固相萃取-高效液相色谱法测定啤酒中的黄腐酚

采用Waters Sep-Pak C18固相萃取小柱对啤酒样品进行分离纯化,建立了啤酒中黄腐酚的固相萃取-高效液相色谱检测方法。选用色谱柱Zorbax Eclipse XDB-C18柱(250 mm×4.6 mm,5 μm),以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,柱温25 ℃,流速0.4 mL/min,检测波长370 nm。在此条件下,黄腐酚分离良好且无杂质峰干扰,在0.5～500 μg/L的范围内线性关系良好(r21),在高、中、低浓度下的加标回收率为91.21%～95.58%,相对标准偏差小于2%。方法的检出限为0.24 μg/L,定量限为0.80 μg/L。该方法简便快速、结果准确、重现性好,是检测啤酒中黄腐酚含量的有效方法。     

液相色谱-电喷雾质谱/质谱法测定高温烹制的淀粉类食品中的丙烯酰胺

以C18反相色谱柱为分析柱,以0.1%甲酸水溶液-甲醇(体积比为98∶2)为流动相,采用同位素稀释液相色谱-电喷雾 质谱/质谱(LC-MS/MS)技术对加热淀粉类食品中的丙烯酰胺进行了测定。利用Oasis HLB固相萃取柱对样品进行净化。方 法的线性范围为10～500 μg/L,线性相关系数为0.9995。方法的定性检出限为6 μg/kg,定量检出限为20 μg/kg。高 、中、低3个浓度水平的加标回收率为96.8%~97.4%,相对标准偏差小于10%。     

固相萃取-离子色谱测定大气颗粒物的甲胺类及其氧化产物

建立了测定大气颗粒物中氧化三甲胺、一甲胺、二甲胺和三甲胺的固相萃取离子色谱的分析方法。选取20 mL甲醇-水(1∶3,V/V)混和液,超声提取石英滤膜,重复提取2次。提取结束后,合并3次提取液共60 mL,上样到固相萃取设备。使用Agilent Accu Bond C_(18)为固相萃取柱富集提取液中的一甲胺、二甲胺、三甲胺和氧化三甲胺。采用0.5 mL乙腈洗脱萃取柱上的甲胺类物质。洗脱后,向溶液中加入1.5 mL去离子水定容,离子色谱定量分析。用阳离子色谱柱PRP X-200(250 mm×4.1 mm,10 μm)为分离柱,以3%(V/V)乙腈和5 mmol/L HNO_3为淋洗液,流动相流速1.0 mL/min,柱温箱温度25℃,30 min内4种胺类物质完全分离。方法线性范围为0.45~1000 μg/kg,精密度在2%~4%之间,检出限为0.09~0.14 μg/kg(0.002~0.003 μg/m~3),加标回收率大于90%。将本方法应用于北京市沙尘和霾天气的细颗粒样品分析中,三甲胺和氧化三甲胺的浓度分别为0.01~0.08 μg/m~3和0.02~0.14 μg/m~3。     

计算机拟合技术研究C18柱在富集PAEs时的萃取条件

利用固相萃取技术富集了水中5种邻苯二甲酸酯类(邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二辛酯(DOP)).借助均匀设计法及计算机回归建模优化技术对5种PAEs的固相萃取条件进行了设计与优化,得到最佳固相萃取条件为: 洗脱剂配比: V(正己烷)∶V(丙酮)=30∶1,洗脱体积2 mL,洗脱流速为4 mL/min,上样流速8 mL/min.富集后的样品用带电子捕获检测器的毛细管气相色谱检测,方法的线性范围为1～1000 μg/L (DMP,DEP,DOP),0.2～100 μg/L (DBP,DEHP);线性回归方程的相关系数为0.9970～1.000,检出限为0.02～0.4 μg/L,方法回收率为69%～117%,相对标准偏差为2.2%～9.5%.     

在线固相萃取/液相色谱-串联质谱法检测饲料中5种喹啉药物残留量

建立了在线固相萃取/液相色谱-串联质谱法检测饲料中5种喹(噁)啉药物的方法.准确称取2 g饲料,用10 mL 0.1％盐酸-甲醇(1:1)提取,提取液用0.2％甲酸稀释10倍,通过双三元液相色谱采用反相在线固相萃取柱在线富集净化,以0.2％甲酸与乙腈梯度洗脱,同时转移至C18色谱柱上进行分离,串联四极杆质谱检测.实验结果表明,5种喹(噁)啉药物在50～ 25 000 μg/kg含量范围内线性良好(r＞0.999);方法的检出限为25 μg/kg,定量下限为50 μg/kg;方法回收率为72.6％～84.6％,批内和批间相对标准偏差(RSD)均小于10％.本方法较传统固相萃取柱净化法更简捷、经济和稳定.     

固相萃取-高效液相色谱法测定水中BPA、NP和OP含量

采用国产新型D4020大孔吸附树脂自制固相萃取柱,研究了柱长、上样速度、样品溶液的pH、盐浓度等因素对壬基酚、辛基酚和双酚A吸附率的影响,确定了最佳固相萃取条件,建立了固相萃取-高效液相色谱测定水中痕量壬基酚、辛基酚和双酚A的分析方法.该法双酚A、壬基酚和辛基酚的检出限分别为0.432 μg/L、0.998 μg/L和1.336 μg/L,回收率为91%～96%,相对标准偏差(RSD)为1.5%～5.6%.方法简便快速、成本低廉,灵敏度高,准确度好,用于实际水样分析,取得满意结果.     

液相色谱-串联四极杆质谱法测定牛奶中128种农药残留

建立了牛奶中128种农药残留的液相色谱-串联质谱检测方法。10 mL牛奶用20 mL乙腈(加4 g硫酸镁和1 g氯化钠)振荡提取两次,上清液浓缩后经C18固相萃取柱(2000 mg填料)净化以除去提取液中的亲脂性化合物等干扰杂质,洗脱液浓缩至约0.5 mL后,于45 ℃下用氮气吹干,加1 mL乙腈-水(体积比为3:2)定容,超声溶解30 s,经0.2 μm微孔滤膜过滤,液相色谱-电喷雾串联质谱测定。2倍检出限和8倍检出限两个添加水平的5次平行实验结果表明: 128种农药在低添加水平(0.14 μg/L～0.62 mg/L)下回收率范围为60.4%～118.4%,相对标准偏差为2.1%～24.3%;高添加水平(0.56 μg/L～2.48 mg/L)下的回收率范围为64.4%～118.5%,相对标准偏差为1.3%～24.1%。各种农药在确定的添加范围内线性关系良好,相关系数高于0.99,方法的检出限(LOD)为0.07 μg/L～0.31 mg/L。该方法通用性强、选择性好、灵敏度高,快速简便。     

在线净化/固相萃取-高效液相色谱法测定饮料中的维生素B12

建立了饮料中痕量维生素B12(VB12)的在线净化/固相萃取-高效液相色谱(HPLC)测定方法。在双梯度HPLC系统上,以磷酸盐缓冲溶液-乙腈为流动相,将2.5 mL样品在线注入SPE柱(Acclaim PA Ⅱ,3 μm,3.0 mm× 33 mm)以富集VB12,通过改变流动相梯度在SPE柱上以正向淋洗方式预分离VB12。被切入分析流路中的VB12在Acclaim PA Ⅱ分析柱(3 μm,3.0 mm×150 mm)上以磷酸盐缓冲溶液-乙腈为流动相,0.5 mL/min流速梯度洗脱分离,使用紫外检测器在361 nm波长下检测,整个分析过程在20 min内完成。VB12峰面积的相对标准偏差(RSD)为2.2%,其保留时间的RSD为0.027%。方法在0.1 ~ 5.0 μg/L质量浓度范围内与其峰面积呈良好的线性关系,线性系数为0.999 9。方法的加标回收率为91%~ 109%,检出限为0.046 μg/L。该方法简单、快速、重现性好,相比于直接大体积进样和传统在线SPE模式,其去除杂质的效率更高、灵敏度更好,是一种测定饮料中痕量VB12的简单、有效方法。     

固相萃取-反相高效液相色谱法测定水中的邻苯二甲酸酯

建立了固相萃取-反相高效液相色谱法检测水中3种邻苯二甲酸酯类物质邻苯二甲酸二甲酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯的方法. 考察了固相萃取柱、洗脱溶剂、洗脱体积、上样速度以及洗脱速度对萃取效率的影响. 通过综合分析, 选定SupelcleanLC-18 SPE Tube固相萃取柱, 甲醇为洗脱剂, 洗脱体积2 mL, 上样速度为4 mL/min, 洗脱速度为1 mL/min. 在此萃取条件下, 萃取回收率在83.4%～121.2%之间. 邻苯二甲酸二甲酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯质量浓度在2～100 mg/L之间均为线性. 经萃取后, 方法的最低检出限分别为邻苯二甲酸二甲酯0.06 μg/L, 邻苯二甲酸二(2-乙基己基)酯0.16 μg/L, 邻苯二甲酸二正辛酯0.08 μg/L. 方法的精密度在10%～15%之间. 应用该方法测定自来水中酞酸酯类化合物的含量, 加标回收率为83.6%～110.2%.     

四氮杂杯[2]芳烃[2]三嗪键合硅胶固相萃取-高效液相色谱法测定河水中硝基苯酚和己烯雌酚

基于四氮杂杯[2]芳烃[2]三嗪键合硅胶吸附剂（NC-Si）,构建了固相萃取-高效液相色谱法同时测定河水中3种硝基苯酚和己烯雌酚的新方法。考察并获得了固相萃取和液相色谱分离的优化条件：将样品溶液pH调至5,以5 mL/min上样,经自制固相萃取柱净化,2 mL氨水-甲醇（2：98,v/v）洗脱;在C8柱上以甲醇-0.1%磷酸溶液为流动相进行梯度洗脱。4种目标分析物的检出限（LOD,S/N=3）为0.03~0.3 μg/L,定量限（LOQ,S/N=10）为0.1~1.0 μg/L;加标回收率为75.5%~104.2%,相对标准偏差（RSD,n=5）小于6.3%。该方法准确、可靠,可用于河水中硝基苯酚及己烯雌酚的灵敏检测。     

Determination of vitamin K1 in emulsified nutritional supplements by solid-phase extraction and high-performance liquid chromatography with postcolumn reduction on a platinum catalyst and fluorescence detection

Determination of small amounts of vitamin K1 (0.8 microg/g) in nutritional supplements with high fat content (20 mg/g) was performed by solid-phase extraction and high-performance liquid chromatography (HPLC) with fluorescence detection after reduction on a platinum oxide catalyst. The concentration ratio of plant oils to vitamin K1 (0.8 microg/g) was about 25,000:1. A sample solution was applied to a solid-phase extraction cartridge and vitamin K1 was eluted with ethanol, followed by HPLC. The proposed method was simple, rapid (analysis time: ca. 12 min), sensitive [detection limit: ca. 0.1 pg per injection (100 microl) at a signal-to-noise ratio of 3:1], highly selective and reproducible [relative standard deviation: ca. 1.3%. (n=5)]. The calibration graph of vitamin K1 was linear in the range of 0-2 pg per injection (100 microl). Recovery of vitamin K1 was over 90% by the standard addition method.     

An improved high-performance liquid chromatographic method with a solid-phase extraction for the determination of piperacillin and tazobactam: application to pharmacokinetic study of different dosage in Chinese healthy volunteers

An improved HPLC method was developed for the determination of piperacillin and tazobactam in human plasma and pharmacokinetic study in Chinese healthy volunteers. Piperacillin and tazobactam in human plasma were extracted by solid-phase extraction and separated on a C(18) column and detected at 220 nm. The mobile phase for piepracillin consisted of 0.01 mol/L sodium dihydrogen phosphate (pH = 4.65) and acetonitrile (71:29, v/v), and that for tazobactam was 0.05 mol/L sodium dihydrogen phosphate (pH = 4.45) and methanol (90:10, v/v). The method was linear in the range 0.25-320.00 microg/mL for piperacillin (r(2) = 0.995) and 0.25-64.00 microg/mL for tazobactam (r(2) = 0.994). The lower limit of quantification of both compounds was 0.25 microg/mL. The intra- and inter-day precisions of piperacillin and tazobactam at three concentrations were all less than 9.2% and accuracies were within the range 97.0-108.0%. The method was used to investigate the pharmacokinetics of piperacillin and tazobactam in 12 volunteers who were intravenously given a dosage of 1.25, 2.50 and 3.75 g in three periods. The results showed that piperacillin sodium-tazobactom sodium (4:1) for injection in Chinese people fits linear dynamics, and the administred dosage can be adjusted with therapeutic effect.     

Enantioselective HPLC-UV method for determination of eslicarbazepine acetate (BIA 2-093) and its metabolites in human plasma

Eslicarbazepine acetate (BIA 2-093) is a novel central nervous system drug undergoing clinical phase III trials for epilepsy and phase II trials for bipolar disorder. A simple and reliable chiral reversed-phase HPLC-UV method was developed and validated for the simultaneous determination of eslicarbazepine acetate, oxcarbazepine, S-licarbazepine and R-licarbazepine in human plasma. The analytes and internal standard were extracted from plasma by a solid-phase extraction using Waters Oasis HLB cartridges. Chromatographic separation was achieved by isocratic elution with water-methanol (88:12, v/v), at a flow rate of 0.7 mL/min, on a LichroCART 250-4 ChiraDex (beta-cyclodextrin, 5 microm) column at 30 degrees C. All compounds were detected at 225 nm. Calibration curves were linear over the range 0.4-8 microg/mL for eslicarbazepine acetate and oxcarbazepine, and 0.4-80 microg/mL for each licarbazepine enantiomer. The overall intra- and interday precision and accuracy did not exceed 15%. Mean relative recoveries varied from 94.00 to 102.23% and the limit of quantification of the assay was 0.4 microg/mL for all compounds. This method seems to be a useful tool for clinical research and therapeutic drug monitoring of eslicarbazepine acetate and its metabolites S-licarbazepine, R-licarbazepine and oxcarbazepine.     

Analytical method for dimethenamid-P in selected raw agricultural commodities by gas chromatography with electron capture detection

A sensitive and simple method for the extraction and quantification of the herbicide dimethenamid-P from several raw agricultural commodities (RAC) is presented. The method provides sensitive and well-defined chromatography with baseline resolution in all matrixes tested. Homogenized samples were extracted with methanol-water, filtered, and then extracted with hexanes. A Florisil solid-phase extraction was then applied for the final cleanup. Sample separation and quantification were performed by gas chromatography with an electron capture detector. The instrument detection limit was 0.007 microg/mL, and the practical quantification limit was 0.003 microg/g (w/w) based on a 25 g sample. Recoveries for a series of fortified plant tissues ranged from 69 to 103%. The study demonstrated selective and sensitive recovery of dimethenamid-P from the RAC tested.     

离子交换固相萃取-气相色谱-质谱联用法测定方便面皮复合包装袋中2,4-二氨基甲苯的迁移量

建立了方便面皮复合包装袋中2,4-二氨基甲苯迁移量的离子交换固相萃取-气相色谱-质谱联用检测方法。样品用4%（v/v）乙酸溶液浸泡,然后采用MCX混合型阳离子交换柱富集净化,以5.0 mL水淋洗小柱,用3.0 mL 5%（v/v）氨化甲醇洗脱样品,洗脱液经过溶剂交换,七氟丁酸酐衍生后,用气相色谱-质谱联用仪对目标物进行检测,外标法定量。2,4-二氨基甲苯在1~50 μg/L范围内,线性相关系数（r）为0.9991,检出限（S/N=3）为0.2 μg/L,定量限（S/N=10）为0.6 μg/L,回收率在89.0%~94.2%之间,相对标准偏差为1.9%~3.6%。该方法的前处理过程无需调节提取液的pH值,也不需要液液萃取,大幅简化了前处理过程,降低了有机溶剂的消耗,具有操作便捷、结果准确的优点,适用于方便面皮复合包装袋中2,4-二氨基甲苯迁移量的检测。     

液相色谱-大气压化学电离串联质谱法测定婴幼儿配方奶粉中的维生素D

建立了婴幼儿配方奶粉中维生素D的液相色谱-大气压化学电离串联质谱(LC-APCI-MS/MS)分析方法。样品经正己烷和甲基叔丁基醚混合溶液提取,ProElut VDC固相萃取柱净化,Kinetex C_(18)色谱柱分离,采用大气压化学电离(APCI)源、正离子扫描和多反应监测(MRM)模式对维生素D_2和维生素D_3进行检测,内标法定量。结果表明维生素D_2和维生素D_3在5~5 000μg/L范围内均具有良好的线性关系,检出限为2μg/kg,定量限为5μg/kg。在5、10和100μg/kg添加水平下,维生素D_2和维生素D_3的回收率为85.2%~105.3%,相对标准偏差为4.7%~8.1%。该方法简便准确,灵敏度高,适用于婴幼儿奶粉中维生素D的测定。     

Application of ultra-high-performance liquid chromatography/tandem mass spectrometry for the measurement of vitamin D in infant formula and adult/pediatric nutritional formula: First Action 2011.11

In an effort to measure vitamin D, ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) was applied to samples. The use of UHPLC-MS/MS decreased the run time by 50%. The UHPLC-MS/MS achieved equal or better separation efficiency with complex food matrixes compared to HPLC-MS/MS. It was also observed that under the optimized conditions of UHPLC, all previtamins of vitamin D3, D2, and isotope-labeled vitamin D3 were baseline-separated from their corresponding vitamins. The sterol isomers found in complex food matrixes that interfere in the analysis were well separated from the analytes. The accuracy of the method was evaluated by analyzing National Institute of Standards and Technology Standard Reference Material 1849 infant reference material. The average vitamin D3 concentration was 0.251 +/- 0.012 microg/g. This showed excellent agreement with the certified value of 0.251 +/- 0.027 microg/g. The spike recovery study of a commercial infant formula matrix showed a range of recovery from 100 to 108%. The LOQ values determined were 0.0022 and 0.0028 microg/g for vitamins D3 and D2, respectively; LOD values were 0.00065 and 0.00083 microg/g for vitamins D3 and D2, respectively.     

Determination of folic acid in tablets by microemulsion electrokinetic chromatography

A microemulsion electrokinetic chromatography (MEEKC) method has been developed and validated for the determination of folic acid, a water-soluble vitamin, in a commercial tablet formulation. The analysis was performed using a microemulsion containing 0.5% (w/w) ethyl acetate, 1.2% (w/w) butan-1-ol, 0.6% (w/w) sodium dodecyl sulfate, 15% (v/v) 2-propanol and 82.7% (w/w) 10 mmol L(-1) sodium tetraborate aqueous buffer at pH 9.2. Direct UV detection at 214nm led to an adequate sensitivity without interference from sample excipients. For quantitative purposes, niacin was used as internal standard. Acceptable precision (<1.2% relative standard deviation (R.S.D.)), linearity (r = 0.9992; range from 160.0 to 240.0 microg/mL), sensitivity (limit of detection (LOD) = 2.98 microg/mL; limit of quantification (LOQ) = 9.05 microg/mL) and recovery (99.8 +/- 1.8% at three concentration levels) were obtained. Based on the performance characteristics, the proposed methodology was found suitable for the determination of folic acid in tablet formulations.     

液相色谱-串联质谱法测定水产品中麻醉剂MS-222残留

建立了液相色谱-串联质谱法测定水产品中麻醉剂3-氨基苯甲酸乙酯甲基磺酸盐(MS-222)残留量的方法。提取液为50%的甲醇及乙酸-乙酸钠缓冲溶液,提取液经C18固相萃取柱净化处理后用液相色谱-串联质谱仪进行测定,外标法定量。流动相为0.5%的甲酸溶液和乙腈(V:V=60:40),流速为0.2 mL/min。该方法的线性范围为0.001～1.0 mg/L,相关系数大于0.999,检出限为1μg/kg,定量限为2μg/kg。加标回收率可以达到80%～110%。