用微量填充色谱柱分析丁烯中异丁烯杂质

微填色谱柱具有柱效高、分析速度快及样品负荷量较大等优点,故可以直接进料和直接与质谱联用,对痕量分析有利。微填色谱柱可用填料范围广,填料用量又少,故可用一些难获得的性能好的填料,由于使用的填料能成批制备,且制柱方法简单,故制柱的重复性好。     

巯基树脂对金属离子的吸附性能(Ⅱ)

研究了自合成的巯基树脂对重金属离子Ag 、Hg2 、Cr3 的吸附容量、吸附动力学、等温吸附过程等静态吸附性能,影响吸附的因素和吸附机理.结果表明,该树脂对上述3种离子吸附能力强,吸附量分别达6.56mmol/g、3.25mmol/g、2.10mmol/g.树脂对各重金属离子等温吸附在实验浓度范围内符合Langmuir或Freundlich方程.吸附机理研究表明,巯基与金属离子发生了离子交换和配位反应,化学吸附起支配作用;另外树脂对Ag 、Hg2 吸附过程中存在一定的氧化还原现象.     

亚汞树脂柱除氯-离子色谱法测定油田采出水中微量挥发性脂肪酸

高矿化度的油田采出水中大量Cl-对离子色谱的测定有严重干扰,需要进行预处理。采用自制亚汞树脂柱去除油田采出水中大量的Cl-,离子色谱法测定了其中的微量挥发性脂肪酸含量。介绍了亚汞树脂柱的制备过程与预处理性能调查。实验结果表明,亚汞树脂柱具有很强的除Cl-能力,提高了离子色谱法测定挥发性脂肪酸的准确度,适用于油田采出水的分析预处理。     

地质样品中Mo同位素测定的前处理方法研究

通过对地质样品中Mo同位素测试前的处理方法的比较,对传统的阴、阳离子树脂交换法进行了改进研究.经改进后的方法实用范围较宽,Mo的回收率达到97.49%±0.27%,Mo同位素质谱分析过程中可能的同重干扰元素Zr、Fe、Mn等的去除效果理想,其它金属元素的去除效果也较理想,且在阴离子交换柱洗脱Mo的过程中总计约需的提取液(盐酸和硝酸)体积只有75mL,只需文献报道用量的45%,从而减少了试剂对样品,特别是对低含量地质样品可能带来的潜在污染.     

ZK-1树脂对对甲基苯胺工业废水的柱吸附研究

选择NDA-150与ZK-01树脂作为吸附剂,以工业对甲基苯胺废水为研究对象,进行了树脂柱吸附废水的研究.工业对甲基苯胺废水中,对甲基苯胺含量为5300mg/L,吸附过程中,流量为1BV/h,温度为303K,NDA-150与ZK-01树脂分别吸附处理废水12BV、19BV时,废水中对甲基苯胺去除率为约98%.实验结果表明,ZK-01树脂吸附处理对甲基苯胺废水能力强于NDA-150,这是由于ZK-01树脂骨架上键联的弱酸基团与氨基生成酸碱络合物的结果.通过分析ZK-1树脂吸附-脱附处理对甲基苯胺废水的稳定性试验与脱附所得回收物质鉴定,ZK-1树脂具有运行稳定与回收物质可利用的特点.     

木质素磺酸钙改性丙烯酸树脂对水中甲基橙的吸附研究

以木质素磺酸钙(LS-Ca)、丙烯酸(AA)为原料,乙二醇二甲基丙烯酸酯(EDMA)为交联剂制备了木质素磺酸钙改性丙烯酸复合吸附树脂(LSAA).采用红外光谱、扫描电子显微镜、热重分析、比表面分析和吸附实验对LSAA树脂的性能进行表征.结果显示,LSAA树脂的初始分解温度为291.2℃,具有良好的热稳定性;表面粗糙,介孔丰富,树脂表面有较丰富的羟基等活性基团.LSAA对甲基橙的吸附过程受p H值的影响,298 K,p H=3时,24 h吸附量为188.33 mg/g;Langmuir和Freundlich方程均能较好地拟合甲基橙在LSAA树脂上的吸附等温线,吸附动力学过程符合准二级动力学方程,吸附为以物理吸附为主的放热过程.KannanSundaram模型拟合说明,LSAA的吸附过程分为吸附剂表面吸附、孔道缓慢扩散及小孔缓慢扩散3个阶段,直线都不经过原点,内扩散不是控制吸附过程的唯一步骤.     

基于BP神经网络研究儿茶素在ADS-8树脂固定床的吸附过程

以信阳毛尖茶叶浸提液为原料,研究儿茶素在ADS-8树脂固定床的吸附过程及优化吸附条件。试验基于BP神经网络建立吸附模型,通过仿真分析上样浓度、柱径比和流速对穿透时间、穿透体积的影响。模型的模拟值与试验值的相关系数为0.992,模拟值与试验值没有显著差异。最佳工艺条件为上样浓度1.5mg/mL,柱径比17:1,流速3.0mL/min。建立的模型可用于模拟儿茶素在ADS-8树脂固定床的吸附过程,结果为吸附树脂法制备儿茶素提供一定的参考。     

铁铅砷镍钴在CL-TBP萃淋树脂柱上的分离性能及其分配系数的测定和应用

测定了铁、铅、砷、镍、钴在CL-TBP萃淋树脂于不同酸度的盐酸和硝酸介质中的分配系数(Kd)值.试验结果表明:在5～9 mol·L-1盐酸介质中铁(Ⅲ)的Kd＞104,即强吸附于CLTBP萃淋树脂柱,而铅、砷、镍和钴在CL-TBP萃淋树脂柱的Kd≤12,即不吸附剂于树脂;在≤2 mol·L-1的硝酸介质中,铁(Ⅲ)的Kd＜12,即不吸附于树脂.用0.5 mol·L-1硝酸作为淋洗液可洗下吸附于柱的铁(Ⅲ).并测定了CL-TBP萃淋树脂的吸附容量.由此建立了萃淋树脂分离、电感耦合等离子体原子发射光谱法测定高纯氧化铁中铅、砷、镍和钴的方法.     

离子交换法从发酵液中提取L-亮氨酸

用离子交换法提取发酵液中的L-亮氨酸,比较了不同型号的强酸性阳离子树脂对L-亮氨酸的静态吸附量和吸附动力学,其中以WA-2型树脂对L-亮氨酸吸附量最大、吸附速度快,适于L-亮氨酸的提取.测定了WA-2型树脂对L-亮氨酸的吸附等温线,并回归得到Freundlich方程.考察了固定床操作工艺条件,结果表明:发酵液经预处理后,以1BV/h流速上柱吸附,上柱量为2BV;再用0.3mol/L的氨水洗脱,速度为1BV/h,洗脱效果较好,L-亮氨酸回收率达到95.7%.提取过程中WA-2型树脂不会受到不可逆的污染,也没有机械损坏,其使用寿命不受影响.     

组装式废水净化装置处理焦铜废水技术总结

本文主要叙述了用“组装式移动床离子交换”装置处理电镀铜产生的焦磷酸铜废水的实验与使用情况。由水泵、过滤器、再生柱、树脂储存斗,流量计以及再生系统及电源箱组成的成套装置,占地仅为1.6M~2;废水最大处理量为2吨/时。工作时,废水经水泵提升先经过白球过滤器过滤,除去机械杂质然后经流量计,逆流进入装有D—231树脂的阴柱进行交换,将废水中铜离子去除,从交换柱上部出来的水继续回用于漂洗过程。交换柱中饱和树脂排至再生柱中进行再生,回收焦磷酸铜原料继续用于生产。再生好的树脂用水压送至储存斗中备用,待下次交换柱饱和排放再生时,从交换柱上部加入交换柱。形成树脂移动循环,完成了焦铜废水处理全过程。     

用新型AP树脂分离铑—铱和同时富集测定铑`铱`铂`钯

铑-铱分离-向被认为是最困难的课题之一,即使文献曾报道Rh-Ir的分离,但实际Rh并未与萃取剂或吸附剂反应,而是与非贵金属离子一同留在溶液中。我们曾用光谱半定量方法研究了AP树脂对Rh、Ir的吸附行为,结果是Rh不被吸附而Ir能被吸附。本文通过改变Rh的离子状态,使之能被AP树脂吸附完全,而与留在溶液中的非贵金属分离,然后在柱上用不同淋洗液再使Rh-Ir分离。     

Detection of volatile organic compounds by temperature-programmed desorption combined with mass spectrometry and Fourier transform infrared spectroscopy

A temperature-programmed desorption (TPD) device connected to a mass spectrometer was used to detect volatile organic compounds from air samples. The main aim was to develop an analytical method, by which both non-polar and polar organic components can be detected in the same run. In TPD, the adsorbed compounds are desorbed from the resin more slowly than in the conventional trapping techniques, such as purge-and-trap technique, in which the resin is flash-heated and the compounds are desorbed at the same time to a cryogenic trap or an analytical column. In TPD, the adsorbent resin acts also as an analytical column. In this way it is possible to obtain more rapid analysis, and also a more simple instrumentation, which can be used on-line and on-site. In this work, a new version of TPD device, which uses a resistor for heating and a Peltier element for rapid cooling, was designed and constructed. Various adsorbent resins were tested for their adsorption and desorption properties of both polar and non-polar compounds. When using a mixture of adsorbent resins, Tenax TA and HayeSep D, it was possible to analyze both polar, low-molecular weight compounds, such as methanol and ethanol, and non-polar volatile organic compounds, such as benzene and toluene, in the same run within 15 min including sampling. The same TPD principle was also tested using a Fourier transform infrared spectrometer as an analytical instrument, and the results showed that it was possible to obtain a separation of similar compounds, such as hexane and heptane, and still retaining the same sensitivity as the original on-line FTIR instrument.     

Ion-exchange preconcentration and group separation of ionic and neutral organic compounds

In many cases sample pretreatment continues to be the most time-consuming and costly step in the analytical process. In the present work it is shown that macroporous ion-exchange resins of low exchange capacity can be used both to preconcentrate organic solutes from aqueous samples and to separate these solutes into groups. Thus, neutral and basic organic compounds are both taken up from aqueous solution by a very short column packed with a special cation-exchange resin. The neutral group of compounds is subsequently eluted with an organic solvent. The bases are then eluted 2 M methylamine in methanol. In a similar manner organic acids are concentrated on a special anion-exchange column. Extensive data are shown to demonstrate the efficiency of the preconcentration and group separation of neutral and basic compounds.     

试剂固定化的流动注射化学发光测定盐酸伊托必利

基于盐酸伊托必利在碱性条件下对铁氰化钾鲁米诺化学发光体系有较强的抑制作用,并采用离子交换固定法将鲁米诺和铁氰化钾全部固定在阴离子交换树脂上,联用流动注射技术建立了测定盐酸伊托必利的新方法。本法的线性范围为1.0~100.0μg/mL,检出限0.2μg/mL,对20μg/mL的盐酸伊托必利11次平行测定,其相对标准偏差为2.1%。单次测定在45 s内完成。此固定化柱可使用200次以上。可用于盐酸伊托必利片剂中盐酸伊托必利的质量检测。     

Determination of amino acids by capillary electrophoresis-electrospray ionization-mass spectrometry: an evaluation of different protein hydrolysis procedures

In this work, a CE equipment, online hyphenated to an IT MS analyzer by a linear sheath liquid interface promoting ESI, was used to develop a method for quantitative determination of amino acids. Under appropriate conditions (BGE composition, 0.8% HCOOH, 20% CH3OH; sheath liquid composition, 0.8% HCOOH, 60% methanol; V ESI, +4.50 kV), analytical curves of all amino acids from 3 to 80 mg/L were recorded presenting acceptable linearity (r >0.99). LODs in the range of 16-172 micromol/L were obtained. BSA, a model protein, was submitted to different hydrolysis procedures (classical acid and basic, and catalyzed by the H+ form of a cation exchanger resin) and its amino acid profiles determined. In general, the resin-mediated hydrolysis yields were overall similar or better than those obtained by classical acid or basic hydrolysis. The resulting experimental-to-theoretical BSA concentration ratios served as correction factors for the quantitation of amino acids in Brazil nut resin generated hydrolysates.     

A fully automated catecholamines analyzer based on cartridge extraction and HPLC separation

Summary A fully automated analyzer is described for the HPLC analysis of catecholamines. Firstly urinary and plasma catecholamines are reacted with diphenylboronic acid giving a complex without requiring a pH-meter step. This complex is strongly retained on a C 18 cartridge and elution with acetic acid solutions shows recoveries higher than 90 %. The catecholamines are eluted also by the mobile phase employed for the HPLC’ analysis. An intelligent autosampler makes the complex and fills a loop with all the solvents necessary for the sample cleanup. It then inverts the flow and pumps the sample and the solvents throught the cartridge. In the elution step the disposable extraction cartridge is positioned on stream with the HPLC analytical column by an automatic sampler. The separation is performed by ion-pair reversed-phase high-performance liquid chromatography, with sodium dodecyl sulphate as pairing ion, a short analytical column and electrochemical detection. The HPLC analysis time is 3 min and the total sample turnover time is 8 min. The recoveries and the precision of the analyzer are given together with correlation with manual HPLC.     

High-Pressure Ion Exchange Chromatography as Applied to the Separation of Complex Biochemical Mixtures

Interest in liquid column chromatography, including ion exchange chromatography, as a separation method has increased markedly in the past few years. Numerous new automated analytical techniques, as well as applications for preparative or production-scale separations, have been developed. This has been particularly true in the areas pertaining to separation and analysis of biochemical mixtures such as physiologic fluids. The recent trend in ion exchange chromatography has been toward achieving two goals: high-resolution analysis in the case of complex mixtures, and high-speed separation when simpler mixtures are involved. In either case, the use of small-diameter ion exchange resin particles coupled with high flow rates (and, in some cases, long columns) requires operation at relatively high column inlet pressures, since the pressure drop through the ion exchange column is dependent on factors such as resin particle size, flow rate, and column length.     

Synthesis and efficiency of a spherical macroporous epoxy-polyamide chelating resin for preconcentrating and separating trace noble metal ions

The determination of noble metals in various materials usually requires their preconcentration and separation from other elements. In spite of the improvements in analytical instrumentation and the development of new analytical techniques such as ICP-MS, which are capable of detecting metal ions at ppt levels, the interference caused by the sample matrix still exists and is perhaps the most serious problem, making a pre-determination enrichment step necessary. Thus, the search for efficient preconcentration and separation methods is essential. A series of chelating resins that can selectively adsorb noble metal ions from aqueous solutions have been described. Functional groups, such as salicylaldoxime and thiosemicarbazide have been incorporated in cross-linked polymers or porous silica gel. These resins have very high selectivity for one or several types of noble metal ion. However, desorption of noble metals from these resins is usually difficult. Hence, the development of an adsorbent from which noble metals can be easily desorbed is needed. In this paper, a new spherical macroporous epoxy-polyamide chelating resin that met this requirement was synthesized by one step reaction. The synthesis of the resin was safe, rapid and more simple and economical than many report adsorbents. Meanwhile, the resin showed more advantages: better acid and alkali resistance; higher adsorption capacity and lower preconcentration concentrations. A resin column procedure combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of trace Rh(III), Ru(III) and Ir(IV) in real samples was established.     

Peptide separations using fluorescence detection.

The formation of fluorophores by the action of o-phthalaldehyde with amino acids and peptides has provided a highly sensitive assay for these compounds. A relatively simple system for the analysis and separation of peptides, in the range 5 nmole to 10 micromole, normally derived from enzymic digestion of proteins, is described. The system comprises a gradient-generating device feeding volatile pyridine buffers via a pump to a column of cation-exchange resin. Eluate from the column is fed through a proportioning pump to a fluorocolorimeter, output from which is displayed on a recorder. For analytical runs the eluate is mixed with o-phthalaldehyde in borate buffer containing Brij 35 and 2-mercaptoethanol prior to its passage into the detector. For preparative work the eluate stream is split, one reacting with 0-phthalaldehyde, the other for collection. Results on the analysis and preparation of tryptic peptides derived from cytochrome c and Salmonella histidinol dehydrogenase are discussed.     

Shipboard analysis of picomolar levels of manganese in seawater by chelating resin concentration and chemiluminescence detection

A new shipboard analytical method for determining picomolar levels of manganese in seawater has been developed. The method is based on a combination of chelating resin column extraction and improved chemiluminescence (CL) detection in a closed flow system. In this method, manganese in sample solution is selectively collected on newly-developed iminodiacetate-immobilized chelating resin, and then eluted with acidic solution containing hydrogen peroxide. The resulting eluent is mixed with luminol solution and aqueous ammonia after removal of iron ions by a chelating resin column, and then the mixture is introduced into the CL cell. The manganese concentration is obtained from the CL intensity. The detection limit (3SD) of manganese is 5 pmol L^–1 from 9 mL of seawater sample. The method was applied to seawater samples collected at the Okinawa Trough.