Determination of Trace Elements in Vegetable Oils and Biodiesel by Atomic Spectrometric Techniques—A Review

Abstract

The determination of trace elements in edible oils and biodiesel using atomic spectrometric methods is reviewed. Problems related to sample pretreatment for appropriate sample introduction and calibration are addressed as well as the strategies to overcome them. Recent trends aimed at simplifying sample manipulation are presented. The applications and scope of atomic absorption spectrometry (AAS), flame optical emission spectrometry (F-OES), inductively coupled plasma–optical emission spectrometry (ICP-OES), and inductively coupled plasma–mass spectrometry (ICP-MS) techniques for the determination of trace metals in edible oils and biodiesel are discussed, as well as some current instrumental new developments.     

ICP-MS测定自来水中的金属元素

利用电感耦合等离子体质谱仪的高灵敏度、高准确性和多元素同时分析的特点,可以快速精确地测定自来水中的微量金属元素含量。由于自来水样品中的有害金属元素含量比较低,需要高灵敏度的分析方法,所以与其他元素分析技术相比ICP-MS优势明显,在自来水样品分析中已经得到了广泛的应用。本文用电感耦合等离子体质谱法(ICP-MS)和原子吸收分光光度法(AAS)测定自来水中的金属元素,并对中国与日本自来水进行了取样分析和比较。     

电感耦合等离子体发射光谱法/质谱法检测地衣样品中主次微量元素的方法优化

地衣是应用广泛的大气污染生物监测器。电感耦合等离子体发射光谱法/质谱法(ICP-MS/AES)是植物元素定性定量分析的重要和高效的方法。但受严重大气污染影响,我国部分地区的地衣元素水平远高于其他植物,且在空间、时间、物种和元素类别方面存在巨大差异。虽然地衣在大气污染监测方面具有良好的应用前景,但我国地衣元素分析测试方面尚缺乏专门的方法学研究,这限制了大气质量的地衣生物监测在我国的开展。因此,有必要对地衣样品元素含量的ICP-MS/AES法进行优化。以国家一级标准物质GBW10014(圆白菜)、GBW10015(菠菜)、GBW10052(绿茶)和地衣标准物质(IAEA-336)为材料,探讨了地衣样品的不同消解方法、取样量、分析谱线、同位素、内标元素及仪器参数对ICP-MS和ICP-AES结果的影响。确定了适用于大批量地衣元素测试的干法灰化-碱熔ICP-AES和微波消解ICP-MS的优化条件,该优化条件具有线性关系好(r>0.999 0)、检出限低、准确度高和精密度好的特点。以优化后的测试方法测定采自我国太行山区和南极阿德利岛的地衣样品,结果表明太行山地衣体内元素含量远高于南极阿德利岛,大气沉降对太行山地衣元素组成的相对贡献也较大。验证了优化方法的适用性,为京津冀环境治理提供科学数据和技术支持。     

Critical Evaluation of Analytical Procedures for the Determination of Lead in Seawater

Abstract: This article presents a critical evaluation of the analytical procedures used for the determination of lead in seawater, which is important because lead is a good indicator of marine pollution caused by human activities. Sampling, storage, and pretreatment techniques are briefly overviewed, including the significance of systematic errors that cannot be corrected later on. The main techniques in this article are electrothermal–atomic absorption spectrometry (ET-AAS), inductively coupled plasma–mass spectrometry (ICP-MS), and voltammetry. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma–optical emission spectrometry (ICP-OES) are treated as well, although their limits of quantification are not sufficient for a determination of lead in unpolluted seawater. Even when separation and preconcentration techniques are applied, these techniques are only capable of detecting lead in polluted coastal seawater. Separation and preconcentration are actually also required for ET-AAS and ICP-MS in order to determine the lowest concentrations of lead found in unpolluted open-ocean seawater, which is still a challenge for the analytical chemist.     

电感耦合等离子体原子发射光谱法测定鲨鱼软骨中的微量元素

用电感耦合等离子体质谱（ＩＣＰ－ＭＳ）对鲨鱼有进行全元素的半定量分析。用电感耦合等离子体原子发射光谱（ＩＣＰ－ＡＥＳ）对其进行微量元素测定，选用钇作内标元素，可较好地克服基体效应，所研究元素的回民率在８１．６－１００．７％之间，铁、锌、硒、铜、锰、钼，钛和锶等元素的测定下限分别是：０．６０、０．５５，０．２１，０．３９，０．０４２，０．２７，０．０３８，０．４８μｇ．ｇ＾－１，实验表明鲨鱼软骨含有     

水飞蓟中无机元素的含量分布及溶出性质的研究

用电感耦合等离子体光谱和电感耦合等离子质谱法测定了水飞蓟果实、加工过程中的水飞蓟油渣及提取物(水飞蓟素)中多种无机元素的含量,结果表明绝大多数元素的含量从油渣-果实-提取物逐渐降低。在此基础上,研究了水飞蓟果实中无机元素的溶出率与浸泡次数的关系,发现大部分元素以可溶态存在,浸泡前4次其总的溶出率远远高于后3次。同时用国家一级标准物质茶叶(GBW07605),验证了方法的准确性和可靠性。     

An Overview of the Use of Yttrium for Internal Standardization in Inductively Coupled Plasma–Atomic Emission Spectrometry

Abstract

Internal standardization is a widely used method for compensating nonspectral interference in inductively coupled plasma (ICP) spectrometry. Emphasis is given on the choice of the suitable element and its specific spectral line as an efficient internal standard. This choice is the result of multi-variable evaluations and analytical applications. In inductively coupled plasma–atomic emission spectrometry (ICP-AES) and other spectrometric techniques several spectral lines of the same or different elements have been evaluated as potential internal standards. Yttrium spectral lines fulfill certain prerequisites and they are favored by a large number of researchers. In our discussed review, we present several reports of ICP-AES techniques that employ yttrium as the internal standard. These reports are classified according to specific sample origin and aim of the research.     

Performance of TXRF among other competitors' analytical techniques

The main purpose of this presentation was to evaluate the performance of total reflection X-ray fluorescence (TXRF) among conventional analytical techniques such as atomic absorption spectrometry (AAS), inductively coupled plasma-optical emission spectrometry (ICP-OES), and inductively coupled plasma-mass spectrometry ICP-MS). In order to perform the study, one sample and a blank acidified with nitric acid (2.0%–2.5% v/v) were distributed among 10 laboratories. The investigated analytes were arsenic, chromium, nickel, and lead within 0.050 to 1.50-mg/L concentration range. A guide protocol was elaborated for the participants in order to normalize the manipulation of the samples. In the particular case of arsenic, atomic fluorescence spectrometry (AFS) was incorporated. The “E_n” statistical test was performed in order to evaluate the results reported by each participant against the assigned value of the sample. Results show an excellent performance of TXRF among the mentioned analytical techniques.     

黑米中微量元素含量的测定

采用高压密封消解罐法对样品进行处理,以电感耦合等离子体-原子发射光谱法(ICP-AES)和原子吸收光谱法(AAS)测定黑米中Mn、Cu、Fe、Mg等微量元素的含量,lCP-AES更佳.回收率为92.2%-109%,相对标准偏差小于2.67%.实验证明,黑米含有丰富的对人体有益微量元素,是一种健康食品.     

肺癌和癌旁组织中55个元素的原子光谱分析

建立了利用原子光谱技术测定人肺组织中55种元素的方法。样品采用冷消化过夜,温控电热板消解。其中49种元素利用电感耦合等离子体质谱(ICP-MS)进行测定;As和Se由原子荧光分光光度计(AFS)测定,K, Na, Ca和Mg由原子吸收分光光度计(AAS)测定。24个元素的测定值与牛肝和人发两种标准物质中的参考值基本吻合。除了Cr, Er和U三元素回收率略为偏高外,其余30种元素的加标回收率均在90％～110％之间。绝大多数元素的精密度在1.7％～10％之间。统计学分析结果表明,共有20种元素的含量在所测17对癌组织和癌旁组织之间具有显著性差异。此方法简便、快速、准确。     

ICP-AES 分析超导粉中杂质元素的干扰系数矩阵校正法

利用ICP-AES法测定了铋系超导前驱粉（BSCCO）中Fe,Cr,Ni,Si,Al和Ba等微量杂质元素,优化了仪器测定参数并研究了酸的种类及浓度对测定结果的影响。系统研究了BSCCO基体元素Bi,Sr,Pb,Ca和Cu对微量杂质元素测定的干扰,分别测定了每个基体元素对测定元素的校正系数并组成交互干扰校正矩阵,采用全选主元高斯消去法计算出基体元素产生的背景等效浓度,再计算出样品的真实浓度。用此方法对合成标样中的上述微量杂质元素进行了测定,分析结果的回收率99.5％～100.5％,测定了实际样品中的杂质元素,并与ICP-MS法进行了对比,二者结果一致。     

红景天中微量元素的测定方法研究

采用高压硝化罐法对试样进行消解,分别用ICP-AES和AAS两种方法测定了红景天中Mg、Fe、Zn、Mn等微量元素的含量,回收率在96.0%—102.0%之间,相对标准偏差均小于2.00%。对两种方法比较无明显差异,但ICP-AES法简单,快速,灵敏度高,准确性好,且多元素同时测定。它能为红景天的药理、药效研究和综合开发利用,提供了广泛的科学依据。     

ICP-AES测定水中铜结果的不确定度评定

介绍了ICP－AES法测定水中铜的不确定度的评定方法。由于等离子质谱仪（ICP－MS）、紫外分光光度计（UVS）、原子吸收分光光度计（AAS）及原子荧光光度计（AFS）等仪器在定量分析中，校准曲线的绘制，标准样品的使用，测定结果的输出等方面与ICP－AES极为相似，因此本方法不仅可以用于水中其他元素和其他材料的测量结果的评定，而且还可以在评定ICP－MS、UVS、AAS、AFS等仪器的测定结果不的确定度时作参考。     

Paper Analysis: Nondestructive and Destructive Analytical Methods

Abstract: Forensic examination and dating documents is an important issue in our society, because documents are used throughout our lives to record everything we do. It starts with our birth certificate and ends with our death certificate. Between them there are receipts, leases, deeds, contracts, checks, wills, sales agreements, and medical records. The validity of all of these documents is often questioned during litigation. This study describes the use of nondestructive analysis of paper (Fourier transform infrared [FTIR] spectroscopy using an attenuated total reflectance [ATR] technique, Raman spectroscopy) and destructive analysis of paper (microscopic analysis of fibers, FTIR analysis of paper ash, inductively coupled plasma–mass spectrometry [ICP-MS]). The results are discussed in detail.     

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.     

Mapping analyses of Fe-diffused mc-Si using M?ssbauer microscope and photoluminescence

Twenty CK chondrites collected in the Antarctica Continent were characterized by inductively-coupled plasma mass spectrometry (ICP-MS), prompt gamma ray analysis (PGA), instrumental neutron activation analysis (INAA), X-ray diffractometry (XRD) and ⁵⁷Fe-M?ssbauer spectroscopy. As a result of elemental analysis, it was revealed that 18.2~26.4 mass% of iron was included in the each chondrite. M?ssbauer spectrum of LEW86258, classified as a typical CK chondrite, was found to be composed of two paramagnetic doublets and two magnetic sextets. M?ssbauer spectra were assigned to the absorption due to forsterite (Mg_1.36Fe_0.64SiO₄) and magnetite (Fe₃O₄), as also confirmed by XRD. XRD study of LAP03834, reclassified from CK to R chondrite, revealed the presence of crystalline phase due to forsterite. These results indicate that LAP03834 and related chondrites, i.e., MET01149, LAP03923 and MAC02453, should be reclassified as R or LL chondrite.     

胃康灵胶囊中15种元素含量分析

微波消解法制备供试品,电感耦合等离子体-质谱(ICP-MS)法测定中成药胃康灵胶囊中15种元素的含量,探讨其宏量、微量元素与疗效的关系。胃康灵胶囊中常量元素含量丰富,微量元素含量差别较大,Fe含量最多,Se含量最少,有害元素含量不高。胃康灵胶囊中元素与胃炎及胃溃疡的治疗密切相关。     

石材主量元素和微量元素测定的酸溶与碱熔分解方法比较

酸溶和碱熔分解石材标样,ICP-AES和ICP-MS法进行常量元素及微量元素的测定,分析结果的比较发现,根据不同的的石材类型、所需分析的元素种类以及研究目的,采用适当的样品分解方法,可以获得准确的常量元素和微量元素数据。     

微波消解/ICP-MS法测定二色补血草中27种元素

采用微波消解及ICP-MS,建立了一种测定二色补血草中Be,B,Na,Al,Mg,P,K,Ca,V,Cr,Mn,Fe,Co,Ni,Cu, Zn,Ga,As,Se,Sr,Mo,Cd,Ba,La,Hg,Pb和Th共27种元素的方法.实验采用国家一级标准物质茶叶(GBW-07605)评价了方法的准确性,通过在线加入Ge,In和Bi三种元素内标液的方法来校正由于基体效应和信号漂移对测量所造成的影响.方法的回收率为92.4%～107.2%,相对标准偏差为1.5%～9.7%,检出限为0.002～0.081 μg·L-2,元素的测定结果表明:二色补血草中含有丰富的Na,K,Ca,Mg和P等常量元素,Fe,Mn,Zn,Cr和Cu等微量元素.实验结果为深入研究二色补血草无机元素与药效的相关性提供了参考数据.     

电感耦合等离子体发射光谱法测定汽油中的氯

应用电感耦合等离子体发射光谱法(ICP-AES)建立了定量分析车用汽油中氯的新方法。方法选择航空煤油作为稀释剂,按稀释剂：样品为4∶1(体积比)进行稀释。选取波长134.724 nm为分析谱线,在辅助气中引入0.050 L·min-1氧气,有效的消除积碳,保持等离子体稳定。方法考察了发射功率,雾化气流量,辅助气流量以及氧气流量对氯信背比的影响,确定了ICP-AES的最佳分析条件,通过标准加入法校正基体效应和信号漂移对测量所造成的影响。方法的加标回收率在96.6％～103.9％之间,相对标准偏差(RSD,n=10) 在1.57%～4.49%之间,方法检出限为0.27 mg·L-1。此方法和微库仑法对样品中有机氯的测定结果基本一致,而且,该方法具有不受元素的存在形态限制的优点,测定的结果为总氯(有机氯和无机氯)含量。方法简便,快速,灵敏,拓展了ICP-AES在非金属元素特别是卤素分析方面的应用,可用于车用汽油中氯含量的日常检测,为车用汽油的质量评价提供技术保障。