Rapid separation and determination of microcystins using monolithic columns in isocratic elution mode by pressurized capillary electrochromatography

As a new wave of technology, polymethacrylate-based monolithic column was prepared and its application in the separation of three kinds of microcystins (MCs) in pressurized capillary electrochromatography with ultraviolet detection was studied. The key factors affecting the separation performance, such as monolithic column, pressure of the pump, component and concentration of mobile phase and the voltage, were investigated and optimized in detail. A baseline separation could be achieved in less than 6 min using a 5 mM borate buffer with a pH of 9.6 and 10% acetonitrile as the mobile phases in isocratic elution, under a voltage of +13 kV and a supplementary pressure of 7.5 MPa. The calibration curves were linear with correlation coefficient r>0.998 over a range of 0.10-25.00 mg/L. The LODs for the three MCs were in the range of 0.03-0.09 mg/L. This method was successfully applied to separate MCs from other compounds in spiked tap water after solid-phase extraction. The lower LODs for MC-LR, MC-YR and MC-RR were obtained to be 0.10, 0.13, 0.16 microg/L, respectively. These results make it clear that this proposed system is accurate and robust enough to be used as a fast separation tool for routine monitoring of MCs in real water samples.     

甲基丙烯酸酯毛细管整体柱分离微囊藻毒素的研究

以甲基丙烯酸丁酯为单体,乙二醇二甲基丙烯酸酯为交联剂,在致孔剂存在的条件下原位聚合制备了甲基丙烯酸丁酯毛细管整体柱(150 μm i.d.)。实验中优化了用此整体柱分离3种微囊藻毒素(MC-LR,-YR和-RR)的色谱条件(流动相种类、缓冲溶液浓度、pH、流动相流速),建立了微囊藻毒素的整体柱毛细管液相色谱分离方法,该法可以在9 min之内实现3种微囊藻毒素的基线分离。将该方法应用于实际水样中微囊藻毒素的分析,成功实现了培养水样和巢湖水样中微囊藻毒素的快速分离,两种样品中均检测到MC-LR。结果表明,所制备的甲基丙烯酸酯毛细管整体柱具有良好的重现性、渗透性,在微囊藻毒素的常规检测中具有很好的应用前景。     

Bamboo charcoal as adsorbent for SPE coupled with monolithic column-HPLC for rapid determination of 16 polycyclic aromatic hydrocarbons in water samples

The coupling of solid-phase extraction (SPE) using bamboo charcoal (BC) as an adsorbent with a monolithic column-high performance liquid chromatography (MC-HPLC) method was developed for the high-efficiency enrichment and rapid determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water. Key influence factors, such as the type and the volume of the elution solvent, and the flow rate and the volume of the sample loading, were optimized to obtain a high SPE recovery and extraction efficiency. BC as an SPE adsorbent presented a high extraction efficiency due to its large specific surface area and high adsorption capacity; MC as an HPLC column accelerated the separation within 8 min because of its high porosity, fast mass transfer, and low-pressure resistance. The calibration curves for the PAHs extracted were linear in the range of 0.2-15 μg/L, with the correlation coefficients (r(2)) between 0.9970-0.9999. This method attained good precisions (relative standard deviation, RSD) from 3.5 to 10.9% for the standard PAHs I aqueous solutions at 5 μg/L; the method recoveries ranged in 52.6-121.6% for real spiked river water samples with 0.4 and 4 μg/L. The limits of detection (LODs, S/N = 3) of the method were determined from 11 and 87 ng/L. The developed method was demonstrated to be applicable for the rapid and sensitive determination of 16 PAHs in real environmental water samples.     

Rapid analysis of triazolopyrimidine sulfoanilide herbicides in waters and soils by high-performance liquid chromatography with UV detection using a C18 monolithic column

In this work, the simultaneous analysis of five triazolopyrimidine sulfoanilide herbicides (flumetsulam, florasulam, metosulam, cloransulam-methyl, and diclosulam) by HPLC using UV detection and a C18 monolithic column is proposed. The mobile phase which was composed of ACN, water, and formic acid was pumped at a high flow rate (5 mmL/min) providing an analysis time of all the compounds in less than 2.3 min. The LODs were in the low microg/L range (i.e. between 60 microg/L for flumetsulam and 90 microg/L for florasulam) and the calibration curves showed good linearity (R2 > 0.9949). The method was applied to the analysis of these compounds in spiked mineral and tap waters and soils after an SPE preconcentration procedure using C18 cartridges. Mean recovery values ranged between 35 and 110% for water samples providing LODs of the whole procedure in the low ng/L level, down to 280 ng/L, and between 77 and 92% for soil samples with LODs down to 9.38 microg/kg. This is the first time that this family of pesticides is simultaneously analyzed in both types of samples by HPLC and also using a monolithic column.     

亲水改性C18填料的制备及其在萃取水中酚类化合物中的应用

通过在甲基丙烯酸十八酯(SMA)中加入亲水性单体甲氧基聚乙二醇甲基丙烯酸酯(PEGMEA),以1-正丙醇/1,4-丁二醇为致孔剂,热聚合得到具有一定亲水性的新型C18填料,并将该填料应用于固相萃取(SPE)富集水中的酚类化合物。实验优化了致孔剂的配比、SPE过程中上样溶液pH值、洗脱剂种类等参数。在上样溶液pH为6.0,以5.0 mL乙腈为洗脱剂的优化条件下,5种酚类化合物在0.5～10 mg/L范围内呈良好的线性关系,检出限为0.16～0.47 mg/L。所制备的亲水改性C18材料已成功用于大辽河水样中酚的检测,平均加标回收率为64.33%～92.14%, 相对标准偏差为4.2%～6.4%(n=3),证明了该填料对环境水样中痕量酚类化合物富集的可靠性。     

疏水整体柱在线固相萃取与高效液相色谱-串联质谱联用测定牛肝中5种阿维菌素类药物残留

建立了牛肝中5种阿维菌素类药物残留的疏水整体柱在线固相萃取结合高效液相色谱-串联质谱测定的方法。以疏水的聚(甲基丙烯酸丁酯-乙二醇二甲基丙烯酸酯)整体柱(10 mm×2.1 mm)作为固相萃取介质,考察了上样流动相和洗脱流速对阿维菌素类药物的萃取效果,优化了梯度洗脱流动相的种类及质谱条件。方法在1~100 μg/L范围内线性关系良好(r>0.995),定量限为5 μg/kg。在5、10、50、100 μg/kg添加水平的回收率为77.4%~98.4%,日内和日间相对标准偏差分别为4.46%~8.03%和4.79%~8.68%,并且该柱反复使用400次后未发现萃取效率降低。结果表明,该整体柱对牛肝中5种阿维菌素类药物能够有效萃取,并且可以重复使用。该方法简单,自动化程度高,可应用于常规阿维菌素类药物残留分析。     

基于整体柱的固相萃取-高效液相色谱法测定尿液中4种羟基多环芳烃

建立了基于聚合物整体柱的固相萃取-高效液相色谱测定尿液中4种羟基多环芳烃（OH-PAHs）的分析方法。在注射器管中合成聚（甲基丙烯酸丁酯-乙二醇二甲基丙烯酸酯）整体柱（poly （BMA-co-EDMA））,并将其用于尿液中4种羟基多环芳烃的前处理,同时考察了上样浓度、淋洗液、洗脱液和洗脱体积对萃取效率的影响。结合高效液相色谱-荧光分析,4种羟基多环芳烃在各自的范围内线性关系良好（r≥0.9991）;方法的检出限和定量限分别为0.06~0.09 ng/mL和0.20~0.30 ng/mL;日内（n=5）和日间（n=3）精密度分别为1.4%~5.3%和2.6%~7.3%。对焦炉工人尿液样品进行加标（3 ng/mL）回收试验,回收率为78.2%~117.0%。该固相萃取柱能够有效萃取和净化尿液中4种羟基多环芳烃,并且可以重复使用。该法简单、准确,可应用于尿液中羟基多环芳烃的分析。     

Analysis of microcystins using high‐performance liquid chromatography and magnetic solid‐phase extraction with silica‐coated magnetite with cetylpyridinium chloride

Microcystins (MCs), produced by freshwater cyanobacteria, can be serious water pollutants, so it is important to monitor their concentration in drinking water. We have developed a method for rapid and accurate determination of microcystin levels in environmental water, using magnetic solid‐phase extraction and high‐performance liquid chromatography with UV detection. The magnetic composite material, which was combined with cetylpyridinium chloride, was prepared by hydrothermal synthesis. The optimal extraction of microcystins in water sample was achieved by optimizing the amount of adsorbent, time of adsorption, ratio of eluting solvent, and volume of eluent. Under the optimal conditions, the limit of detection of MC‐LR was 0.001 μg/L, and the limit of quantification was 0.0028 μg/L. The limit of detection of MC‐RR was 0.001 μg/L, and the limit of quantification was 0.003 μg/L. These values are far lower than those established by the International Health Organization for the maximum concentration of microcystins in drinking water. The magnetic solid‐phase extraction adsorbent used in this method has the advantages of simple preparation, low price, and easy solid–liquid separation, and it can be used for the rapid and sensitive monitoring of trace microcystins in environmental water samples.     

基于一种新型有机聚合物整体柱的毛细管电色谱技术用于利尿剂的分离与检测

采用自制的新型有机聚1-十六碳烯-三羟甲基丙烷三甲基丙烯酸酯［poly(1-hexadecene-co-TMPTMA)］整体柱,建立了一种同时分离检测6种利尿剂(氯噻酮、氢氯噻嗪、美托拉宗、吲哒帕胺、坎利酮和螺内酯)的毛细管电色谱(CEC)新方法,并成功应用于志愿者实际尿样的分析测定。在最佳实验条件下,6种利尿剂包含2种中性物质(坎利酮和螺内酯)和2种同分异构体(美托拉宗和吲哒帕胺)在11.0 min内得到基线分离,柱效分别达到218000、176000、143000、121000、108000、103000 塔板/m。6种利尿剂在1.15～86.0 μg/mL范围内呈良好的线性关系,相关系数R2 ≥0.990 8,检出限(LOD)在0.35～0.65 μg/mL范围内,回收率为81.9%~105%,相对标准偏差(RSD)小于4.7%。结果表明,实验所建立的基于poly(1-hexadecene-co-TMPTMA)整体柱的CEC方法,具有良好的重复性和稳定性,能够实现对多种利尿剂的同时分离检测。该方法已成功应用于来自志愿者实际尿样的分析,该方法可以用于利尿剂类药物的初筛。     

Rapid separation and sensitive detection method for beta-blockers by pressure-assisted capillary electrochromatography-electrospray ionization mass spectrometry

A new method for rapid separation and sensitive detection of beta-blockers by pressure-assisted capillary electrochromatography (pCEC) with electrospray ionization mass spectrometry (ESI-MS) using silica-based monolithic column was studied in this paper. The proposed method has been confirmed to be very powerful since the fast mass transfer property and good permeability of silica monolithic column was used in this pCEC-ESI-MS system. In this work, a silica monolithic column was prepared with sol-gel method for simultaneous fast separation of beta-blockers. Furthermore, in order to obtain the highly selective and sensitive result of pCEC-ESI-MS, both the CEC separation and MS detection parameters were optimized in detail. Under the optimized conditions, namely 80% acetonitrile and 20% 20 mmol/L ammonium acetate (pH 6.0) as the mobile phase, 20 kV and 8 bar as the separation voltage and the assisted pressure, isopropanol/water (1:1, v/v) containing 7.5 mmol/L acetic acid as the sheath liquid, and 3 microL/min as the flow rate of sheath liquid, seven beta-blockers were well separated within 11 min with detection limits in the range of 0.15-0.80 ng/mL (defined as S/N=3). The recoveries of spiked urine samples of these beta-blockers were between 86.3 and 103% with the RSDs lower than 8.0%. The real samples from some male volunteers were successfully analyzed and confirmed with the proposed method. Comparing with GC-MS or LC-MS, the new method has some superiority (such as fast analysis capacity and simple pretreatment) in clinical practice and doping control.     

固相萃取-超高效液相色谱-电喷雾串联质谱法同时测定地表水中9种微囊藻毒素

建立了固相萃取-超高效液相色谱-电喷雾串联三重四极杆质谱(SPE-UPLC-ESI-MS/MS)联用技术分析水中9种微囊藻毒素的方法。样品经SPE提取和净化后,以Waters ACQUITY UPLCTM BEH C18色谱柱为分离柱,以含0.1%甲酸乙腈和含0.1%甲酸水作为流动相进行梯度洗脱,电喷雾离子源电离、正离子多反应监测模式质谱进行定性和定量分析。9种微囊藻毒素在0.1～50 μg/L或0.5～100 μg/L质量浓度范围内线性良好,相关系数为0.9990～0.9998,方法的检出限(以3倍信噪比计)为0.1～0.5 ng/L;高、中、低3个添加水平的回收率为75.8%～109%,相对标准偏差为0.49%～10.0%。结果表明,该方法灵敏、准确,检测范围广,分析速度快。应用该方法检测了杭州市两处水库水样中的微囊藻毒素,分别检出了3种和8种微囊藻毒素。     

Separation of inorganic anions on a high capacity porous polymeric monolithic column and application to direct determination of anions in seawater

A commercially available 4.6 mm id x 50 mm polymethacrylate-based monolithic strong anion exchange column (ProSwift SAX-1S) designed for the separation of proteins has been successfully used to separate small inorganic anions in the presence of a seawater sample matrix. Using a hydroxide eluent with suppressed conductivity detection the ion exchange capacity of this column declined over time; however, using KCl as the eluent, the column performance was stable with a capacity of 530 microequiv. for nitrate. The optimum conditions for the separation of iodate, bromate, nitrite, bromide and nitrate were assessed by constructing van Deemter plots using 1.00 and 0.100 M KCl. Efficiencies of up to 26 700 plates/m were recorded using 1.00 M KCl, at a flow rate of 0.20 mL/min but iodate was not baseline resolved from the void peak. By reducing the concentration of the eluent to 0.100 M, efficiencies of up to 39 900 plates/m could be obtained at 0.35 mL/min. By employing a linear gradient ranging from 0.05 to 1.00 M KCl the ions dissolved in distilled water or a salt water matrix could be baseline separated in less than 3 min at a flow rate of 2.50 mL/min.     

超高效液相色谱/串联质谱法分析水中的微囊藻毒素

建立了超高效液相色谱/质谱快速、准确、高灵敏度地测定水体中痕量微囊藻毒素（MCYST）的分析方法,并用于实 际样品的分析。采用固相萃取法富集净化样品。该法在5 min内即可完成4种MCYST（LR、RR、LW、LF）的分离及检测;LR 、RR、LW、LF的定量检测限、回收率分别为1.3～6.0 ng/L、91.1%～111%;工作曲线的线性相关系数大于0.99,线性范 围达3个数量级。实际样品分析表明,在所测定的水库水样中均检出了LR和RR,其质量浓度分别为0.0447～2.73 μg/L和0.0208～1.36 μg/L;而在所有的检测样品中均未检出LW和LF。     

超高效液相色谱-串联质谱法测定水华样品中微囊藻毒素及其基质效应的消除

超高效液相色谱-串联质谱法(UPLC-MS/MS)由于其快速、简便的特点,目前广泛应用于水中微囊藻毒素的测定。由于蓝藻水华样品基质比较复杂,UPLC-MS/MS在复杂基质的分析过程中容易发生基质效应问题,严重影响其定量分析结果的准确性。通过稀释样品、优化梯度洗脱程序、减少进样量等方法有效地降低或消除了基质干扰及基质效应问题。7种目标物在各自线性范围内线性关系良好,相关系数(r2)≥0.99;检出限和定量限分别为0.064~0.103μg/L和0.213~0.343μg/L。通过稀释样品、减少进样量等措施,成功测定了水华爆发时实际样品中的微囊藻毒素,并有效降低了基质效应的干扰。该法为微囊藻毒素的准确测定提供一定的参考,对保障饮用水源地的安全具有十分重要的意义。     

Analyses of non-steroidal anti-inflammatory drugs by on-line concentration capillary electrochromatography using poly(stearyl methacrylate-divinylbenzene) monolithic columns

This study describes the ability of on-line concentration capillary electrochromatography (CEC) coupled with UV or mass spectrometry (MS) for the determination of nine common non-steroidal anti-inflammatory drugs (NSAIDs) in water samples. A series of poly(stearyl methacrylate-divinylbenzene) (poly(SMA-DVB)) monolithic columns, which were prepared by single step in situ polymerization of divinylbenzene (DVB), stearyl methacrylate (SMA) and vinylbenzenesulfonic acid (VBSA, charged monomer), were developed as separation columns for the first time. The effects of polymerization condition of monolithic columns on analyte separations were examined, and the results indicated that separation performances were markedly improved in monolithic columns prepared with short reaction time (3 h) and low SMA:DVB ratio (40/60 ratio of SMA:DVB). Subsequently, an on-line concentration step of step-gradient elution was combined to this CEC system, and by optimizing the difference in eluent strength between the sample matrix and mobile phase, all NSAIDs detection sensitivity were improved (limit of detection (LOD) was 3.4-10 μg/L for UV, and 0.01-0.19 μg/L for MS). When compared to the best CE and LC reports on NSAIDs analyses so far, this on-line concentration CEC method provided better detection ability within shorter separation time (12 min) when either UV or MS detector was employed. This is the first report for on-line concentration CEC with MS detection applied in trace solute analyses of real samples.     

Pressure-assisted capillary electrochromatography with electrospray ionization-mass spectrometry based on silica-based monolithic column for rapid analysis of narcotics

A pressure-assisted CEC (pCEC) with ESI-MS based on silica-based monolithic column was developed for rapid analysis of narcotics. Combining the extremely high permeability and separation efficiency of silica-based monolithic column with the high selectivity and sensitivity of pCEC-ESI-MS, the developed system exhibited its prominent advantages in separation and detection. A systematic investigation of the pCEC separation and ESI-MS detection parameters was performed. Experiment results showed that the optimized separation efficiency could be obtained at 8 bar assisted pressure with 25 kV separation voltage, using the solution containing 65% ACN v/v and 20 mmol/L ammonium acetate with pH 6.0 as running buffer. 3 microL/min of sheath liquid was considered as the optimized flow rate since it could provide the maximum signal intensity. Under the optimum conditions, the tested five narcotics could be completely separated within 10 min with the detection limit in the range of 2.0-80 nmol/L. The proposed method has been successfully used for detection of narcotics in real urine samples.     

Optimization of separation of heavy metals by capillary electrophoresis with contactless conductivity detection

The separation of four toxic metal ions (Cr(3+) , Pb(2+) , Hg(2+) , Ni(2+) ) was achieved by optimizing the composition of the histidine/tartaric acid background electrolyte. An on-column preconcentration technique, viz. field amplified sample injection, was performed to improve the sensitivity. This method afforded an enhancement factor of up to 91,800 fold with the LODs ranging from 0.005 to 2.32 μg/L, which were well below the maximum contaminant levels set by the United States Environmental Protection Agency. The robustness of this method was demonstrated with its application to the analysis of real samples including tap water, drain water, and reservoir water with recoveries between 90 and 120%.     

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。     

超高效亲水作用色谱-串联质谱法检测水中的苦味酸及苦氨酸

建立了一种超高效亲水作用色谱-串联质谱检测水中苦味酸及其降解产物苦氨酸的方法。采用Acquity UPLC BEH HILIC亲水作用色谱柱（100 mm×2.1 mm,1.7 μm,Waters）分离,用电喷雾电离串联质谱检测。地表水样品经过0.2 μm滤膜过滤之后即可直接进样,加标回收率达89%~107%;废水样品通过固相萃取（SPE）净化后进样分析,加标回收率达72%~101%。方法重复性的相对标准偏差为4.9%~14.7%。本方法对苦味酸和苦氨酸的检出限分别为0.1 μg/L和0.3 μg/L。此方法快速、准确,特异性强,灵敏度高,样品前处理方法简便易行,适用于地表水、废水样品的检测。     

磁固相萃取-液相色谱法测定环境水样中有机紫外防晒剂

采用自制的聚离子液体功能化磁性材料有效富集有机紫外防晒剂，并与高效液相色谱-二极管阵列检测器（HPLC-DAD）联用，建立了环境水样中痕量有机紫外防晒剂的检测方法。研究系统考察了解吸溶剂、吸附和解吸时间、样品pH值、离子强度等因素对萃取性能的影响。在最佳萃取条件下，水杨酸辛酯的线性范围为0.5~200.0 μg/L，其他有机紫外防晒剂的线性范围为0.2~200.0 μg/L；6种目标物的检出限（LOD，S/N=3）和定量限（LOQ，S/N=10）分别为0.009~0.13 μg/L和0.031~0.43 μg/L。所建方法成功用于实际环境水样中有机紫外防晒剂的测定，不同加标水平下目标物的加标回收率为71.4%~120%，相对标准偏差均低于10%。研究表明，所建方法具有操作简便、萃取速度快、灵敏度高和环境友好等特点，可用于环境水样中有机紫外防晒剂的检测。