Analytical Evaluation of an Integrated Ultrasonic Nebulizer-hydride Generator System for Simultaneous Determination of Hydride and Non-hydride Forming Elements by Microwave Induced Plasma Spectrometry

ABSTRACT

The commercial ultrasonic nebulizer NOVA-DUO (ultrasonic nebulizer dual capillary system USN/DCS) has been evaluated for the simultaneous determination of classical hydride forming (As, Bi, Ge, Sb, Se, Sn) and conventional non-hydride forming (Ba, Ca, Fe, Li, Mg, Sr) elements by microwave induced plasma-optical emission spectrometry (MIP-OES). Simultaneous mixing and nebulization of the two solutions (acidified sample and reductant) on the piezoelectric transducer, with the possibility of flow rate adjustment, permits a wide variation of sensitivity. The hydrides and aerosols were rapidly transported via a stream of Ar carrier to a MIP for simultaneous multi-element determination by OES. A univariate approach and simplex optimization procedure was used to achieve optimized conditions and derive analytical figures of merit. Analytical performance of the ultrasonic nebulization system was characterized by determination of the limits of detection (LODs) and precision (RSDs) with the USN/DCS observed at 11 µL min^?1 flow rate. The experimental concentration detection limits for simultaneous determination, calculated as the concentration giving a signal equal to three times of standard deviation of the blank (LOD, 3σ_blank criterion, peak height) were 1.3, 5.9, 6.6, 1.8, 3.6, 2.6, 41, 8.1, 11, 7.5, 9.2, and 12 ng mL^?1 for As, Bi, Ge, Sb, Se Sn, Ba, Ca, Fe, Li, Mg, and Sr, respectively. The method offers relatively good precision (RSD ranged from 9 to 13%) for liquid analysis and microsampling capability. Interference effects by transition metals have been shown to be corrected by the addition of thiourea, as a pre-reducing agent and masking agent. The accuracy of the method was verified by the use of certified reference materials (NRCC DOLT-2, NRC GBW 07302, NIST SRM 2710, NIST SRM 1643e) and by aqueous standard calibration technique. All results obtained for reference materials were in agreement with certified values at 95% confidence level by Student t-test.     

Ultrasonic Nebulization,Multimode Sample Introduction System for Simultaneous Determination of Hydride-Forming,Cold Vapor,and Non-Hydride-Forming Elements by Microwave-Induced Plasma Spectrometry

A novel synergic effect of ultrasonic nebulization (USN) and a multimode sample introduction system (MSIS) when used in combination has been exploited for efficient generation of conventional hydride-forming (As, Bi, Ge, Sb, Se, Sn), Hg vapor, and non-hydride-forming (Ba, Ca, Li, Mg, Sr) elements. The ultrasonic nebulizer supplied a microliter sample to a quartz oscillator, converting liquid into aerosol at the entrance of the MSIS spray chamber. The argon carrier gas is passed to remove and transport the generated vapor species (from the MSIS) and aerosol (from the USN) to a microwave-induced plasma (MIP) for simultaneous element determination by optical emission spectrometry (OES). The experimental concentration detection limits for simultaneous determination, calculated as the concentration giving a signal equal to three times the standard deviation of the blank (LOD, 3σ_blank criterion, peak height) were 0.3, 1.5, 1.9, 0.5, 1.7, 0.6, 0.8, 9, 1.6, 1.9, 2.2, and 2.9 ng mL^?1 for As, Bi, Ge, Sb, Se, Sn, Hg, Ba, Ca, Li, Mg, and Sr, respectively. The method offers relatively good precision (RSD ranged from 5% to 9%) for liquid analysis and microsampling capability. The methodology was validated through determination of elements in four certified reference materials (NIST 2710, NRC GBW 07302, NRCC DOLT-2, NIST 1643e) and by the aqueous standard calibration technique. Good agreement with certified values was obtained when this approach was applied to the determination of hydride-forming, cold vapor, and other elements in biological and environmental certified reference materials.     

Method Development for Simultaneous Determination of Transition (Au,Ag, Cd,Cu, Mn,Ni, Pb,Zn) and Noble (Pd,Pt, Rh) Metal Volatile Species by Microwave-Induced Plasma Spectrometry Using Ultrasonic Micronebulizer Dual Capillary Sample Introduction System

ABSTRACT

The commercial ultrasonic nebulizer NOVA-DUO (Optolab, Warsaw, Poland) has been evaluated for the simultaneous determination of transition (Au, Ag, Cd, Cu, Mn, Ni, Pb, Zn) and noble (Pd, Pt, Rh) volatile metal species by microwave induced plasma–optical emission spectrometry (MIP-OES). Simultaneous mixing and nebulization of the two solutions (acidified sample and reductant) on the piezoelectric transducer, with the possibility of flow rate adjustment, permits a wide variation of sensitivity. The vapor-phase species were rapidly transported via a stream of Ar carrier to an MIP–OES for simultaneous multi-element determination. A univariate approach and simplex optimization procedure was used to achieve optimized conditions and derive analytical figures of merit. Analytical performance of the ultrasonic nebulization system was characterized by determination of the limits of detection (LODs) and precision (RSDs) with the ultrasonic nebulizer/dual capillary system (USN/DCS) observed at 15 µL min^?1 flow rate. An improvement in detection limits was achieved compared with pneumatic nebulization. Detection limits are superior to conventional pneumatic nebulization of elements. The experimental concentration detection limits for simultaneous determination, calculated as the concentration giving a signal equal to three times of standard deviation of the blank (LOD, 3σ_blank criterion, peak height), were 2.49, 1.75, 3.39, 2.13, 4.80, 6.21, 4.26, 2.01, 7.65, 3.92, and 4.65 ng mL^?1 for Au, Ag, Cd, Cu, Mn, Ni, Pb, Pd, Pt, Rh, and Zn, respectively. The method offers relatively good precision (RSD ranged from 8 to 12%) for liquid analysis and microsampling capability. The accuracy of the method was verified by the use of digested certified reference materials (NRCC TORT-1, NIES CRM-13, NIST SRM 2710, INCT SBF-4) and by aqueous standard calibration technique. The measured elements content in reference materials was in satisfactory agreement with the certified values.     

Emission Spectrometric Analysis of Fresh Waters with U-Shaped D.C. Arc with Aerosol Supply

Abstract

The application of a U-shaped d.c. arc with aerosol supply for analysis of fresh waters has been described. Limits of detection obtained with d.c. plasma compare well with those reported for ICP. A number of spectral lines and molecular bands were examined and the most suitable are selected to ensure the best limits of detection or wide dynamic ranges. Limits of detection in ng ml^?1, given in the parenthesis, following the element symbol, are: Al(0.9), B(0.6), Ba(0.2), Be(0.15), Ca(0.05), Cd(3.5), Co(1.1), Cr(0.2), Fe(2.4), Ga(0.5), Hg(9.0), K(0.3), Li(0.008), Mg(0.4), Mn(0.3), Mo(0.7), Na(0.04), Ni(2.0), P(45), Pb(12), Si(9.0), Sr(0.04), Zn(1.3).     

Characterization of Indian Ayurvedic herbal medicines for their metal concentrations using WD‐XRF spectrometry

This article describes the details of metal concentrations evaluated using wavelength dispersive X‐ray fluorescence (WD‐XRF) spectrometry. A total of 22 elements, Na, Mg, Al, Si, P, S, K, Ti, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Hg, Pb, Ba, Au, and Sn from 16 Ayurvedic medicines were characterized. The method was validated by analyzing the six certified reference materials of soil standards [NIST SRM‐2710, CRM 027‐050 (US‐EPA certified), PS‐1, TILL‐1 and TILL‐4 (Canadian certified reference material, CCRMP) and JSO‐1 (Japanese certified reference material)]. The elemental concentrations in all the standards are found to be within ± 10% of the reported values. Crystalline phases in the individual drug samples were explained by powder X‐ray diffraction (XRD) technique. Qualitative phase identification was done using the ICDD database. Copyright © 2010 John Wiley & Sons, Ltd.     

偏振能量色散X射线荧光光谱法在土壤环境监测中的应用

以土壤和水系沉积物标准物质为校准样品,采用粉末样品压片制样.建立了偏振能量色散X射线荧光光谱仪测定土壤中As、Ba、Cu、Co、Cd、Cr、Mo、Mn、Ni、Pb、Sr、Ti、V、Zn、Rb、Sc、Bi、Si、Al、Fe、Ca、Mg、Na、K 24种元素的方法.该方法采用Al、CaF2、Fe、Zn、KBr、Al2O3、...     

Raman Spectra of Alkali and Alkaline Earth Metal Salts of Inosine 5′-Monophosphoric Acid

Crystalline Li(I), Na(I), K(I), Mg(II), Ca(II), Sr(II), Ba(II) and Cd(II) salts of inosine 5′-monophosphoric acid, H₂(IMP), were obtained and characterized by Raman spectroscopy. Splitting of the imidazolic 1480 cm⁻¹ band was observed for the N(7)-bound Ca(IMP)·6H₂O, Ba(IMP)·6H₂O, Sr(IMP)·6H₂O and Cd(IMP)·4H₂O compounds. The Li(I), Mg(II), Ca(II) and Cd(II) ions bind directly to the phosphate group, and no direct coordination involving the carbonyl C(6)O group was observed in the compounds reported here. Some Raman spectral features in the 750–700 cm⁻¹ range seem to reflect the nucleoside structure of the inosine moiety     

The Mineral Content of Rhizona cyperi after Microwave-Assisted Digestion and Determination by AAS

ABSTRACT

Rhizoma cyperi (tuberal part of Cyperus rotundus Linn) obtained from 15 different zones of China was studied to determine the contents of 16 trace elements such as 4 minor (Ca, K, Mg, and Na), 9 trace (Co, Cr, Cu, Fe, Mn, Mo, Ni, V, and Zn), and 3 toxic (Ag, Cd, and Pb) elements. The concentration determination of 16 elements was performed by atomic absorption spectrophotometry (AAS) after microwave-assisted digestion. A microwave-assisted digestion procedure based on the mixture nitric acid–hydrogen peroxide was evaluated. The method was successfully validated with the good recoveries (97–105%) against CRM GBW07603 (bush twigs and leaves). The calibration curve furnished good linear correlation coefficients (r = 0.9956–0.9999), excellent recoveries (99.35–103.7%), and limits of detection (LOD = 1–50 ng·mL^?1) suitable to determine in Rhizoma cyperi. The results showed that K, Ca, Mg, and Na were the most abundant of the major elements in Rhizoma cyperi with average concentrations of K, 26,221 µg·g^?1; Ca, 1097 µg·g^?1; Mg, 714 µg·g^?1, and Na, 293 µg·g^?1, respectively. K element was determined for the first time in this plant.     

ICP-AES测定乌药饮片及其煎煮液中无机元素的含量

选择硝酸-双氧水作为消解体系,分别采用微波消解和电热板直接消解法对乌药饮片及其煎煮液进行消解,然后用电感耦合等离子体发射光谱法（ICP-AES）同时测定了全药、一次煎煮液及二次煎煮液中的Al、B、Ba、Ca、Co、Cr、Cu、Fe、K、Li、Mg、Mn、Ni、P、Pb、V、Zn、Be、Cd、Sr、Na等21种元素。加标回收率在82.0%—115.2%之间,相对标准偏差均小于10%,具有良好的精密度和准确度。各元素的检出限在0.3—12.9μg/L之间,能满足中草药中无机元素的测试要求。实验结果表明乌药中含有丰富的K和Ca元素,Mg、Al、Fe、Mn的含量也相对丰富,而乌药各次煎煮液中无机元素的溶出率各不相同,为进一步探讨乌药中元素含量与其药效的相关性,指导合理用药提供科学依据。     

土壤中常量及微量元素的ICP光谱分析

本文叙述了土壤中Ca、Mg、Na、Sr、Ba、Mn、Fe、V、Cr及Ti等元素简单快速的ICP-AES测定方法。用HClO_4、HNO_3及HF在聚四氟乙烯高压罐中溶解祥品,用H_3BO_3络合过量的HF。采用基体匹配法校正干扰。方法的准确度、精密度及检出限均较好。     

Online Preconcentration/Determination of Cadmium Using Grape Bagasse in a Flow System Coupled to Thermospray Flame Furnace Atomic Absorption Spectrometry

Abstract

Thermospray flame furnace atomic absorption spectrometry (TS‐FF‐AAS) was employed for Cd(II) determination after online preconcentration. In this system, Cd(II) ions were adsorbed onto a minicolumn packed with grape bagasse. The elution of the metal ions was made with 1 mol L^?1 HCl. Various parameters, such as pH, eluent type, concentration, volume, flow rate for preconcentration, and effect of interfering ions on the retention of the metal ions have been studied. The optimum pH for the adsorption was 3.0. The enrichment factor was 33.7. The limits of detection and quantification for Cd(II) were 0.03 and 0.11 µg L^?1, respectively. The repetitivity and precision were 5.0 (5 minicolumns) and 4.6% (n=18). The stability of the minicolumns was evaluated from successive preconcentration/elution cycles (80 cycles, RSD 3.9%). The proposed method was applied for cadmium determination from certified reference materials, and good agreement was obtained at the 95% confidence level.     

Preconcentration and Determination of Manganese and Nickel from Various Water Samples by Nano Zirconium Oxide/Boron Oxide

ABSTRACT

This work assesses the potential of the adsorptive material nano zirconium oxide/boron oxide (ZrO₂/B₂O₃) for removal of trace Mn(II) and Ni(II) from environmental samples. This method is based on the sorption of Mn(II) and Ni(II) ions directly onto nanosorbent, followed by the elution and determination by flame atomic absorption spectrometry (FAAS). Experimental parameters, including pH of sample solution, volume and concentration of eluent, sample volume, and flow rate of sample solution, that affect the recovery of the Mn(II) and Ni(II) ions from model solutions have been optimized. Under the optimum conditions, adsorption isotherms and adsorption capacities have been examined. The recoveries of Mn(II) and Ni(II) were 96% ± 2% and 95% ± 3% at 95% confidence level, respectively. The analytical detection limits for Mn(II) and Ni(II) were 1.9 and 4.9 µ g L^?1, respectively. Adsorption capacities of the nano ZrO₂/B₂O₃ were found as 92.8 mg g^?1 for Mn and 168.4 mg g^?1 for Ni. The accuracy of the method was checked by analyzing certified reference material (SPS-WW1 wastewater) and spiked real samples. The method was applied for the determination of analytes in water samples.     

Determination of Silver by Chemical Vapor Generation with In Situ Trapping Flame Atomic Absorption Spectrometry

ABSTRACT

The hyphenation of chemical vapor generation with an integrated atom trap system for flame atomic absorption spectrometry (CVG-IAT-FAAS) was evaluated for determination of silver in real samples (coal fly ash, sediment, and nickel alloy). The volatile species of silver were formed by reaction with sodium tetrahydroborate(III) in the presence of nitric acid. A new CVG-IAT-FAAS design (versus a water-cooled single silica tube, double-slotted quartz tube) significantly improved the sensitivity and detection limits compared with conventional flame atomic absorption spectrometry (FAAS) for determination of silver. The concentration limit of detection was 0.7 ng mL^?1 for Ag. The overall efficiency of the vapor generation process was estimated to be ca. 12%. For a 2 min in situ preconcentration time, sensitivity was enhanced 143-fold for Ag using the vapor generation atom trapping technique, compared to conventional FAAS. Sensitivity can be further improved by increasing the collection time. The precision of measurement at 10 ng mL^?1 of Ag was 10% RSD. The accuracy of this method was validated by analyses of NRC GBW 07302 (Stream Sediment), BCS CRM No. 346 (Nickel Alloy), NIST SRM 2710 (Montana Soil), NRCC LUTS-1 (Lobster Hepatopancreas), and NIST SRM 1643e (Trace Element in Water) certified reference materials. The measured Ag contents in these five reference materials were in satisfactory agreement with the certified values (spanning the range of 0.066–35 µg g^?1).     

ICP-OES/ICP-MS测定葵花子中28种无机元素

建立了葵花子中微量元素组成的分析方法。采用HNO₃+H₂O₂混合酸为消解体系经微波消解葵花子样品,电感耦合等离子体发射光谱(ICP-OES)法测定葵花子中Al,B,Ca,Fe,K,Mg,Na,Si,P和S,电感耦合等离子体质谱(ICP-MS)法测定葵花子As,Ba,Cd,Co,Cr,Cu,Li,Mn,Mo,Ni,Pb,Rb,Sr,Sn,Sb,Ti,V和Zn。采用国家一级标准物质大米(GBW10045)验证了方法的准确性,结果表明,标准物质的测定结果与参考值基本一致,葵花子中Ca,K,Mg,P,S的含量较高。该方法具有良好的准确性和精密度。     

Methodology for the determination of minor and trace elements in petroleum cokes by wavelength‐dispersive X‐ray fluorescence (WD‐XRF)

This article describes a methodology for the analysis of minor and trace elements in petroleum cokes by wavelength‐dispersive X‐ray fluorescence (WD‐XRF) spectrometry. The methodology was developed in order to have a rapid and reliable control method of these elements, because they determine coke end uses. There are a number of standard methods of chemical analysis by WD‐XRF or inductively coupled plasma atomic emission spectrometry (ICP‐OES) techniques. However, the standards that use WD‐XRF measurement give detection limits (L_D) above 10 mg·kg^?1 and only analyse a few elements of interest, whereas the ICP‐OES method requires extensive sample handling and long sample preparation times, with the ensuing errors. In order to improve the method described in the standard ASTM D6376 and reach the L_D and quantification limits (L_Q) required, the different stages of the process, ranging from sample preparation to measurement conditions: analytical line, detector, crystal, tube power, use of primary beam filters, and measurement time, were optimised. The samples were prepared in the form of pressed pellets, under conditions of high cleanliness of the mills, crushers, presses, and dies, and of the laboratory itself. The following reference materials were used in measurement calibration and validation: SRM 1632c, SRM 2718, SRM 2719, SRM 2685b, AR 2771, AR 2772, SARM 18, SARM 19, and CLB‐1. In addition, a series of materials were analysed by WD‐XRF and ICP‐OES, and the results were compared. The developed methodology, which uses WD‐XRF, is rapid and accurate, and very low L_D and measurement uncertainties were obtained for the following elements: Al, Ba, Ca, Cr, Cu, Fe, Ge, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, V, and Zn. Copyright © 2010 John Wiley & Sons, Ltd.     

Methodology for the Determination of Stoichiometry and Metal Impurities in New PZT Ceramics by Inductively Coupled Plasma Optical Spectrometry (ICP OES)

ABSTRACT

An inductively coupled plasma optical emission spectrometry (ICP OES) method for Pb, Zr, Ti, Sr, Cr, Fe, Cu, Mn, and Al determination in PZT-ceramics is described. Careful analytical work was carried out in order to evaluate precision, accuracy, and matrix interference. Different procedures were investigated for the ceramics decomposition. Axially viewed plasma operating conditions were evaluated for trace elements (Al, Fe, Cu, Mn, and Cr) in presence of sample matrix. The relative standard deviation (RSD) ranged from 0.7 to 3.9%, whereas the analytes recoveries in the spiked samples ranged from 92 to 119%. The detection limits (LODs) of trace elements ranged from 2.4 to 2.6 µg g^?1. The developed method is useful for evaluating the PZT-ceramics synthesis.     

Trace Metals Analysis of Legal and Counterfeit Cigarette Tobacco Samples Using Inductively Coupled Plasma Mass Spectrometry and Cold Vapor Atomic Absorption Spectrometry

ABSTRACT

A closed-vessel microwave-digestion method was developed for the determination of trace amounts of Be, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba, Tl, and Pb by inductively coupled plasma mass spectrometry and Hg by cold-vapor atomic absorption spectrometry in cigarette tobacco samples. In order to gauge the effectiveness of the digestion procedure, recovery studies were conducted using solutions prepared from National Institute of Standards and Technology Standard Reference Material 1573a Trace Elements in Tomato Leaves and Polish Certified Reference Material Virginia Tobacco Leaves. Limits of detection were below 1 µg g^?1 for all elements studied. Samples from two genuine-brand and three counterfeit packs were analyzed. The mean amounts of Be, As, Mo, Cd, Sb, Tl, Pb, and Hg were higher in counterfeit cigarettes, while the amounts of V, Cr, Mn, Co, Cu, Zn, Se, and Ba were comparable among legal and counterfeit cigarettes; the amount of Ni was higher in the legal cigarettes. Evaluation of Be, As, Mo, Cd, Sb, Tl, Pb, and Hg with their potential hazards for smokers is briefly discussed.     

中草药中多种微量元素的ICP-AES同时测定研究

本文提出了中草药漏芦中多种微量元素的等离子体原子发射光谱（ＩＣＰ－ＡＥＳ）同时测定的方法,并以ＧＢＷ０８５０１桃叶标准样进行对照测定。标准样的测定值与参考值吻合较好,试样分析结果满意。该方法具有灵敏、准确及多元素同时测定,操作简便,快速等优点,适应于中草药及其各种剂型中多元素同时测定。     

A Rapid Method for the Determination of Trace Element Impurities in Silicons Oils by ICP-MS After Microwave-Assisted Digestion

Abstract

A microwave-assisted digestion procedure has been developed for the treatment of silicone oil samples. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentration level of 40 trace element impurities, like Li, Na, Mg, Al, P, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Sr, Rb, Zr, Nb, Mo, Ag, Cd, Sn, Sb, Ba, La, Ce, Nd, Hf, W, Au, Pb, Hg, Th, Bi and U in these samples, having obtained average relative standard deviation values of 9.6%. The methodology developed has been tested by recovery studies on different natural samples spiked with known amounts of Mg, Cr, Mn, Fe, Zn and Pb at concentration levels of 10, 0.5, 5, 5, 10 and 1 μg g^?1 and recovery percentage values varies from 97 to 105 %.     

ICP-AES法测定西藏大骨节病区及非病区饮用水中的微量元素

运用ICP-AES法准确测定了西藏地区大骨节病区和非病区中沟水、河水、泉水和溪水等四种饮用水中Cu,Zn,Fe,Ca,Mg,Mn,Al,K,Ba,P,Sr,Cd,V,Cr,Ni,Pb和Co等多种微量元素的含量。该方法的相对标准偏差在0.80％～2.83％之间,标准物质的测定结果满意,方法简单可靠。文章通过对测定结果的分析,得出西藏不同地区、不同饮用水类型中微量元素的含量差异,为改善西藏大骨节病区居民的生活饮用水提供了科学理论依据。