A Novel Sample Introduction Technique for the Simultaneous Determination of As,Se,Ge and Hg in Chinese Medicinal Material

A novel technique of Moveable Reduction Bed Hydride Generator（MRBHG）was applied tohe hydride generation or cold vapor generation of As，Se，Ge，and Hg existing In TraditionalChinese Medicinal Material（TCM）．The simultaneous determination of the multi－elements wasperformed with ICP－MS．A solid reduction system involving the use of potassiumtetraborohydride and tartaric acid was applied to generating metal hydride or cold vaporefficiently．The factors affecting the metal cold vapor generation were studied．The mainadvantage of the technique is that only a 4μL volume of sample was required for the cold vapor

EVALUATON OF MICROWAVE PLASMA TORCH FOR ATOMIC FLUORESCENCE SPECTROMETRY WITH AN ULTRASONIC NEBULIZATION SAMPLE INTRODUCTION SYSTEM

In this paper, a new MPT(microwave plasma torch) device has been used as a atomizer for atomic fluorescence spectrometry. Spme elements, such as Zn, Cd, Hg, Pb, As, Co, Mg, Cu, Ag, Mn, Fe have been investigated in detail.

Studies on Volatilization of Zirconium from Electrothermal Graphite Furnace for Sample Introduction into Inductively Coupled Plasma

Element zirconium reacted with polytetrafluoroethylene (PTFE) dispersed in isopropanol-water mixture to form volatile fluoride when heated in an electrothermal graphite furnace, and the fluorides formed subsequently were vaporized into ICP for atomization and excitation. The technique provides a picogram detectkm limit and adequate precision of 4% relative standard deviation. Linear dynamic range covers over three orders of magnitude. The process of sample preparation it very convenient. It is expected that the method proposed is suitable for determination of other refractory elements.

Atomic Emission Spectrometry of Inductively Coupled Plasma with Sample Introduction by Electrothermal Vaporization

A system is described in which a graphite furnace electrothermal vaporization device is employed for the introduction of microlitre liquid sample into an inductively coupled argon plasma. The technique provides a picogram detection limit and an adequate precision with a relative standard deviation of 4%. Mechanism of analyte condensation in transport process is explored. As an application, the technique combined with DDTC/CCl4 extraction is used to enrich and determine non- rare earth impurities in highly pure La2O3.

Determination of Some Elements by MIP-AAS Spectrometry with Ultrosonic Nebulization Sample Introduction System

Atmospheric pressure plasmas are not only powerful sources for excitation but also very good atomizers. In the early developing stage, the inductively coupled plasma (ICP) was investigated as an atomizer for atomic absorption spectrometry (AAS). A multiple pass system,a T-shaped plasma cell,and a long-path torch was used to increase the absorption path length. But all these ICP-AAS systems gave low sensitivities for most

Magnetic nanoparticles used in headspace extraction coupled with DSI-GC-IT/MS for analysis of VOCs in dry Traditional Chinese Medicine

A novel magnetic method using polystyrene modified magnetic nanoparticles to perform thermoheadspace extraction was successfully developed for extraction and preconcentration of volatile organic components in dry Traditional Chinese Medicine（TCM） based on gas chromatography-ion trap/mass spectrometry with a Chromato Probe direct sample introduction device. The dried fruit of Amomum testaceum Ridl. was used as the object TCM. The optimum parameters of headspace magnetic solid-phase extraction were investigated, in which desorption solvent ethyl acetate played a key role in this method,and the headspace extraction temperature of 90℃ and the headspace extraction time of 15 min finally decided. Headspace solid-phase microextraction method was also used to analyze volatile compounds in the TCM to compare with the proposed method. The results show that 60 components were identified totally by two methods; most of the low boiling point chemical compounds are isolated by this new method. In this work, an environmental-friendly and cheap analytical method was established, and a new approach to analyze volatile compounds in dry Traditional Chinese Medicine was also provided.

Development of a Novel Kilowatt Microwave Plasma Torch Source for Atomic Emission Spectrometry

Traditional low power-microwave plasma torch（MPT） excitation source of atomic emission spectrometry was shown to be good for the introduction of dry aerosols, but poor for wet sample aerosols. In this work, some significant modifications have been made to traditional MPT. A new MPT excitation source working at kilowatt microwave power has been developed. The kilowatt MPT source can sustain stable plasmas with double or even more filaments, presenting a ＂bell＂ form, where the region around the converging point is the optimum region for analysis. The tolerance to aqueous aerosol of the torch is enhanced significantly compared to the traditional one. Therefore, the desolvation system that the low power MPT source has to be relied on can be gotten rid of. A set of favorable detection results have been obtained with direct wet sample aerosol introduction. The kilowatt MPT source is expected to become a practical excitation source for atomic emission spectrometry that will be widely used.