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11.
高分辨等离子体质谱法直接测定高纯镓中的痕量元素 总被引:9,自引:0,他引:9
建立高分辨电感耦合等离子体质谱法(HR-ICP-MS)测定高纯镓样品中Be、Mg、A l、S i、Ti、V、Cr、Mn、Fe、Co、N i、Cu、Zn、Ge、As、Mo、Ag、Cd、In、Sb、Ba、Pb、B i等痕量元素的方法。样品用HNO3 HC l经微波消解后,试液直接进样用HR-ICP-MS法同时测定上述元素,在高分辨质谱测量模式下避免了大量的质谱干扰,详细地研究了HC l和高纯镓所产生的基体效应,以Sc、Rh、Tl作为内标元素校正了基体效应,讨论和确定了实验的最佳测定条件。结果表明,23种痕量元素的检出限在0.001~0.21μg/L之间;回收率在89.8%~111.6%之间,相对标准偏差(RSD)小于3.3%。 相似文献
12.
《Journal of separation science》2003,26(8):701-708
A micellar electrokinetic chromatographic and a fast reversed‐phase liquid chromatographic method have been developed for determination of the purity of phenoxymethylpenicillin. The optimized running buffer composition was 40 mM phosphate–borate–125 mM SDS–3.5% (v/v) methanol. The HPLC method employed a monolithic silica C18 column and a mobile phase composed of phosphate buffer, pH 3.5, and ACN, the flow‐rate being 3.5 mL/min. Both methods were successfully validated. Linearity, intermediate precision, limits of quantitation, accuracy, and a good correlation of the HPLC and MEKC results were demonstrated. Both methods proved to be fast and reliable and sufficiently sensitive. A combination of the two methods can be very useful in impurity profiling. 相似文献
13.
For the major, minor and trace element analysis of the inorganic compounds of a Ruhr-Saar coal different preparation techniques are investigated with X-ray fluorescence analysis, electron microprobe and classical wet chemical methods minimizing sample weight at standard preparation times and analytical accuracies. Considering accuracy as well as preparation efforts, determinations by electron microprobe on small sample amounts (<50 mg) proved to be superior to the other methods.Abbreviations AAS
atomic absorbtion spectrometry
- EMA
electron microprobe analysis
- IC
ion chromatography
- ISE
ion sensitive electrode
- PHOT
photometry
- WCA
wet chemical analysis
- XRF
X-ray fluorescence analysis
- LTA
low temperature plasma ashing
- HTA
high temperature ashing
- l.o.i.
loss on ignition 相似文献
14.
Summary Based on a thorough knowledge of the actual system precision significance testing of the primary eigen values, resulting from principal component analysis of the two-dimensional data array of HPLC with photodiode-array detection, is a powerful means to uncover unresolved chromatographic peaks. The implementation of this chemometric technique for assuring peak homogeneity and results showing the efficiency for two-component peaks in regard to spectral characteristics, chromatographic resolution and absorbance ratio of the investigated compounds are presented. 相似文献
15.
This paper details the analysis of the enantiomers of omeprazole, using aqueous CE coupled with MS detection. Following our
previously published work: where a non-aqueous CE–UV method was developed for omeprazole and 5-hydroxy-omeprazole; coupling
to electro-spray ionization (ESI) MS detection has now been investigated, using a sheath-flow interface for introduction.
An aqueous CE method was developed and designed to afford increased compatibility with ESI–MS detection, employing an ammonium
acetate buffer system (pH 5.8). Common partial filling methods could not be utilized to avoid the entrance of cyclodextrin
into the MS, and therefore a modified method of non-continuous-flow CE–MS was applied, with the CE separation carried out
without applied ESI voltage, before reapplying and allowing flow into the MS for data collection. A chiral CE separation of
omeprazole and 5-hydroxyomeprazole was achieved, and chiral CE resolution of omeprazole has been demonstrated using MS detection. 相似文献
16.
Petra Spitzer Bruno Rossi Yves Gaignet Stéphane Mabic Uwe Sudmeier 《Accreditation and quality assurance》2005,10(3):78-81
There is currently a major issue with the calibration of conductivity meters used for high purity water: the lack of availability of a reference material or reference methods for low conductivity ranges (conductivity below 1 S cm–1 at 25.0 °C, resistivity >1 M cm at 25.0 °C). This paper describes the current status of conductivity measurements in high purity water. A new and improved approach, currently being investigated, should allow us to make the calibration of conductivity meters used for low conductivity ranges traceable to the SI.Milipore, Milli-Q and Elix are registered trademarks of Millipore Corporation. 相似文献
17.
A simple and inexpensive equipment for the optical resolution of enantiomers (and separation of diastereomers) on triacetylcellulose in ethanol at elevated pressure is described. It involves a closed circuit of solvent (pump—column—detector—pump) allowing a continuous chromatography up to 16 cycles without stopping the flow or handling fractions.This useful and versatile method permitting also the determination of enantiomeric purities is illustrated by several examples of centro-, axial- and planarchiral arenes and metallocenes.Herrn Prof. Dr.U. Schmidt, Stuttgart, zum 60. Geburtstag gewidmet. 相似文献
18.
β-三氟甲基-β甲氧基β-苯基乙胺(TMPEA)是含氨基功能团的手性试剂[1].由于胺可将按酸转变成酸胺,该试剂已成功地用于手性有机酸对映体的纯度测定[2].考虑到胺同样可将醛酮转变成亚胺,本文进一步探讨了TMPEA用于手性醒酮对映体纯度测定的可行性.用R-(-)-TMPEA及dl-TMPAE分别与下列4种手性酮反应,制备相应的非对映异构亚胶:比较光活亚胺及相应的非对映异构体混合物亚腔的NMR谱,可确定各组非对映异构亚胺‘HNMR位移差(以OCH为探针基团)和’‘FNMR的位移差(以CF为探针基团)(表1).TablelCheffiicalshif… 相似文献
19.
The assembly strategy to prepare a monolayer of bovine serum albumin on the surface of silica gel supported gold nanoparticles is described. The stereo‐specific recognition ability of this material was evaluated by enantioresolution of Dansyl‐norvaline. For enantiomeric separation, the influences of buffer concentration and the concentration of organic modifier on the separation performance were investigated. A better separation in terms of enantioresolution and peak shape was found with the phosphate concentration at 30 mM. Moreover, the peak shape and resolution can be improved by the addition of methanol solution. Enantioresolution of Dansyl‐norvaline was obtained from this material at optimized conditions. It appears that the immobilization of a monolayer of bovine serum albumin on gold nanoparticles as the chiral selector of Dansyl‐derivative amino acid is promising. 相似文献
20.
Summary A method is described for the determination of the enantiomeric purity (enantiomeric excess) of the anticholinergic drug oxyphenonium. The method for this quaternary ammonium compound is based on the direct HPLC analysis with a chiral stationary phase. Two kinds of 1-acid glycoprotein-bonded phases were used.For the detection a post-column extraction with fluorescence detection of the ion-pair counter ion dimethoxyantracene sulphonate was used. 相似文献