反相高效液相色谱法测定平邑

用高效液相色谱法（ＨＰＬＣ）分析平邑甜茶内源ＡＢＡ、ＩＡＡ,选用Ｓｐｈｅｒｉｓｏｒｂ Ｃ１８反相柱,用ＵＶ检测器进行检测,使ＡＢＡ、ＩＡＡ得到很好的分离,测定方法迅速简便,流动相为甲醇、乙酸和水,系统研究了ｐＨ值、纯化方法对测定结果的影响,确定适合平邑甜茶ＡＢＡ、ＩＡＡ提取的分离条件。方法的精密度为：变异系数分别为２．８３和２．７９,最低检出限（信噪比＝２）分别为３．２７和３．２６ｎｍｏｌ／Ｌ,线     

反相高效液相色谱法测定万寿菊中的玉米黄质

用反相高效液相色谱法测定万寿菊中的玉米黄质。以丙酮与石油醚提取色素,色谱柱Kromasil(C184.6 mm×150mm),乙腈∶甲醇∶二氯甲烷(体积比为70:20:10)为流动相,在450 nm下检测玉米黄质。结果表明,玉米黄质的质量分数为0.158%,玉米黄质的回收率是94.7%~98.1%,平均回收率为96.4%(RSD=1.36%)。该方法简便、准确,有良好的重现性,技术参数指标符合食品理化分析的要求。     

反相高效液相色谱法测定血浆游离氨基酸

本文报告了采用高效液相色谱法反相梯度洗脱,邻苯二甲醛和β-巯基乙醇柱前衍生化,荧光检测分血浆游离氨基酸。实验采用线性洗脱,在50分钟内可同时测定18种氨基酸,血浆样品的预处理简单,衍生化反应的时间仅需1分30秒,血浆样品的实际进样量少于1μl。本测定方法的精确度高,各个氨基酸保留时间的变异系数平均为0.89%±0.45%(SD),峰面积的变异系数平均为2.06%±1.76%(SD),各个氨基酸的浓度在15—150μmol/L的范围中,线性关系的相关系数平均为0.985±0.0305(SD)。准确性好,各个氨基酸的回收率平均为97.6%±5.1%(SD)。实验还讨论了氨基酸分离时溶液pH值、柱温、离心速度等因素对分析结果的影响。     

反相高效液相色谱法测定厌氧菌有机酸代谢产物

建立反相高效液相色谱测定厌氧菌代谢发酵有机酸产物(乙酸、乳酸)的方法并用于测定乳酸菌代谢发酵产物中的含量。反相高效液相方法是一种简单、准确、灵敏的方法,可用于同时定量测定厌氧菌的有机酸代谢产物。     

反相高效液相色谱法测定烟叶中的游离氨基酸

用不同浓度的乙醇溶液提取烟样中的游离氨基酸 ,结果显示 ,存在最佳的乙醇溶液浓度 ,使烟样中被提取的游离氨基酸总量最大 ;对比了活性炭、乙醚、5 %磺基水杨酸、阳离子交换柱的纯化效果 ,发现阳离子交换柱的纯化效果较其它三种试剂要好。在提取和纯化之后 ,采用OPA、FMOC联合在线衍生反相高效液相色谱法测定了烟样中的游离氨基酸 ,该方法使烟样中的氨基酸和亚氨基酸能被同时测定 ,并且分析方法的重现性和回收率均令人满意。最后用该方法对云南B2 F98(上部、橘黄、二等烟叶 ,98年产 )烟叶中的游离氨基酸进行了测定 ,有 15种氨基酸被测出 ,其中Pro含量最高 ,约占总量的 2 5 % ,Thr含量最低 ,约占总量的 1%。     

反相高效液相色谱法测定发酵液中L-精氨酸含量

建立了一种用反相高效液相色谱测定发酵液中精氨酸含量的方法。以丙氨酸为内标物,2,4-二硝基氟苯为柱前衍生剂,用C18色谱柱在柱温30℃下,于362nm波长处检测,精氨酸质量浓度在0．Sg／L～1g／L时,其峰面积与内标物峰面积的比值和精氨酸的质量浓度的线形相关系数大于0．9998,加标回收率在104％左右。     

反相高效液相色谱法测定血清中γ-氨基丁酸

建立一种高灵敏度的氯甲酸芴甲酯柱前衍生荧光检测反相高效液相色谱法测定血清中γ-氨基丁酸的方法.内标为己氨酸, 固定相为Shim-Pack CLC-ODS(M), 4.6 mm×150 mm, 填充料为5μm; 流动相采用二元梯度洗脱, A相为0.05 mol/L醋酸钠缓冲液∶水∶四氢呋喃∶冰乙酸(250∶100∶15∶2.2), B相为乙腈∶甲醇(4∶1).系统研究了pH值、反应时间、离子强度及衍生化试剂用量对衍生化反应的影响, 确定最佳反应条件和最佳色谱条件.方法的精密度为批内变异系数＜4.6%,批间变异系数＜6.1%;最低检出限(信噪比＝2)为3.1 nmol/L;线性范围为50～1000 nmol/L, γ²＝0.9992;平均回收率为97.1%.     

Separation of oligo-RNA by reverse-phase HPLC.

A rapid and highly reproducible chromatographic technique has been developed for analysis and purification of complex mixtures of oligoribonucleotides. The method utilizes a column of microparticulate porous silica beads fully derivatized with octadecylsilyl groups. The column is eluted with gradients in acetonitrile/water/ammonium acetate pumped at pressures of 1500-300 psi. Most separations are completed in 5-15 min. with usually better than 1% reproducibility of absolute retention times and about 0.1% reproducibility of relative retention times. A single column accomplishes separations of mononucleosides, mononucleotides, and larger oligomers through at least 20-mers. The absolute detection limit is approximately 1 pmole of base though most of the analytical separations described use approximately 1 nmole. In favorable circumstances it is possible to use the analytical colums to purify approximately 1 mg of an oligonucleotide in a single 10-30 min. elution.     

效应面法优化石榴皮抑菌物的提取工艺

采用单因素和效应面法对石榴皮抑菌物提取条件进行优化,并对结果进行验证。结果发现:最佳提取温度为59℃、时间为73 min、液料比为40∶1(mL/g)。实验证明石榴皮提取物对枯草杆菌具有很强的抑制作用,且所用工艺简单易行,说明效应面优化法建立的数学模型预测结果可靠。     

新疆石榴皮多酚的提取及其对酪氨酸酶的抑制作用

优化新疆石榴皮多酚的提取工艺,并研究石榴皮提取物对酪氨酸酶的抑制作用。采用超声波辅助法提取石榴皮多酚,通过单因素试验和正交试验确定其最佳提取工艺条件:丙酮体积分数70%、超声波功率200 W、提取温度40℃、料液比1∶35 g/m L、提取时间50 min、提取2次,在此条件下石榴皮多酚得率为23.77 mg/g。同时测定了石榴皮多酚提取物对蘑菇酪氨酸酶的抑制活性,石榴皮多酚提取物质量浓度在12 mg/m L时,对酪氨酸酶活力的相对抑制率为44.05%。该研究为从石榴皮中提取天然酪氨酸酶抑制剂提供了实验依据。     

石榴皮抗氧化活性成分的提取及其组分的研究

以DPPH抑制率为指标,研究石榴皮中抗氧化活性成分。采用超声波法进行提取,通过正交实验确定了最佳提取工艺为:乙醇浓度60%、pH3、料液比(m/v)1∶15、提取3次,每次40 min。石榴皮粗提物依次用石油醚、氯仿、乙酸乙酯、正丁醇、水萃取,经D101大孔吸附树脂纯化,并采用液相色谱-质谱联用法(LC-MS)对石榴皮抗氧化成分进行鉴定。结果表明,石榴皮粗提物中,正丁醇部位对DPPH的抑制率最高,达62.68%,液-质联用鉴定出安石榴苷的两种异构体为石榴皮中最主要的抗氧化成分。     

Characterization of polymerized polyphenols by size-exclusion HPLC

Various kinds of high-molecular-mass polyphenols such as condensed tannins, hydrolyzable tannins, and polymerized anthocyanins, were readily characterized by a new size-exclusion HPLC method. This rapid analytical method may also be useful for the profiling of molecular mass distribution of polyphenolic constituents in many kinds of food materials.     

Antioxidant properties of gallocatechin and prodelphinidins from pomegranate peel

Gallocatechins and a range of prodelphinidins were purified by high performance liquid chromatography from pomegranate peel. Gallocatechin, gallocatechin-(4-8)-catechin, gallocatechin-(4-8)-gallocatechin and catechin-(4-8)-gallocatechin were all identified, purified and quantified by LC-DAD-MS and MS-MS. The antioxidant properties of these compounds were assessed using two methods: (i) inhibition of ascorbate/iron-induced peroxidation of phosphatidylcholine liposomes; and (ii) scavenging of the radical cation of 2,2-azinobis (3-ethyl-benzothiazoline-6-sulphonate, ABTS) relative to the water-soluble vitamin E analogue Trolox C (expressed as Trolox C equivalent antioxidant capacity, TEAC). The prodelphinidin dimers were potent antioxidants in the aqueous phase, being much more effective than the gallocatechin monomer. However, in the lipid phase, only one of the dimers (gallocatechin-(4-8)-catechin) was significantly more effective than the monomer in the inhibition of lipid peroxidation of phosphatidylcholine vesicles. This study represents the first report on the antioxidant properties of prodelphinidins.     

Purification of [I]-vasoactive intestinal peptide by reverse-phase HPLC

VIP was labeled with sodium ¹²⁵iodide, and ¹²⁵I-VIP was purified by reverse-phase high performance liquid chromatography. Optimal separations of ¹²⁵I-VIP and unlabeled VIP were obtained using two C₁₈-Novapak columns in series and a gradient of acetonitrile in triethylamine phosphate for elution. The specific activity of the ¹²⁵I-VIP was 1.99±0.21 Ci/μmole, approaching the maximum specific activity of monoiodinated VIP (2.26 Ci/μmole). Radioimmunoassay and radioreceptorassay for VIP were more sensitive (2.6-fold, and 2.5-fold, respectively) using ¹²⁵I-VIP purified by HPLC compared to ¹²⁵I-VIP obtained from an open-end cellulose column. These results demonstrate the advantage of preparing purified ¹²⁵I-VIP by HPLC for the accurate assay of VIP and VIP-receptors in tissues and biological fluids.     

HPLC法测定不同产地和品种柠檬果皮中柠檬苦素和诺米林含量

该研究建立了同时测定檬苦素和诺米林含量的高效液相色谱法,并采用该方法对8种不同柠檬样品中柠檬苦素和诺米林含量进行了测定。色谱条件如下:安捷伦Eclipse XDB-C18(250 mm×4.6 mm,5μm)色谱柱,流动相为0.1%磷酸水溶液(A)-乙腈(B),梯度洗脱,流速为1.0 mL·min^-1,柱温为30℃,波长为210 nm。结果表明:3个产地尤力克果皮中柠檬苦素含量依次为云南瑞丽(EUR_D)、四川安岳(EUR_C)和广东河源(EUR_Y),诺米林含量依次为EUR_D、EUR_C和EUR_Y;不同品种柠檬果皮中柠檬苦素含量依次为北京柠檬(M_NM)、粗柠檬(R_NM)、无核柠檬(S_NM)、热那亚(RNY)、里斯本(LSB),诺米林含量依次为S_NM、R_NM、LSB、RNY和M_NM。综上结果表明,不同产地和品种柠...     

Purification of [125I]-vasoactive intestinal peptide by reverse-phase HPLC

VIP was labeled with sodium ¹²⁵iodide, and ¹²⁵I-VIP was purified by reverse-phase high performance liquid chromatography. Optimal separations of ¹²⁵I-VIP and unlabeled VIP were obtained using two C₁₈-Novapak columns in series and a gradient of acetonitrile in triethylamine phosphate for elution. The specific activity of the ¹²⁵I-VIP was 1.99±0.21 Ci/μmole, approaching the maximum specific activity of monoiodinated VIP (2.26 Ci/μmole). Radioimmunoassay and radioreceptorassay for VIP were more sensitive (2.6-fold, and 2.5-fold, respectively) using ¹²⁵I-VIP purified by HPLC compared to ¹²⁵I-VIP obtained from an open-end cellulose column. These results demonstrate the advantage of preparing purified ¹²⁵I-VIP by HPLC for the accurate assay of VIP and VIP-receptors in tissues and biological fluids.     

Determination of ADP-ribosyl arginine anomers by reverse-phase high-performance liquid chromatography

A simple and rapid method for the determination of ADP-ribosyl arginine anomers was devised. Analysis is performed by reverse-phase high-performance liquid chromatography on a 5-micron Cosmosil 5C18 column and uv detection. ADP-ribosylation of arginine by hen liver ADP-ribosyl-transferase and the effect of pH on anomerization are also presented.