收率为94.0%～117.0%,相对标准偏差为2.0%～9.7%(n=4),方法的检出限均为20.0 ng/L;6种喹诺酮类抗生素在加标质量浓度分别为5.0 ng/L和20.0 ng/L时的回收率为63.6%～93.9%,相对标准偏差为1.6%～8.1%(n=4),方法的检出限为0.4 ng/L。结果表明,所建立的方法可成功地应用于近岸海域表层环境水样中目标抗生素残留的分析。     

固相萃取-毛细管液相色谱测定食品和水样中有机磷和氨基甲酸酯类杀虫剂残留

采用乙腈提取、固相萃取（SPE）富集浓缩技术结合自行研制开发的毛细管液相色谱（CLC）仪,同时分离测定了食品和水样中1种有机磷和3种氨基甲酸酯类杀虫剂残留。对影响SPE效率和CLC分离检测的各类因素进行了优化,包括固相萃取柱种类、样品pH、洗脱剂种类和体积、上样速率、盐效应、上样体积、检测波长、流动相种类和比例等。结果表明,4种杀虫剂在6 min内达到完全分离,检出限为0.35~1.20 μg/kg,定量限为1.17~4.00 μg/kg。使用该SPE-CLC法对西红柿、黄瓜、苹果样品和自来水、湖水水样进行加标回收测定,得到食品中加标回收率为72.41%~107.15%,相对标准偏差≤8.12%;水样中加标回收率为71.45%~109.25%,相对标准偏差≤9.28%。该法能够满足农药多残留分析要求。     

管内硼亲和固相微萃取-高效液相色谱全自动在线联用检测茶饮料中的顺式二羟基化合物

自动化联用分析技术对于降低人力强度、提高效率和保证数据重现性等具有重要意义。硼亲和固相微萃取(BA-SPME)是近十年出现的用于富集顺式二羟基化合物的独特工具,但BA-SPME与高效液相色谱(HPLC)的自动化在线联用还未见报道。该文报道了一种新颖的管内BA-SPME-HPLC全自动在线联用方法,用于分析茶饮料中的顺式二羟基化合物。该自动化在线联用方法利用自动进样器通过六通阀的切换实现流路连接。制备了管内BA-SPME毛细管,考察了涂层柱的柱容量,并对其形貌进行了表征,考察并优化了影响实际样品分离效果的因素。最后,利用该联用方法对3种不同品牌的茶饮料进行了分析,并对沏茶温度对茶水中顺式二羟基化合物含量的影响进行了评价。     

中空纤维三相液相微萃取-高效液相色谱法测定环境水样中7种苯氧羧酸类除草剂

建立了利用中空纤维三相液相微萃取-高效液相色谱联用技术(HF-LPME-HPLC)同时测定环境水中痕量麦草畏(dicamba)、氟草烟(fluroxypyr)、4-氯苯氧乙酸(4-CPA)、2甲4氯(MCPA)、2,4-滴(2,4-D)、2,4-滴苯氧丁酸(2,4-DB)和2甲4氯苯氧丁酸(MCPB)等7种苯氧羧酸类除草剂的分析方法。考察了萃取剂﹑接受相和给出相pH值、萃取时间﹑搅拌速度和盐效应等对检测的影响,通过正交试验优化萃取条件,得到的最佳萃取条件为正辛醇作萃取剂,给出相pH为3,接受相pH为12,萃取30 min,搅拌速度400 r/min。结果表明7种除草剂在较宽的线性范围内线性良好,相关系数为0.9953～0.9988,检出限(信噪比为3)为0.2～1.0 μg/L,富集倍数为76.7～121,加标回收率为68%～104%,相对标准偏差为3.2%～8.1%。该法灵敏度高、操作简单、检测快速、有机溶剂消耗少,为环境水样中痕量苯氧羧酸类除草剂残留的分析提供了有益的参考。     

基于十八烷基三甲基溴化铵修饰的磁性粒子在线磁性固相萃取-高效液相色谱法测定水样中磺酰脲类农药

采用溶胶-凝胶法制备表面修饰了十八烷基三甲基溴化铵的磁性粒子作为萃取剂，研制了一种在线磁性固相萃取（on-line MSPE）装置，建立了on-line MSPE与高效液相色谱联用测定水样中两种磺酰脲类农药（氯磺隆、苄嘧磺隆）的方法。实验优化了在线磁性固相萃取条件并进行方法学考察，证明该方法具有良好的线性关系（两种目标物的线性相关系数均≥ 0.9997）和较低的检出限（两种目标物的检出限分别为0.32和1.12 μg/L）。将此法用于3种环境水样中两种磺酰脲类农药的检测，水样中均检出氯磺隆，均未检出苄嘧磺隆。两种目标物加标回收率为70.0%~113.4%。该方法高效、简便，在分离富集环境水样中磺酰脲类农药方面有一定的应用前景。     

分子印迹固相萃取-高效液相色谱法测定猪肉中红霉素残留

采用沉淀聚合法,以红霉素（erythromycin,ERY）为模板,甲基丙烯酸（methacrylic acid,MAA）为功能单体,乙二醇二甲基丙烯酸酯（ethyleneglycoldimethacrylate,EGDMA）为交联剂,甲醇/乙腈（1:4,v/v）为致孔剂制备了ERY分子印迹聚合物（molecularly imprinted polymers,MIPs）。通过扫描电镜、平衡吸附实验等对制备的印迹和非印迹聚合物进行表征和测定,结果表明所制备的MIPs对ERY具有特异性吸附作用。Scatchard分析证明MIPs对ERY的吸附存在两类不同结合位点,最大表观结合量（Q_max）和平衡解离常数（K_d）分别为Q_max1=45.24 mg/g,K_d1=0.028 g/L; Q_max2=87.53 mg/g,K_d2=0.20 g/L。以制备的MIPs为吸附剂的分子印迹固相萃取柱,结合高效液相色谱法能够快速检测猪肉样品中的ERY残留,线性范围为0.5~50 mg/L（r²=0.9994）,检出限（S/N=3）为0.2 mg/kg。猪肉样品中不同添加水平下ERY的加标回收率为95.2%~104.2%,相对标准偏差（RSD）小于5%。该方法选择性好,灵敏、可靠,可用于猪肉等复杂食品样本中ERY残留的检测。     

A simple and rapid method for simultaneous determination of benzoic and sorbic acids in food using in-tube solid-phase microextraction coupled with high-performance liquid chromatography

A simple, rapid and sensitive on-line method for the simultaneous determination of benzoic and sorbic acids in food was developed by coupling in-tube solid-phase microextraction (SPME) to high-performance liquid chromatography (HPLC) with UV detection. The diethylamine-modified poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic capillary selected as the extraction medium exhibited a high extraction capability towards benzoic and sorbic acids. To obtain optimum extraction performance, several in-tube SPME parameters were investigated, including pH value, inorganic salt, and the organic solvent content of the sample matrix. After simple dilution with 0.02 mol/L phosphate solution (pH 4.0), carbonated drink, juice drink, sauce and jam samples could be directly injected for extraction. For succade samples, a small amount of acetonitrile was required to extract analytes prior to dilution and subsequent extraction. The linearity of the method was investigated over a concentration range of 5–20000 ng/mL for both analytes, and the correlation coefficients (R ² values) were higher than 0.999. The detection limits for benzoic and sorbic acids were 1.2 and 0.9 ng/mL, respectively. The method reproducibility was tested by evaluating the intra- and interday precisions; relative standard deviations of less than 4.4 and 9.9%, respectively, were obtained. Recoveries of compounds from spiked food samples ranged from 84.4 to 106%. The developed method was shown to be suitable for the routine monitoring of benzoic and sorbic acids in various types of food samples.     

基于低共熔溶剂的整体式萃取头的制备及其对湖水中3种多环芳烃的固相微萃取（英文）

采用氯化胆碱-乙二醇低共熔溶剂(DES)作致孔剂,制备了聚(甲基丙烯酸丁酯-乙二醇二甲基丙烯酸酯)[poly(BMA-EDMA)]固相微萃取头,并与超高效液相色谱法(UPLC)结合测定了湖水中的3种多环芳烃(PAHs)。实验与不使用DES致孔剂的固相微萃取头和商品化聚二甲硅氧烷(PDMS)萃取头进行比较,含DES的poly(BMA-EDMA)固相微萃取头的富集效果最好。系统考察了萃取条件(萃取时间、萃取溶剂、解吸时间、解吸溶剂及离子强度)对水样中多环芳烃萃取效率的影响。在最优的实验条件下,3种多环芳烃类化合物(萘、联苯、菲)的线性范围为0.1~6.0 mg/L(r≥0.990 3),检出限为2.1~4.9μg/L,回收率为86.4%~111.3%,相对标准偏差(RSD,n=6)为11.2%~15.1%。该法操作简便,稳定性好,成本低,适用于实际环境水样中多环芳烃类化合物的测定。     

在线固相萃取-液相色谱法直接测定水中超痕量多环芳烃

建立了在线固相萃取-液相色谱直接测定水体中16种超痕量多环芳烃（PAHs）的方法。水样经高速离心后，加入适量甲醇，配制成40%（体积分数）甲醇水溶液，直接进样2 mL至在线固相萃取流路，进行萃取富集，再通过阀切换将洗脱的PAHs转移至分析流路进行分离检测。16种PAHs在各自范围内线性关系良好，相关系数均大于0.996；方法的检出限为0.14~12.50 ng/L，其中苯并[a]芘（B（a）P）的检出限为0.38 ng/L。实际水样在10、40和200 ng/L加标水平下的加标回收率为76.1%~134.9%，RSD为0.3%~16.6%。B（a）P在1 ng/L加标水平下的回收率为71.8%~92.7%，RSD为3.9%。结果表明，该方法操作简单，灵敏度高，溶剂消耗量少，可满足水样中PAHs，尤其是B（a）P的超痕量分析要求。     

Hollow‐fiber liquid‐phase microextraction combined with capillary HPLC for the selective determination of six sulfonylurea herbicides in environmental waters

A three‐phase hollow‐fiber liquid‐phase microextraction combined with a capillary LC method using diode array detection was proposed for the determination of six sulfonylurea herbicides, triasulfuron, metsulfuron‐methyl, chlorsulfuron, flazasulfuron, chlorimuron‐ethyl, and primisulfuron‐methyl, in environmental water samples. Different factors that can affect the extraction process such as extraction solvent, acidity of the donor phase, composition and pH of the acceptor phase, salt addition, stirring speed, and extraction time were optimized. Under the optimum conditions, detection and quantitation limits between 0.1 – 1.7 and 0.3 – 5.7 μg/L, respectively, and enrichment factors ranging from 71 to 548 were obtained. The calibration curves were linear within the range of 0.3 – 40 μg/L. Intra‐ and interday RSDs were <6.3 and 8.4%, respectively. The relative recoveries of the spiked ground and river water samples were in the range of 69.4 – 119.2 and 77.4 – 111.7%, respectively. The results of the study revealed that the developed methodology involves an efficient sample pretreatment allowing the preconcentration of analytes, combined with the use of a miniaturized separation technique, suitable for the accurate determination of sulfonylurea herbicides in water.     

Microwave assisted micellar extraction coupled with solid phase microextraction for the determination of organochlorine pesticides in soil samples

Microwave assisted micellar extraction (MAME) coupled with solid phase microextraction (SPME) and HPLC-UV determination have been used for the determination of five organochlorine pesticides from agricultural soil samples. A non-ionic surfactant, Polyoxyethlylene 10 Lauryl Ether was used, and the different variables for the optimization of MAME and SPME procedures were studied. This method was applied successfully to the determination of these pesticides in several kinds of agricultural soil samples with different characteristics. Most of the compounds studied can be recovered in good yields with R.S.D. lower than 9% and detection limit ranged between 56-96 ng g⁻¹ for the pesticides studied.     

The determination of volatile organic compounds in soils using solid phase microextraction with gas chromatography-mass spectrometry

Solid phase microextraction (SPME) was applied in the development of a protocol for the analysis of a number of target organic compounds in landfill site samples. The selected analytes, including aromatic hydrocarbons, chlorinated hydrocarbous, and unsaturated compounds, were absorbed directly from a headspace sample above a soil layer onto a fused silica fiber. Following exposure, the fiber was thermally desorbed in the injection port of the gas chromatograph and eluted compounds were detected using a mass selective detector. The stability and sensitivity of the extraction technique were examined at five temperatures (22–60°C) using a 100μm polydimethylsiloxane fiber. Calibrations, using soil samples spiked with selected solvents (0.5–30 μg/g), were linear; trichloroethene (r² = 0.992) and benzene (r² = 0.998). SPME was applied to the examination of a municipal landfill where 8 sites were sampled, at three depths, resulting in the detection of xylene (maximum 2.8 μg/g) and a number of other non-target organic contaminants.