尿毒症患者血清及正常人尿液内中分子物质的分离分析

采用凝胶色谱法，以２０６ｎｍ处的紫外吸收为检测手段，分别从尿毒症患者血 清及正常人尿液内分离出Ａ，Ｂ两个中分子峰，而从正常人血清中分离出来的Ａ峰远低 于尿毒症患者血清的Ａ峰；在Ｂ峰的位置正常人血清未出现明显的吸收．运用该方法 不仅提高了凝胶色谱的分离效果，且能方便地得到中分子级分的纯品．对清除了淋洗 液组分的中分子级分进行紫外和红外扫描，结果发现来源于尿毒症患者血清及正常人 尿液的Ａ峰物质具有相同的紫外吸收且红外吸收光谱极其相似，而不同来源的Ｂ峰物 质虽然紫外吸收相同，但它们的红外吸收却存在一定的差异．采用离子交换色谱法对Ｂ 峰物质进行进一步的分离，以２３０ｎｍ处的紫外吸收为检测手段，正常人尿液的Ｂ峰物 质被分离成１７个亚峰，尿毒症血清的Ｂ峰物质被分离成１３个亚峰．其中绝大部分亚峰 的出峰位置（洗脱体积）相同．     

稀土元素对铬酵母中铬含量影响的研究

研究了稀土化合物在铬酵母制备过程中对总铬和有机铬含量的影响作用。镧、铈、镨、钕等轻稀土化合物均能明显提高铬酵母中总铬和有机铬的含量 ,其中镧化合物对铬酵母中总铬和有机铬含量的提高作用最显著 ,总铬含量可达到 70 8.33μg·g- 1 ,有机铬含量可达到 6 39.0μg·g- 1 ,是未加稀土铬酵母样品的近 3倍 ;添加钕化合物的铬酵母中有机铬占总铬的比例最高 ,可达到 97.5 %。通过紫外光谱分析 ,发现有机铬在 2 6 0nm处有特征吸收峰 ,通过红外光谱分析 ,发现有机铬在 478cm- 1 处有特征吸收峰 ,而加稀土化合物的铬酵母样品在此两处的吸收峰值均高于未加稀土的铬酵母样品     

溶剂萃取法制备的纳米CeF3紫外吸收性能研究

利用Cyanex 923萃取法制备了纳米级CeF3微粉,并研究了分散剂、 CeF3量、 CeF3预处理灼烧温度和微粉粒径分布等因素对CeF3紫外吸收行为的影响. 结果表明,CeF3在255 nm附近有特征吸收峰;分散剂的极性强弱、 分散物浓度的改变都会影响吸收峰的强弱;随着粒径的减小,紫外吸收峰发生明显的红移. 此外还研究了TiO2包覆CeF3的紫外吸收性质,复合材料在250～400 nm区间内同时出现了TiO2和CeF3的特征吸收峰,复合材料的吸光域范围扩展.     

二维红外光谱法分析纤维素

采用二维红外光谱法分析纤维素。在293~393K范围内,分别测定脱脂棉纤维的一维红外光谱、二阶导数红外光谱和去卷积红外光谱。结果表明:脱脂棉纤维中的α-纤维素在559cm-1有一个的红外特征吸收峰,β-纤维素在893,1 206,1 235cm-1处有红外特征吸收峰;随测定温度的升高,559cm-1处红外吸收强度降低,893,1 206,1 235cm-1处红外吸收强度增加。进一步采用二维红外光谱研究温度对于脱脂棉纤维结构的影响,结果表明:随测定温度的升高,脱脂棉纤维红外特征吸收峰强度增加的顺序为893cm-11 235cm-11 206cm-1559cm-1。     

傅里叶变换-红外光谱法快速测定面粉中滑石粉

提出了应用衰减全反射(ATR)傅里叶变换-红外光谱(FT-IRS)法快速检测面粉中混入的滑石粉,测定中采用中红外检测器。根据滑石粉的标准红外光谱图并为避免面粉的吸收干扰,选择滑石粉在3 674.96 cm-1及668.16 cm-1两处的特征吸收峰作为判定面粉中是否含有滑石粉的依据,并且其吸收强度随滑石粉含量的增加而增加。由于面粉中滑石粉质量分数低于0.5%和0.2%时,分别在上述两吸收峰波长处已不呈现吸收,方法中将1%(质量分数)作为滑石粉的检出限。此外,根据吸收峰的吸收强度可估算出滑石粉的含量。方法中选用的主要仪器工作条件为:①扫描范围为4 000～650 cm-1;②分辨率为8 cm-1;③扫描信号累加次数为32;④衰减全反射压力常数为100。     

镧铬酵母中铬含量的测定

采用在培养基中加入La2O3的方法，制备得到了镧铬酵母，并对其总铬、无机六价铬及有机铬的含量进行了分析，结果表明：镧铬酵母中总铬含量可达到708．3μg／g，有机铬含量可达到639．0μg／g，是未加La2O3的铬酵母样品的近3倍；而六价无机铬占总铬的百分含量却由1．60％降至0．72％。通过紫外光谱和红外光谱分析，发现有机铬在260nm和478cm^-1处有特征吸收峰。     

紫外吸收试剂对反相液相色谱-间接紫外检测法分析烷基磺酸盐的影响

研究了不同背景紫外吸收试剂对无紫外光吸收的烷基磺酸盐检测的影响。采用反相C18色谱柱的高效液相色谱-间接紫外检测法,以背景紫外吸收试剂-有机溶剂为流动相分离烷基磺酸盐。研究不同背景紫外吸收试剂对分离检测烷基磺酸盐的影响规律和分离机理。结果表明,不同类型的背景紫外吸收试剂测定烷基磺酸盐的色谱峰类型不同。阳离子型背景紫外吸收试剂测定烷基磺酸盐时,样品峰均为正峰;阴离子型和两性离子型背景紫外吸收试剂时,样品峰均为倒峰。比较不同的背景紫外吸收试剂,发现采用阳离子型紫外吸收试剂测定烷基磺酸盐的色谱峰更好,其中以咪唑离子液体最佳,检测响应值最高。     

生物滤池中生物膜和出水悬浮物的元素分析和红外光谱比较

对生物滤池中不同高度的生物膜和出水悬浮物的碳氢氮三元素和红外光谱进行了分析比较.元素分析结果表明,悬浮物的无机成份比生物膜高.悬浮物和生物膜的红外吸收光谱图主要由蛋白质的吸收带、碳水化合物的吸收带组成.1655 cm-1处的吸收峰为酰胺Ⅰ带,是C=O的伸缩振动,1542 cm-1的吸收峰是酰胺Ⅱ带,是N-H的弯曲振动和C-N的伸缩振动,1240 cm-1是酰胺Ⅲ带,是C-N的伸缩振动和N-H的弯曲振动引起的.1460 cm-1处的吸收峰为CH3和CH2的弯曲振动峰.悬浮物的蛋白质特征峰强度比生物膜低,而1050cm-1处的吸收峰强度比生物膜大.     

华蟾素注射液有效组份的分离和鉴别

分别用水、50%乙醇洗脱HP-20大孔树脂分离华蟾素注射液,得到0.125%非极性组份和0.3625%极性组份。薄层色谱检测发现,极性组份用Dragendoff显色剂喷洒有斑点呈桔红色,推断为生物碱类物质;非极性组份喷洒20%乙酸-硫酸溶液有紫色斑点出现,推断为甾体强心甙类物质。高效液相色谱检测发现,非极性组份在40min以后出现紫外吸收峰,尤以47、51和53min以后出现的吸收峰明显;极性组份在10min以前有明显的紫外吸收峰,且与华蟾素注射液相应位置出现的紫外吸收峰相似。     

丁基黄药在CuO表面吸附的二维连续在线原位ATR-FTIR光谱研究

运用连续在线原位衰减全反射傅里叶变换红外光谱(ATR-FTIR)技术测定了纳米CuO表面对丁基黄药的吸附行为. 在FTIR 谱图中发现有峰的红移现象,吸收峰由1200 cm^-1偏移到1193 cm^-1,用超纯去离子水脱附,峰强度只有微小的变化,可判断丁基黄药在CuO表面发生了很强的化学吸附. 通过对吸附行为进行二维(2D)红外光谱分析,分辨出吸附过程中光谱强度的变化顺序. 二维异步相关光谱测定结果表明,1265 cm^-1处振动吸收峰最先引起光谱强度的变化,1265 cm^-1处吸收峰可归因为表面反应生成的双黄药和黄药分子聚集体的复合峰. 根据1200 cm^-1处黄药特征吸收峰强度的变化,进行吸附动力学模拟,得出CuO对丁基黄药的最大吸附量为529 mg·g^-1,且吸附符合拟二级吸附动力学过程.     

尿毒症中分子毒物的分离鉴定

自从1972年Babb等提出中分子假说以来,人们做了很多努力去分离鉴定尿毒症中分子毒性物质．Chu等通过凝胶色谱和离子交换色谱发现来自尿毒症患者血清和正常人尿液的A-3亚峰物质均含有6种成分,分子量分别为839．69,873．69,1007．94,1106．67,1680．28和2015．16．该组分在病人尿液中明显缺失,说明A-3亚峰物质可能是正常人通过尿液排出,肾衰病人难以通过尿液排出,导致在体内积累的物质;     

尿毒症中分子毒物的分离及飞行时间质谱分析

尿毒症被认为是因为患者肾衰而毒素在体内滞留所致^[1]。1972年Babb等^[2]提出“中分子假说”,认为分子量在300－2000范围内的中等分子量的物质是尿毒症的主要毒性物质。从此,人们作了大量的努力去分离和鉴定尿毒症中分子毒物。然而尿毒症中分子毒物的成分极其复杂^[3],从设定的中分子组分中分离得到的大都是些分子量小于800的小分子物质^[4]。因而对中分子假说一直存在争议^[5].我们对尿毒症患者及正常人的血清和尿液进行凝胶色谱分离,从尿毒症血清和尿液及正常人尿液中得到两个中分子峰A,B。将不同来源的A峰中的分子毒物进行离子交换色谱的分离和比较,得到了仅存在于尿毒症血清和正常人尿液的A－3亚峰,经脱盐和飞行时间质谱分析,确定了该组分内含有分子分别为839．69,1007．94,2015．16,16,873．69,1106．67和1680．28的6种化合物。     

Isolation and purification of uremic middle molecules by multi-step liquid chromatography

Isolation and comparison of uremic sera and urine and normal sera and urine were performed by gel permeation chromatography, anion exchange chromatography and re-versed-phase high performance liquid chromatography. Two uremic middle molecular fractions (A and B) were obtained from uremic sera and urine and normal urine by gel permeation chromatography, but not from normal sera. The anion exchange chromatographic results of fraction A from different origins demonstrate that subfraction A-3 could be excreted in urine by healthy subject, but accumulated in uremic serum for renal failure of patient with uremia. After desalinization subfraction A-3 was analyzed by MALDI-TOF-MS. The results show that subfraction A-3 consists of six compounds with molecular weight 839, 873, 1007.94, 1106, 1680 and 2015 respectively. Finally, by reversed-phase high performance liquid chromatography, subfraction A-3 was further resolved into six independent fractions. Thus, the isolation and purification of six middle molecular c     

慢性肾衰患者血清中分子物质浓度变化及其对Na,K-ATP酶的抑制作用

慢性肾功能衰竭是指在各种慢性肾脏疾病的基础上,缓慢出现肾功能减退而不可逆转的肾衰竭综合症由于患者肾功能衰竭,使得一些正常人本可以排出体外的代谢产物滞留在体内,导致肌体的一系列病变,涉及到人体的肠胃、免疫、心血管、内分泌、皮肤和骨骼等各个系统．20世纪70年代以来,中分子物质在患者体内的毒性作用开始引起众多研究者的关注．然而,由于这类物质成分复杂,对其分离鉴定工作还面临着很多困难,它们与慢性肾衰患者的临床症状之间的因果关系及致病机理仍不甚明确．在前期研究中,我们采用凝胶色谱法分离尿毒症患者血清,得到两个中分子物质峰A和B,     

尿毒症中分子毒物吸附剂的研究(Ⅲ)——酸性氨基酸修饰交联壳聚糖

以球状壳聚糖为载体,酸性氨基酸为配体,合成了尿毒症中分子毒物吸附剂,并测试了其血液相容性.为了研究吸附剂对尿毒症患者体内多肽蓄积物的吸附性能,选取分子量不同的6种多肽作为体内蓄积多肽的模拟物进行吸附实验.研究表明,吸附剂对多肽模拟物产生一定的吸附作用.在此基础上又对尿毒症患者血清超滤液进行了吸附实验,结果显示,吸附剂对血清中分子级分的清除率为10.3%.     

Analysis of Ultraviolet-Absorbing Compounds in Human Urine by High Performance Liquid Chromatography

Abstract

Ultraviolet (UV)-absorbing compounds in human urine were analyzed by means of high-performance liquid chromatography using the column of macroreticular anion exchange resin maintained at 60°C. The sample was eluted with a linear gradient of water to 0.25 M ammonium perchlorate-acetonitrile (85:15) at 0–50 min and with 0.25 M ammonium perchlorate-acetonitrile (85:15) at 50–70 min and monitored with absorption at 254 nm. Reproducible chromatograms were obtained and 68 well resoluted peaks were numbered. The storage of a urine sample at ?-20°C for 7 weeks did not significantly affect the chromatogram. The correlation coefficients of every pair of the numbered peaks were calculated to examine the daily variations and the individual difference of the UV-absorbing urine components.     

Infrared absorptions of the H(2)O ... H(2) complex trapped in solid neon

When a sample of neon to which have been added less than 1% each of H(2) and H(2)O is deposited at 4.3 K, the infrared spectrum of the resulting solid includes an absorption by the vibrational fundamental of H(2), which is normally infrared inactive. New absorptions are also associated with the vibrational fundamentals of the H(2)O in the sample. Similar results are obtained for deuterium-enriched samples. The new peaks are assigned to the van der Waals complex of H(2)O with H(2). As has been found in earlier theoretical, gas-phase, and solid-state studies of this and closely related systems, the infrared absorptions arise principally from complexes involving ortho-H(2), for which J=1.     

联苯胺类共轭共聚物的金属配合物催化法合成及性质

联苯二胺 ,3,3′ 二甲基联苯二胺在次氯酸钠介质中氧化制备了相应的N ,N′ 二氯联苯醌二亚胺 ,3,3′ 二甲基 N ,N′ 二氯联苯醌二亚胺 .通过红外 (FT IR) ,核磁共振 (1 H NMR)等进行了表征 .研究了此化合物在二价镍配合物存在下 ,与 2 ,5 二溴噻吩制成的Grignard试剂共聚的方法 ,并得到了联苯醌二亚胺与噻吩交替共聚的共轭聚合物 .该合成方法所得聚合物的纯收率分别为 6 3% ,88% .循环伏安测定表明该类聚合物具有一定的电化学活性 ,紫外 可见光谱中分别在 310nm ,4 5 0nm处 (共聚物Ⅰ )和 2 90nm ,4 30nm处 (共聚物Ⅱ )出现吸收峰 .根据聚合物的粉末X 射线衍射图 (XRD) ,对所得聚合物的结晶性也做了初步探讨 .     

Hydrogen-bonded assembly and binding affinity of the multi-point acceptor and isophthalic acid

Supermolecular complexes formed by oligophenyleneethynylene derivatives and isophthalic acid were studied using AM1 method to obtain binding energy. Electronic spectra and IR spectra of the complexes were calculated by INDO/CIS and AM1 methods based on AM1 geometries. Results indicated that the dimer could be formed by the monomers via hydrogen bonding because of the negative binding energy. Binding energy of the complexes was affected by electronegativity and steric effects of the substituents. The first UV absorptions and IR frequencies of N-H bonds of the complexes were both red-shifted compared with those of the monomers. The complexes could bind small molecules via hydrogen bonds, resulting in the change in UV absorptions and an increase in IR frequencies of N-H bonds.     

Electronic states of o-nitrobenzaldehyde: a combined experimental and theoretical study

The experimental UV/vis absorption spectrum of ortho-nitrobenzaldehyde (o-NBA) has been assigned by means of MS-CASPT2/CASSCF, TD-DFT, and RI-CC2 theoretical computations. Additional information on the nature of the absorbing bands was obtained by comparing the o-NBA spectrum with that of related compounds, as, e.g., nitrobenzene and benzaldehyde. For wavelengths larger than approximately 280 nm, the absorption spectrum of o-NBA is dominated by a series of weak n pi* absorptions from the NO2 and CHO groups. These weak transitions are followed in energy by a more intense band, peaking at 250 nm and arising from charge transfer pi pi* excitations involving mainly benzene and nitro orbitals. Finally, the most intense band centered at 220 nm has its origin in the overlap of two different absorptions: the first one localized in the NO2 substituent and the second one arising from a charge transfer excitation involving the NO2 and the CHO fragments, respectively.