古老沉积岩中痕量氨基酸的气相色谱分析

在以往的氨基酸气相色谱分析中,对于生化、医药、石油及食品等样品中的氨基酸分析,广泛使用三氟醋酸酐作为氨基酸的酰化剂。但是对于古老的沉积岩和生物化石等样品中的氨基酸分析还不能足以解决标本中痕量氨基酸的各组份定量分析,甚至难以在气相色谱上出峰。为了解决这一问题,本实验主要使用了酸性异丁醇和七氟丁酸酐作为氮基酸的衍生剂,并且通过电子捕获检测器以便实现对大约6亿年前的沉积岩标本中氨基酸各组份的气相色谱定量分析。     

β-环糊精包覆碳纳米管基质用于氨基酸及小分子聚合物的MALDI-FT MS研究

制备了可用作氨基酸及小分子聚合物的MALDI-FTMS分析基质的β-环糊精包覆多壁碳纳米管.通过引入β-环糊精改善其碳纳米管亲水性.所制备的β-环糊精包覆多壁碳纳米管的扫描电镜图表明,该碳纳米管呈现纳米带状结构.与通常的氧化碳纳米管相比,所制备的β-环糊精改性CNT具有更低的背景信号.进一步采用氨基酸及聚乙二醇等小分子化合物对所制备的碳纳米管进行评价,得到很强的氨基酸及聚乙二醇的碱金属离子加合峰,表明该材料可使小分子化合物解吸离子化,且背景干扰小不会影响到小分子化合物检测.由此可见,制备的β-环糊精包覆多壁碳纳米管适于小分子化合物的MALDI-MS分析.     

UPLC-MS/MS测定蛋白胨中17种游离氨基酸

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)测定蛋白胨中17种游离氨基酸的方法.样品经水溶解定量稀释后,无需衍生直接进样.17种游离氨基酸经过Syncronis C18色谱柱分离,采用含有0.1％(V/V)甲酸的5％(V/V)甲醇水溶液进行等度洗脱,在电喷雾离子源、正离子模式下,采用多反应监测模式进行监测,外...     

反相高效液相色谱对DABTH—氨基酸的分离与鉴定

应用反相高效液相色谱(RP-HPLC)技术,采用等度洗脱。对20种标准DABTH-氨基酸进行了分离与鉴定,灵敏度达到pmol水平;并以溶菌酶为模式蛋白,经手工DABITC/PITC双偶联方法对其N端部分序列进行Edman降解,其降解产物DABTH-氨基酸用RP-HPLC技术进行了鉴定,蛋白质微量序列分析的灵敏度达到nmol水平.     

氨基酸的光辅助氧化化学发光及其分析应用

氨基酸与溴酸钾混合液经紫外光照射后与鲁米诺反应产生较强的发光信号,且在一定条件下氨基酸浓度与发光强度成线性关系,据此建立了一种氨基酸测定方法。在优化的条件下,该方法对五种氨基酸的检出限在0.004μg/mL~0.06μg/mL范围内;分别对0.5μg/mL的五种氨基酸平行测定7次,其相对标准偏差在2·3%~4.2%范围内。初步考察了该方法与液相色谱联用测定氨基酸的可行性。     

氨基酸柱前衍生化的3种新荧光试剂的光谱特性及高效液相色谱研究

合成了３种新的荧光标记试剂：吖啶－Ｎ－乙酰氯，咔唑－９－乙酰氯和咔唑－９－丙酰氯。它们的最大发射降激发波长分别为４３０ｎｍ，３６８ｎｍ，和３６５ｎｍ。３种衍生化试剂与氨基酸形成的衍生物在ｐＨ６．５的条件下结合梯度洗脱程序在Ｃ１８反相柱上对色谱条件进行了优化。     

聚甲基丙烯酸甲酯固定化碳纳米管作为MALDI基质的研究

将聚甲基丙烯酸甲酯材料在多壁碳纳米管表面原位聚合, 利用这种修饰的碳纳米管作为基质辅助激光解析离子化(MALDI)的基质, 利用修饰后的碳纳米管可以“溶解”的特性实现了稳定的MALDI离子化, 并且消除了在低质量端的基质噪音. 此类聚合物衍生的碳纳米管具有相对较好的亲水性表面, 可“溶解”在溶剂中. 此方法适用于有机小分子、多肽、聚合物和蛋白质酶解肽段的质谱分析. 实验表明聚甲基丙烯酸甲酯固定化碳纳米管能有效地吸收和传递激光能量, 可与样品充分地分散混合, 质谱检测背景低, 重现性好, 具有较宽的可测质量范围. 此方法在小分子快速检测和蛋白质组学方面有很大的应用前景.     

HPLC Off-Line Mass Spectrometry MALDI of Amino Acids in Carbon Sorbents

A high performance liquid chromatography and a mass spectrometry matrix-assisted laser desorption/ionization (MALDI) methods were used to select the conditions of both successful separation and to identify amino acids and peptides on the carbon sorbents. For the first time the graphitized and nongraphitized carbon blacks were used for the identification of amino acids and peptides by the MALDI method. It was shown that an increased surface area of carbon blacks led to a sharp increase in the intensities of the detected peaks of protonated molecular ions and adducts with alkali metal cations of the amino acids and peptides under study.     

Elucidation of O-Phosphoryl and N-Phosphoryl Amino Acids by Electrospray Ionization Tandem Mass Spectrometry

Mass spectroscopic characteristics of phosphoryl amino acids were studied in detail by positive and negative electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Besides N-diisopropyloxyphosphoryl amino acids (N-DIPP-AA), O-phospho- and O-diisopropyloxyphosphoryl amino acids (O-DIPP-AA) were studied and compared to N-DIPP-AA. The fragmentation pathways of [M H]^ ,[M Na]^ and [M-H]^- ions of phosphoryl amino acids were summarized. In addition to several similar patterns, each of them showed its characteristic fragmention.     

Covalent Functionalization of Carbon Nanotube by Tetrasubtituted Amino Manganese Phthalocyanine

The multiwall carbon nanotube (MWCNT) bonded to 2, 9, 16, 23-tetraamino manganese phthalocyanine (TAMnPc) was obtained by covalent functionalization, and its chemical structure was characterized by TEM. The photoconductivity of single-layered photoreceptors, where MWCNT bonded by TAMnPc (MWCNT-b-TAMnPc) served as the charge generation material(CGM), was also studied.     

A Novel MALDI Matrix for Analyzing Peptides and Proteins: Paraffin Wax Immobilized Matrix

制作出一种新型的石蜡固化基质,并将其用于多肽以及蛋白质的MALDI-FTMS分析。在其制作过程中通过加热将固体石蜡融化并均匀涂敷在不锈钢靶板上,在不同温度下滴加基质溶液于石蜡涂层及不锈钢靶板上,分别制得不同形式的基质点。三维视频显微镜表征各基质点的表观形貌,并对比其上样前后的形貌变化。通过在不同基质点上分析多肽混合液以及牛血清白蛋白酶解液,以评价该固化基质的性能。MALDI-FTMS分析结果表明石蜡涂层内固化基质方法检测灵敏度明显优于其它几种状况下的样品分析方法。     

氨基化环糊精与氨基酸包络物的电喷雾质谱研究

电喷雾质谱(ESI-MS)作为一种软电离质谱技术,已应用于研究准气相状态下通过各种非共价相互作用所形成的非共价复合物。本研究利用电喷雾飞行时间质谱(ESI-TOF-MS)测定了合成的氨基化环糊精与5种氨基酸所形成的1∶1包络物的结合常数(K),考察了质谱条件及溶液条件对结合常数的影响,通过比较结合常数的大小,探讨了氨基化环糊精与氨基酸在准气相状态下的作用方式。     

Determination of Free D‐Amino Acids in Mammalia by Chiral Gas Chromatography–Mass Spectrometry

Quantities of D‐amino acids were determined in body fluids (urine, blood plasma and blood serum, milk) of mammals (hamster, horse, bovine, sheep, pig, and dog). Amino acids were isolated using a cation exchanger and converted into their N(O)‐pentafluoropropionyl (or trifluoroacetyl) amino acid 2‐propyl esters. Enantiomers were separated and quantified on a Chirasil‐L‐Val capillary column with mass spectrometric detection using selected ion monitoring. D‐Enantiomers of most protein L‐amino acids were detected. Largest absolute and relative amounts in most cases were determined for D‐Ser and D‐Ala in urine. Stereoisomers of 2,6‐diaminopimelic acid were also measured in bovine, ovine, and porcine urine. Since D‐amino acids were detected in all representative classes of the major orders of Mammalia, namely Artiodactyla, Perissodactyla, Rodentia, and Carnivora, and taking reports in the literature into account, it is postulated that D‐amino acids occur in all mammals.     

Adsorption of Dyes Using Multi-walled Carbon Nanotube Hydrogel

The hydrophilic multi-walled carbon nanotube(MWCNT)hydrogel was prepared using acrylic acid,acrylamide and hydrophilic MWCNT.The orthogonal experiment was applied to optimize the synthetic conditions.The MWCNT hydrogel was characterized by Fourier transform infrared spectrophotometer(FTIR)and scanning electron microscopy(SEM)analysis.The MWCNT hydrogel was used as the adsorbent to adsorb water-soluble cationic dye.This study evaluated the adsorption performance of hydrogels on four dyes of safranine Ts crystal violet,malachite green and methylene blue in water.The effects of the amount of hydrogel,the size of hydrogel,pH;and the temperature on the adsorption performance were investigated.The adsorption kinetic and adsorption isotherm curves were measured.The experimental results show that the MWCNT hydrogel can be easily separated from water and the adsorption capacity is much greater compared to the hydrogel without MWCNT.The MWCNT hydrogels can be used in wastewater treatment with a great potential.     

心脏胶原蛋白中交联氨基酸的质谱分析

心脏衰竭可能与心脏胶原蛋白交联异常有关,因为交联过程对心脏胶原蛋白的机械强度起决定作用.研究表明,某些交联氨基酸的含量可以用作对应胶原蛋白交联异常的分子标记,但心脏胶原蛋白交联异常的分子标记尚不清楚.本研究建立了串联质谱的分析方法可以高选择性的检测水解胶原蛋白质中两种重要的交联氨基酸-吡啶诺林(PYD)和去氧吡啶诺林(DPD).在小鼠心室胶原蛋白酸性水解产物中检测到DPD,未检测到PYD,说明PYD与心脏胶原蛋白的交联过程无关,而DPD在心脏胶原蛋白交联中起更重要的作用,有可能成为与心脏衰竭相关的分子标记.本研究提供了一种基于质谱的研究心脏胶原蛋白交联产物的方法,也可用于其它胶原蛋白的分析.