牙本质中天冬氨酸消旋化程度的测定——手性毛细管气相色谱法与高效液相色谱法的比较

应用手性毛细管气相色谱法（酸性异丙醇、三氟乙酸酐为衍生试剂）、高效液相色谱法（邻苯二甲醛－Ｎ－乙酰－Ｌ－半胱氨酸为手性衍生试剂）同时测定人类第一磨牙牙本质中天冬氨酸的消旋化程度，结果表明，两者均可有效地用于天冬氨酸对映体的分离测定，但气相色谱检测限（０．２ｐｍｏｌ）低于高效液相色谱（１．０ｐｍｏｌ），而变异系数（７％）、总分析时间（１００ｍｉｎ）均高于高效液相色谱（分别对应为４％，３１ｍｉｎ）。     

Determination of Vitamin D3 Metabolites Using High‐Performance Liquid Chromatography or Immunoaffinity Chromatography

Our investigation of the analysis of vitamin D₃ metabolites has been reviewed. The development of high‐performance liquid chromatographic methods for the quantitative determination of 25‐hydroxyvitamin D₃ 3‐sulfate and 25‐hydroxyvitamin D₃, which are the major circulating metabolites of vitamin D₃ in human serum/plasma, has been described. The developed methods were applied to the determination of the correlation between the concentration of the sulfate and its genin in healthy subjects and patients with chronic renal failure. The development of immunoaffinity chromatography immobilizing the highly specific anti‐1,25‐dihydroxyvitamin D₃ antibody for the pretreatment of radioreceptor assay of 1,25‐dihydroxyvitamin D₃, which is the active metabolite of vitamin D₃, is also described.     

反相高效液相色谱与质谱联用分析合成七肽的消旋产物

采用反相高效液相色谱(RP-HPLC)与质谱(MS)联用技术对固相法化学合成七肽(H2N-PFNSLAI-COOH,M r 760.9)时出现的消旋产物进行了分析。根据弱疏水性合成七肽粗品特性,提出了充分利用吸附和分配双重保留机制的“早期吸附”概念,以此优化色谱条件得到4个峰形良好的色谱峰;质谱分析表明:4谱峰具有相同的m/z761.5[M H] 值,对每一消旋产物进行在线多肽测序,并利用串联质谱(MSn)谱图叠加的方法,得到b轴和y轴两套片段信息,成功确定了合成七肽的4个消旋产物。     

Separation of Anthraquinones by Capillary Electrophoresis and High‐Performance Liquid Chromatography

The separation and determination of twelve anthraquinones, viz. anthraquinone 1, chrysphanol 2, aloe‐emodin 3, alizarin 4, anthraquinone‐2‐carboxylic acid 5, purpurin 6, sennoside B 7, sennoside A 8, emodin 9, quinalizarin 10, rhein 11, and anthraflavic acid 12, were achieved by capillary electrophoresis (CE) and high‐performance liquid chromatography (HPLC). Detection at 260 nm with a buffer solution containing 30 mM sodium borate (adjusted to pH = 10.56 with 0.05N NaOH) and acetonitrile (9 : 1) in CE or with a linear gradient elution containing 20 mM KH₂PO₄ with 0.05% phosphoric acid (pH = 2.91) and methanol in HPLC was found to be the most suitable approach for this separation. Contents of six components (2, 3, 7, 8, 9, 11) in crude Rhei Rhizoma extract could easily be determined within 39 min by CE or 63 min by HPLC. The effects of buffers on this separation and the validation of the two methods were studied.     

高效液相法测定叶酸片中叶酸的含量

建立了高效液相色谱法测定叶酸片中叶酸含量的方法。采用Symmetry C18色谱柱(150×4.6mm,3.5μm),以磷酸盐缓冲溶液(PBS,pH=6.3)为流动相,检测波长254nm,柱温35℃。叶酸在0.04～0.36μg/mL范围线性良好(r=0.9999),平均加标回收率为99.4%(RSD=0.44%)。该方法简便准确,精密度良好,适用于叶酸片中叶酸含量的测定。     

反相高效液相色谱-增敏化学发光同时测定VB1和VC

本文基于维生素B1(VB1)、维生素C(VC)对鲁米诺(Luminol)和铁氰化钾(K3[Fe(CN)6])化学发光反应的增敏作用原理,建立了反相高效液相色谱(RP-HPLC)分离、柱后化学发光检测VB1与VC的新方法。当在鲁米诺中加入KBr时可以大大增敏该反应。本法已成功运用于蜂蜜和复合维生素片中VB1与VC的测定。     

高效液相色谱法测定生物催化法生产中的己二酸

己二酸是一种重要有机化合物,具有强极性和离子性的特点,由于在210 nm以上有弱的紫外吸收,故用气相色谱(GC)或高效液相色谱(HPLC)直接分离测定均有一定困难。为此,本文从研究乙酸缓冲溶液中己二酸-铜络合物的紫外吸收光谱出发,建立了高效液相色谱紫外检测己二酸的方法。通过实验确定了最优色谱条件。本法测定己二酸的线性相关系数为0.998,回收率为97.5%,检出限为0.32 mg/mL。此方法可用于监测生物催化法生产的己二酸,优化生产条件。     

高效液相色谱柱后化学衍生法测定食品中的VB1及叶酸含量

研究柱后化学衍生荧光检测高效液相色谱分离测定食品中维生素B1和叶酸的方法。采用C18柱,以含有3．5％乙腈的pH5．0磷酸盐缓冲溶液(0．05mol／L)作为流动相反相分离。色谱流出液在柱后与0．4％的过二硫酸钾溶液在线汇合后流经—Teflon管化学反应器时,维生索B1和叶酸转化为强荧光产物,由荧光检测器测定。在最佳条件下,进样20μL,维生素B1和叶酸工作曲线的线性范围分别为0．21～4．2mg／L和0．10～2．0mg／L,峰面积的相对偏差均为2．0％,回收率及实际样品测定结果满意。     

A modified HPLC method for the determination of aspartic acid racemization in collagen from human dentin and its comparison with GC

The D/L ratio of aspartic acid enantiomers in proteins of low turnover is generally accepted as a reliable procedure for age determination. In our study, twelve samples of eyetooth dentin were analyzed for age determination. The pure insoluble collagen isolated from eyetooth dentin was obtained by an EDTA demineralization process. Free amino acids obtained after collagen hydrolysis were converted into o-phthaldialdehyde-N-acetyl-L-cysteine (OPA-NAC) derivatives for HPLC analysis under modified conditions and into trifluoroacetic acid isopropyl esters for GC analysis, respectively. The modified HPLC procedure used phosphate buffer and acidified sample matrix prior to injection which resulted in suppression of peak tailing of both diastereomers, thus allowing achievement of both good selectivity and good resolution. To ensure the high accuracy of the developed method the other parameters, i.e. specificity, precision, linearity, LOD, and LOQ, were also determined. Nine collagen samples covering the age range of 18 to 84 years were used for the determination of coefficient of racemization (KR) and calculation of parameters for age estimation. The regression equations for the data set analyzed were as follows: KR= 0.0005 x age + 0.0262 (R2 = 0.9639) for HPLC, and KR= 0.0006 x age + 0.0319 (R2 = 0.9374) for GC, respectively.     

高效液相色谱法测定精对苯二甲酸中主要有机杂质

本文建立了期货交割精对苯二甲酸(PTA)样品中主要杂质的快速测定方法,该法对羧基苯甲醛(4-CBA)和对甲基苯甲酸(p-TOL)在0～50.0 mg/kg和0～300.0mg/kg范围内有较好的线性关系,相关系数R=0.9990,平均回收率在89.30%～104.28%,该方法为期货交割PTA样品品质提供了良好的技术支持.     

反相高效液相色谱法测定小鼠中脑内D-天冬氨酸和D-谷氨酸

建立了测定生物样品中微量D-天冬氨酸、D-谷氨酸的高效液相色谱法。以邻苯二甲醛(OPA)-N-异丁酰基-L-半胱氨酸柱前衍生氨基酸对映体,醋酸钠-甲醇-乙腈混合液为流动相,在Shim-packVP-ODS柱上,采用梯度淋洗技术,2种氨基酸对映体在40min内完全分离。以荧光检测,D-天冬氨酸(D-Asp)、D-谷氨酸(D-Glu)的浓度在1.0×10-8～1.0×10-6mol/L时,其浓度与峰面积呈良好的线性关系。当信噪比为3(S/N=3)时,D-Asp和D-Glu的检出限分别为2.0×10-9mol/L和1.0×10-9mol/L。将方法运用于帕金森模型小鼠中脑中D-Asp和D-Glu含量的测定,对照组与模型组中脑D-Asp含量无显著性差异,D-Glu含量呈现显著性差异。推测在脑组织里,内源性的D-Asp的合成及转运不受神经毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶(MTPT)的毒害仍保持原有的动态平衡;而D-Glu可能具备与L型对映体相似的兴奋毒性,参与帕金森疾病的发病机制。     

高效液相色谱法测定细胞分裂素的方法研究

利用高效液相色谱法测定水稻愈伤组织和微生物发酵产品中的玉米素，二氢玉米素，核糖基玉米素和核糖基二氢玉米素。样品用抽提液抽提，经Ｂｉｏ－Ｒｅｘ７０弱阳离子交换柱和ＸＡＤ－７／Ｓｅｐ－ｐａｋＣ１８复合柱净化和富集后，直接用ＨＰＬＣ分析，方法回收率达９４％～８４％，相对标准偏差小于３．３％。最低检测限达２．０ｎｇ。     

2,2-二苯基-1-苦肼基-高效液相色谱法快速筛选亚麻籽抗氧化活性成分

为了更加迅速地筛选到亚麻籽复杂提取物中的抗氧化活性物质及其活性强弱,以开环异落松树脂酚二葡萄糖苷(SDG)、开环异落叶松树脂酚(SECO)和肠二醇(ED)3种木酚素为研究对象,建立了抗氧化活性能力筛选的2,2-二苯基-1-苦肼基-高效液相色谱法(DPPH-HPLC法)。液相色谱条件为:流动相为乙腈和水,经反相色谱柱Waters XBridge C18分离,检测波长为280 nm。DPPH-HPLC法的步骤是:将单一或者混合抗氧化剂分别与DPPH混合,放置20 min,作为待测液,将同样量的相应抗氧化剂作为对照液,分别进行液相色谱分析获得其含量,计算出相应的抗氧化剂清除率(SRA),活性顺序为:SDG>SECO>ED。结合超高效液相色谱-飞行时间质谱联用法,鉴定出亚麻籽中5种抗氧化物,筛选其抗氧化能力分别为:SDG异构体(5)>SDG(4)>7α-[(β-D-glupyranosyl)oxy]-1-methoxyisolariciresinol(1)>(6R,7R,8S)-1-Methoxyisolariciresinol(2)>蜀葵苷元二葡萄糖苷(3)。结果表明,建立的DPPH-HPLC法能够有效完成复杂亚麻籽提取物的抗氧化活性物质筛选。     

高效液相色谱法快速测定人血清中丙戊酸含量

建立了血清中丙戊酸的高效液相色谱快速分析法。用ＺｏｒｂａｘＯＤＳ柱,ｐＨ４．２硫酸水溶液为流动相,检测波长２１０ｎｍ,流速０．８ｍＬ／ｍｉｎ,线性范围０．８２μｍｏｌ／Ｌ～１．８ｍｍｏｌ／Ｌ（ｒ＝０．９９６）,最低检测限０．８２μｍｏｌ／Ｌ,平均回收率为９８．３２％±２．２７％,日内与日间的变异系数分别为３．３１％（ｎ＝５）和４．８２％（ｎ＝７）。     

超高效液相色谱法测定原料乳中的水杨酸

建立了原料乳中水杨酸的检测方法.样品经乙腈提取，采用超高效液相色谱进行测定.在ZORBAX Eclipse Plus C18反相柱上分离，梯度洗脱，流动相为磷酸水和磷酸甲醇，DAD检测.水杨酸的线性范围为0.5~20 μg/mL，相关系数平方（R²）大于0.995，检出限为0.5 mg/kg，定量限为1.25 mg/kg，3个不同水平的加标回收率为88.0%~118.9%，相对标准偏差不大于10%.方法具有操作简单、重现性好、灵敏度高、杂质干扰小等特点，可以用于原料乳中水杨酸的检测.     

高效液相色谱法测定发酵醪液中的衣康酸

采用AminexHPX－87H色谱柱和折光检测器,以4mmol／L硫酸为洗脱剂,分析土曲霉发酵醪液中的衣康酸获得满意的结果。     

Upper Critical Solution Temperature‐Type Thermal Response of Soluble Multi‐l‐Arginyl‐Poly‐l‐Aspartic Acid (cyanophycin) Conjugated with Maltodextrin

Multi‐l ‐arginyl‐poly‐l ‐aspartic acid (MAPA), also known as cyanophycin, can incorporate lysine into the side‐chain position of arginine when being prepared with recombinant Escherichia coli. The soluble fraction (sMAPA) is known to display both lower critical solution temperature (LCST) and upper critical solution temperature (UCST) responses at the physiological condition. In an attempt to alter the UCST thermal response, maltodextrin was employed to conjugate onto the amine group of lysine of sMAPA via the formation of Schiff base. In phosphate buffered saline, the UCST of the conjugates appeared around 50–62°C, depending on the extent of conjugation. In contrast to the unmodified sMAPA, the UCST of the conjugate became independent of pH ranging from 1 to 11. Heating the conjugate solution to complete transparent caused a delayed and partial recovery of the original turbidity during subsequent cooling. However, the turbidity can be restored by further precipitation with ethanol or isopropanol followed lyophilization and re‐dissolution. At room temperature, below UCST, the agglomerates exhibited a size of around 200–400 nm under TEM and DLS. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2048–2055     

高效液相色谱-紫外检测法测定人体尿液中的蝶呤-6-羧酸

建立了人体尿液中蝶呤-6-羧酸的高效液相色谱-紫外分析新方法. 运用Lichrospher C18柱(250×4.6 mm,5 μm),甲醇-水(70∶30,V/V)为流动相,流速为0.4 mL/min,可较好地将尿液中蝶呤-6-羧酸与其它共存干扰物质分离.在355 nm检测波长下,蝶呤-6-羧酸在0.19～4.8 μg/mL范围内与色谱峰面积呈良好线性关系,相关系数为0.9999,方法检出限为0.015 μg/mL.尿液经0.45 μm滤膜过滤后,可直接进样分析,方法简便,应用于癌症病人和健康人尿样中蝶呤-6-羧酸测定,结果较好.方法的加标回收率为94.6%～100.2%,相对标准偏差为0.81%～ 5.07% .