固相萃取-高效液相色谱-串联质谱法同时测定蜂蜡中氯霉素、甲砜氯霉素、氟苯尼考和其代谢产物氟苯尼考胺残留

首次建立了一种同时测定蜂蜡中氯霉素、甲砜氯霉素、氟苯尼考和其代谢物氟苯尼考胺等药物残留的固相萃取-高效液相色谱-串联质谱分析方法。根据蜂蜡脂溶性的特点,试样采用正己烷溶剂预溶解,用水提取2次后经混合型阳离子交换固相萃取柱（MCX）净化,用InertSustain Swift C₁₈柱（100 mm×2.1 mm, 1.9 μm）分离,多反应监测（MRM）模式串联质谱进行测定,以内标法定量。结果表明,在0.1~10 ng/mL范围内4种测定物均具有较好的线性关系,相关系数大于0.99,方法定量限（S/N>10）为0.1 μg/kg。对阴性蜂蜡在0.1、0.3和1.0 μg/kg等3个添加水平下分别进行加标回收试验,实际样品中4种测定物质的平均回收率在65.0%~113.2%之间,相对标准偏差（RSD,n=6）小于20%。应用本方法对15个蜂蜡样品进行检测,结果表明有4批次样品检出氯霉素类药物残留。本方法快速、灵敏、准确,适用于日常大批量蜂蜡样品中氯霉素类药物及其代谢物残留的定性、定量分析。     

超高效液相串联质谱法测定食品中的乌洛托品

利用液相串联质谱法测定食品中乌洛托品。样品经乙腈提取、正己烷除脂,Oasis MCX固相萃取柱净化,以乙腈-10mmol/L乙酸铵溶液为流动相,超高效液相色谱-串联质谱仪进行分析。结果表明:在0~100μg/L,乌洛托品所得的回归方程呈良好的线性关系,相关系数大于0.999。该方法检出限(S/N=3)和定量限(S/N=10)分别为0.3和1.0μg/kg。该方法的平均回收率为86.2%~94.2%,RSD为1.67%~3.06%。该方法快速、准确和灵敏,适用于食品中乌洛托品的测定及确认。     

固相萃取-气相色谱-串联质谱法测定淡水鱼鱼肉中的五氯酚

目的建立采用固相萃取-气相色谱-串联质谱联用为基础的淡水鱼鱼肉中五氯酚的测定方法。方法淡水鱼鱼肉经粉碎后,液液萃取,MAX柱净化,乙酸酐-吡啶溶液衍生成五氯苯乙酸酯,气相色谱-串联质谱仪进行定性和定量分析。结果在1、5、20μg/kg 3个水平下的回收率范围为85.6%~98.4%,相对标准偏差小于10%,方法的定量限为0.85μg/kg(S/N=10),检出限为0.26μg/kg(S/N=3)。结论该方法具有良好的回收率及稳定性,适用淡水鱼鱼肉中五氯酚的测定。     

固相萃取-气相色谱-串联质谱法测定蔬菜中的 16种多环芳烃

目的建立固相萃取-气相色谱-串联质谱法测定蔬菜中16种多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的分析方法。方法样品经正己烷-二氯甲烷匀浆提取,经中性硅胶-中性氧化铝复合固相萃取柱净化后,用多反应监测(multiple-reaction monitoring,MRM)正离子扫描方式进行检测,气相色谱-串联质谱法测定,内标法定量。结果 16种目标物在2~250 ng/m L范围内呈线性关系良好,方法的检出限(S/N=3)为0.09~0.51μg/kg,定量限(S/N=10)为0.31~1.68μg/kg。在2、5、20μg/kg 3个加标水平下的平均回收率为添加平均回收率范围为70.6%~109.2%,相对标准偏差(RSD)为1.95%~10.4%。结论该方法选择性好、抗干扰能力强,能满足国内外法规的要求,可用于蔬菜中多环芳烃残留的日常检测。     

同位素稀释法-超高效液相色谱-串联质谱法测定豆芽中6种喹诺酮类药物残留

目的建立通过式固相萃取(solid phase extraction,SPE)柱净化、氘代同位素内标、超高效液相色谱-串联质谱法同时测定豆芽中6种喹诺酮类药物残留的方法。方法用0.1%甲酸-乙腈作为提取溶剂,经通过式固相萃取柱净化提取液,超高效液相色谱-串联质谱测定豆芽中6种喹诺酮药物残留。结果 6种喹诺酮在5.0～200μg/L范围内线性关系良好,r~2≥0.999;方法检出限(S/N=3)为0.7μg/kg,定量限(S/N=10)为2.0μg/kg;加标水平为2.0～80μg/kg时,平均回收率在85.5%～119.4%,相对标准偏差(relative standard deviation,RSD)(n=6)为0.13%～9 93%。结论本方法前处理简单,定量结果准确,回收率高,可以应用于大批次豆芽中喹诺酮药物残留的监测。     

动物肌肉、内脏和牛奶中咪唑脲苯残留量的高效液相色谱测定及液相色谱-串联质谱确证

目的建立固相萃取净化-高效液相色谱和液相色谱-串联质谱测定动物组织和牛奶中咪唑脲苯残留量的分析方法。方法残留的咪唑脲苯采用1%三氟乙酸-乙腈(1:4,v/v)提取,Oasis WCX固相萃取柱净化,高效液相色谱外标法定量,并经液相色谱-串联质谱确证。结果咪唑脲苯检出限为10μg/kg(S/N≥3),定量限为25μg/kg(S/N≥10);在LOQ、MRL和2MRL三个添加水平下重复分析6次,回收率为72.7%~101%,相对标准偏差为1.2%~6.9%。结论该方法稳定、可靠,适用于动物组织和牛奶中咪唑脲苯的测定。     

固相萃取-高效液相色谱-串联质谱法测定蜂胶中氯霉素残留

该文建立固相萃取结合高效液相色谱-串联质谱技术(solid phase extraction-high performance liquid chromatography-tandem mass spectrometry,SPE-HPLC-MS/MS)测定蜂胶中氯霉素残留的检测方法。蜂胶样品经乙腈溶解,氢氧化钙溶液沉淀杂质,Bond Elut Plexa固相萃取柱(6mL,200mg)净化,Kinetex C18色谱柱(50mm×2.1mm,2.6μm)分离,以水-乙腈为流动相梯度洗脱分离,在负模式下,采用多反应监测(multiple reaction monitoring,MRM)模式检测,内标法定量。结果表明,氯霉素在0.1μg/L~500.0μg/L范围内线性关系良好(R2>0.99),检出限为0.4μg/kg,定量限为1.0μg/kg。氯霉素在蜂胶样品中添加水平为1、2、10μg/kg时平均回收率为93.2%~103.4%,日内和日间相对标准偏差分别为0.98%~3.95%和0.93%~5.37%(n=5)。该方法操作简便,耗时短,灵敏度高,稳定性好,适用于蜂胶中氯霉素残留筛查检测及定量分析。     

固相萃取小柱-超高效液相串联质谱测定牛奶中氯霉素

建立可靠的前处理方法,采用超高效液相色谱-串联质谱法检测牛奶中氯霉素。样品经乙酸乙酯提取,分析了分别经C18及MCS固相萃取柱净化、富集的结果;以乙腈-0.05%氨水为流动相,经C18色谱柱分离,采用多反应检测负离子模式进行定性及定量分析。结果表明,MSC固相萃取柱具有较好的回收率,氯霉素的方法检出限为0.004μg/kg,方法定量限为0.01μg/kg,在0.01、0.25、1.00μg/kg 3个加标水平下回收率分别为71.0%、53.8%、50.4%。本法灵敏度高、重复性好,可满足牛奶样品中痕量氯霉素残留的测定。     

超高效液相色谱-串联质谱法测定乳饼中的氯霉素

目的建立一种超高效液相色谱-串联质谱法(ultra high performance liquid chromatography tandem mass spectrometry, UPLC-MS/MS)检测乳饼中氯霉素的分析方法。方法样品经乙酸乙酯提取,分析了分别经C18(100 mm×2.1 mm, 1.7μm)及MCS固相萃取柱净化、富集的结果;以乙腈-0.05%氨水为流动相,经C18色谱柱分离,采用多反应检测负离子模式进行定性及定量分析。结果 MSC固相萃取柱具有较好的回收率,氯霉素的方法检出限为0.004μg/kg,方法定量限为0.01μg/kg,在0.10、0.50、1.00、10.00 ng 4个加标水平下回收率分别为76.4%、101%、62.4%、61.1%。结论本方法灵敏度高、重复性好,可满足乳饼样品中痕量氯霉素残留的测定。     

超高效液相色谱-电喷雾串联质谱测定食品中对位红的检测方法研究

建立了超高效液相色谱-电喷雾串联质谱法测定食品中对位红的检测方法。样品经提取后,采用了Waters Oasis HLB作为固相萃取小柱,进行样品净化,经超高效液相色谱分离后采用电喷雾串联质谱进行定性及定量检测。线性范围为0.1～1.0mg/L,线性相关系数为0.999。方法的定性检出限(S/N=3)为0.26μg/kg,定量检出限(S/N=10)为0.85μg/kg。高、中、低3个浓度水平的加标回收率范围为80.5%～109.5%,相对标准偏差小于10%。     

人参多糖提取工艺优化及其组成分析

以超临界脱脂、脱皂苷后的人参渣为原料,采用超临界辅助热水浸提法提取人参多糖,采用正交试验确定提取人参多糖的最佳工艺条件。结果表明：在萃取压力30 MPa、萃取温度80 ℃、萃取时间1.5 h 、物料粒度0.20 mm、原料-夹带剂比例1∶2.5（g/mL）时,人参多糖提取率为（38.03±1.43）%,多糖纯度为（54.71±2.16）%,与热水浸提法相比,提取率和纯度分别提高了16.15%和13.44%。采用高效液相色谱法和高效凝胶渗透色谱法对人参多糖中的单糖组成和多糖平均分子质量进行分析,发现人参多糖含有较多的葡萄糖以及少量的半乳糖、阿拉伯糖,且超临界辅助热水浸提法中这3 种单糖的含量均显著高于热水浸提法。超临界辅助热水浸提法与热水浸提法提取的人参多糖重均分子质量分别为123 847 u和127 016 u,但是超临界辅助热水浸提法的人参多糖中多糖种类多于热水浸提法。     

无花果总黄酮闪式提取工艺优化及其抗氧化活性

本研究基于单因素实验并结合Box-Behnken设计优化闪式提取无花果总黄酮的工艺,通过考察乙醇体积分数、提取电压、液料比以及提取时间等因素对总黄酮提取的影响,获得无花果总黄酮闪式提取的最佳条件,并对其抗氧化活性进行了研究。结果表明,响应面优化无花果总黄酮的最佳提取工艺条件为:乙醇体积分数50%,液料比50:1 mL/g,提取时间80 s,提取电压150 V。在此条件下无花果总黄酮的提取量为(36.94±0.02) mg/g,与预测值36.98 mg/g误差仅为0.103%,证实了结果的准确可靠。抗氧化实验显示无花果总黄酮对DPPH自由基的清除效果优于抗坏血酸,而对ABTS+自由基的清除效果弱于抗坏血酸,其对OH自由基清除的IC₅₀为0.098 mg/mL,与抗坏血酸(IC₅₀为0.159 mg/mL)相比,黄酮对OH自由基的清除效果更好。闪式提取无花果总黄酮提取量较高且耗时更短,表明闪式提取法应用于无花果黄酮提取更具优势。无花果总黄酮具有较好的抗氧化活性,有望为功能性食品或保健品的开发提供理论基础。     

微波辅助提取红车轴草异黄酮的工艺研究

采用密闭微波提取装置对红车轴草异黄酮成分进行提取工艺的研究。通过单因素和正交试验对红车轴草异黄酮提取工艺中乙醇浓度、微波功率、料液比、提取时间和提取次数等影响异黄酮提取率的因素进行探讨。红车轴草异黄酮的最佳提取工艺参数为:乙醇浓度70%,微波功率高火(750W),料液比1:15,提取时间1min,提取三次,异黄酮提取率可达到98.91%。与超声波提取、乙醇回流提取和索氏提取相比,微波提取具有提取速度快,选择性好及操作方便等特点。     

A systematic approach for extraction of phenolic compounds using parsley (Petroselinum crispum) flakes as a model substrate

The impact of extraction methodology and polarity of extraction solvents on the assay of phenolic compounds was investigated using parsley (Petroselinum crispum) flakes as a model substrate. This systematic study was undertaken to address substantial variations in the extraction procedures, solvents and conditions as described in the recent literature. Five different extraction procedures [shaking, vortex mixing, sonication, stirring and pressurized liquid extraction (PLE)] and three different solvents (methanol, ethanol and acetone), with five different solvent to water ratios per solvent, were used for extraction. Extracts were analyzed for phenolic content by high‐performance liquid chromatography and Folin–Ciocalteu assays. The yields of phenolic compounds extracted with a pressurized liquid extractor were comparable to or better than those of four classical extraction procedures. Optimum extraction efficiency with PLE was obtained when extractions were performed with four extraction cycles using ethanol–water (50:50, v/v). The amount of apiin (4,5,7‐trihydroxyflavone 7‐apiosylglucoside) and malonylapiin (apigenin malonylapiosylglucoside) isolated from parsley varied with the composition of extraction solvent. Apiin extractability was found to be a maximum when the solvent (ethanol, methanol or acetone) to water ratio was 30:70 (v/v), whereas higher amounts of malonylapiin were isolated with a reverse solvent to water ratio (70:30, v/v). Malonylapiin was not detected when parsley samples were extracted with organic solvent to water ratios of 10:90 (v/v) and 30:70 (v/v). Published in 2006 by John Wiley & Sons, Ltd     

Determination of polybromodiphenyl ethers (PBDEs) in milk cream by gas chromatography-mass spectrometry.

An analytical method for polybromodiphenyl ethers (PBDEs) in milk cream has been optimized. The six PBDEs targeted were chosen on criteria of toxicity and occurrence in environmental matrices. Three methods of extraction were tested and compared in terms of lipid recovery yields and repeatability. The sample preparation process includes two steps: extraction by accelerated solvent extraction (ASE) and purification by solid phase extraction (SPE). The preferred method of extraction used a hexane/methylene chloride/methanol (5 : 2 : 1, v/v) solvent mixture. Three extraction cycles were carried out per sample at a temperature of 80 degrees C and a pressure of 1500 psi. The method was validated on milk cream samples spiked with the specified PBDEs. Recoveries for the whole sample preparation process (extraction and cleanup) for cream samples spiked at 10 and 100 ng g(-1) were greater than 80% (ranging from 81 to 106%) at both concentrations for BDE-99, -100, -153 and 154. Recoveries were lower (ranging from 65 to 75%) for BDE-28 and BDE-47. PBDEs were quantified by GC/MS detection with selected ion monitoring (SIM) using three ions formed by electron capture. The method was successfully tested on real samples.     

Determination of polybromodiphenyl ethers (PBDEs) in milk cream by gas chromatography-mass spectrometry

An analytical method for polybromodiphenyl ethers (PBDEs) in milk cream has been optimized. The six PBDEs targeted were chosen on criteria of toxicity and occurrence in environmental matrices. Three methods of extraction were tested and compared in terms of lipid recovery yields and repeatability. The sample preparation process includes two steps: extraction by accelerated solvent extraction (ASE) and purification by solid phase extraction (SPE). The preferred method of extraction used a hexane/methylene chloride/methanol (5 : 2 : 1, v/v) solvent mixture. Three extraction cycles were carried out per sample at a temperature of 80 degrees C and a pressure of 1500 psi. The method was validated on milk cream samples spiked with the specified PBDEs. Recoveries for the whole sample preparation process (extraction and cleanup) for cream samples spiked at 10 and 100 ng g(-1) were greater than 80% (ranging from 81 to 106%) at both concentrations for BDE-99, -100, -153 and 154. Recoveries were lower (ranging from 65 to 75%) for BDE-28 and BDE-47. PBDEs were quantified by GC/MS detection with selected ion monitoring (SIM) using three ions formed by electron capture. The method was successfully tested on real samples.     

Determination of polybromodiphenyl ethers (PBDEs) in milk cream by gas chromatography–mass spectrometry

An analytical method for polybromodiphenyl ethers (PBDEs) in milk cream has been optimized. The six PBDEs targeted were chosen on criteria of toxicity and occurrence in environmental matrices. Three methods of extraction were tested and compared in terms of lipid recovery yields and repeatability. The sample preparation process includes two steps: extraction by accelerated solvent extraction (ASE) and purification by solid phase extraction (SPE). The preferred method of extraction used a hexane/methylene chloride/methanol (5 : 2 : 1, v/v) solvent mixture. Three extraction cycles were carried out per sample at a temperature of 80°C and a pressure of 1500 psi. The method was validated on milk cream samples spiked with the specified PBDEs. Recoveries for the whole sample preparation process (extraction and cleanup) for cream samples spiked at 10 and 100 ng g^?1 were greater than 80% (ranging from 81 to 106%) at both concentrations for BDE-99, -100, -153 and 154. Recoveries were lower (ranging from 65 to 75%) for BDE-28 and BDE-47. PBDEs were quantified by GC/MS detection with selected ion monitoring (SIM) using three ions formed by electron capture. The method was successfully tested on real samples.     

忧遁草茎中黄酮类化合物的提取工艺优化及比较

为筛选适合忧遁草茎中黄酮类化合物的提取方法,以得率为评价指标,在单因素基础上,通过正交试验优化纤维素酶法和有机溶剂浸提法提取忧遁草茎中的黄酮类化合物工艺;采用ABTS自由基法、DPPH自由基法和还原力法比较提取物的抗氧化性。结果表明,纤维素酶辅助提取忧遁草茎中黄酮类化合物的最佳工艺条件为:乙醇浓度80%(v/v)、温度55 ℃、pH5.0、底物质量浓度30 g/L、酶用量300 U/g、时间1.5 h;有机溶剂浸提的最佳工艺条件为:乙醇浓度80%(v/v)、温度55 ℃、料液比1:15 (g/mL)、时间2.5 h。纤维素酶辅助提取忧遁草茎中的黄酮类化合物得率为(1.32±0.11)%(w/w),高于有机溶剂浸提法的(1.05±0.08)%(w/w)。2种提取方法得到的黄酮化合物均具有较强的抗氧化性,其中纤维素酶辅助提取物清除ABTS自由基和DPPH自由基的半抑制浓度(IC50)值分别为(1.94±0.04)、(0.178±0.013)mg/mL,低于有机溶剂提取物的(2.76±0.05)、(0.200±0.015)mg/mL,说明酶法提取物的抗氧化性强于有机溶剂浸提法。忧遁草茎中黄酮类化合物提取采用纤维素酶辅助提取较为适宜。     

响应面试验优化碱溶酸沉法提取山药储藏蛋白工艺

以河南焦作白玉山药为原材料,在单因素试验的基础上,采用响应面法中的Box-Behnken试验设计,对影响山药储藏蛋白提取率的3 个影响因素即抽提pH值、液料比和抽提时间进行优化。结果表明：各因素对山药储藏蛋白提取率有显著影响,因素影响主次顺序为：抽提pH值＞液料比＞抽提时间,提取山药储藏蛋白的最佳工艺条件为抽提pH 8.5、液料比3∶1（mL/g）、抽提时间20 min,在此条件下山药储藏蛋白提取率的最大理论值为57.88%,实际蛋白提取率为57.74%。所得山药储藏蛋白提取回归模型显著,拟合性好,可用于预测山药储藏蛋白提取率。     

花椒多酚提取工艺响应面优化及动力学分析

以多酚收率为优化指标,对花椒中多酚的提取工艺进行研究,通过单因素试验考察处理温度、提取时间、溶剂体积分数、料液比和提取液pH值对多酚提取过程的影响。利用Box-Behnken响应面分析法优化多酚提取的最佳工艺条件为提取溶剂为乙醇溶液、溶剂体积分数48.23%、料液比1∶29.34（g/mL）、处理温度48.99?℃、提取时间1.75?h、提取液pH?3,在此条件下进行5?次平行实验,预测的多酚收率为55.06?mg/g。此外,研究不同温度下总酚的传质动力学,通过平板模型以Fick第一定律为基础建立了花椒多酚提取的动力学模型,并求解出速率常数、相对萃余率及活化能等关键模型参数,为花椒多酚提取的工厂放大和深入研究提供一定依据。