共查询到20条相似文献,搜索用时 78 毫秒
1.
减压P350微色谱柱分离富集光度法测定矿石中微量锆 总被引:2,自引:0,他引:2
研究了P_(350)微色谱柱分离富集锆的行为及影响柱效的因素。确定了分离锆的最佳条件,提出了P_(350)微色谱柱分离、邻氯苯基荧光酮胶束增溶光度法测定矿石中微量锆的方法,经标准矿样验证,结果良好。 相似文献
2.
3.
4.
二苯并-18-冠-6-甲醛聚合物柱色谱分离富集化学发光法测定痕量金 总被引:5,自引:0,他引:5
研究了用一种新的高分子冠醚聚合物(二苯并-18-冠-6-甲醛聚合物)作为色谱柱的固定相,分离富集痕量金,再用化学发光法进行测定;在盐酸介质中,高分子冠醚对金的吸附率可达100%,吸附的金可被硫脲完全解吸,吸附容量为19.40mg/g;化学发光法测定操作简便,效果令人满意;研究结果表明:把高分子冠醚聚合物作为分离富集手段与具有高灵敏度的化学发光法结合进行痕量分析是一种很有前途的方法。 相似文献
5.
6.
采用MEMS技术设计了一种多道微型气相色谱柱,运用深槽刻蚀技术(DRIE),对器件刻蚀深400μm,微型色谱柱总长度为50cm,每道宽40μm,4道多道柱。采用静态涂覆法对色谱柱涂覆SE-54固定相。将多道色谱柱与30 m长的安捷伦HP-5毛细管柱多道色谱柱比较,烷烃混合物在两种柱内都被完全分离,混合物在多道柱内的保留时间比在毛细管柱内缩短了两倍,塔板数达到15342 plates/m,是毛细管柱的3倍。多道色谱柱被用于分离苯,甲苯及苯酚致癌组分,所有组分在1 min之内被完全分离。在时间上比之前报道的6 m长微型色谱柱缩短了3倍,实现了快速分离效果。 相似文献
7.
萃淋树脂微色谱柱分离富集-苯基荧光酮光度法测定中草药中痕量锗和钼 总被引:1,自引:0,他引:1
研究了在微色谱柱中以CL-TBP萃淋树脂为固定相,运用零空床体积洗脱技术,反相萃取分离痕量Ge、Mo。洗脱体积仅1.0~1.2 mL便可实现两元素的连续分离。洗脱液用苯基荧光酮-溴化十六烷基三甲基溴化铵(PF-CTMAB)光度法进行测定。该树脂对Ge、Mo的动态吸附容量分别为34.8 mg/g和67.4 mg/g,加标回收率分别为91.4%~98.6%和96.6%~101.3%,相对标准偏差(RSD)分别在2.53%~5.74%和1.91%~4.12%之间。方法用于中草药中痕量Ge、Mo的测定,结果满意。 相似文献
8.
9.
微型柱在线分离-ICP-MS法测定高纯氧化铕中的14个稀土杂质 总被引:7,自引:0,他引:7
研究了微型柱在线分离-电感耦合等离子质谱法(ICP-MS)测定高纯Eu2O3中痕量Tm的方法,研制了Cyanex272负载树脂微型分离柱,优化了分离Eu2O3基体的实验条件,在线分离测定时间为25min。建立了在线柱分离测定Tm,内标补偿法直接测定其余稀土杂质的高纯Eu2O3中14个稀土杂质的ICP-MS分析方法。方法检出限为0.01μg/g-0.15μg/g,加标回收率为91.5%-110%,相对标准偏差为1.7%-4.9%。可满足快速测定99.999%Eu2O3中14个稀土杂质的要求。 相似文献
10.
11.
Summary Systematic studies on the anion-exchange behaviour of thorium in malic acid solution on Amberlite IRA-401 have been carried
out. Acids such as HNO3, HCl, H2SO4, HClO4 and salts such as NH4Cl, (NH4)2SO4, NaClO4, NaCl and NaNO3 have been tested as eluants for thorium, their efficiency being evaluated in terms of their distribution coefficients. HNO3 is the best eluent for thorium. Methods have been developed for the separation of thorium from several elements in malic
acid media using selective adsorption or selective elution. The proposed method is applied to the analysis of thorium in monazite
where HClO4 is a better eluant than HNO3. The method is simple and the accuracy about ±3%. 相似文献
12.
Pei Liang Yongchao Qin Bin Hu Tianyou Peng Zucheng Jiang 《Analytica chimica acta》2001,440(2):207-213
A new method using a microcolumn packed with nanometer TiO2 as solid-phase extractant has been developed for the simultaneous preconcentration of trace amounts of Cu, Mn, Cr and Ni prior to their measurements by inductively coupled plasma atomic emission spectrometry (ICP-AES). Effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes have been investigated. The adsorption capacity of nanometer TiO2 was found as 0.108, 0.149, 0.039 and 0.034 mmol g−1 for Cu, Cr, Mn and Ni, respectively. The separation of analytes can be achieved from water samples with a concentration factor of 50 times. The method has been applied for the determination of trace elements in biological sample and lake water with satisfactory results. 相似文献
13.
A selective matrix removal/separation/enrichment method, utilizing a microcolumn of a chelating resin with SH functional groups (Duolite GT-73), was proposed for the determination of Sb(III) in waters by segmented flow injection-hydride generation atomic absorption spectrometry (SFI-HGAAS). The resin was selective to Sb(III) at almost all pH and acidity values employed, whereas Sb(V) was not retained at all and could be determined after a pre-reduction step with l-cysteine. Spike recoveries were tested at various concentration levels in different water types and were found to vary between 85 and 118%. Accuracy of the proposed methodology was checked by analyzing a standard reference material and a good correlation was found between the determined (13.3 ± 1.1 μg l−1) and the certified value (13.79 ± 0.42 μg l−1). The method was applied to several bottled drinking water samples for antimony determination with and without preconcentration and none of the samples were found to contain antimony above the permissible level (5 μg l−1). The characteristic concentration (the concentration of the analyte corresponding to an absorbance of 0.0044) was 0.55 μg l−1 and the 3 s limit of detection (LOD) based on five times preconcentration was 0.06 μg l−1. The applicability of the microcolumn separation/preconcentration/matrix removal method for flow injection systems was also demonstrated. 相似文献
14.
The potential of multiwalled carbon nanotubes (MWNTs) as solid-phase extraction adsorbent for the separation and preconcentration of gold has been investigated. Gold could be adsorbed quantitatively on MWNTs in the pH range of 1–6, and then eluted completely with 2 mL of 3% thiourea in 1 mol L− 1 HCl solution at a flow rate of 0.5 mL min− 1. A new method using a microcolumn packed with MWNTs as sorbent has been developed for the preconcentration of trace amount of Au prior to its determination by flame atomic absorption spectrometry. Parameters influencing the preconcentration of Au, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been examined and optimized. Under the optimum experimental conditions, the detection limit of this method for Au was 0.15 µg L− 1 with an enrichment factor of 75, and the relative standard deviation (R.S.D) was 3.1% at the 100 µg L− 1 Au level. The method has been applied for the determination of trace amount of Au in geological and water samples with satisfactory results. 相似文献
15.
Preconcentration of trace impurities form large-sized samples of uranium metal and thorium oxide using a small column of Chelex-100 followed by their determination using graphite furnace atomic absorption spectrometry (GFAAS) is reported. A 0.5–10-g amount of the sample (uranium metal or thorium oxide) was dissolved, complexed with ammonium carbonate and subjected to the ion-exchange procedure. The retained analytes were eluted with 2–4 M nitric acid and brought to a small volume for a final dilution to 10-25 ml for their determination using GFAAS. The validity of the separation procedure and recoveries at μg kg−1 levels was checked by standard addition; the recoveries were> 95%. 相似文献
16.
Bile acids are a group of compounds essential for lipid digestion and absorption with a steroid skeleton and a carboxylate side chain usually conjugated to glycine or taurine. Bile acids are regulatory molecules for a number of metabolic processes and can be used as biomarkers of various disorders. Since the middle of the twentieth century, the detection of bile acids has evolved from simple qualitative analysis to accurate quantification in complicated mixtures. Advanced methods are required to characterize and quantify individual bile acids in these mixtures. This article overviews the literature from the last two decades (2000–2020) and focuses on bile acid analysis in various human biological samples. The methods for sample preparation, including the sample treatment of conventional (blood plasma, blood serum, and urine) and unconventional samples (bile, saliva, duodenal/gastric juice, feces, etc.) are shortly discussed. Eventually, the focus is on novel analytical approaches and methods for each particular biological sample, providing an overview of the microcolumn separation techniques, such as high-performance liquid chromatography, gas chromatography, and capillary electrophoresis, used in their analysis. This is followed by a discussion on selected clinical applications. 相似文献
17.
分光光度法测定钨矿中微量钨 总被引:3,自引:0,他引:3
提出了一种测定钨矿中微量钨的分光光度法。该法摩尔吸光系数ε为9.6× 1 0 4 L· mol-1· cm-1,相对标准偏差 <2 % ,加标回收率为 95%~ 1 0 4 %。WO3 含量在 0~ 30 μg/50 m L 范围内满足比尔定律 相似文献
18.
Summary Thorium in uranium is determined directly at trace levels by an XRF method. Uranium oxide samples are put in the form of double layer pellets and analysed by using Philips PW-1220 X-ray spectrometer. The typical value of the precision of the method at 200 ppm level is ±10% and estimation range is 50–1000 ppm of thorium in uranium.
Direkte Bestimmung von Thorium in Uranoxid durch Röntgenfluorescenz-Spektrometrie
Zusammenfassung Mit Hilfe der beschriebenen Methode kann Th in Spurenkonzentrationen direkt bestimmt werden. Die Uranoxidproben werden als Doppelschicht-Tabletten eingesetzt und mit Hilfe eines Philips PW-1220 Röntgenspektrometers analysiert. Die Genauigkeit im Bereich von 200 ppm beträgt ±10%. Der Anwendungsbereich liegt bei 50–1000 ppm.相似文献
19.
A new automatic method for preconcentration and separation of radium in water samples has been developed. Such method combines both multisyringe (MSFIA) and multi-pumping (MPFS) flow analysis techniques allowing to analyze larger sample volumes with a higher throughput than other previous methodologies. Ra adsorbed on MnO2, deposited on cotton fiber, is eluted with hydroxylamine and subsequently coprecipitated with BaSO4. 226Ra activity is determined off-line by using a low background proportional counter. The procedure yield is (90 ± 3)% and its lower limit of detection 0.05 Bq L−1. This method has been applied satisfactorily to different types of spiked water (tap, mineral and seawater). 相似文献
20.
An atomic-absorption method is described for the determination of vanadium in ores. With a nitrous oxide-acetylene flame and 200 ppm of Al(3+) added to the sample, a sensitivity of 0.2 ppm for 1% absorption can be obtained. Iron above 0.015M interferes but can be extracted into isopropyl ether from 8M hydrochloric acid; the hydrochloric add itself then interferes and must be removed by evaporation. 相似文献