Determination of Carbon by Means of Microwave Plasma Torch Atomic Emission Spectrometry

The determination of carbon by means of microwave plasma torch atomic emission spectrometry(MPT-AES) was studied. Aqueous samples were introduced with a pneumatic nebulization system. The detection limit for carbon was 0. 047μg/mL.The method was applied to the analysis for tap water and results were satisfactory.

Determination of Elements of Groups Ⅲ A and ⅣA Using Microwave Plasma Torch Atomic Emission Spectrometry

The determination of the elements of groups ⅢA and ⅣA by means of microwave plasma torch atomic emission spectrometry(MPT AES) was studied systematically. Sample solutions were introduced into the plasma with a pneumatic nebulizer in continuous sampling mode and flow injection (FI) mode. The emission characteristics of these elements were investigated in details, and the basic data obtained are very important to the development of MPT AES. The analytical performances were examined. For most elements, the detection limits obtained by this method were principally the same as those obtained by inductively coupled plasma atomic emission spectrometry (ICP AES).

Studies on Combination of Flow Injection and Microwave Plasma Torch-Atomic Emission Spectrometry

Although the flow injection(FI) as a sample introduction technique has been extensively applied to atomic spectrometry, such as ICP-AES and AAS, very little has been done so far on coupling FI to microwave plasma systems. Gehlausen et al. determined aqueous fluorine by coupling flow injection analysis (FIA) with HeMIP

On Line Anion Exchange Preconcentration in Microwave Plasma Torch Atomic Emission Spectrometry

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Determination of Cd,Pb and Sr by Microwave Plasma Torch Atomic Emision Spectrometry Using an Electrothermal Vaporization Sample Introduction System

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A Study on Determination of Some Trace Nonmetals by Microwave Induced Plasma Atomic Emission Spectrometry

In general, atomic emission spectrometry (AES) is an excellent technique for determination of metal elements. However, its capability of determining nonmetals has not been developed well. The major reasons are the resonance lines of most nonmetals lie in the vacuum ultraviolet spectral region and the ionic lines of these elements are difficult to be used because the ionization potentials of the elements are very high. And furthermore only He plasma can efficiently excit those ionic resonance lines. The practical application of HeICP-AES to determining the nonmetals is also difficult because its operating and perchace costs are very high. In contrast to HeICPAES, the costs of He microwave induced plasma (MIP)-AES are relatively low, HeMIP has a high excitation capability which can excite ionic lines of various nonmetals and the nonmetals can be determined by HeMIP-AES with a high sensitivity.

Evaluation of Atomic Fluorescence Spectrometry for Determination of Mercury Using a Low-Powered Argon Microwave Plasma Torch (MPT)

The Microwave-Induced Plasma (MIP) has received considerable attention during the past decade since theintroduction of the Becnakker Cavity. It has been commonly used as an atomization cell for atomic emission spectrometry (AES) and atomic absorption spectrometry (AAS), and a great success was achieved for both techniques. More

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.

A Study on the Determination of Copper by Microwave Induced Plasma Atomic Emission Spectrometry (MIP-AES)

The determination of copper by MIP-AES was investigated in detail. Aqueous samples were introduced from an ultrasonic nebulizer and the solvent was removed by a desolvation device before introduction of the aerosol into the MIP. The desolvation system consisted of a condenser associated with a concentrated H2SO4 absorption cell. Various experimental conditions and interferences from easily ionised elements (EIEs) were also studied and some practical samples were analyzed.

Quantitative Determination of Density of Ground State Atomic Oxygen from Both TALIF and Emission Spectroscopy in Hot Air Plasma Generated by Microwave Resonant Cavity

Two experimental techniques have been used to quantify the atomic oxygen density in the case of hot air plasma generated by a microwave （MW） resonant cavity. The latter operates at a frequency of 2.45 GHz inside a cell of gas conditioning at a pressure of 600 mbar, an injected air flow of 12 L/min and an input MW power of 1 kW. The first technique is based on the standard two photon absorption laser induced fluorescence （TALIF） using xenon for calibration but applied for the first time in the present post discharge hot air plasma column having a temperature of about 4500 K near the axis of the nozzle. The second diagnostic technique is an actinometry method based on optical emission spectroscopy （OES）. In this case, we compared the spectra intensities of a specific atomic oxygen line （844 nm） and the closest wavelength xenon line （823 nm）. The two lines need to be collected under absolutely the same spectroscopic parameters. The xenon emission is due to the addition of a small proportion of xenon （1% Xe） of this chemically inert gas inside the air while a further small quantity of H2 （2~） is also added in the mixture in order to collect OH（A- X） and NH（A-X） spectra without noise. The latter molecular spectra are required to estimate gas and excitation temperatures. Optical emission spectroscopy measurements, at for instance the position z=12 mm on the axis plasma column that leads to a gas measured temperature equal to 3500 K, an excitation temperature of about 9500 K and an atomic oxygen density 2.09× 1017＋ 0.2×1017 cm-3. This is in very good agreement with the TALIF measurement, which is equal to 2.0×101T cm-3.

CORRECTION OF WING INTERFERENCE WITH KALMAN FILTERING IN INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY

A Kalman filter was developed for correction of wing interference in ICP-AES.Modeling wing interference theoretically instead of experimentally, the filter can compensate the shift in wavelength position in scans, and therefore reduce the effect of the interference on detection limit.

In Situ Analysis of Tobacco Leaves Based on Microwave Plasma Torch Desorption Ionization Mass Spectrometry

Tobacco is an important economic crop worldwide.Tobacco leaves contain a large number of natural products.Therefore,the analysis of tobacco composition is crucial for the control of tobacco safety and quality assessment.Microwave plasma torch desorption ionization mass spectrometry(MPT-MS) is an emerging ambient mass spectrometry(AMS) technique that can be used for rapid real-time analysis of s amples without pretreatment.Our work focuses on the chemical composition analysis of tobacco using MPT-MS,and 14 compounds were detected in green flue-cured tobacco leaves,while 30 compounds were detected in cured flue-cured tobacco leaves,which confirms that curing can enhance the flavor of cigarettes.Furthermore,we successfully in situ identified characteristic fragment ions of α/β-CBD(α/β-cembranoids),an important aroma compound in tobacco by MPT-MS.The results demonstrate the capability of MPT-MS for in situ analysis of tobacco components and its potential for evaluating tobacco quality.

Evaluation of Microwave Plasma Torch (MPT) as an Excitation Source for Determination of Mercury

The microwave plasma atomic spectrometry is an important branch of the plasma atomic spectrometry. Since the first use of microwave induced plasma（MIP） as an excitation source for spectral Chemical analysis by Broida and Chapmanin in 1958, especially the introduction of TM;cavity by Beenakker in 1976 and of surfatron by Moisan in 1979 with which an atmospheric pressure helium MIP could be obtained, MIP has received considerable attention as a new excitation source for spectrometric analysis. However, since MIP suffers from the in ability to analyse the aqueous sam-

A Perspective of Laser Sampling for Inductively Coupled Plasma-Atomic Emission Spectro metry for Rock and Mineral Analysis

The development of laser sampling for optical emission spectrometry is reviewed . Advantages and limitations of pulsed laser sampling are compared with those of continuous laser sampling . A novel method of laser sampling of liquid samples for inductively coupled plasma -atomic emission spectrometry has been proposed , and its analytical performance investigated.Experimental results showed that,as a method of sample introduction , laser vaporization of liquid samples enjoyed certain advantages , e.g.,much higher sensitivity, much lower detection limit and reduced sample volume , over solution nebulization . A perspective of the application of laser sampling-inductively coupled plasma - actomic emission spectrometry for rock and mineral analysis is estimated as well.

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.

黑果枸杞中矿物元素溶出特性研究

黑果枸杞,茄科枸杞属,富含多种矿物质元素,这对人体生长发育有重要的生物学作用。黑果枸杞作为一种药食同源的物质,为了解其营养价值、指导健康食用及进一步功能开发,有必要分析矿物质溶出特性,并进行相关性分析。黑果枸杞样品制备以硝酸和过氧化氢为消解酸,微波消解仪制备消解液,以不同温度纯水浸提制备浸泡液,试验建立了电感耦合等离子体光谱法测定消解液和浸泡液中K、Na、Ca、Mg、Zn、Fe、Mn、Cu、Li、Sr十种矿物元素含量的实验方法,并进行了矿物元素溶出特性研究及相关性分析。在优化的光谱分析条件下,十种元素线性关系好(r>0.9995)、检出限低(<0.01 mg·L^(-1))、准确度高、精密度好。加标回收率在97.2%~101.8%之间,相对标准偏差小于1.99%。实验发现,黑果枸杞中矿物元素含量丰富,含量最高的是K,其次是Na、Ca、Mg,然后是Fe、Li和Sr,含量较低的是Mn、Zn、Cu。黑果枸杞中K/Na值大于8,属于典型的高钾低钠食品。Ca、Mg、Fe、Zn、Li、Sr、Mn、Cu也是人体中多种酶、激素和维生素中不可缺少的活性因子,是一种理想的食品。黑果枸杞浸泡液中,除Li与Ca、Zn、Fe之间,Mg与Zn之间关系不明显外,其余元素间呈显著正相关或极显著正相关。表明,各矿物质元素中不存在明显的拮抗作用。矿物质元素的溶出率与浸泡时间及提取温度有关。实验采用沸水和40℃纯水浸泡黑果枸杞样品,选取浸提时间5、10和20 min三个时间点研究提取温度及时间对溶出率的影响。十种元素中K、Na、Zn溶出率最高,可能是因为三种元素多以离子形式存在,容易提取。Ca、Mg、Sr、Mn、Cu含量差异大,溶出率相近,可能是价态相近,提取效率相近。Li溶出率受提取温度影响很大,沸水浸泡溶出率是40℃温水的的1.5~2倍,Fe在微量元素中含量最高,溶出率却最低,主要是由于Fe与蛋白质结合,不易萃取。试验数据可为健康食用黑果枸杞及进一步开发利用提供理论参考。

电感耦合等离子体发射光谱法测定土壤中有效磷的不确定度评价

为准确测定土壤中有效磷的含量,采用电感耦合等离子体光谱仪进行测定,并对测定过程中相关因素引起的不确定度进行评定。整个实验过程中不确定度来源主要包括以下5个方面:(1)样品称量时引入的不确定度u(m);(2)加入浸提液时浸提液体积V引入的不确定度u(V);(3)标准溶液配置时引入的不确定度u(C_(s));(4)标准曲线拟合引入的不确定度u(C0);(5)样品测量重复性引入的不确定度u(R)。结果表明,样品测量重复性、标准溶液配置、标准曲线拟合在整个实验中引入的不确定度影响较大。因此,在实际样品测定过程中,一定要注意对结果有影响的不确定度因素,加强质量控制,使结果准确可靠。

电感耦合等离子体发射光谱法测定石灰岩中游离二氧化硅

建立电感耦合等离子体发射光谱(ICP-AES)法和粉末压片制样-X射线荧光光谱(XRF)法联合测定石灰岩中游离二氧化硅含量。准确称取经105℃烘干2 h的石灰岩样品0.1000 g,置于30 mL聚四氟乙烯坩埚中,加入8m L浓磷酸,置于300℃电热板上沸腾20 min,冷却后定容在100 mL容量瓶中,静置12 h。采用ICP-AES测定溶解在溶液中的二氧化硅含量,采用XRF测定石灰岩中二氧化硅总含量,用总的二氧化硅含量减去溶液中二氧化硅的含量就得出了游离二氧化硅的含量。经4种标准物质验证,游离二氧化硅含量分析结果与标准值满足规范中相对误差允许限的要求。该方法操作步骤更为简便,分析速度快,低含量游离二氧化硅结果准确度高,适用于批量石灰岩样品中游离二氧化硅含量分析。

微波消解-电感耦合等离子体原子发射光谱法测定硼铁中硅铝磷的含量

采用盐酸、硝酸和氢氟酸经微波消解样品,使用电感耦合等离子体原子发射光谱法(ICP-AES)对硼铁中硅、铝、磷的含量进行测定。方法确认了最佳微波消解条件,选择Si 288.158 nm、Al 394.401 nm、P 213.618 nm为分析谱线。干扰试验结果表明,在选定的分析谱线下样品中共存元素对待测元素的干扰可忽略。试验方法应用于硼铁实际样品中硅、铝、磷含量的测定,精密度试验测定结果的相对标准偏差(n=11)为1.77%~2.76%,加标回收率为96%~103%。按照该方法测定硼铁标准样品中硅、铝、磷的含量,测定值与认定值相吻合。

电感耦合等离子体原子发射光谱法测定锆合金中5种元素的含量

提出了电感耦合等离子体原子发射光谱法测定锆合金中锡、铌、铁、铬、镍含量的方法。取样品0.1 g,加入5 mL水、5 mL硝酸和0.5 mL氢氟酸,于100℃加热5 min,用水定容至25 mL。设置仪器射频功率为1300 W,雾化气流量为0.80 L·min^(-1),进样量为2.0 mL·min^(-1),测定5种元素在Sn 242.949 nm、Nb 309.418 nm、Fe 259.941 nm、Ni 221.648 nm、Cr 267.716 nm等分析谱线处的响应强度,基质匹配法定量。结果表明:锡、铌的质量浓度在150μg·mL^(-1)以内,铁、铬、镍的质量浓度在15μg·mL^(-1)以内分别与对应的响应强度呈线性关系;锡检出限(3s)为16μg·g^(-1),其他元素检出限(3s)均低于3.0μg·g^(-1);各元素方法重复性的相对标准偏差(n=10)均小于2.0%,加标回收率为99.0%~109%;采用锆合金标准物质SRM360b进行验证,测定值均在认定值的不确定度范围内。