应用不同柱前衍生法于HPLC测定西洋参中的氨基酸

通过微波水解衍生方法与柱前衍生方法测定西洋参中的氨基酸成分并进行对比,评价两种方法使用的合理性与应用价值。通过微波水解衍生及柱前衍生两种不同的衍生方法测定同一来源的西洋参药材中的氨基酸成分含量,比较两种实验方法的操作性、准确合理性及测定氨基酸成分含量。两种实验方法平均回收率及相对标准偏差为:柱前衍生法回收率90.1%~101.7%、RSD 0.9%~3.9%,微波水解衍生法90.1%~113.1%、RSD 1.1%~9.5%(除个别氨基酸在酸水解过程中易被破坏)。柱前衍生法主要测定游离氨基酸的含量,其中西洋参根中的精氨酸占总量的59%。微波衍生法明显缩短了氨基酸分析时间,实验操作上体现显著优势。柱前衍生法准确、可靠,测定产物稳定。测定西洋参干燥根中游离的精氨酸含量占游离氨基酸总量的一半以上,含量最高,为西洋参的化学成分与药理作用的进一步研究提供参考依据。     

高效液相色谱法对农业样品中氨基酸含量的测定

介绍了采用一种新型的国产氨基酸色谱柱ＹＷＧＡ—Ａ柱,对与农业有关的多种样品进行氨基酸测定的方法。这种色谱柱可使全部氨基酸得到完全的分离,且柱效高,柱压低,价格便宜。农业样品的品种多,比较复杂,文中还对不同样品的前处理做了简要叙述。氨基酸的分析方法采用的是柱前衍生ＯＰＡ法,还对此方法测定中的一些问题进行了讨论。     

柱前衍生反相高效液相色谱法测定绞股蓝茶叶中17种游离氨基酸含量

建立2,4-二硝基氟苯柱前衍生化-反相高效液相色谱法测定绞股蓝茶叶中17种游离氨基酸的含量。以Phenomenex Gemini NX C18(4.6mm×250mm,5μm)为分析柱,采用梯度洗脱,流动相A为0.05mol·L-1乙酸钠(pH=6.4,含0.1%N,N-二甲基甲酰胺),流动相B为乙腈-水(1∶1,v/v),检测波长为360nm,柱温35℃;经方法学考察,该方法具有良好的稳定性和重现性。测定结果表明,绞股蓝茶叶中17种游离氨基酸总量为39.79mg·g-1,其中人体必需氨基酸占游离氨基酸总量的36.57%。从氨基酸含量考虑,绞股蓝茶叶具备一定的开发利用价值。     

柱前衍生化HPLC同时测定霍山石斛中13种游离氨基酸含量

为建立柱前衍生化HPLC同时测定霍山石斛中13种游离氨基酸的方法。采用Waters XBridge C_(18)色谱柱(250 mm×4. 6 mm,5μm);流动相为0. 1 mol/L醋酸钠缓冲液-乙腈∶水(4∶1),梯度洗脱;流速1. 0 mL/min,柱温35℃;检测波长254 nm。在该色谱条件下霍山石斛中13种游离氨基酸分离较好,平均加样回收率为92. 7%~104. 3%,RSD 2. 5%。该方法简便、准确、重现性好,适用于霍山石斛中13种游离氨基酸的同时测定。     

伊枯草菌素A发酵过程中游离氨基酸的HPLC分析

建立一种快速、高效测定游离氨基酸含量的异硫氰酸苯酯(PITC)柱前衍生高效液相色谱法,并利用此方法分析检测iturin A发酵过程中游离氨基酸的动态变化。以异硫氰酸苯酯(PITC)为衍生化试剂,采用Venusil-AA(4.6 mm×250 mm,5μm)氨基酸分析专用柱,并优化HPLC检测色谱条件。结果表明:梯度洗脱程序、流动相pH值、色谱柱温对分析时间、色谱峰分离及峰型具有重要影响。当最优色谱条件为:流动相A为0.1 mol/L无水乙酸钠缓冲溶液(pH6.4±0.1)-乙腈(66∶5),流动相B为乙腈-水(4∶1),流速1.0 mL/min,检测波长254 nm,色谱柱温40℃,梯度程序洗脱,35 min内可完全分离16种氨基酸,且各氨基酸在一定浓度范围内线性关系良好(R2均大于0.9986),加标回收率在83.84%-108.02%之间,RSD值均小于2.77%。该方法耗时短、操作简便、准确可靠,具有良好的精密度和稳定性。通过此方法研究分析伊枯草菌素A发酵过程中各游离氨基酸含量变化规律,发现其氨基酸浓度变化规律大致分为三类。     

Xterra RP18柱高效液相色谱法快速分离测定氨基酸

建立了一种用XterraRP1 8色谱柱快速分离测定水解氨基酸的方法。所采用的色谱条件是 :WatersAlliance系统 ,柱温 5 6℃ ,流速 1 .8ml/min ,检测波长 2 4 8nm ,梯度分离 ,运行周期 2 5min,柱反压低于 2 0 0 0Psi。在 1 7.5min内分离了包括AMQ、NH3 和牛磺酸在内的 2 1种氨基化合物 ,适应于复合氨基酸注射液、含牛磺酸的氨基酸口服液及水解氨基酸样品的分析测定     

HPLC测定不同海拔小叶金露梅17种氨基酸含量

目的:建立高效液相色谱法测定小叶金露梅中17种氨基酸含量的方法。方法:采用N,N-二硝基氟苯柱前衍生氨基酸后测定;色谱柱为Phenomenex Gemini 5μC18,流动相为醋酸钠(pH=6.40)和50%乙腈,采用梯度洗脱,检测波长为360nm,外标法计算含量。结果:17种氨基酸线性关系、精密度、稳定性、重复性良好,加样回收率为97.4%～102.8%(RSD为1.21%～2.5%)。各海拔的氨基酸总量范围是10%～14.79%,在不同海拔小叶金露梅中氨基酸平均质量分数顺序为亮氨酸>天冬氨酸>异亮氨酸>组氨酸>丝氨酸>精氨酸>丙氨酸>苯丙氨酸>缬氨酸>谷氨酸>脯氨酸>甘氨酸>赖氨酸。小叶金露梅含有7种必需氨基酸,它们的含量均大于48%。本方法简便、准确,为小叶金露梅药理提供理论依据。     

两种柱前衍生反相高效液相色谱法测定血液和尿液中游离氨基酸

建立以PITC法和AQC法为柱前衍生试剂测定血液和尿液中游离氨基酸含量的测定方法。采用Waters-e2695操作系统,色谱柱为Shim-vp,ODS(250mm×4.6mm,5μm)(日本,岛津公司),以甲醇/乙腈/水和醋酸钠溶液(pH 6.5)为流动相,梯度洗脱。分别采用紫外和荧光检测器对血液和尿液中游离氨基酸进行含量测定。结果显示,两种衍生化方法灵敏度好、分离度高,具有良好的线性范围(r>0.990 0),准确度高(平均回收率为75.1%～127.0%),进样精密度好(RSD为0.12%～3.42%)。PITC法在尿液中游离氨基酸含量测定中显示了良好的测试准确性;而AQC法测定尿液中组氨酸、苏氨酸、脯氨酸超出线性范围,需要对尿样的前处理进行深入研究。     

不同产地滇重楼须根中氨基酸类成分的UPLC分析与评价

建立柱前衍生-超高效液相色谱法测定滇重楼须根中15种氨基酸含量,对不同产地样品进行分析评价。采用UPLC-PDA仪器,使用ACQUITY UPLC BEH C_(18)色谱柱(2.1 mm×150 mm,1.7μm),流动相A为0.1 mol/L乙酸钠溶液(冰醋酸调节pH=6.5)-乙腈(97∶3),B为乙腈-水(4∶1),梯度洗脱,检测波长254 nm,流速0.2 mL/min。滇重楼须根中检出15种氨基酸线性关系良好(r≥0.999 7),平均回收率RSD均小于3.00%。各产地均以天门冬氨酸和谷氨酸含量为最高,栽培滇重楼须根氨基酸平均含量高于野生品。本研究建立了分析评价滇重楼须根中氨基酸类成分的方法,为滇重楼须根的资源开发与利用提供科学依据。     

日立835-50型氨基酸自动分析仪蛋白质水解液分析新方法

本文报道了在日立835—50型氨基酸自动分析仪上,采用4×150mm 柱代替2.6×150mm 柱进行蛋白质水解液分析的方法。本法与仪器说明书提供的标准分析相比,具有分离率高,费用低等优点。各氨基酸峰位复现性和峰面积复现性均优于仪器的规定指标。日立835—50型氨基酸自动分析仪是目前应用广泛,性能较好的氨基酸分析装置。但仪器说明书提供的标准分析(蛋白质水解液分析)法分离率较低,若采用高分离平方法进行分析则所需时间又太长。为了能适应某些工作的要求,需研究分析速度快又具有较高分离率的方法。参照日立公司有关技术资料,我们探讨了采用4×150mm 柱代替2.6×150mm 柱,分析周期为62分钟的蛋白质水解液分析方法,现简要报道如下。     

Bias Assessment of General Chemistry Analytes using Commutable Samples

Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.     

微弱发光分析技术应用实例(二)

微弱发光测量仪是根据微弱发光分析技术研制的测量样品微弱发光的仪器.BPCL型微弱发光测量仪具有多种重要功能,可满足生物、医学、化学等领域研究与应用的需要.简要介绍微弱发光测量仪在DNA氧化损伤规律的研究中的应用实例.说明了这种技术和仪器的先进性与实用性.     

Utility of protein electrophoretic analysis in the characterization of malignant tissues

High-resolution electrophoresis of samples from malignant tissues and tumour cells has developed from a simple analytical tool to a high-tech system requiring a lot of satellite techniques. Though this developmental history now demands additional expensive instrumentation and a detailed knowledge of protein chemistry, the usefulness of this technique in tumour biology has been dramatically enhanced. Consequently, electrophoretic techniques combined with additional high-resolution and sensitive analytical tools can now be used to elucidate a particular phenotype of a cancer cell; moreover, the chemical nature of this phenotype can be revealed. The way from the protein backwards to the gene is now open!     

Matrix solid phase dispersion (MSPD)

A review of the many uses of matrix solid phase dispersion (MSPD) in the extraction and analysis of a variety of compounds from a range of samples is provided. Matrix solid phase dispersion (MSPD) has found particular application as a somewhat generic analytical process for the preparation, extraction and fractionation of solid, semi-solid and/or highly viscous biological samples. Its simplicity and flexibility contribute to it being chosen over more classical methods for these purposes. MSPD is based on several simple principles of chemistry and physics, involving forces applied to the sample by mechanical blending to produce complete sample disruption and the interactions of the sample matrix with a solid support bonded-phase (SPE) or the surface chemistry of other solid support materials. These principles are discussed as are the factors to be considered in conducting a MSPD extraction.     

Matrix solid phase dispersion (MSPD)

A review of the many uses of matrix solid phase dispersion (MSPD) in the extraction and analysis of a variety of compounds from a range of samples is provided. Matrix solid phase dispersion (MSPD) has found particular application as a somewhat generic analytical process for the preparation, extraction and fractionation of solid, semi-solid and/or highly viscous biological samples. Its simplicity and flexibility contribute to it being chosen over more classical methods for these purposes. MSPD is based on several simple principles of chemistry and physics, involving forces applied to the sample by mechanical blending to produce complete sample disruption and the interactions of the sample matrix with a solid support bonded-phase (SPE) or the surface chemistry of other solid support materials. These principles are discussed as are the factors to be considered in conducting a MSPD extraction.     

Metrology in physics,chemistry, and biology

The association of physics and chemistry with metrology (the science of measurements) is well documented. For practical purposes, basic metrological measurements in physics are governed by two components, namely, the measure (i.e., the unit of measurement) and the measurand (i.e., the entity measured), which fully account for the integrity of a measurement process. In simple words, in the case of measuring the length of a room (the measurand), the SI unit meter (the measure) provides a direct answer sustained by metrological concepts. Metrology in chemistry, as observed through physical chemistry (measures used to express molar relationships, volume, pressure, temperature, surface tension, among others) follows the same principles of metrology as in physics. The same basis percolates to classical analytical chemistry (gravimetry for preparing high-purity standards, related definitive analytical techniques, among others). However, certain transition takes place in extending the metrological principles to chemical measurements in complex chemical matrices (e.g., food samples), as it adds a third component, namely, indirect measurements (e.g., AAS determination of Zn in foods). This is a practice frequently used in field assays, and calls for additional steps to account for traceability of such chemical measurements for safeguarding reliability concerns. Hence, the assessment that chemical metrology is still evolving.     

Lead-210 content of food samples in India

Summary The paper presents results of measurements made on cereals and composite meal samples collected from Bombay market for their lead-210 content. The details of sampling and analytical chemistry procedures are also given. The Pb-210 contents of most of these samples were in the range of 1–5 pCi/kg of cereals samples. The concentrations in composite meal samples were mostly in the range of 1–3.5 pCi of²¹⁰Pb per composite meal. The assessment of daily intake of this isotope through food-stuffs has been made.     

High‐throughput microanalysis of large lignocellulosic sample sets by pyrolysis‐gas chromatography/mass spectrometry

High‐throughput analytical techniques to assess the chemistry of lignocellulosic plant material are crucial to plant cell‐wall research. We have established an analytical platform for this purpose and demonstrated its usefulness with two applications. The system is based on analytical pyrolysis, coupled to gas chromatography/mass spectrometry – a technique particularly suited for analysis of lignocellulose. Automated multivariate‐based data‐processing methods are used to obtain results within a few hours after analysis, with an experimental batch of 500 analyzed samples. The usefulness of multivariate sample discrimination methods and hierarchical clustering of samples is demonstrated. We have analyzed an Arabidopsis mutant collection consisting of 300 samples representing 31 genotypes. The mutant collection is presented through cluster analysis, based on chemotypic difference, with respect to wild type. Further, we have analyzed 500 thin sections from five biological replicate trees to create a spatial highly resolved profile of the proportions of syringyl‐, guaiacyl‐ and p‐hydroxyphenyl lignin across phloem, developing and mature wood in aspen. The combination of biologically easy to interpret information, the low demand of sample amount and the flexibility in sample types amenable to analysis makes this technique a valuable extension to the range of established high‐throughput biomaterial analytical platforms.     

Techniques for high-throughput characterization of peptides, oligonucleotides and catalysis efficiency

Combinatorial processes have been widely applied to many disciplines in chemistry and biology. The vast numbers of unique entities generated by combinatorial synthesis have led to the development of high-throughput methods for characterizing samples, to avoid bottlenecks created by the application of conventional, serial-based analytical techniques. In recent years, high-throughput and novel methods utilizing mass spectrometry, multiplexed capillary electrophoresis, various forms of optical detection, and even sound waves have been investigated for a variety of applications.     

Molecular chemistry imaging to reveal structural features of various plant feed tissues

Synchrotron Fourier transform infrared (FTIR) microspectroscopy as a rapid, direct, and non-destructive analytical technique can explore molecular chemical features of the micro-structure of biological samples. However, the application of this synchrotron technology to feed science and feed chemistry is extremely rare. This article reviews that with synchrotron FTIR microspectroscopy, the molecular chemistry of various feed tissues could be imaged. These images revealed spatial intensity and distribution of chemical functional groups in various feeds tissues within cellular dimensions. Such information can be used for plant breeding program for selecting superior variety of plant for targeted feed purposes and for prediction of feed quality and nutritive value. The final purpose of this article shows that Synchrotron FTIR microspectroscopy can be used for biological structure study.