反相高效液相色谱法测定人参源胶囊中人参皂苷Rh2的含量

目的 测定人参源胶囊中人参皂苷Rh2的含量.方法 采用反相高效液相色谱法,色谱柱:ODS-C18(5μm,250 mm×4.6 mm),流动相:乙腈-水(60:40),流速: 1.0 mL/min,检测波长:203 nm,柱温:30℃.结果 人参皂苷Rh2在0.08～0.24 mg/mL的浓度范围内,其进样量与峰面积呈良好的线性关系,r=0.999 2,平均回收率为99.75%(n=6).结论 本法简便、快捷、准确,重复性好,可用于人参源胶囊含量的测定和质量控制.     

超高效液相色谱法测定清咽含片中罗汉果皂苷V

目的建立超高效液相色谱法(ultra performance liquid chromatography,UPLC)测定清咽含片中罗汉果皂苷V含量的方法。方法色谱条件为色谱柱:XSELECT HSS T_3(100 mm×2.1 mm,2.5μm);流动相:乙腈:0.1%磷酸水溶液,梯度洗脱,流速:0.4 mL/min;柱温:40℃;进样量:5μL;检测波长:203 nm。结果结果表明,罗汉果皂苷V线性范围为0.033~0.333 mg/mL(r=1.0000),检出限66.4μg/g,定量限221.6μg/g,精密度(relative standard deviation,RSD)为1.5%,平均回收率97.6%(n=9)。结论此法操作简单、准确、快速,可作为清咽含片中罗汉果皂苷V含量的检测方法。     

变波长高效液相色谱法同时测定葡萄酒中7种人工合成色素及防腐剂

建立了葡萄酒中7人工合成色素和防腐剂的高效液相色谱测定方法。方法采用ZORBAX Eclipse XDB-C18(4.6mm×250mm×5μm)反相色谱柱,流动相为20mmo L/L乙酸铵-甲醇(梯度洗脱),流速1.0m L/min,柱温30℃,进样量20μL。该方法的检出限0.2mg/L,线性范围0.40-50μg/m L,加标回收率98.9-104.1%,相对标准偏差为1.03-2.00%(n=4)。     

双柱在线净化系统快速检测动植物油脂中的苯并(a)芘

该文建立了双色谱柱在线净化-超高速液相色谱仪联用检测动植物油脂(猪油、花生油、茶籽油、大豆油、调和油)中苯并(a)芘方法。采用正己烷-异丙醇溶液提取试样中苯并(a)芘,提取液过滤后进样,利用试验组建的双色谱柱系统进行在线净化,第一根色谱柱为分离、富集柱,采用Kromasil反C_(18)(4. 6 mm×150 mm,5μm)柱;第二根色谱柱负责进一步分离苯并(a)芘,采用Chrom Spher pi(80 mm×3. 0 mm,5μm)色谱柱。试验结果表明,样品中苯并(a)芘含量在1. 0～20. 0 ng/mL,与峰面积呈良好线性关系,相关系数r~2为0. 999 6,检出限为0. 08μg/kg,在1. 00、5. 00、10. 00μg/kg加标水平下,加标回收率为82. 0%～91. 6%,相对标准偏差为1. 89%～4. 29%。该方法可用于常见动植物油脂等易受苯并(a)芘污染的样品的快速检测。     

HPLC测定过山厥提取物中山柰素含量

目的 建立高效液相色谱法测定过山厥提取物中山柰素含量.方法 Hypersil ODS2(4.6 mm×200 mm,5μm)色谱柱,甲醇-0.07％磷酸(50∶50)为流动相,检测波长268 nm,流速1.0 mL/min,柱温25℃.结果 山柰素浓度在4.99～12.98mg/L线性关系良好,回归方程为Y=58 735X-44 779 (R2=0.9983);平均回收率99.8％,RSD=0.97％;重复性良好,RSD=1.14％(n=5).结论 该方法简单、可靠、专属性强,可用于过山厥提取物中山柰素的含量测定.     

高效液相色谱法测定发酵辣椒中的有机酸

建立了高效液相色谱法同时分析发酵辣椒中8种有机酸的方法.采用Hypersil-ODS2色谱柱(4.6mm×200mm,5μm),色谱条件为:2%甲醇-0.05mol/L KH2PO4(pH2.8)作为流动相,流速0.8ml/min,柱温17℃,进样量5μl,检测波长214nm.在此条件下,8种有机酸能够得到较好的分离,回收率92.87%～106.15%,RSD＜3%.同时还比较了不同提取方法的提取效果,表明加热提取比超声波提取的效果更好.     

高效液相色谱-串联质谱法测定双壳类水产品麻痹性贝类毒素

目的采用Supelco ENVI-Carb柱净化双壳类水产品中的麻痹性贝类毒素(PSP),建立高效液相色谱-串联质谱(HPLC-MS/MS)法检测双壳类水产品中的PSP,为水产品中的PSP检测提供方法依据。方法选用色谱柱TSK-GEL Amide-80(2.0 mm×250 mm,5μm),以2 mmol/L甲酸铵-50 mmol/L甲酸水和95%乙腈水(含2 mmol/L甲酸铵-50 mmol/L甲酸)为流动相,采用梯度洗脱进行分离。样品用1%乙酸溶液进行提取,上清液加入氨水后(pH=4.0)经Supelco ENVI-Carb柱净化,将洗脱液抽干收集,上机测定。多重反应监测(MRM)模式检测。结果PSP的线性范围为8.1~705.0μg/kg,检出限为10~35μg/kg,回收率在47.0%~91.3%之间。结论本方法提取效果好、基质效应小,适用于双壳类水产品中麻痹性贝类毒素的痕量检测。     

高效液相色谱法测定枣叶中酸枣仁皂苷B的含量

建立了一种测定枣叶中酸枣仁皂苷B含量的高效液相色谱分析方法,色谱条件为:色谱柱Hypersil BDS C18(4.6 mm×200 mm,5μm);流动相为乙腈:水(35:65,v/v),加入甲酸0.05%;流速为0.8 mL/min;柱温30℃;检测波长204 nm。结果表明:酸枣仁皂苷B在20~1000μg/m L范围内具有良好的线性关系(r2=0.9999),平均加标回收率为100.1%,最低检出限1.1μg/mL。采用开发的高效液相色谱法对14个品种的大枣及酸枣的幼叶中酸枣仁皂苷B的含量进行了测定,其含量在0.91~2.67 mg/g之间。     

钛胶反相高效液相色谱法测定饮料中的咖啡因

建立了利用钛胶反相柱快速测定饮料中咖啡因的含量的高效液相色谱方法.色谱条件:分离柱为Titania Sachtopore - RP柱(250mm×4.6mm i.d.,5μm),柱温30℃,流动相为水∶甲醇=83∶17 (V/V),流速1 mL/min,检测波长273nm.线性范围为12 - 900μg/mL,此范围内标准曲线线性良好(R2=0.9998).最低检出限(S/N =3)为0.03 μg/mL,样品加标回收率范围为98.6％～102.2％,精密度即相对标准偏差(n=9)小于0.23％.本法简单易操作、分析速度快,精密度和准确度均取得满意效果,适用于各种饮料样品中咖啡因的定量分析.本研究不仅是对食品中咖啡因检测方法的补充,更重要的是发挥了钛胶固定相不可比拟的优势.     

葡萄酒有机酸的HPLC分析中色谱条件的优化

本文优化了反相高效液相色谱测定葡萄酒有机酸的色谱条件.研究表明,采用Waters Atlantis T3反相C18色谱柱(4.6mm×150mm,5μm),保护柱为Waters Atlantis T3 Security Guard(4.6mm ×1.5mm,5μm),含1%甲醇的0.02mol/L磷酸二氢钾(pH2.7)为流动相,等度洗脱,流速为0.8mL/min,UV紫外检测器,柱温40℃,检测波长为210nm和243nm,能将7种有机酸有效分离.精密度和回收率分析表明,该方法操作简单、准确率高.     

Comparative studies on Ophiopogonis and Liriopes based on the determination of 11 bioactive components using LC–MS/MS and Hierarchical clustering analysis

Radix Ophiopogonis and Radix Liriopes are two widely used herbal medicines and functional foods with similar pharmacological activities and clinical efficacies. In order to figure out whether phytoequivalence of species leads to therapeutic equivalence and consistency, in this study, a novel sensitive and selective high performance liquid chromatography-tandem mass spectrometric method (HPLC-MS/MS) has been developed for the simultaneous analysis of 11 bioactive components (6 steroidal saponins and 5 flavonoids) and then was applied for comparing in Radix Ophiopogonis and Radix Liriopes from different habitats. Separation was performed using a C₁₈ analytical column with gradient elution of acetonitrile and 0.3‰ acetic acid (v/v) at a flow rate of 0.8 mL/min. Multiple-reaction monitoring (MRM) scanning was employed with switching electrospray ion source polarity between positive and negative modes in a single run. All calibration curves showed good linearity (r² > 0.9915) within the test ranges. The intra-day and inter-day precision for 11 analytes were less than 3.7% and 4.2%, respectively. The recoveries were between 95.3% and 106.7%. Fifty-three batches of commercial samples from different sources were analyzed using the developed method. Hierarchical clustering analysis (HCA) and content analysis were performed to differentiate and classify the samples. The results demonstrated that steroidal saponins were the major components in both Liriopes species, and a low content of flavonoids could become an important symbol of distinction between Ophiopogonis and Liriopes. The developed method could successfully differentiate between Ophiopogonis and Liriopes.     

八种野菜氨基酸及维生素的含量分析

采用柱前衍生反相高效液相色谱法测定贵州8种野菜(鸭儿芹、蓝布正、鱼香菜、灰菜、剪刀菜、豆瓣菜、清明菜、水芹)中17种氨基酸含量,并采用高效液相色谱法测定了其中的维生素A、维生素E、维生素B1、维生素B2的含量。结果表明,在所测定的野菜中,豆瓣菜,灰菜、鱼香菜氨基酸总量和必需氨基酸含量较高;清明菜维生素A含量最高,鱼香菜、水芹、剪刀菜富含维生素E,蓝布正、豆瓣菜、清明菜富含维生素B1,豆瓣菜维生素B2含量最高。这些野菜具有较高的营养价值。     

襄麦冬黄酮提取及其体外活性研究

以襄麦冬为原料,利用索氏提取器提取黄酮并对其体外抗氧化(维生素C作为阳性对照)、抑菌活性进行研究。结果显示,襄麦冬黄酮的羟自由基清除能力、DPPH自由基清除能力比维生素C强,而其还原力、超氧阴离子自由基清除能力比维生素C弱。在一定浓度范围内,襄麦冬黄酮的抗氧化活性随其浓度的增加而增大。抑菌活性研究结果发现,襄麦冬黄酮对金黄色葡萄球菌和枯草芽孢杆菌均有一定的抑菌作用,对金黄色葡萄球菌的抑菌作用更强,最大抑菌圈直径可达18.80 mm,对金黄色葡萄球菌和枯草芽孢杆菌的最小抑菌浓度均为7 mg/mL。结果表明,襄麦冬黄酮具有一定的抗氧化活性和抑菌活性,可为襄麦冬活性成分进一步开发利用提供参考。     

基于指纹图谱和化学计量分析的鳕鱼肝油软胶囊掺假植物油鉴定

目的 建立一种基于脂肪酸气相色谱(gas chromatography, GC) 指纹图谱技术结合化学计量分析的鳕鱼肝油软胶囊中掺假植物油的鉴定方法。方法 采用GC法测定不同来源鳕鱼肝油软胶囊脂肪酸指纹图谱, 经拟合后构建对照指纹图谱, 并进行样品相似度评价。模拟制备鳕鱼肝油软胶囊中掺入不同种类、不同比例植物油的掺假样品, 以其中14个共有脂肪酸峰的相对峰面积作为数据源, 输入SIMCA-P数据分析软件进行主成分分析(principal component analysis, PCA)及掺假模型建立。结果 获得鳕鱼肝油软胶囊GC对照指纹图谱及三维掺假识别模型, 44批样品经相似度评价发现有2批拟似掺假植物油, 将拟似样品色谱数据标准化后导入SIMCA-P软件, 显示2批样品均掺了大豆油, 掺假比例约为15%和35%。结论 脂肪酸GC指纹图谱结合化学计量分析为鳕鱼肝油软胶囊中掺假植物油的鉴定提供一种可靠准确的检测手段, 可快速有效识别鳕鱼肝油掺假行为。     

不同麦冬添加量对发酵红枣汁品质的影响

结合红枣高营养价值与麦冬的高保健价值的优点,利用酵母菌制备发酵红枣汁,探究不同麦冬添加量（0、2%、4%、6%、8%、10%、15%、20%）对发酵红枣汁色泽、滋味、风味等指标的影响,并对结果进行主成分分析（PCA）及聚类分析（CA）。结果表明,麦冬添加量对发酵红枣汁品质影响显著（P＜0.05）。与未添加麦冬对照相比,麦冬添加量在2%～20%时,红绿值（a*值）均随之上升,麦冬添加对黄蓝值（b*值）影响显著（P＜0.05）,麦冬添加量2%～10%时趋向红-黄色;麦冬添加量为6%时明亮度（L*值）最大。麦冬添加量在2%～20%时,可以明显提升红枣汁的鲜味、丰度;苦味值降低;可以有效减少异味。综上,麦冬最适添加量为10%,该条件下发酵红枣汁色泽、风味良好。     

三文鱼水产品掺假情况调查

目的调查广东省市售三文鱼水产品掺假情况。方法应用实时荧光PCR技术检测大西洋鲑鱼和虹鳟鱼的方法,对广东省内批发市场、超市、餐饮寿司店和网络平台等场所的三文鱼掺假情况进行调查。结果98批次样品中,有6批次未检出大西洋鲑鱼,未检出率为6.12%。通过PCR测序结果鉴定,这6批次未检出大西洋鲑鱼的样品中,4批次为虹鳟鱼,1批次为王鲑,1批次为银鲑。结论三文鱼水产品掺假情况较少,但掺假风险仍然存在,建议监管部门加强监管。     

Inhibition kinetic and mechanism of polyphenol oxidase from various sources by diethyldithiocarbamic acid

Inhibition kinetics and mechanism of polyphenol oxidases (PPO) partially purified from various sources such as Thymbra spicata L. var. spicata and Ocimum basilicum L., and of mushroom PPO bought from Sigma by diethyldithiocarbamic acid have been described using catechol, 4-methylcatechol and pyrogallol as substrates. The inhibition type was competitive for O. basilicum L. PPO using catechol and 4-methylcatechol as substrates, for mushroom PPO using catechol, 4-methylcatechol and pyrogallol as substrates, and for T. spicata L. var. spicata PPO using 4-methylcatechol as a substrate; uncompetitive inhibition for T. spicata L. var. spicata PPO using pyrogallol as a substrate; and non-competitive inhibition for O. basilicum L. and T. spicata L. var. spicata PPO using pyrogallol and catechol as substrates, respectively. The inhibition effect of diethyldithiocarbamic acid on enzymatic browning varied greatly from one phenol to another and from one enzyme to another. Hence, no general rule can easily be established with regard to the type of inhibition observed.     

Reverse-Phase HPLC Analysis of Reference Cheddar Cheese Samples for Assessing Accelerated Cheese Ripening

Applying water extracts from Cheddar cheese to an octadecyl vinyl alcohol copolymer column using a reliable auto-sampling system provided highly repeatable HPLC patterns. Two batches of standard samples of mild, medium, sharp, and extra-sharp and one batch of abused samples (rapidly aged under abnormal conditions) were analyzed. Principal component similarity (PCS) analysis indicated similar shifts of plots due to aging of the standard batches, while the plot for the abused batch deviated from the pathway of normal aging. PCS may be useful for analysis of accelerated ripening effects as well as finding unusual samples during quality control.     

Targeted and non-targeted detection of lemon juice adulteration by LC-MS and chemometrics

Economically motivated adulteration (EMA) of lemon juice was detected by LC-MS and principal component analysis (PCA). Twenty-two batches of freshly squeezed lemon juice were adulterated by adding an aqueous solution containing 5% citric acid and 6% sucrose to pure lemon juice to obtain 30%, 60% and 100% lemon juice samples. Their total titratable acidities, °Brix and pH values were measured, and then all the lemon juice samples were subject to LC-MS analysis. Concentrations of hesperidin and eriocitrin, major phenolic components of lemon juice, were quantified. The PCA score plots for LC-MS datasets were used to preview the classification of pure and adulterated lemon juice samples. Results showed a large inherent variability in the chemical properties among 22 batches of 100% lemon juice samples. Measurement or quantitation of one or several chemical properties (targeted detection) was not effective in detecting lemon juice adulteration. However, by using the LC-MS datasets, including both chromatographic and mass spectrometric information, 100% lemon juice samples were successfully differentiated from adulterated samples containing 30% lemon juice in the PCA score plot. LC-MS coupled with chemometric analysis can be a complement to existing methods for detecting juice adulteration.     

吹扫捕集GC/MS法测定紫苏不同变种叶片中的挥发性成分

采用吹扫捕集技术对紫苏不同变种叶片中的挥发性成分进行富集,以气质联用仪(GC-MS)进行鉴定,运用面积归一化法确定各组分的相对含量。结果表明,分别属于紫苏属植物3 个变种的4 份试材之间叶片挥发油的组分和相对含量差异显著。4 份紫苏试材共检测出31 种挥发油成分,但其共有的成分仅有顺-3- 己烯醛、石竹烯和圣亚麻三烯3 种。野生紫苏变种的主要成分是柠檬烯(77.90%)、石竹烯(14.33%)、顺-3- 己烯醛(4.9%)、胡椒酮(1.71%),回回苏变种的主要成分是石竹烯(30.65 %)、柠檬烯(24.60%)、顺-3- 己烯醛(21.82%)、紫苏醛(17.70%),紫苏变种1(来源于河北安国市)的主要成分是5- 乙叉-1- 甲基- 环庚烯(52.79%)、顺-3- 己烯醛(19.98%)、石竹烯(13.60%)、紫苏醛(9.46%),紫苏变种2(来源于广西灵山县)的主要成分是紫苏醛(31.86%)、5- 乙叉-1- 甲基- 环庚烯(31.68%)、顺-3- 己烯醛(21.50%)、石竹烯(10.47%)。