微波消解-混合模式电感耦合等离子体质谱法测定土壤或沉积物中银、锡、硼

本研究使用硝酸-盐酸-氢氟酸混合消解液和高通量微波密闭消解试样,通过优化质谱进样系统,调节质谱分析模式,建立了微波消解-混合模式电感耦合等离子体质谱法同时测定土壤或沉积物中银、锡、硼。结果表明：使用混合酸消解液有利于试样中难消解的硼硅酸盐和硅锡化合物消解彻底;使用微波密闭消解方式可以提高样品消解效率,避免易挥发元素硼的损失;使用聚四氟乙烯（PTFE）雾化器和雾化室、蓝宝石中心管可有效降低由氢氟酸溶液介质腐蚀石英进样系统引入的仪器本底值;选择氦气（He）作为碰撞气,采用动能歧视模式（KED）分析银和锡,可有效降低多原子离子的干扰,特别是地球化学丰度更高的锆、铌、锌和氧、氮、氩形成的多原子离子对107Ag的干扰;选择标准模式（STD）分析硼,可有效提高对硼的方法灵敏度。在此基础上,银、锡、硼的检出限分别为0.007、0.12、0.43 mg/kg,方法精密度（RSD,n=12）和误差（RE,n=12）分别在2.29%~9.53%和-9.95%~6.10%之间。相比传统的原子发射光谱法,本方法具有分析流程简单、工作效率高、检出限低等优势,更适合大批量样品的多元素同时分析。     

微波消解微波等离子体炬原子发射光谱法测定芦荟中Fe和Pb的含量

用微波等离子体炬(MPT)为激发光源,氩气为等离子体工作气体,用气动雾化进样,采用标准加入法研究微波等离于体炬原于发射光谱法(MPTAES)测定芦荟中Fe和Pb的方法。详细考察溶液硝酸浓度、微波前向功率、载气流量、工作气流量、氧屏蔽气流量等实验参数对测定的影响,还考察共存离子对测定的影响。同时,还通过常规消解方法与微波消解方法相比较,得出微波消解微波等离子体炬原子发射光谱法具有简单、快速、准确、待测元素不受污染等特点。结果表明,微波消解微波等离子体炬原子发射光谱法可以作为研究芦荟中微量元素的含量的一种行之有效的方法。     

微波消解ICP-AES法测定高铬铸铁中多种元素

高铬铸铁中C和Cr的含量均较高,分析测定其化学成分时,采用常规化学酸溶法分解试样非常困难,而采用微波消解法分解样品,用电感耦合等离子体原子发射光谱法(ICP-AES)检测高铬铸铁样品中多种元素含量,其精密度和准确度能够满足科研、生产的需要。     

微波消解-ICP-MS测定无纺布中8种金属元素

建立无纺布中8种金属元素的微波消解-电感耦合等离子体质谱的分析方法。应用Cs内标,仪器信号漂移和样品的基体效应能得到很好的补偿。对所测定元素,方法的检出限为0.01~0.10ng/mL,回收率为82%~116%,RSD小于10%(n=5)。     

微波消解—ICP-AES法测定镁质耐火材料中次量元素

采用微波消解技术进行样品前处理,建立了电感耦合等离子体原子发射光谱法同时测定镁质耐火材料中次量元素的分析方法。通过大量条件试验,确定了测定的最佳条件。对标样和样品进行测定,结果表明,该方法简便、快速,数据准确、可靠。     

电感耦合等离子体原子发射光谱法测定镍铁中硅、锰、磷、铬、铜和钴

采用电感耦合等离子体原子发射光谱（ICP-AES）法测定镍铁中硅、锰、磷、铬、铜和钴。通过对溶样酸比较和谱线考察研究,选择了合适的溶样酸及各元素最佳分析谱线,优化仪器工作条件,测定元素检出限、测定低限,进行精密度和准确度试验。方法准确、简便、快速,实现镍铁中硅、锰、磷、铬、铜和钴六个元素同时测定,分析结果令人满意。     

基于腔内原位探测的空间冷原子微波钟

原子钟作为目前最精密的计时仪器,在国民经济和国家安全各领域发挥着重要作用。 在地球轨道卫星上运行高精度原 子钟,可以在地球大范围内开展高精度时间同步与比对。 不同于以往通过抛射冷原子团两次经过微波腔实现 Ramsey 微波作用 的空间冷原子钟,提出了一种新型的基于腔内原位探测的空间冷原子微波钟方案,在同一微波谐振腔内先后完成铷 87 原子的 激光冷却、原子微波相互作用、冷原子探测等过程。 该方案可以更好的利用微重力环境提高钟周期中原子与微波相互作用时间 的占空比,从而有效减小 Dick 效应对原子钟性能的影响。 介绍了冷原子微波钟系统设计与工作原理,给出了微重力环境下性 能分析和预期指标,最后展示了冷原子微波钟地面测试中获得的大约为 1. 35×10 -12 τ -1/ 2 的频率稳定度,初步展示了新型空间冷 原子钟方案的可行性。     

微波消解/ICP-AES同时测定维药材中多种微量元素

目的:准确检测出所选维药中17种微量元素的含量。方法:测定出采用微波消解样品、电感耦合等离子体原子发射光谱法(ICP-AES)同时测定维药材中:铁、锌、铜、钼、镍、钴、锰、铬、硅、锡、硒等17种微量元素的含量。结果:在最佳仪器工作条件下,所得结果较理想。结论:与常规分析方法相比,该法快速简便、准确率高、精密度好,用于标准样品、实际样品的分析,结果令人满意。     

高温合金中钌元素的分析测定

介绍了用电感耦合等离子体原子发射光谱法（ICP—AES）法测定高温合金中钌元素的分析方法。本文从样品溶解,谱线和测量条件的选择等几个方面进行了试验。研究了基体和共存元素（Ni、Co、Cr、Mo、Nb、Ta、W）对钌元素测定的影响,选择240．272nm作为钌元素分析线,采用基体匹配法制备标准曲线,选定仪器的最佳工作条件。试验结果的精密度和准确度表明,本方法快速、准确,可以满足高温合金中钌元素的分析要求：检出限为0．01μg／mL,RSD〈10％。回收率90％-101％。     

微波消解-电感耦合等离子体质谱法测定铬铁合金中的10种痕量元素

将微波消解与电感耦合等离子体质谱法相结合,优化了铬铁合金溶解方法。优化电感耦合等离子体质谱仪的仪器参数,利用标准加入法校正基体效应。在此基础上,建立了一套电感耦合等离子体质谱法检测铬铁合金中砷、锡、锑、镉、汞、铅、镧、铈、铊、铋10种痕量元素的检测分析方法。检出限、加标回收、精密度相关实验表明:该方法检出限在0.04~0.3μg/L之间;加标回收率在85.6~114.1%%之间;精密度在1.4~3.5%之间。该方法简单、快速、高效,可满足铬铁合金市场上对杂质元素含量检测的需求。     

激光诱导等离子体光谱仪实验装置的构建

激光诱导等离子体光谱仪是一种具有实时在线、非接触、多元素同时探测等优点的分析仪器。它无需制备样品,是钢铁冶炼中在线元素快速检测的仪器之一。本文将线阵CCD放置于罗兰圆上,搭建了一台紫外波段的激光诱导等离子体光谱仪实验装置,光谱分辨率达0.1nm,覆盖的光谱波段为235～260nm,主要用于检测钢铁材料中的C元素。实验结果表明,该系统的搭建是成功的。     

Spectrometer for Optical Detection of the Electron Spin Resonance with an Increased Level of Microwave Power

A spectrometer for optical detection of the electron spin resonance (ESR) spectra of short-lived radical-ion pairs produced by ionizing radiation is described. The setup is based on a standard ESR spectrometer equipped with an adapter for optical detection of spectra and a microwave amplifier. In a solution of n-terphenyl in alkanes, the spin-locking effect has been observed. At a microwave power of 10 W, the microwave magnetic induction is 0.5 mT.     

A broadband Fourier transform microwave spectrometer based on chirped pulse excitation

Designs for a broadband chirped pulse Fourier transform microwave (CP-FTMW) spectrometer are presented. The spectrometer is capable of measuring the 7-18 GHz region of a rotational spectrum in a single data acquisition. One design uses a 4.2 Gsampless arbitrary waveform generator (AWG) to produce a 1 mus duration chirped pulse with a linear frequency sweep of 1.375 GHz. This pulse is sent through a microwave circuit to multiply the bandwidth of the pulse by a factor of 8 and upconvert it to the 7.5-18.5 GHz range. The chirped pulse is amplified by a traveling wave tube amplifier and broadcast inside the spectrometer by using a double ridge standard gain horn antenna. The broadband molecular free induction decay (FID) is received by a second horn antenna, downconverted, and digitized by a 40 Gsampless (12 GHz hardware bandwidth) digital oscilloscope. The second design uses a simplified pulse generation and FID detection scheme, employing current state-of-the-art high-speed digital electronics. In this spectrometer, a chirped pulse with 12 GHz of bandwidth is directly generated by using a 20 Gsampless AWG and upconverted in a single step with an ultrabroadband mixer. The amplified molecular emission is directly detected by using a 50 Gsampless digital oscilloscope with 18 GHz bandwidth. In both designs, fast Fourier transform of the FID produces the frequency domain rotational spectrum in the 7-18 GHz range. The performance of the CP-FTMW spectrometer is compared to a Balle-Flygare-type cavity-FTMW spectrometer. The CP-FTMW spectrometer produces an equal sensitivity spectrum with a factor of 40 reduction in measurement time and a reduction in sample consumption by a factor of 20. The CP-FTMW spectrometer also displays good intensity accuracy for both sample number density and rotational transition moment. Strategies to reduce the CP-FTMW measurement time by another factor of 90 while simultaneously reducing the sample consumption by a factor of 30 are demonstrated.     

Base-line suppression in microwave spectroscopy using frequency modulation and harmonic detection

In a microwave spectrometer, systematic variations of the rf source amplitude with frequency can cause a spurious signal (base line) which severely limits the attainable sensitivity. Normally, the base line is eliminated by using Stark or Zeeman modulation. However, these modulation methods cannot be used in an experiment on nonparamagnetic molecular ions contained in a glow discharge. This paper discusses a technique which we have used to reduce the base line by a factor of about 10(-5) and which can be used to study the spectra of species contained in a glow discharge. The scheme uses wideband sinusoidal frequency modulation of the microwave source combined with synchronous detection at the nth harmonic of the modulation frequency. The system produces a signal proportional to the nth derivative with respect to frequency of the base line. However, the signal due to an absorption line is only slightly smaller than that produced by other modulation methods. The system may be considered to behave like a high-pass filter which discriminates against features that vary slowly with frequency.     

电感耦合等离子发射光谱法在食品分析中的应用

电感耦合等离子发射光谱法作为多元素的分析检测手段,能同时得出数十种元素的分析结果,方便、快捷,在多种样品的分析过程中起着举足轻重的作用。尤其是食品分析,不仅能够指导人们对食品中营养元素的添加量,而且对食品的污染可进行全程检测,使等离子发射光谱法这一快速、便捷的检测手段更深入地运用到食品领域,这对提高膳食营养、保证食品安全、提高食品质量具有十分重要的意义。     

微波消解-ICP-MS法同时测定营养素补充剂中20种元素

建立了微波消解-电感耦合等离子体质谱(ICP-MS)法测定营养素补充剂中铜、铁、锌、锰、钙、镁、钾、磷、锶、钼、镍、钒、硒、锡、铬、铅、镉、砷、汞和锑共20种营养及有害元素的分析方法。通过对微波消解条件、质谱条件的优化、内标物的选择,克服高盐复杂基体对痕量元素测定的干扰,选择高浓度元素的低丰度质量数扩大线性范围。结果表明,铜、锌、铁、锰、钙、镁、钾、磷在0~50mg/L、汞在0~10μg/L、其他元素在0~50μg/L线性良好,相关系数在0.9992~1.0000之间,方法检出限为0.021μg/kg~21μg/kg,方法精密度为0.8%~5.7%。用该方法测定国家标准物质奶粉GBW(E)10017和芹菜GBW10048,测定结果与标准值无显著差异。方法简便、快速,可实现多种样品中含量在1%以下的主、微量元素同时测定。     

高灵敏度膜进样VOCs在线检测质谱仪的研制

新研制了一台高灵敏度膜进样VOCs在线检测质谱仪。以聚二甲基硅氧烷(Polydimethylsiloxane,PDMS)膜系统作为进样接口,采用真空紫外灯单光子软电离技术,与垂直加速反射式飞行时间质量分析器联用。性能测试表明该仪器质量精度优于1×10-4,分辨率优于600,对苯、二甲苯、氯苯的响应时间优于20s,谱图清晰,三者定性检测限分别可达到6ppb、17ppb、24ppb,线性检测范围优于3个数量级,适合定性、定量分析,能够广泛应用于环境中VOCs的快速、在线检测。     

Invited Review Article: Microwave spectroscopy based on scanning thermal microscopy: resolution in the nanometer range

Scanning thermal microscope-detected ferromagnetic resonance (SThM-FMR) combines a thermal near-field microscope with a FMR spectrometer and detects the thermal response due to resonant microwave absorption by measuring the resistivity change in the thermal nanoprobe. The advantage of this technique is to provide imaging capabilities at fixed resonance conditions as well as local microwave spectroscopy at the nanoscale. A technique that uses the same setup but detects the thermoelastic response of the sample is the scanning thermoelastic microscope-detected FMR (SThEM-FMR). This latter technique is advantageous when FMR spectra of single nanostructures have to be recorded at a fixed position. The experimental setups and the signal generation processes of SThM/SThEM-FMR are described in detail. With the SThM-FMR setups a temperature resolution of 1 mK and a local resolution of 30 nm are actually achieved. With SThEM-FMR the obtained local resolution is 10 nm. The detection limits of both techniques can be as low as 10(6) spins. To demonstrate the potential of these new techniques SThM/SThEM-FMR investigations of local magnetic anisotropies, magnetization dynamics of single nanodots and inhomogeneous FMR excitations due to finite size effects are presented. Simultaneously, information on the magnetic parameters, the topography, and the thermal properties is provided. To describe the further potential of this recently developed SThM-FMR technique, combined magnetoresistance and FMR investigations are presented and an outlook on possible future applications is given.     

微波消解-ICP-MS法同时测定软胶囊中10种痕量元素

为应对国家食品、药品安全的限量要求,采用微波消解法对软胶囊进行前处理,电感耦合等离子体质谱法（ICP-MS）同时测定软胶囊中铅、镉、砷、汞、铬、硒、铜、铁、锰和镍等10种痕量元素,并对测定条件进行了优化。结果表明：汞元素在0~10 μg/L范围内,其他元素在0~50 μg/L范围内的线性关系良好,线性相关系数r在0.999 4~0.999 9之间,方法检出限为0.011~0.21 μg/kg;考察了方法精密度,测定结果的相对标准偏差（RSD）为1.2%~5.7%;对各元素进行了3个不同浓度水平下的加标回收率实验,平均回收率为90.0%~110.0%。采用该方法测定了角鲨鱼肝NRCDOLT-3和奶粉GBW10017中的相应元素,测定结果与标准值无显著差异,验证了该方法测定多种不同基体软胶囊中痕量元素的实用性。