高效液相色谱法测定非天然氨基酸的光学纯度

 以（1- 氟-2,4-二硝基苯基）-5-L-缬氨 酰胺为手性试剂、反相高效液相色谱法测定非天然氨基酸的光学 纯度。梯度洗脱,流动相A：含体积分数为0.1％的三氟乙酸的乙腈,流动相B：体积分 数为0.1％的三氟乙酸水溶液。L-和D-对映体得到良好分离。准确测定了25种非天然 氨基酸L-和D-对映体的光学纯度。     

HPLC Detemination of Amino Acids in Latex Hydrolyzates Deproteinized with Alkaline Proteinase

采用盐酸水解、邻苯二甲醛－氯甲酸芴甲酯（OPA－FMOC）柱前衍生反相高效液相色谱法测定了经碱性蛋白酶脱蛋白处理后的天然胶乳中可溶性蛋白质的氨基酸含量。从16种氨基酸的变化考察了所选酶对乳胶中可溶性蛋白质的水解性能,以氨基酸总量变化评价脱蛋白的效果。结果表明,所选用的碱性蛋白酶对胶乳中的可溶性蛋白的肽键都能水解,在水解过程中蛋白质的氨基酸的组成是变化的。该法对胶乳中可溶性蛋白质的检出限达1.5mg/L（进样5μL,S/N=2）,结果不受蛋白质中氨基酸组成变化的影响。对牛血清白蛋白的氨基酸组成分析结果表明,该法准确度高。     

高效液相色谱法分析天然饮水中的腐植质

In this work,we developed an HPLC method and designed a novel program to analyse the humus in natu-ral drinking water,which includes emichment in small column,elution with methanol-water and HPLC quali-tative and quantitative determination with standard compound.At the same time, we presernt the analyticaldata of about 80 naturd drinking water samples from Shanxi,Yunnan and Heilongjiang provinces.     

高效液相色谱法在青霉素生产工艺中的应用

A method of simutaneous determination of phenylacetic acid and peniciline in manufacture by high performance liquid chromatography has been proposed.The effective value of peniciline and content of phenylacetic acid in ferment solutions of different periods in production were measured.The method is accurate,convenient and fast.     

反相高效液相色谱法测定血清中的游离氨基酸

肝脏是氨基酸(支链氨基酸除外)新陈代谢的重要器官,而且对维持氨基酸代谢的平衡起重要的作用。当肝细胞严重损害时就会引起氨基酸代谢障碍和紊乱,使氨基酸之间比例失调,尤其明显地是支链氨基酸与芳香族氨基酸比值发生改变。根据该比值的改变情况既可预测肝性脑病,又可判断肝脏疾病的严重程度,而且氨基酸的测定对许多疾病的诊断及治疗均具有重要的价值,     

高效液相色谱法测定地骨皮中18种氨基酸北大核心CSCD

采用高效液相色谱法测定地骨皮中18种氨基酸的含量。地骨皮样品用10-乙基吖啶酮-2-磺酰氯为柱前衍生试剂进行衍生化。以Akasil-C18色谱柱为固定相,用乙腈(5+95)溶液和乙腈(95+5)溶液以不同比例混合的溶液为流动相进行梯度洗脱,用荧光检测器测定。18种氨基酸的线性范围均为32fmol^100pmol,检出限(3S/N)在2.06~8.65fmol之间。加标回收率在96.4%~107%之间,测定值的相对标准偏差(n=6)在均小于4.0%。     

反相高效液相色谱法测定果汁中的有机酸

介绍了用反相高效液相色谱(RP HPLC)测定果汁中有机酸的方法。应用反相C18色谱柱,5g·L-1磷酸二氢铵(pH3.0)溶液作为流动相,流速为1.0ml·min-1,检测波长为210nm,能将果汁中的8种有机酸一次分离测定,重现性好,回收率为94.0%～115.5%。     

高效液相色谱法测定肌肉组织中的磷酸肌酸

 采用反相离子对液相色谱法测定肌肉组织中的磷酸肌酸 (PCr)的含量。样品经高氯酸溶液沉淀蛋白 ,匀浆后离心 ,上清液用KOH溶液中和后用反相液相色谱法分离测定。方法的最低检测限为 2mg/L(S/N≥ 3) ,PCr在 5mg/L～ 10 0mg/L范围内与其峰面积呈良好的线性关系 (r =0 .9992 ) ;PCr的平均回收率为 99.34 % ;测定结果的日内RSD <4.42 % ,日间RSD <8.6 7%。方法准确、灵敏、快速 ,适用于动物和人体肌肉组织中PCr含量的测定。     

高效液相色谱法测定生物组织中的组胺

通过比较各种分析柱的分离效果,建立了用离子交换柱分离,邻苯二甲醛柱后衍生荧光检测分析生物组织中组按的液相色谱方法,并对流动相的离子强度和ＰＨ进行了优化,确定了４０ｍｍｏｌ／ＬｐＨ５．５０的柠檬酸钠缓冲液作为流动相为最佳条件。分析时间缩短为１５ｍｉｎ。     

乌拉尔甘草叶中氨基酸的反相高效液相色谱快速测定

用邻苯二甲醛柱前荧光衍生梯度洗脱的方法分析了乌拉尔甘草叶中14种氨基酸的含量，为利用甘草叶作为饲料提供了科学参考；该法操作简单，衍生反应迅速，灵敏度高，重复性好。     

大亚湾沉积物中氨基酸的垂直分布——沉积物柱样W0中的水解氨基酸

测定了采自大亚湾近岸海域的一个长60cm的沉积物柱样W0中15种水解氨基酸的含量；结果表明，15种水解氨基酸含量均随深度而下降，其中苏氨酸、丝氨酸、甘氨酸、丙氨酸、精氨酸、缬氨酸、苯丙氨酸、亮氨酸、异亮氨酸的含量以及水解氨基酸总量随深度的变化可用指数方程c＝c0e^-kx加以描述；天冬氨酸、谷氨酸、丝氨酸、甘氨酸、丙氨酸和缬氨酸是大亚湾沉积物中最丰富的氨基酸。     

Voltammetric Sensing of Amino Acids in the Presence of Cu(II) in Acidic and Alkaline Solutions

A number of amino acids have been determined at carbon film electrodes in the presence of copper. Strongly acidic, 0.1 M HCl, in the presence of 0.1 mM Cu(II), as well as alkaline, 0.1 M NaOH, solution permit successful measurement of individual amino acids, clearer separation between oxidation of Cu and Cu‐complexes occurring in alkaline solution. Electrochemical impedance showed that Cu(II) facilitates charge transfer, particularly in alkaline medium. Square wave voltammetry with preconcentration increased the response compared to linear sweep voltammetry. Protein hydrolysis rates were monitored through determination of amino acids produced by decomposition, injecting samples into alkaline electrolyte solution.     

脑蛋白水解物中氨基酸的柱前衍生高效液相色谱测定

通过升高色谱柱温度,结合线性梯度洗脱的分离模式调整色谱分离的选择性,提出了一种测定脑蛋白水解物注射液中氨基酸含量的2,4-二硝基氟苯(DNFB)柱前衍生高效液相色谱方法。本法采用Kromasil C18(250×4.6 mm i.d.,5μm)色谱柱,柱温44℃,在30 min内以3个线性梯度能完全分离17种氨基酸,定量线性范围为0.2~1.0mg/L;加标回收率为89%~108%。该法具有适用性好、稳定性高等特点,也可以应用于其它种类样品中氨基酸的测定。     

Theoretical Studies on Complexes of Calcium Ion with Amino Acids

The complexes formed by calcium ion and 12 common amino acids were investigated systematically in the gas phase at the level of MP2/6-311＋＋G（d,p）//MP2/6-3 1G（d,p）.The results show that the salt-bridge structure is the most preferred motif for Ca2＋ binding aliphatic amino acids without heteroatom in the side chain,while charge-solvated（CS） structure is the most preferred motif for Ca2＋ binding other amino acids except for glutamine and lysine.IR spectra of Gln-Ca2＋ and Asn-Ca2＋ complexes were calculated and compared well with the available experiments.From the study in aqueous solution,the bidentate salt-bridge structure was determined to be the most favorable for all the twenty kinds of amino acids to chelate Ca2＋ to both the oxygen atoms of the negatively carboxylate group in the backbone.     

Determination of Amino Acidsas Their N-Hydroxy-succinimidyl-3-indolylacetate Derivatives by Reversed-phase HPLC

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The Biosynthesis of Aromatic Amino Acids and its Regulation

Microorganisms synthesize the aromatic amino acids phenylalanine, tyrosine, and tryptophan, as well as the related compounds p-aminobenzoic acid, tetrahydrofolic acid, p-hydroxybenzoic acid, ubiquinone, vitamin K, and nicotinic acid, by a highly branched route passing through shikimic acid. The biosynthesis is not regulated in the same way in all the organisms studied. The regulation is strongly dependent on the ability of the enzymes involved to be resolved into isozymes, their ability to be inhibited, and their activation, repression, and induction.     

Syntheses of Nucleoside Derivatives Containing Fmoc- or Trityl-protected Amino Acids

Facile direct esterification reactions between 2‘, 3‘-O-isopropylidene-nucleosides and Fmoc- or trityl-protected amino acids via N, N-dicyclohexyl-carbodiimide(DCC) mediated condensation are described. These reactions offer a mild and convenient method to synthesize aminoacylated nucleoside derivatives.     

The HPLC Enantioresolution of Selected Native or Derivatized Amino Acids on Teicoplanin Bonded Chiral Stationary Phase Using a Methanol‐Based Mobile Phase

The facile HPLC enantiomeric resolution of a variety of selected native or derivatized amino acids is carried out on the glycopeptide antibiotic teicoplanin bonded chiral stationary phase using a methanol‐based mobile phase and found very sensitive to the structural variations. This mobile phase is mainly composed of methanol. Organic additives such as acetic acid and triethylamine are introduced to the mobile phase in small percentages to control the analyte's retention time. Additive of low viscosity such as ethyl ether or petroleum ether is incorporated in the mobile phase as well to improve the resolution. Further increasing its percentage in the mobile phase deteriorates the resolution slightly; however, it extends the retention scale of enantiomers. The change in enantioselectivity is found to be insignificant under these circumstances. The hydrogen bonding and π‐π complexation in the hydrophobic pocket of teicoplanin chiral selector is believed to be the mechanism mainly responsible for the enantioresolution observed in this report.