Quantification of trace amounts of impurities in high purity cobalt by high resolution inductively coupled plasma mass spectrometry

A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb） in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.

Determination of trace elements in high purity nickel by high resolution inductively coupled plasma mass spectrometry

The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material （NIST SRM 671）. The relative standard deviation （RSD） is less than 3.3%. Results for determination of trace elements in high purity nickel were presented.

Quantification of Trace Amounts of Impurities in High Purity Cobalt by High Resolution Inductively Coupled Plasma Mass Spectrometry

An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au and Pb in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects due to the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination was tested and discussed. Correction for matrix effects, Sc, Rh and Bi were used as internal standards. The detection limits is 0.003-0.57 μg/g, the recovery ratio is 92.2%-111.2%, and the RSD is less than 3.6%. The method is accurate, quick and convenient. It has been applied to the determination of trace impurities in high purity cobalt with satisfactory results.

Trace amounts of impurities in electrolytic manganese metal by sector field inductively coupled plasma mass spectrometry

An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.

Conductivity effects during the transition from collisionless to collisional regimes in cylindrical inductively coupled plasmas

A numerical model is developed to study the conductivity effects during the transition from collisionless to collisional regimes in cylindrical inductively coupled argon plasmas at pressures of 0.1-20 Pa.The model consists of electron kinetics module,electromagnetics module,and global model module.It allows for self-consistent description of non-local electron kinetics and collisionless electron heating in terms of the conductivity of homogeneous hot plasma.Simulation results for non-local conductivity case are compared with predictions for the assumption of local conductivity case.Electron densities and effective electron temperatures under non-local and local conductivities show obvious differences at relatively low pressures.As increasing pressure,the results under the two cases of conductivities tend to converge,which indicates the transition from collisionless to collisional regimes.At relatively low pressures the local negative power absorption is predicted by non-local conductivity case but not captured by local conductivity case.The two-dimensional(2D)profiles of electron current density and electric field are coincident for local conductivity case in the pressure range of interest,but it roughly holds true for non-local conductivity case at very high pressure.In addition,an effective conductivity with consideration of non-collisional stochastic heating effect is introduced.The effective conductivity almost reproduces the electron density and effective electron temperature for the non-local conductivity case,but does not capture the non-local relation between electron current and electric field as well as the local negative power absorption that is observed for nonlocal conductivity case at low pressures.

Self-consistent Kinetic Description of the Low-Pressure Solenoidal Inductively Coupled Argon Discharge

Using an one-dimensional slab model, we have studied the electron energy distribution, the anomalous skin effect, and power absorption in the solenoidal-inductively-coupled argon discharge under low pressures (≤ 1.33 Pa). The electron energy distribution function and rf electromagnetic field in the plasma are determined self-consistently by the linearized Bolztmann equation incorporating with the Maxwell equations. The numerical results show that, at low pressures, the electron energy distribution function exhibits a non-Maxwellian distribution with a long high-energy tail. The anomalous skin effect is greatly enhanced under low pressures and the negative power absorption is also obtained.

Effect of Sample Matrix on Radial and Axial Profiles of Ion Abundance in Inductively Coupled Plasma Mass Spectrometry

In inductively coupled plasma mass spectrometry (ICP-MS) analysis, only a few options are available to deal with non-spectroscopic interferences. Considering that diluting the sample is impractical for traces analysis, other alternatives must be employed. Traditionally, the method of standard additions is used to correct the matrix effect but it is a time consuming method. Others methods involves separation techniques. Another way to overcome matrix interferences is to understand the mechanism involved and adjust plasma viewing conditions to reduce or eliminate the effect. In this study, the effect of various concomitant elements in ICP-MS was assessed by measuring the distribution of selected singly charged analyte ions (Al, V, Cr, Mn, Ni, Co, Cu, Zn, As, In, Ba, La, Ce, Pb), doubly charged ions (La, Ce, Ba and Pb) and oxides ions (BaO) in the presence of concomitant elements spanning a mass range from 23 (Na) to 133 (Cs) u.m.a. and different ionization energies. Concomitant elements are alkali metals, alkaline earth metals and Si. Analyte ion suppression was observed while moving the ICP across and away from the sampling interface with or without a single concomitant element. Matrix effect measures were realised, firstly, to highlight the relation between the signal extinction of an analyte and the masse of the concomitant element, and secondly to highlight the relation between the removal of the analyte signal and the first ionization energy of the element of matrix. A dependence upon both the mass of the matrix element and the mass of the analyte was observed. The suppression seems increased with increasing matrix element mass and decreased with increasing analyte mass. The effect of the mass of the matrix element was the more significant of the two factors. If space-charge effects were found to be significant for matrix elements of much lower mass, it seems diffusion also played an active part for heavier matrix elements. Finally, some evidence was found for a shift in ion-atom equilibrium for dications and for energy demand regarding oxides.

<i>In Situ</i>Analysis of Copper Alloys by Femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry: Constrains on Matrix Effects

Direct analysis of copper-base alloys using laser ablation techniques is an increasingly common procedure in cultural heritage studies. However, main discussions remain focused on the possibility of using non-matrix matched external reference materials. To evaluate the occurrence of matrix effects during in situ microanalysis of copper-base materials, using near infrared femtosecond laser ablation techniques (NIR fs-LA-ICP-MS), two bronzes, i.e., (Sn-Zn)-ternary and (Sn)-binary copper-matrix reference materials, as well as a reference synthetic glass (NIST-SRM-610) have been analyzed. The results have been compared to data obtained on a sulfide-matrix reference material. Similar values in relative sensitivity averages of 63Cu, 118Sn and 66Zn, as well as in 118Sn/63Cu and 66Zn/63Cu ratios were obtained, for all analyzed matrix types, i.e., copper-base-, silicate-, and sulfide-reference materials. Consequently, it is possible to determinate major and minor element concentrations in copper alloys, i.e., Cu, Sn and Zn, using silicate and sulfide reference materials as external calibrators, without any matrix effect and over a wide range of concentrations (from wt.% to ppm). Equally, Cu, Sn and Zn concentrations can be precisely determined in sulfides using homogeneous alloys (reference) materials as an external calibrator. Thus, it is possible to determine Cu, Sn and Zn in copper-base materials and their ore minerals, mostly sulfides, in a single analytical session, without requiring specific external calibrators for each matrix type. In contrast, immiscible elements in copper matrix, such as Pb and Fe show notable differences in their relative sensitivity values and ratios for different matrix-materials analyzed, implying that matrix-matched external calibrations remain to be applied for their trace quantification.

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。

ICP-QQQ-MS法分析婴幼儿谷物辅助食品中镉含量的干扰及其校正

建立三重串联四极杆电感耦合等离子体质谱(inductively coupled plasma triple quadrupole mass spectrometry,ICP-QQQ-MS)法测定婴幼儿谷物辅助食品中镉(Cd)含量的方法。研究单四极杆氦气碰撞模式(SQ-He)、串联四极杆氦气碰撞模式(QQQ-He)、串联四极杆氧气反应模式(QQQ-O_(2))3种碰撞/反应模式下质谱测量中存在的各类干扰,并进行逐一分析、消除。结果显示,抗基体、抗氧化物和多原子离子干扰能力均为QQQ-O_(2)>QQQ-He>SQ-He,采用QQQ-O_(2)模式联合标准加入法可获得更为准确的干扰消除效果。通过引入干扰校正方程,有效解决由于同量异位素锡(Sn)干扰导致的Cd同位素丰度比与天然丰度比不一致问题。QQQ-O_(2)模式下同位素稀释质谱法与标准加入法测量Cd的结果等效一致,证明婴幼儿谷物辅助食品中Cd测量时受到的基体效应和质谱干扰被有效消除。所建方法为使用ICP-QQQ-MS准确测定复杂基体样品中Cd提供重要参考。

有机化合物对电感耦合等离子体质谱(ICP-MS)法测定食品中总砷的影响

为研究有机化合物对电感耦合等离子体质谱(ICP-MS)法测定食品中总砷的影响,分析总结一般规律,为食品中总砷的准确测定提供理论依据。通过考察甲醇和乙醇等14种有机化合物对ICP-MS法测定砷的动能歧视模式(KED)信号值和动态反应模式(DRC)信号值的影响,分析各有机化合物的电离能、极性和溶解度等性质,推测其在ICP-MS法测定体系中对砷响应信号值增敏或者抑制的可能机理。结果表明,有机化合物对ICP-MS的KED模式测定砷离子As^(+)的信号值有增敏效应,对DRC模式测定氧化砷离子AsO^(+)信号值的影响小于KED模式测定As^(+)的信号值,而且过程也更为复杂。相反,氮氧化物会减弱As^(+)和AsO^(+)的信号值。锗、铟等内标元素原子与砷原子在等离子体中电离行为和灵敏度的差异,使得内标元素校准砷测定信号的漂移受到干扰。推测有机化合物影响ICP-MS测定砷响应信号值的可能机理是:有机化合物和氮氧化物经电离或裂解之后分别生成碳离子或多原子碳离子和氮氧离子或氮氧基团,碳离子或多原子碳离子会与砷原子发生电荷转移反应,增强As^(+)或AsO^(+)的信号值,同时有机化合物也可能会与As^(+)竞争氧气而降低AsO^(+)的信号值,而具有强电负性的氮氧基团可能会与As^(+)和AsO^(+)发生电荷转移反应而减弱其信号值。有机化合物对砷的ICP-MS响应信号值的影响可能是受到有机化合物电离能、溶解度、极性和分子结构等综合因素的结果。

电感耦合等离子体质谱法测定化妆品中汞元素的含量

针对电感耦合等离子体质谱法(ICP-MS)测定汞元素时存在汞记忆效应严重,且消除时前处理过程复杂的问题,提出了此项研究。取样品0.5000 g置于聚四氟乙烯消解罐中,加入5 m L硝酸和1 m L 30%(质量分数)过氧化氢溶液,置于100℃恒温消解仪中加热30 min,冷却,将消解罐密封置于微波消解仪中,消解后冷却,打开消解罐,置于100℃恒温消解仪中15 min,将消解溶液转移至25 m L容量瓶中,用水洗涤消解罐数次,清洗液与消解溶液合并,用水定容至25 m L,与清洗试剂[2 mg·L^(-1)金元素标准使用液或2%(质量分数,下同)L-半胱氨酸溶液]配制的20μg·L^(-1)186Re内标溶液在线混匀后,采用ICP-MS进行测定。结果表明,清洗试剂可消除0.5~5μg·L^(-1)汞元素标准溶液的汞记忆效应,对下一个样品的测定结果不产生影响。汞元素的质量浓度在0.5~5μg·L^(-1)内与所对应的信号强度与内标元素信号强度比呈线性关系,采用2 mg·L^(-1)金元素标准使用液配制内标溶液时,检出限(3s)为0.0010 mg·kg^(-1),采用2%L-半胱氨酸溶液配制内标溶液时,检出限(3s)为0.0012 mg·kg^(-1)。按照标准加入法进行回收试验,回收率为90.2%~104%,测定值的相对标准偏差(n=6)均小于9.0%。方法用于3种市售化妆品分析,使用2种清洗试剂配制的内标溶液得到的检出量一致,为0.0080~0.13 mg·kg^(-1)。

沸水提取-电感耦合等离子体发射光谱法测定土壤有效硼

建立了沸水提取-电感耦合等离子体发射光谱法测定土壤中有效硼。称取样品10.0 g,过250μm筛风干,置于石英三角瓶中,加入20.00 mL的提取剂(符合GB/T 6682规定的一级水,水中铁的质量浓度不大于10 mg/L),沸水浴浸10 min,回流冷凝5 min,滤液采用离心过滤,选择硼249.773 nm为分析谱线,用ICP-AES法测定土壤有效硼。经3种土壤标准物质和3种土壤样品验证,土壤有效硼质量浓度在0~2.0 mg/L范围内与光谱强度的线性关系良好,相关系数为0.9999,方法检出限为0.003 mg/kg,定量限为0.012 mg/kg,测定值的相对标准偏差为2.16%~6.46%(n=8),相对误差为1.01%~2.45%。当有效硼质量分数小于0.50 mg/kg时,测定值的最大偏差为0.05 mg/kg;当有效硼质量分数大于0.50 mg/kg时,测定值的最大偏差为0.06 mg/kg,标准物质测定值均在不确定度范围内。该方法检出限低,精密度和准确度较高,可操作性强,适用于批量土壤样品有效硼的测定,质量控制结果满足第三次全国农业土壤普查内业测试和全程质量控制规程的要求。

电感耦合等离子体发射光谱法(ICP-OES)检测电解二氧化锰痕量杂质时基体效应影响的研究

电解二氧化锰有去极化作用,作为正极活性物质可有效提高放电容量,其质量的优劣对电池性能至关重要。随着电池生产销售在2006年实现无汞化,电池中不再含有能屏蔽重金属的腐蚀、减少自放电的汞齐,多数电池用电解二氧化锰要求铁、钴、镍、钒、铅、铜、钼、砷、锑含量低于一定限值,以防止这些有害金属杂质引起电池内部自放电、气涨、枝晶穿刺隔膜和漏液等不良反应。这些有害金属杂质常使用电感耦合等离子体发射光谱法(ICP-OES)同时进行分析,方法精确度高、分析速度快,但操作过程中受到基体效应干扰严重,尤其当杂质元素含量低至痕量范围内时,干扰信号可能会增强、削弱或覆盖待测元素信号,造成检测结果不准确。研究以SPECTRO ARCOS型号ICP-OES光谱仪为例,结合仪器特性和实际工作经验,对检测过程中出现的干扰特点进行分析,探讨基体效应消除或扣除的方法,以保障检测结果的准确性。

超级微波消解-ICP-MS法测定贝类水产品中天然铀、钍含量及其年有效剂量估算

建立超级微波消解-电感耦合等离体质谱法快速测定水产品中的天然铀、钍含量的方法,利用检测数据及方法模型估算其所致的年有效剂量。结果表明,铀、钍的定量限分别为0.022 4、0.025 4 mg·kg^(-1),加标回收率分别为94.6%、91.7%;102批次贝类水产品(含虾类)中铀含量最高为0.069 mg·kg^(-1),钍含量最高为0.250 mg·kg^(-1),结果均小于《食品中放射性物质限制浓度标准》(GB 14882—1994)中肉鱼虾类铀、钍规定值5.4 mg·kg^(-1)和3.6 mg·kg^(-1);估算出贝类水产品中天然铀、钍儿童年待积有效剂量为0.346 23 μSv·a^(-1),成人年待积有效剂量为0.447 30 μSv·a^(-1)。

ICP技术在水产食品重金属检测中的应用

随着水产养殖业的发展,重金属污染逐渐成为食品安全的重大隐患。本文简要分析电感耦合等离子体(Inductively Coupled Plasma,ICP)技术的工作原理及其水产食品重金属检测中应用存在的问题,包括样品前处理复杂导致产生检测误差、基质效应导致检测灵敏度下降,以及多元素共存影响检测准确性等,并提出优化前处理流程、改进仪器校准和引入干扰消除技术等对策。研究结果表明,ICP技术能有效提升检测性能,为保障水产食品安全提供了重要的技术支持。

滇西北高山峡谷矿区碱性土壤速效钾、有效磷含量的测定

土壤速效钾、有效磷是衡量土壤钾素和磷素的重要指标,准确分析土壤速效钾、有效磷的含量对地球化学调查的生态修复、合理施肥、改良土壤、提高产量、保护环境以及人体健康的调查研究有着重要参考价值。以云南西北部高山峡谷矿区土壤为研究背景条件,对采集的123件送检土壤样品中速效钾和有效磷含量进行测定。采用pH为7.5的NH_(4)HCO_(3)浸提,离心机分离,用电感耦合等离子体发射光谱(ICP-OES)法进行测定,方法检出限为速效钾0.015 mg/kg、有效磷0.006 mg/kg;所选标准物质的相对误差小于2%,相对标准偏差(RSD)小于5%,该方法检测限低、线性范围广、缩短前处理流程、降低成本提高效率、结果准确稳定、绿色环保,可适用于实验室大批量生产土壤速效钾和有效磷的测定。

激光剥蚀电感耦合等离子体质谱鉴别蓝色圆珠笔色痕

建立了法庭科学中蓝色圆珠笔色痕的激光剥蚀电感耦合等离子体质谱鉴别方法。对95种不同来源的蓝色圆珠笔进行了分析,依据所含金属元素种类的差别将95种圆珠笔分为34类,其中26类圆珠笔根据元素种类的差别可直接区分,其余8类依据元素间响应值之比进行区分,对字痕载体纸张的考察结果表明了纸张对检测结果无影响。实验结果表明方法重现性良好,精密度<10%,与传统分析技术相比,本方法可获得更好的鉴别结果,95种蓝色圆珠笔中有88种可使用该方法有效鉴别。该方法简便快速、精密度良好、对样本宏观无损,适合法庭科学对蓝色圆珠笔鉴定的需要。

电感耦合等离子体质谱法同时测定地质样品中痕量碘溴硒砷的研究Ⅰ.不同介质及不同阴离子形态对测定信号的影响

研究了半熔 -电感耦合等离子体质谱法 (ICP -MS)同时测定地质样品中痕量碘、溴、硒和砷等非金属元素的可行性。重点研究了不同介质中碘以及溴、砷、硒不同形态对测定信号的影响。比较并讨论了在纯水溶液、0 .0 7mol/LNH3·H2 O溶液以及 0 .32mol/LHNO3溶液中碘等元素不同形态阴离子的ICP -MS信号强度和记忆效应问题。相同浓度但不同形态的碘离子(I- 、IO-3 、IO-4 )在不同溶剂介质中其ICP -MS离子计数率不一致 ,I- 的信号比其他两种形态碘变化大 ,尤其是在HNO3介质中 ,信号很强 ,但波动大而且无规则性。在弱酸或稀NH3·H2 O介质中 ,碘信号比较稳定。选择稀NH3·H2 O清洗进样系统 ,显著降低了碘、溴的记忆效应。在弱酸或弱碱性介质中 ,碘、溴、硒和砷等非金属元素具有较高的信背比 ,可用ICP

微量进样/ICP-MS体系中的基体效应研究

考察了自行组装的高效微量进样系统在 2 2 μL/ min低提升量下电感耦合等离子体质谱的基体效应 .质量数和电离电位不同的基体元素质量浓度为 2 g/ L时 ,低质量数分析元素受到一定的干扰 ,而对于高质量数分析元素 ,其信号几乎不受基体元素干扰 ,归一化信号值接近 1 .对于体积分数为 5 %的有机基体样品溶液 ,此微量高效雾化系统测得的归一化信号值多接近 0 .5 .实际样品中常见的基体元素 K,Na,Ca和 Mg质量浓度低于 5 0 0 mg/ L,以及乙醇和乙酸体积分数小于 1 %时 。