Multi-residue analysis of pesticide residues in mangoes using solid-phase microextraction coupled to liquid chromatography and UV-Vis detection

A sensitive and efficient solid‐phase microextraction method, based on liquid chromatography and UV–Vis detection, was developed and validated as an alternative method for sample screening prior to LC‐MS analysis. It enables the simultaneous determination of ten pesticides in mango fruits. The fiber used was polydimethylsiloxane while optimum SPME conditions employed have been developed and optimized in a previous work. The desorption process was performed in static mode, using acetonitrile as a solvent. The results indicate that the DI‐SPME/HPLC/UV–Vis procedure resulted in good linear range, accuracy, precision and sensibility and is adequate for analyzing pesticide residues in mango fruits. The limits of detection (0.6–3.3 μg/kg) and quantification (2.0–10.0 μg/kg) were achieved with values lower than the maximum residue levels (MRLs) established by Brazilian legislation for all pesticides in this study. The average recovery rates obtained for each pesticide ranged from 71.6 to 104.3% at three fortification levels, with the relative standard deviation ranging from 4.3 to 18.6%. The proposed method was applied for the determination of the aforementioned compounds in commercial mango samples and residues of azoxystrobin, fenthion, permethrin, abamectin and bifenthrin were detected in the mango samples, although below the MRLs established by Brazilian legislation.     

中空纤维三相液相微萃取-高效液相色谱法测定水中的4种酚类化合物

建立了中空纤维液-液-液三相微萃取-高效液相色谱法测定水中4种酚类化合物的方法.实验系统地优化了影响萃取效率的因素(包括有机溶剂种类、接收相浓度、分散相pH值、加盐量、转速及萃取时间).得到的最佳萃取条件为:萃取剂为正辛醇,接收相NaOH溶液的浓度为0.09 mol/L,分散相的pH为4,萃取时间为40 min,搅拌速...     

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。     

Determination of phenols in environmental water samples by two-step liquid-phase microextraction coupled with high performance liquid chromatography

In this work, a two-step liquid-phase microextraction (LPME) method was presented for the extraction of phenols in environmental water samples. Firstly, the polar phenol in water samples (donor phase) was transferred to 1-octanol (extraction mesophase) by magnetic stirring-assisted LPME. Subsequently, target analytes in the 1-octanol was back extracted into 0.1 mol/L sodium hydroxide solution (acceptor phase) by vortex-assisted LPME. By combination of the two-step LPME, the enrichment factors were multiplied. The main features of this two-step LPME for phenols lie in the following aspects. Firstly, the extraction can be accomplished within relatively short time (ca. 20 min). Secondly, it was compatible with HPLC analysis, avoiding derivatization step that is generally necessary for GC analysis. Thirdly, high enrichment factors (296-954 fold) could be obtained for these analytes. Under the optimized conditions, the linearities were 10-1000, 1-500, 1-500, 5-500 and 1-500 ng/mL for different phenols with all regression coefficients higher than 0.9985. The limits of detection were in the range from 0.3 to 3.0 ng/mL for these analytes. Intra-and inter-day relative standard deviations were below 7.6%, indicating a good precision of the proposed method.     

微波辅助-顶空液相微萃取在线联用-高效液相色谱法测定环境水样中的敌敌畏

基于微波辅助-顶空液相微萃取联用(MAE-HS-LPME)这一样品前处理方法,采用高效液相色谱法(HPLC)对水样中的敌敌畏残留量进行了测定。对影响萃取的因素如萃取剂、微波辐射功率、萃取时间、离子强度和样品基质的pH值等进行了考察。萃取条件为: 选用二甲苯作萃取剂,萃取时间为15 min,微波辐射功率300 W,NaCl含量为5%,pH为2.5。在最佳条件下,敌敌畏的检出限(信噪比为3时)为0.96 μg/L,定量限(信噪比为10时)为3.20 μg/L,萃取富集倍数为54,实际水样的加标回收率为87.4%～103%。与传统的前处理方法相比,本方法具有简便、快速、高效、节省溶剂、选择性好、应用范围广的特点。     

Determination of telmisartan in rat tissues by in-tube solid-phase microextraction coupled to high performance liquid chromatography

A poly(methacrylic acid-ethylene glycol dimethacrylate, MAA-EGDMA) monolithic capillary was used for the direct and on-line extraction of telmisartan from Sprague-Dawley rat tissue (heart, kidney, and liver) homogenates. Under optimized conditions, the tissue homogenates were simply diluted with a mixture of phosphate buffer (pH 2)/ACN (90:8 v/v), and then injected for extraction only after centrifugation and filtration. Coupled to HPLC with fluorescence detection, the method was linear over the range of 1.25-1500 ng/g for telmisartan in heart and kidney, 12.5-15 000 ng/g in liver with correlation coefficients over 0.9992. The detection limits were found to be in the range from 0.24 to 1.8 ng/g. RSDs for intra- and inter-day ranged from 1.2 to 8.1%. The determination of telmisartan in treated rat tissues was achieved by using the proposed method.     

基于溶胶凝胶技术的在线固相萃取与高效液相色谱联用测定饮用水中的雌激素残留

建立了固相萃取与高效液相色谱在线联用测定水样中3种雌激素(己烯雌酚、己烷雌酚、双烯雌酚)痕量残留的方法。以溶胶凝胶技术合成的聚合物为固相萃取材料,对水样中的雌激素进行萃取富集,考察了样品溶液不同pH、上样流速及洗脱溶剂等条件对合成材料富集效果的影响。结果表明,在优化的条件下,该方法对3种雌激素的检出限(S/N=3)为0.07~0.13 μg/L,样品中的加标回收率为82.31%~99.43%,相对标准偏差(RSD)为1.61%~7.15%。方法简便可靠,适用于饮用水中雌激素的痕量残留检测。     

Emulsification liquid phase microextraction followed by on-line phase separation coupled to high performance liquid chromatography

An emulsification liquid phase microextraction followed by on-line phase separation coupled to high performance liquid chromatography (HPLC) is introduced based on a novel idea for the separation of dispersed organic phase from aqueous phase. In this method, the dispersed organic extraction phase was filtered using an in-line filter and it was separated from the water sample. The new approach is simple and, in addition to improving some limitations of the conventional emulsification liquid phase microextraction, eliminates the need for centrifugation in the phase separation step.     

在线净化/固相萃取-高效液相色谱法测定饮用水和环境水体中的百草枯和敌草快

建立了在线净化/固相萃取(SPE)-高效液相色谱(HPLC)快速、准确测定饮用水和环境水体中的两种痕量除草剂百草枯和敌草快的方法。样品用大体积自动进样器注入在线净化小柱并流经固相萃取小柱,通过双梯度高效液相色谱系统中的上样泵实现净化和富集后,通过阀切换将固相萃取小柱切换至分析流路中;用分析泵将待测物从富集柱冲洗至分析柱进行测定。上样泵流速和分析泵流速分别为0.7和0.6 mL/min,采用等度洗脱方式完成两种除草剂的分离和检测。检测波长分别为260 nm (百草枯)和311 nm (敌草快),进样体积为2.5 mL,整个分析时间为16 min。该方法在1.0～20 μg/L范围内线性关系良好,两种除草剂的线性相关系数均大于0.9980,检出限分别为0.10和0.12 μg/L(S/N=3)。该方法前处理简单,快速,可用于饮用水和环境水体中痕量除草剂的测定。     

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。     

整体柱在线固相微萃取-高效液相色谱法分析爽肤水中痕量雌激素

以甲基丙烯酸缩水甘油酯(GMA)为功能单体、乙二醇二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂、甲醇及正己烷(14∶5,v/v)为二元致孔剂,通过原位聚合反应制备了聚甲基丙烯酸缩水甘油酯(Poly(GMA-co-EDMA))毛细管整体柱。研究表明,制备的Poly(GMA-co-EDMA)整体柱具有良好的通透性和较低的柱压(1.5×106Pa,冲洗流速0.5 mL/min)。该整体柱对雌二醇、炔雌醇、雌酮和己烯雌酚的富集倍数分别为86、116、77和86。构建了整体柱在线微萃取接口装置,建立了整体柱在线固相微萃取-高效液相色谱(HPLC)测定爽肤水中痕量雌二醇、炔雌醇、雌酮和己烯雌酚的分析方法。该分析方法的检出限(S/N=3)为0.05~0.20μg/L。将方法应用于爽肤水中雌激素的检测,加标回收率为69.3%~111.3%,RSD5.0%。所建立的方法简单、快速、灵敏、准确,可满足爽肤水中痕量雌激素的分析。     

液-液-液微萃取-高效液相色谱法测定人尿液中的美沙酮

建立了液-液-液微萃取与高效液相色谱联用技术快速分析尿样中美沙酮的方法.对有机溶剂种类、体积、样品溶液的pH值、萃取时间、搅拌速度进行了优化.方法的线性范围为0.05～10 mg/L,检出限为0.025 mg/L,相对标准偏差小于5%.     

Determination of cephalosporin antibiotics in water samples by optimised solid phase extraction and high performance liquid chromatography with ultraviolet detector

A reliable and robust analytical method based on solid phase extraction (SPE) and high performance liquid chromatography (HPLC) with ultraviolet (UV) detector was developed for the simultaneous determination of five cephalosporin antibiotics (Ceftazidime, Cefradine, Cefaclor, Cefotaxime and Cefoperazone) in various water samples. Under optimised conditions, it was applicable to preconcentrate up to 500?ml of water samples in the OASIS HLB cartridges with reasonable recoveries for all the cephalosporin antibiotics tested. Recoveries were as follows: deionised water, tap water and groundwater, between 84.2 and 98.9%; surface water, between 71.2 and 81.0%; influent and effluent of wastewater treatment plant (WWTP), between 56.9 and 72.1%. The method detection limits (MDLs) for different water samples were in the range of 26 to 59?ng?l^?1. Real water samples were analysed using the proposed approach to demonstrate the applicability and validation. Negative results were obtained for the tap water and groundwater. However, all the selected cephalosporin antibiotics were identified in the influent and effluent of a local WWTP at ng?l^?1–µg?l^?1 level. In addition, Ceftazidime was found in surface water with a concentration of 0.75–2.60?µg?l^?1. The results indicate that the ‘pseudo-persistent’ contamination of cephalosporin antibiotics in the water environment could not be neglected.     

Determination of aflatoxins in cereal flours by solid-phase microextraction coupled with liquid chromatography and post-column photochemical derivatization-fluorescence detection

A new method for the determination of aflatoxins B₁, B₂, G₁, and G₂ (AFB₁, AFB₂, AFG₁, AFG₂) in cereal flours based on solid-phase microextraction (SPME) coupled with high performance liquid chromatography with post-column photochemical derivatization and fluorescence detection (SPME–HPLC–PD–FD) has been developed. Aflatoxins were extracted from cereal flour samples by a methanol:phosphate buffer (pH 5.8, I = 0.1) (80:20, v/v) solution, followed by a SPME step. Different SPME and HPLC–PD–FD parameters (fiber polarity, temperature, pH, ionic strength, adsorption and desorption time, mobile phase) have been investigated and optimized. This method, which was assessed for the analysis of different cereal flours, showed interesting results in terms of LOD (from 0.035 to 0.2 ng g⁻¹), LOQ (from 0.1 to 0.63 ng g⁻¹, respectively), within and inter-day repeatability (2.27% and 5.38%, respectively) linear ranges (up to 20 ng g⁻¹ for AFB₁ and AFG₁ and 6 ng g⁻¹ for AFB₂ and AFG₂), and total raw extraction efficiency (in the range 55–59% at concentrations in the range 0.3–1 ng g⁻¹ and 49–52% at concentrations in the range 1–10 ng g⁻¹). The results were also compared with the purification step carried out by conventional immunoaffinity columns.     

SPME-GC联用测定环境水样中的酚类化合物

建立了固相微萃取与气相色谱联用技术测定环境水样中酚类化合物的方法. 探讨了pH、离子强度、萃取头类型、萃取时间以及解析时间等条件对酚类化合物萃取量的影响, 优化了GC仪器条件. 在优化的条件下, 酚类化合物的响应值与浓度有良好的线性关系, 线性范围为0.20～200 μg/L, 检出限在0.019～0.10 μg/L之间, 相对标准偏差(RSD, n=5)为4.4%～11%, 水样平均加标回收率为92.2%～101.9%, 所建立的方法可测定环境水样中的酚类化合物.     

Determination of alkaloids in Corydalis yanhusuo using hollow-fibre liquid phase microextraction and high performance liquid chromatography

Hollow fibre based liquid phase microextraction (HF-LPME) with high performance liquid chromatography (HPLC) was developed for the determination of alkaloids in Corydalis yanhusuo. Three alkaloids (protopine, tetrahydropalmatine, tetrahydroberberine) were extracted from a 10 mL alkaline sample (donor phase) to an organic phase impregnated in the pores of the hollow fibre, and then, they were extracted to an acidic solution (acceptor phase) in the lumen of the fibre. The extract was determined directly by HPLC. Parameters affecting the HF-LPME include the organic solvent, pH of the donor and the acceptor phase, the extraction time and the stirring speed were investigated systematically. To minimize the error of the injection, palmatine was added as an internal standard (I.S.). Under optimal conditions, calibration curves were obtained in the range of 0.1–1.0 mg L⁻¹ with a reasonable linearity (r ² > 0.993) and the limits of detection (LODs) ranged between 10.0 × 10⁻³ mg L⁻¹ and 13.7 × 10⁻³ mg L⁻¹. Additionally, enrichment factors with 100 to 184-fold were obtained. The method was then applied to the crude extract of Corydalis yanhusuo successfully.     

移液枪头式固相微萃取-高效液相色谱法测定细胞培养液中的4种生物碱

建立了移液枪头式固相微萃取(SPME)-高效液相色谱检测细胞培养液中4种生物碱(黄柏碱、药根碱、巴马丁和小檗碱)的分析方法。以甲基丙烯酸为反应单体、乙二醇二甲基丙烯酸酯为交联剂、偶氮二异丁腈为引发剂,在移液枪头内进行原位聚合反应,制备含有弱阳离子交换整体固定相的SPME枪头。样品经SPME净化后,用高效液相色谱-紫外检测法进行分析,流动相为乙腈-磷酸二氢钾溶液(0.05 mol/L,pH 4),紫外检测波长为270 nm,外标法定量。4种生物碱的检出限(S/N=3)为0.16~0.39μg/L;以空白细胞培养液进行加标回收率试验,加标回收率为92.73%~97.91%,相对标准偏差(RSD)为0.14%~3.31%。该方法简单、灵敏、准确,能够用于细胞培养液中微量生物碱的分析研究。     

固相萃取-高效液相色谱法测定地表水中的苯并三唑和苯并噻唑

建立了固相萃取-高效液相色谱分析地表水中苯并噻唑、苯并三唑、5-甲基-苯并三唑、5-氯-苯并三唑及5,6-二甲基-苯并三唑的方法。地表水样品采用HLB固相萃取柱富集净化后,在甲醇-水(55:45, v/v)流动相中用ZORBAX SB-C18色谱柱(250 mm×4.6 mm, 5 μm)分离,紫外检测,外标法定量。结果表明,5种目标化合物在0.064～80 mg/L范围内均呈良好的线性关系,线性相关系数均大于0.9999,仪器检出限为1.9～3.2 μg/L。空白自来水样中的加标回收率为87.8%～125.6%,相对标准偏差(n=3)为0.4%～9.4%。应用该方法测定了大连自来水及辽河入海口水样,在辽河入海口地表水中检出苯并噻唑、苯并三唑、5-甲基-苯并三唑、5-氯-苯并三唑。     

固相微萃取高效液相色谱法测定食品中己烯雌酚

建立了固相微萃取(SPME)-高效液相色谱(HPLC)联用测定食品中己烯雌酚(DES)的方法.考察了萃取纤维头、萃取时间、解吸时间和盐的添加对萃取效果的影响.在此基础上,采用正交试验,以解析液组成、萃取液pH和搅拌速度为3因素筛选出了最佳固相微萃取条件.该分析方法的线性范围为0.02 ～2.0μg/ml,工作曲线线性良...     

Determination of fluoroquinolones in edible animal tissue samples by high performance liquid chromatography after solid phase extraction

In the present work, a rapid, accurate, and sensitive method has been developed for the quantitative determination of five fluoroquinolones (enoxacin, ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin) in edible animal tissues (muscle tissue, liver, kidney, and eggs). The separation was accomplished on an Inertsil (250 x 4 mm) C8, 5 microm, analytical column, at ambient temperature within 15 min. The mobile phase consisted of a mixture of citric acid (0.4 mol L(-1))-CH3OH-CH3CN (87:9:4% v/v). UV detection at 275 nm yielded the following limits of detection: 100 pg per 20 microL injected volume for enoxacin, norfloxacin, and ciprofloxacin, 20 pg for ofloxacin, and 200 pg for enrofloxacin. Peaks in real samples were identified by means of a photodiode array detector. The method was validated in terms of intra-day (n = 8) and inter-day (n = 8) precision and accuracy. Tissue samples were purified from endogenous interference by solid-phase extraction using Oasis HLB cartridges. The solid-phase extraction protocol was optimized in terms of retention and elution. Recovery rates at fortification levels of 40, 60, and 80 ng/g ranged from 82.5% to 111.1%. The applicability of the method was examined using real samples from a chicken treated orally with the five studied fluoroquinolones.