The determination of 52 elements in marine geological samples by an inductively coupled plasma optical emission spectrometry and an inductively coupled plasma mass spectrometry with a high-pressure closed digestion method

An improved analytical method to determine the content of 52 major, minor and trace elements in marine geological samples, using a HF-HCl-HNO_3 acid system with a high-pressure closed digestion method（HPCD）, is studied by an inductively coupled plasma optical emission spectrometry（ICP-OES） and an inductively coupled plasma mass spectrometry（ICP-MS）. The operating parameters of the instruments are optimized, and the optimal analytical parameters are determined. The influences of optical spectrum and mass spectrum interferences, digestion methods and acid systems on the analytical results are investigated. The optimal spectral lines and isotopes are chosen, and internal standard element of rhodium is selected to compensate for matrix effects and analytical signals drifting. Compared with the methods of an electric heating plate digestion and a microwave digestion, a high-pressure closed digestion method is optimized with less acid, complete digestion,less damage for digestion process. The marine geological samples are dissolved completely by a HF-HCl-HNO_3 system, the relative error（RE） for the analytical results are all less than 6.0%. The method detection limits are 2–40μg/g by the ICP-OES, and 6–80 ng/g by ICP-MS. The methods are used to determine the marine sediment reference materials（GBW07309, GBW07311, GBW07313）, rock reference materials（GBW07103, GBW07104,GBW07105）, and cobalt-rich crust reference materials（GBW07337, GBW07338, GBW07339）, the obtained analytical results are in agreement with the certified values, and both of the relative standard deviation（RSD） and the relative error（RE） are less than 6.0%. The analytical method meets the requirements for determining 52 elements contents of bulk marine geological samples.

Diagnostics of Argon Inductively Coupled Plasma and Dielectric Barrier Discharge Plasma by Optical Emission Spectroscopy

An experimental setup was built up to carry out radio frequency (RF) inductively coupled plasma (ICP) and dielectric barrier discharge (DBD), and to depict the optical emission spectra (OES) of the discharges. OES from argon ICP and DBD plasmas in visible and near ultraviolet region were measured. For argon ICP, the higher RF power input (higher than 500 W for our machine), the higher degree of argon plasma ionization. But that doesn't mean a higher mean electron energy. With the increase in the power input, the mean electron energy increases slightly, whereas the density of electron increases apparently On the contrary, argon DBD discharge behaves in the manner of a pulsed DC discharge on optical emission spectroscopy and V-I characteristics. DBD current is composed of a series of pulses equally spaced in temporal domain. The Kinetics of DBD emission strength is mainly governed by the frequency of the current pulse.

Determination of potassium content as principal components in pyrotechnic compositions used for fireworks and firecrackers based on inductively coupled plasma optical emission spectrometric approach （ICP-OES）

Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element of potassium is conunonly found in potassium nitrate and potassium perchlorate in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that potassium nitrate content in pyrotechnics is between 10% to 60% and the potassium perchlorate content is between 20% to 70%,which counted in the content of potassium element is between 4% to 23%. Concept of this method： considering the weight of the sample is 400rag,constant volume is 1L and the concentration of potassium is between 10 mg/L to 90 mg/L in sample solution, the determination scope of the method for the potassium content would be between 1% to 23%.Further experiments proved that the fitting correlation coefficient of potassium calibration curve is 0.9997 or higher, recovery is 89.15%-100.23%.The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.

Determination of magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrackers based on inductively coupled plasma optical emission spectrometric approach （ICP-OES）

Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrackers. Elements of magnesium and aluminum are commonly found in aluminum powder or magnesium-aluminum alloy powder in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that the magnesium content in pyrotechnics is between 8% to 30% and the aluminum content is between 8% to 35%（roughly）.Concept of this method： suppose the weight of the sample is 400rag,constant volume is IL and the concentlation of magnesium and aluminum is between 12mg/L to 160mg/L in sample solution, the determination scope of the method for magnesium and aluminum content would be between 3% to 40%.Further experiments proved that the fitting correlation coefficient of the magnesium calibration curve is 0.9999 or higher, recovery is 101.01% -101.96%.The fitting correlation coefficient of the aluminum calibration curve is 0.9999 or higher, recovery is 99.36%-103.07%. The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.

Optical Emission Spectroscopic Studies of ICP Ar Plasma

The ion line of 434.8 nm and atom line of 419.8 nm of Ar plasma produced by an inductively coupled plasma （ICP） were measured by optical emission spectroscopy and the influences from the working gas pressure, radio-frequency （RF） power and different positions in the discharge chamber on the line intensities were investigated in this study. It was found that the intensity of Ar atom line increased firstly and then saturated with the increase of the pressure. The line intensity of Ar^＋, on the other hand, reached a maximum value and then decreased along with the pressure. The intensity of the line in an RF discharge also demonstrated a jumping mode and a hysteresis phenomenon with the RF power. When the RF power increased to 400 W, the discharge jumped from the E-mode to the H-mode where the line intensity of Ar atom demonstrated a sudden increase, while the intensity of Ar^＋ ion only changed slightly. If the RF power decreased from a high value, e.g., 1000 W, the discharge would jump from the H-mode back to the E-mode at a power of 300 W. At this time the intensities of Ar and Ar^＋ lines would also decrease sharply. It was also noticed in this paper that the intensity of the ion line depended on the detective location in the chamber, namely at the bottom of the chamber the line was more intense than that in the middle of the chamber, but less intense than at the top, which is considered to be related to the capacitance coupling ability of the ICP plasma in different discharge areas.

Effect of Low-Frequency Power on Etching Characteristics of 6H-SiC in C4F8/Ar Dual-Frequency Capacitively Coupled Plasma

Dry etching of 6H silicon carbide （6H-SiC） wafers in a C4Fs/Ar dual-frequency capacitively coupled plasma （DF-CCP） was investigated. Atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS） were used to measure the SiC surface structure and compositions, respectively. Optical emission spectroscopy （OES） was used to measure the relative concentration of F radicals in the plasma. It was found that the roughness of the etched SiC surface and the etching rate are directly related to the power of low-frequency （LF） source. At lower LF power, a smaller surface roughness and a lower etching rate are obtained due to weak bombardment of low energy ions on the SiC wafers. At higher LF power the etching rate can be efficiently increased, but the surface roughness increases too. Compared with other plasma dry etching methods, the DF-CCP can effectively inhibit CχFγ films＇ deposition, and reduce surface residues.

Investigation of Capacitively Coupled Argon Plasma Driven by Dual-Frequency with Different Frequency Configurations

Low pressure argon dual-frequency （DF） capacitively coupled plasma （CCP） is generated by using different frequency configurations, such as 13.56/2, 27/2, 41/2, and 60/2 MHz. Characteristics of the plasma are investigated by using a floating double electrical probe and optical emission spectroscopy （OES）. It is shown that in the DF-CCPs, the electron temperature Te decreases with the increase in exciting frequency, while the onset of 2 MHz induces a sudden increase in Te and the electron density increases basically with the increase in low frequency （LF） power. The intensity of 750.4 nm emission line increases with the LF power in the case of 13.56/2 MHz, while different tendencies of line intensity with the LF power appear for other configurations. The reason for this is also discussed.

Diagnosis of a low pressure capacitively coupled argon plasma by using a simple collisional-radiative model

This paper proposes a simple collisional-radiative model to characterise capacitively coupled argon plasmas driven by conventional radio frequency in combination with optical emission spectroscopy and Langmuir probe measurements. Two major processes are considered in this model, electron-impact excitation and the spontaneous radiative decay. The diffusion loss term, which is found to be important for the two metastable states （4s[3/2]2, 4s＇[1/2]0）, is also taken into account. Behaviours of representative metastable and radiative states are discussed. Two emission lines （located at 696.5 nm and 750.4 nm） are selected and intensities are measured to obtain populated densities of the corresponding radiative states in the argon plasma. The calculated results agree well with that measured by Langmuir probe, indicating that the current model combined with optical emission spectroscopy is a candidate tool for electron density and temperature measurement in radio frequency capacitively coupled discharges.

Elemental Content in Brown Rice by Inductively Coupled Plasma Atomic Emission Spectroscopy Reveals the Evolution of Asian Cultivated Rice

The phylogenetic relationship for classification traits and eight mineral elements in brown rice （Oryza sativa L.） from Yunnan Province in China was carried out using microwave assisted digestion followed by inductively coupled plasma atomic emission spectroscopy, and the analytical procedures were carefully controlled and validated. In general, the results show that the mean levels of K, Ca, Mg, Fe and Cu in brown rice for 789 accessions of rice landraces was distinctly lower than that of improved cultivars. They further demonstrate that Ca plays an important role in the differentiation of subspecies indica-japonica, especially to enhance adaptation of cold stress, and that five mineral elements in brown rice enhance the eurytopicity from landrace to improved cultivar. Hierarchical cluster analysis, using average linkage from SPSS software based on eight mineral elements in brown rice, showed that Yunnan rice could be grouped into rice landrace and improved cultivar, with the rice landrace being further clustered into five subgroups, and that, interestingly, purple rice does not cluster with either of the groups. Our present data confirm that indica is the closest relative of late rice and white rice, and that they constitute rice landraces together, whereas japonica is the closest relatives of non-nuda, early-mid and glutinous rice. It is further shown that japonica, non-nuda, early-mid, glutinous, white and red rice might be more primitive than indica, nuda, late, non-glutinous and purple rice, respectively.

Effects of Different Pretreatment Methods on Determination of Microelements in Feed

[ Objective] To study the effects of different pretreatment methods on determination of microelement in feed and thus find the best pre treatment method for each microetement, t Method] The samples （concentrated feeding stuff and fodder） were pretreated through throe methods, that is, dry incineration method, HNOs HCIO, wetdecomposition method and microwave digestion method. Then the content of seven kinds of mi croelement （AI, Ca, Cu, Fe, Mn, Se and Zn） was determined by inductively coupled plasma atomic emission spectrometer （ICPAES）. I Result] These three methods were all suitable for the determination of Cu, Mn and Zn in concentrated feeding stuff and the determination of Cu and Ca in fodder. The content of Cu and Ca was higher in fodder detected by HNO3 HCIO, wetdecomposition method. The microwave digestion method was suitable for the determination of AI and Ca in concentrated feeding stuff and the determination of AI, Fe, Mn and Zn in fodder. The dry incinera tion method was fit for the determination of Fe in concentrated feeding stuff. [ Condusionl The content of different microelements should be deter mined after the feed is treated with different Ioretreatment methods.

微波消解-双向观测电感耦合等离子体发射光谱(ICP-OES)法测定油漆中11种金属元素

针对油漆市场中假冒伪劣产品泛滥、消费者权益受损及市场秩序混乱的问题,通过对消解方法、酸消解体系、波长选择、观测模式及发射功率的深入研究,建立了微波消解-双向观测电感耦合等离子体原子发射光谱法,结合外标法进行定量分析油漆中11种金属元素,判断质量差异的方法。实验结果表明,11种元素在0~10 mg/L的浓度与等离子体发射强度呈现出良好的线性关系,线性相关系数均超过0.995。方法检出限在0.05~3.5 mg/kg,精密度达到0.08%~8.5%(n=6),精密度测试验证了方法的可靠性。以11种元素为横坐标,油漆中元素的相对含量为纵坐标,构建了7种油漆的金属元素指纹图谱。结果表明,不同类型的油漆含有不同种类和含量的金属元素。元素图谱分析表明,半成品底漆黑色、清漆与PP哑黑底漆在元素含量分布及种类上呈现出相似性,而红色汽车漆、黄色汽车漆及蓝色汽车漆与其他油漆在元素特征上则存在显著差异。方法具有操作简便、检测速度快、灵敏度高等优点,为油漆的同一性鉴定提供了有力的技术支撑,也为司法鉴定和消费者权益保护提供了重要依据。

基于RSM模型对王水-氯酸钾消解-ICP-OES法测定锑矿石中锑的条件优化

锑是一种全球重要的战略矿产资源,快速准确测定锑矿中锑含量对锑矿的勘查和开采具有重要指导意义。采用响应曲面法(RSM)对电感耦合等离子体发射光谱法(ICP-OES)测定锑的实验条件进行优化。以氯酸钾加入量、溶解温度、提取液浓度为单因素,确定单因素变量分别为0.4~1.6 g、70~130℃、5%~35%;根据RSM中的Box-Behnken(BBD)设计,选择锑矿石测定值为响应值,建立三因素三水平面实验,得到二次多项式回归模型。对该模型进行方差分析并判断其显著性,其中模型F=421.94、P<0.0001、模型的R^(2)=0.9982、R_(adj)^(2)=0.9958、CV(变异值)=1.49%、S/N(信噪比)=59.54,可以解释超过98%的响应值变化。通过研究结果显示,在氯酸钾加入量0.9 g、溶解温度100℃、提取液盐酸浓度为15%的条件下,可以获得最佳的测定效果。4个锑矿石标准物质测定结果相对误差是0.34%~0.89%,相对标准偏差(RSD)是0.54%~1.1%,满足岩石矿物分析准确度和精密度控制要求,表明基于RSM模型优化锑矿石中锑量测定的方法准确可靠。RSM在复杂样品分析中的应用的展示,为分析化学方法优化提供了有效的实验工具。

多种检测方法在土壤重金属含量检测中的对比研究

采用传统混酸消解法,对标准的土壤样品进行前处理。对比电感耦合等离子体质谱法(ICP-MS)、电感耦合等离子体发射光谱法(ICP-OES)、原子吸收光谱法(AAS)等3种检测方法测定土壤中Cu、Ni、Pb三种元素的差异。结果表明,3种检测方法在准确度、精密度、线性范围等方面都能够达到日常测定要求,应根据实际情况选择测定方法。

电感耦合等离子体原子发射光谱法测定固体生物质燃料中微量元素

对比分析了固体生物质燃料中微量元素样品前处理方式,确定了微波消解程序,给出了电感耦合等离子体原子发射光谱法测定微量元素的方法检出限,各微量元素线性方程相关系数≥0.999,平均回收率在87.72%~109.49%之间。采用标准物质对方法准确性和重复性进行验证,各元素测定值均在标准证书值范围内,相对标准偏差在0.59%~6.25%。通过7家实验室协同试验,给出了方法精密度。F检验和t检验表明,电感耦合等离子体原子发射光谱法与火焰原子吸收光谱法不存在显著性差异。

电感耦合等离子体原子发射光谱法测定锆镍合金粉中锆

建立电感耦合等离子体原子发射光谱法测定锆镍合金粉中的锆含量。采用硝酸-氢氟酸溶解样品,选择339.198 nm谱线作为锆元素分析谱线,通过基体匹配法消除镍基体干扰。锆的质量分数在0.1%~40%范围内与光谱发射强度线性关系良好,相关系数为0.9997,方法检出限为0.0054%,定量限为0.018%。采用所建方法对锆镍合金模拟样品和锆镍合金粉样品进行测定,测定结果的相对标准偏差为0.208%~0.408%(n=11),样品加标回收率为98.9%~102.5%。该方法能够快速、准确地测定锆镍合金粉中的锆含量。

电感耦合等离子体发射光谱法测定氧化铝为载体的钯催化剂中钯含量

建立了氧化铝载体钯催化剂中钯含量的电感耦合等离子体发射光谱测定法。通过酸种类及用量的对比实验最终确定了样品前处理方法,并对仪器工作参数进行了优化。方法检出限为2.55 mg/kg。金属钯元素加标回收率为94.0%~101.0%,相对标准偏差为1.46%,钯测量结果的相对扩展不确定度为4.2%。该方法快速、准确,可为科研生产提供数据支撑。

ICP-OES法测定黄年糕中19种元素

建立了电感耦合等离子体发射光谱同时测定黄年糕中19种元素的方法,钾、钠采用径向观测,其余元素采用轴向观测。结果表明,各元素标准曲线的相关系数均大于0.9995,方法检出限和定量限均满足检测需求,平均加标回收率在81.6%~113.5%,相对标准偏差均小于10%。该方法准确性、可靠,适用于食品中多元素的检测。

Comparison of heating mechanisms of argon helicon plasma in different wave modes with and without blue core

In this work,we investigated the discharge characteristics and heating mechanisms of argon helicon plasma in different wave coupled modes with and without blue core.Spatially resolved spectroscopy and emission intensity of argon atom and ion lines were measured via local optical emission spectroscopy,and electron density was measured experimentally by an RFcompensated Langmuir probe.The relation between the emission intensity and the electron density was obtained and the wavenumbers of helicon and’Trivelpiece-Gould’(TG)waves were calculated by solving the dispersion relation in wave modes.The results show that at least two distinct wave coupled modes appear in argon helicon plasma at increasing RF power,i.e.blue core(or BC)mode with a significant bright core of blue lights and a normal wave(NW)mode without blue core.The emission intensity of atom line 750.5 nm(lArⅠ750.5nm)is related to the electron density and tends to be saturated in wave coupled modes due to the neutral depletion,while the intensity of ion line 480.6 nm(IArⅡ480.6nm)is a function of the electron density and temperature,and increases dramatically as the RF power is increased.Theoretical analysis shows that TG waves are strongly damped at the plasma edge in NW and/or BC modes,while helicon waves are the dominant mechanism of power deposition or central heating of electrons in both modes.The formation of BC column mainly depends on the enhanced central electron heating by helicon waves rather than TG waves since the excitation of TG waves would be suppressed in this special anti-resonance region.

Laser Induced Breakdown Spectroscopy for Comparative Quantitative Analysis of Betel Leaves from Pakistan

Laser induced breakdown Spectroscopy(LIBS)was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air.Pulsed Nd∶YAG(1064 nm)in conjunction with a suitable detector(LIBS 2000+,Ocean Optics,Inc)having the optical resolution of 0.06 nm was used to record the emission spectra from 220 to 720 nm.Elements like Al,Ba,Ca,Cr,Cu,P,Fe,K,Mg,Mn,Na,P,S,Sr,and Zn were found to present in the samples.The relative abundances of the observed elements were calculated through standard calibration curve method,integrated intensity ratio method,and weight percentage LIBS approach.LIBS findings were validated by comparing its results with the results obtained using a typical analytical technique of Inductively Coupled plasma-optical emission spectroscopy(ICP-OES).Limit of detection(LOD)of the LIBS system was also estimated for heavy metals.The experience gain through this work implies that LIBS could be highly applicable for testing the quality and purity of food products.

偏硼酸锂熔融-电感耦合等离子体发射光谱法测定铍矿石中的铍及主量元素

广泛赋存在花岗伟晶岩和热液石英脉中的铍矿石是铍最重要的矿物载体,目前铍矿石系统分析仍以传统化学法为主,影响分析效率,亟待开发一种简单高效的铍矿石中多元素分析方法。本文建立了一种基于偏硼酸锂熔融-电感耦合等离子体发射光谱(ICP-OES)测定铍矿石中铍及主量元素的定量分析方法,使用4∶1熔剂-样品比,950℃下熔融15min后,通过超声提取制备溶液。偏硼酸锂熔融法能有效地分解铍矿石中的氧化物,克服了传统酸溶或碱熔无法检测硅、钠、钾等元素的局限。本方法通过校准曲线与样品基体匹配,加入铕作内标等措施消除基体效应,实现了各元素(以氧化物计)低至0.003%~0.2%的检出限,满足铍精矿质量检测需求。对绿柱石、香花石、日光榴石样品(BeO含量范围为0.14%~13.33%)测定的相对标准偏差(RSD)小于6.83%,与混合酸酸溶分析方法的测定值相对偏差为0.06%~21.28%。通过标准物质GBW07150、GBW07151和GBW07183验证,本方法精密度和准确度均符合地质矿产实验室测试质量管理规范,适用于多种类型铍矿石样品中铍及主量元素的快速连续分析。