981 resultados para HPLC-ICP-MS


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本论文分为两部分:1. 综述部分(第一章和第二章),评述了悬浮进样方式在电感耦合等离子体发射光谱法(ICP-OES)中的研究与应用;电感耦合等离子体质谱(ICP-MS)中碰撞/反应池技术研究的新进展。2. 实验部分(第三章至第九章),内容包括针对不同性质的样品悬浮液选择适当的稳定剂和悬浮雾化ICP-OES的校准方法研究;以混合碰撞/反应气体解决难度较大的高纯氧化钕中稀土杂质测定的干扰问题;以及浊点萃取-石墨炉原子吸收法测定环境样品中痕量镉、氢化物发生-原子荧光光谱法测定铅基合金中砷和植物样品中锗等实用性强的分析方法研究。 ICP的传统进样方式是将样品转化成水溶液形式,以溶液方式进样。然而大多数样品是以固态形式存在,许多样品相当难溶或难熔。采用直接固体进样方法对这些样品进行分析,是分析工作者追求的目标之一。悬浮液进样是一种固体直接进样方法,除了具有其它固体进样技术的优点外,其最大优点是可以像溶液雾化一样用标准水溶液校准。本研究针对实际分析工作中遇到的具体样品,对悬浮进样ICP-OES技术进行了比较深入的研究,成功解决了样品处理繁琐和样品难以处理等困难。对特殊地质样品和激光晶体材料(Nd:YAG)的悬浮进样分析进行了探索。主要工作为:①建立分析地质样品中主量和微量元素的方法,标准水溶液可以成功地用于校准。优点是可以同时对地质样品中的Si和其它元素进行分析,避免了传统分析时需分别处理样品的麻烦。②探索了分析铌钽矿中铌和钽的应用。由于铌和钽具有强抗化学腐蚀性,所以溶液进样分析时样品处理过程复杂。结果表明,以标准水溶液校准时,只要样品研磨时间延长至5 h,即可获得悬浮进样的满意的回收率。③研究了分析掺钕钇铝石榴石(Nd:YAG)中钕掺杂量的可行性。研究表明,加入适量聚丙烯酸作分散剂并调节pH为6,可以得到稳定悬浮液;以通用标准加入法(GSAM)校准可以得到满意的结果。 我国的稀土资源占世界的80%以上,高纯稀土氧化物是高科技领域中的重要材料。碰撞/反应池技术是目前四极杆ICP-MS消除干扰的先进技术,可以选择性地减少某些基体干扰,使背景和检测限得到显著的改进。本实验选择氧化钕(有7个同位素)作为研究对象,采用碰撞/反应池技术重点解决四极杆ICP-MS方法对高纯Nd2O3中稀土杂质进行测定时,基体Nd对Tb、Dy和Ho严重的氧化物或氢氧化物干扰难题。研究结果如下:①在四极杆高分辨率模式下,可以消除Nd对Pr的相邻峰的拖尾干扰;②采用碰撞/反应池技术,设计了10% O2-10% Ar-80% He混合气体作为碰撞/反应气,将Tb、Dy和Ho分别转化为相应的氧化物离子进行测定,成功地消除了基体Nd对Ho的干扰;Nd对Tb和Dy造成干扰的表观浓度显著降低。本方法可直接测定纯度为6N的高纯Nd2O3中的Ho;对纯度为6N的高纯Nd2O3中的Tb和Dy进行扣除,可以分析纯度达5N的高纯Nd2O3中的Tb和Dy。与文献报道的其它消除基体Nd干扰的方法相比较,此方法能够对纯度更高的Nd2O3进行直接分析,且操作简便。此方法也可进一步拓宽,有望解决其它轻稀土氧化物对中重稀土检测的质谱干扰问题。 论文的7~9章的工作包括:浊点萃取-GFAAS测定环境样品中痕量镉、HG-AFS分析铅基合金中砷和植物样品中锗的研究。针对实际分析工作中的具体困难,以上工作分别解决了分析元素含量低、测定干扰严重及样品处理的问题,建立了实用性强、准确度高的分析方法,具有实际应用价值。

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采用高效液相色谱与电喷雾质谱联用技术,对生附片的化学成分进行了系统的研究.并辅以提取离子色谱方法.发现微量的化学成分.通过保留时间,质荷比及多级串联质谱数据,共鉴定了48个成分,其中双酯型生物碱8个,单酯型生物碱7个,脂型生物碱29个.其中双酯型生物碱是生附片中的主要成分,而单酯型和脂型生物碱的含量和种类较少.

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目的:通过HPLC、ESI-MS指纹图谱对中药西洋参与北沙参进行鉴别。方法:利用HPLC和ESI-MS技术,优化西洋参、北沙参提取物的色谱和质谱分离分析条件,建立二者HPLC、ESI-MS指纹图谱。结果:确定出西洋参与北沙参HPLC的各色谱峰相对保留时间;根据MS图中各成份的m/z值,确定相应成分的分子量。二者的液相色谱和质谱指纹图谱完全不同。结论:通过HPLC、ESI-MS指纹图谱可以完全鉴别中药西洋参与北沙参,方法简单准确,重现性好,具有实用价值。

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To study the content variation of ginsenosides and alkaloids during combination of ginseng with veratrum nigrum, the ginsenosides and alkaloids in the decoction of ginseng with veratrum nigrum were analyzed and compared by high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) and electrospray ionization-mass spectrometry (ESI-MS). In the compatible decoction, eight ginsenosides and eight alkaloids. were detected, and the contents of six ginsenosides were found to be reduced, on the contrary, the contents of six alkaloids were increased. During combination of ginseng with veratrum nigrum, the contents of ginsenosides were reduced and those of the toxic alkaloids were increased. From the chemical point of view, the traditional theory is right that ginseng and veratrum nigrum are incompatible with each other.

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Metabolic profiles caused by rare earth complex were investigated using NMR and ICP-MS techniques. Male and female Wistar rats were treated orally with Changle (A kind of rare earth complex applied in agriculture to raise the production of crops) at dose of 2, 5 and 20 mg (.) kg(-1) body weight/day respectively for 90 d. Urine and serum samples are collected on 90 d. The relative concentrations of important endogenous metabolites in urine and serum are determined from H-1 NMR spectra and the contents of the four rare earth elements ( La, Ce, Pr and Nd) constituting Changle in the serum samples are measured by ICP-MS technique. Changle-induced renal and liver damage in rats is found based on the increase in the amounts of the amino acids, trimethylamine N-oxide, N, N-dimethyglycine, dimethylamine, succinate, aketoglutarate and ethanol as well as rare earth concentrations. The similarities and differentiations are found in the alteration patterns of metabolites and rare earth concentrations in serum.

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A method was developed for the determination of trace and ultratrace amounts of REE. Cd. In. Tl. Th. Nb, Ta. Zr and Hf in soils and sediments. With NaOH-Na2O2 as the flux. Ti(OH)(4)-Fe(OH)(3) co-precipitation as the preconcentration technique and inductively coupled plasma mass spectrometry (ICP-MS) for measurement, the whole procedure was concise and suitable for batch analysis of multi-element solutions. An investigation was carried out of the Ti(OH)(4)-Fe(OH)(3) co-precipitation system, and the results obtained showed that the natural situation of Ti tightly coexisting with Nb. Ta, Zr and Hf in geological samples plays a very important role in the complete co-precipitation of the four elements. The accuracy of this procedure was established using six Chinese soil and sediment certified reference materials (GSS and GSD). and the relative errors between the found and certified values were mostly below 10%.

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A method was developed for the determination of lanthanum in the cytoplasm of human erythrocytes after they were incubated in lanthanum nitrate or citrate solutions. The lanthanum concentration in the cytoplasm of incubated erythrocytes is much higher than that in normal erythrocytes. It is suggested lanthanum can transport through the membrane of erythrocyte in vitro. Solutions containing chelator are unsuitable to be washing buffer in the investigation.

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An off-line chelation system combined with ICP-MS technique was developed for the quantitative determination of trace elements in seawater, namely V, Co, Ni, Cu, Zn, Mo, Cd, Pb, U and rare earth elements(REEs). The system was built based on an ion chromatography equipped with MetPac((R)) CC-I chelation columns which had a strong selective chelation to these target elements within a pH range 5.2-5.6. Acidified seawater samples and NH4Ac(2 mol/L) were blended to meet suitable pH before being injected into the chelation column, thus target elements were retained while alkali and alkaline metals were excluded. Then chelated elements were eluted by HNO3 (1 mol/L) and samples were collected for ICP-MS analysis. Varying the ratio of input( gen. 200 mL) to output( gen. 5 mL), the target elements which were concentrated as 40 times as their concentrations were far beyond instrumental quantification limits. At last, a certificated seawater CASS-4 was introduced and our detected values were in good agreement with those certified values.

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利用荧光衍生试剂1,2-苯并-3,4-二氢咔唑-9-乙基对甲苯磺酸酯(BDETS)作为脂肪酸柱前衍生化试剂,采用梯度洗脱在Eclipse XDB-C_8色谱柱上对游离脂肪酸(FFA)(油酸、亚油酸、软脂酸和硬脂酸)衍生物进行分离.利用柱后在线的串联质谱以大气压化学电离源(APCI)正离子模式实现了各组分的质谱定性.荧光检测的激发和发射波长分别为λ_(ex)=333 nm,λ_(em)=390 nm.脂肪酸的线性回归系数大于0.9990,检出限为3.38~6.59 nmol/L.建立的方法具有良好的重现性.利用此方法对超临界CO_2提取的唐古特白刺籽油中几种游离脂肪酸进行了分析.结果表明白刺籽油中含有大量的游离不饱和脂肪酸.