手持式激光诱导击穿光谱仪现场测定钢铁制品中铬镍锰铜硅

钢铁中各元素组成及含量对钢种质量和性能都有重要影响,实时、快速对钢铁中各元素进行有效检测分析是目前钢铁行业的关注重点。实验探讨了手持式激光诱导击穿光谱(LIBS)技术在钢铁中多元素同步、快速分析方面的可行性:选取3个钢铁标准样品,以Cr(I) 520.84nm、Ni(I)232.003nm、Mn(I) 403.075nm、Cu(I) 324.753nm、Si(I) 288.16nm作为分析谱线,以Fe(I) 373.486nm作为内标谱线,考察了手持式LIBS分析仪对钢铁标准样品分析的精密度和正确度。标样验证试验结果表明,手持式LIBS分析仪快速定量分析Cr、Ni、Cu及Si 4种元素的准确性较高,对于Mn的定量分析存在一定的系统偏差,但也基本能反映元素含量。随机选取不同种类的钢铁材料日常实际样品,采用实验方法进行快速定量分析,同时以电感耦合等离子体原子发射光谱(ICP-AES)进行对照,绘制两种方法测定结果的线性趋势图,并与理想趋势线(y=x)进行对比。结果表明,Cr、Ni、Cu及Si 4种元素的LIBS与ICP-AES测试结果表现较一致,Mn的测试结果普遍较ICP-AES偏低,但二者存在较好的相关性。在整个试验过程中,手持式LIBS分析仪测试一组数据的时间平均为5s,该技术用于钢铁行业快速定量分析是可行的。     

Online calibration of laser-induced breakdown spectroscopy for detection of heavy metals in water

In order to reduce the fluctuation of LIBS detection spectrum of liquid sample, the full-spectrum sum method and the internal standardization method is adopted, using an equal-RSD normalization algorithm to calibrate the detection spectrum. Experiment result shows that the full-spectrum sum method reduced the RSD of parallel samples of Cd and Cr to 9.4％ and 11.06％ from 28.32％ and 31.93％ respectively, yielded better overall calibration than the singleelement internal standardization approach, thereby suggesting that the former method is convenient and effective for online calibration of LIBS for detection of aqueous heavy metals.     

激光诱导击穿光谱在乳制品质量检测中的应用

乳制品是人体健康必需营养的重要来源之一,因此保证乳制品的质量和安全至关重要。作为一种新型的激光烧蚀原子发射光谱技术,激光诱导击穿光谱已经在乳制品的定性和定量分析方面展现出了巨大的应用潜力。本文简要介绍了激光诱导击穿光谱的检测原理,综述了激光诱导击穿光谱在乳制品中矿物质元素、重金属元素、脂肪和蛋白质含量,以及牛奶掺假物检测方面的最新研究进展。最后,探讨了激光诱导击穿光谱在乳制品质量检测方面存在的问题并对其发展趋势进行了展望。     

基于磁场约束下激光诱导击穿光谱技术的重金属检测研究

为提高激光诱导击穿光谱(laser induced breakdown spectroscopy, LIBS)技术定量分析的精度,开展了磁场约束下LIBS技术对土壤中重金属元素检测的研究,并采用多谱线强度归一化内标法进行数据处理。通过比较磁场强度分别为0 T、0.3 T、0.8 T、1.25 T时的光谱特性,得到光谱强度和信噪比(signal-to-noise ratio,SNR)随磁场强度增大而增大,在1.25 T磁场强度时,样品元素Cd和Cu的光谱强度和SNR要比无磁场作用分别增强了34.77%、56.33%和40.83%、74.12%,构建了磁场强度为1.25 T时的Cd和Cu元素定量分析模型。结果显示,相对于传统内标法,采用多谱线强度归一化内标法的元素检测限分别从52.78 mg/kg和49.18 mg/kg降低到23.87 mg/kg和18.06 mg/kg;相关系数分别从0.961 3和0.942 7提高到0.996 9和0.999 3。本实验研究改善了LIBS的光谱特性,提高了定量分析的精度,采用多谱线强度归一化内标法降低了重金属的检出限和测量误差。     

激光诱导击穿光谱设备在线冰铜成分检测应用进展

利用自主研发的基于激光诱导击穿光谱(LIBS)技术的激光成分分析仪对铜冶炼现场冰铜固体和熔体成分进行了在线检测,并与取样制样后实验室的X射线荧光光谱(XRF)检测结果进行了对比.分析数据为研发设备现场投用后具备对比数据的1 294炉次,包括878炉次固体冰铜和416炉次熔体冰铜.LIBS设备在线检测与取样制样后固体XR...     

冶金分析表征支撑冶金与材料工程科技高质量发展

40年来《冶金分析》聚焦冶金与材料工程的科学技术进步,刊载论文展现了问题导向性、技术引领性、对象多样性、内涵丰富性、学科交融性、论文可参考性等鲜明特色,已成为冶金分析领域最具影响力的专业学术刊物,有力地支撑了冶金与材料工程科技的高质量发展。     

Simultaneous Determination of Trace Lead and Chromium in Water Using Laser-Induced Breakdown Spectroscopy and Paper Substrate

Toxic metals such as lead and chromium in aqueous solutions have been analyzed simultaneously by laser-induced breakdown spectroscopy(LIBS), in which the ordinary printing paper is used as a liquid absorber which was immerged into Pb(NO3)2and Cr(NO3)3aqueous solution to enrich the heavy metals. This method overcomes the drawbacks of splashing and low sensitivity in ordinary LIBS analysis of water, in which a laser beam is directly focused on a liquid surface. A good signal intensity and reproducibility has been demonstrated. The Pb 405.78 nm and Cr 427.48 nm spectral lines are used as the analytical lines. The variation of line intensity with immersion time was investigated. The calibration curve for quantitative measurement of Pb and Cr in water was established, and the detection limits are 0.033 mg/L and 0.026 mg/L respectively,which is about 2-3 orders of magnitude better than that in the ordinary LIBS analysis of heavy metal in solution.     

Measurements of hydrocarbons using laser-induced breakdown spectroscopy

Methods of quickly and rapidly measuring gas composition in combustion systems are of great practical interest. Optical methods such as Raman spectroscopy are quite useful in understanding fluid mixing, optimizing combustion, and minimizing emissions. However, many existing optical methods are limited by the need for some knowledge of the reaction progress, as they measure mole fractions of molecular reactant or product species. Other methods measure condensed-phase (spray) concentrations before combustion, or flame emission directly, to infer composition. Here we describe the use of laser-induced breakdown spectroscopy (LIBS) for direct measurement of atomic species over a wide range of mixture fractions of C₃H₈, CH₄, and CO₂ in air. Atomic emission from a laser-induced plasma is observed and ratios of elemental lines present in the spectra are used to infer composition in reactants and in flames. The method has spatial resolution on the order of 1 mm, and equivalence ratio can be determined from the spectra obtained from a single shot of the laser, avoiding time averaging of signals. In this paper we demonstrate that LIBS can be used to obtain quantitative equivalence ratio measurements for propane and methane in air. The C/(N+O) atomic ratio is used to quantify mixture fraction of C₃H₈ in air, and data from individual breakdown events have a standard deviation of 3% of the mean for mixtures of 0, 1, and 2% propane in air. The strength of the C, O, and N lines in the spectral window 700-800 nm is investigated for binary mixtures of C₃H₈, CH₄, and CO₂ in air. The dependence of the atomic emission on the concentration of carbon and hydrogen is investigated in the present paper, as well as the influence of experimental parameters such as the laser power and the temporal gating of the detector.     

激光烧蚀光谱-电感耦合等离子体质谱联用技术

激光烧蚀光谱（LAS）技术具有空间分辨率高,样品用量少,制样简单,分析速度快,可远程、实时、在线分析多相物质（气态、液态、固态）的特点,是近年来发展迅速的一种分析技术,具有广阔的应用前景,但它对痕量元素的分析能力不足。电感耦合等离子体质谱(ICP-MS)技术具有灵敏度高和多元素及同位素同时检测的能力,在微痕量元素精密分析方面具有很大的优势,但对基体元素分析存在困难。将LAS和ICP-MS技术相结合,形成LAS和LA-ICP-MS联用技术（LAS-ICP-MS）,可充分利用两种技术的优势,形成互补技术,为地质分析提供一种便捷、可靠的分析手段：利用LAS技术,可预先监测样品的大致含量与信号的稳定性等参数,筛选适用于LA-ICP-MS分析的样品,避免因元素含量过高引起的LA-ICP-MS采样锥锥口易堵塞,基体效应过大,以及因样品均匀性差或激光参数未优化等因素影响分析的准确性和精密度等问题;利用LA-ICP-MS技术,可对激光进样条件和原子化、离子化条件分开进行优化,从而改善仪器的分析性能。将LAS-ICP-MS用于岩石矿物分析,表现出其良好的应用前景     

固态和液态钢的激光诱导等离子体比较

比较了产生于室温固态钢以及高温液态钢上激光诱导等离子体的特征、原子铁的激发温度以及电子密度。通过在386～400nm波长范围的中性铁原子发射谱线, 由波尔兹曼作图法确定了铁原子的激发温度。通过测量AlI394.4nm的谱线宽度, 估算了电子密度。对固体钢来说, 铁元素的激发温度从延迟时间为10μs时的10800K下降到延迟时间为80μs时的7300K。当延迟时间分别为10μs和70μs时, 产生于固态钢和液态钢上等离子体间的激发温度并没有显著差别。在铁元素和铝元素大部分的中性原子线中, 可以观察到液态钢的谱线宽度比固态钢的谱线宽度更窄。当激光脉冲的观察延迟时间均为10μs时, 产生于液态钢上等离子体的电子密度大约为(0.99±0.15)×10¹⁷/cm³, 这相当于产生在固态钢上等离子体电子密度的46%。