Elemental analysis of flour-based ready-oven foods by slurry sampling inductively coupled plasma optical emission spectrometry

A slurry sampling technique has been utilised for the determination of Na, K, Ca, Mg, S, P, Fe, Mn, Cu and Zn in wheat-flour and flour-based ready-oven foods using ICP-OES and a direct aqueous calibration technique. For 0.1% w/v suspension of flour in 0.1% w/v Triton X-100 and 6% v/v HNO₃, the procedural limits of detection (all in mg kg⁻¹) for Na, K, Mg, Ca, P, S, Fe, Zn, Mn and Cu were 7.51, 61.1, 0.645, 1.59, 5.25, 4.58, 1.50, 1.07, 0.867 and 1.58, respectively. The precision was expressed as the relative standard deviation (RSD) of 5–10% (n = 10) for 0.1% w/v suspension of wheat-flour. The accuracy was confirmed by the analysis of reference materials wheat-flour GBW 08503 and rice flour NIST 1568a.     

Determination of macro and trace element in multivitamins preparations by inductively coupled plasma optical emission spectrometry with slurry sample introduction

A slurry sampling technique has been utilised for elemental analysis of multivitamins preparations using inductively coupled plasma-emission spectrometry (ICP-OES). For results comparison, samples were mineralised. Slurry concentration 0.1–0.2% m/v in 6% v/v HNO₃, was used. The calibration by water standard solutions, slurry standards and standard additions were tested for determination above-mentioned elements in slurries. The method offers good precision for macro elements (RSD ranged from 5% to 10%). For in-home control sample, the measured concentrations are in satisfactory agreement with independent laboratories. For the analysed multivitamin preparations, the found element concentration is compared to amount declared by producer. The concentrations of Ca, Mg, P, K, Fe, Mn, Zn, Cu and Cr, Ni, V were determined in the range 1000–100,000 and 5–50 μg g⁻¹, respectively. The slurry ICP-OES analysis was found to be suitable for quality control monitoring of multivitamin preparations and could be useful as a routine procedure.     

Trace elemental composition of curry by inductively coupled plasma optical emission spectrometry (ICP-OES)

A methodology based on inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted acid digestion was developed to determine the content of traces elements in curry samples from the Spanish market. The methodology was validated in terms of accuracy by the analysis of citrus and tomato leaf reference materials achieving comparable results with the certified values. The trace metal content of curry samples was compared with data available from previously published reports concerning Indian samples, especially in terms of heavy metal composition, in order to guarantee the quality of the commercially available spices in the European countries. Values found for the analysis of arsenic, lead and cadmium were significantly lower than the maximum limit allowed by European Union statutory limits for heavy metals and lower than those obtained for Indian curry leaves reported by Indian research teams by using neutron activation and γ-ray analysis.     

电感耦合等离子体质谱法在药品元素检测中的应用

药品及药品原料中含有的重金属及有害元素如砷、汞、铅、铬、镉等会对身体产生很大的毒副作用,而药品及药品原料中含有的必需微量元素及矿物质元素如铁、铜、锌、锰、硒、硅等摄入过量、不足也会不同程度引起人体生理的异常。因此,药品中元素检测对于药品质量控制具有重要的意义。常见药品中元素的检测方法有原子吸收光谱法、电感耦合等离子体发射光谱法、原子荧光光谱法、比色法、电感耦合等离子体质谱法等。本文对电感耦合等离子体质谱法在药品检测中的应用包括重金属及有害元素检测、微量及矿质元素检测、常规元素检测、同位素元素检测、元素形态检测进行了探讨。结果表明,电感耦合等离子体法用于药品的元素检测时,线性关系、精密度、检出限和回收率都符合检测需求。电感耦合等离子体质谱法检出限低,线性范围宽,可实现多元素同时测定和同位素元素检测,且与其他分离设备联用可用于元素形态分析,因此被广泛应用于药品的元素检测。     

电感耦合等离子体质谱法检测进口清酒中 20种矿物元素

目的建立进口清酒中钠、镁、铝、钾、钙、铬、锰、铁、钴、镍、铜、锌、砷、硒、锶、银、镉、钡、汞、铅20种元素的电感耦合等离子体质谱快速测定法。方法以硝酸处理进口清酒样品,通过超声排除产生的氮氧化物黄色气体,再以超纯水稀释,使用电感耦合等离子体质谱测定清酒中20种元素的含量。结果实验回收率在92.4%~109%之间,RSD为2.10%~5.92%,检出限分别为:钠、钙为1.0 mg/L,,钾为0.5 mg/L,铝、镁、铁、锌为0.1mg/L,钡为0.05 mg/L,铬、锰、钴、镍、铜、砷、硒、锶、银、镉、汞、铅为0.01 mg/L,线性范围分别为:钠、钙为3.0~200 mg/L,钾为1.5~200mg/L,铝、镁、铁和锌为0.3~10.0 mg/L,钡为0.15~10.0mg/L,铬、锰、钴、镍、铜、砷、硒、锶、银、镉和铅为0.03~10.0 mg/L,汞为0.03~0.20 mg/L。结论该检测方法操作简便、快速、灵敏度高、重新性好,适用于进口清酒样品的多元素同时检测。     

电感耦合等离子体质谱法测定蜂蜜中的微量元素

建立了用带八极杆碰撞/反应池的电感耦合等离子体质谱仪(ORS-ICP-MS)测定蜂蜜中Na、Mg、Al、K、Ca、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Mo、Cd、Ba、Hg、Pb等18种微量元素的方法。样品用HNO3+H2O2分解后,试液直接用ORS-ICP-MS法同时上述微量元素。采用八极杆碰撞/反应池技术,在池内引入惰性气体氦气或氢气,有效地消除了多原子离子对待测元素的干扰,确定了实验的最佳测定条件。结果表明,各元素的检出限在1.05～73.45ng/L之间,加标回收率在92.2%～106.8%之间,相对标准偏差(RSD)小于2.73%。     

ICP-MS法测定粮食中16种稀土元素

目的研究电感耦合等离子体质谱法(ICP-MS)测定粮食中16种稀土元素。方法样品采用微波消解,优化仪器的各项操作参数,考察了内标元素及方法的分析性能指标。结果测定了大米、玉米、面粉等粮食中16种稀土元素,相对标准偏差(n=6)在0.2%～2.1%之间,加标回收率在90.5%～109.0%之间,检出限小于0.007 ng/ml。结论建立的分析方法准确、灵敏、快速、简便,符合痕量元素分析要求。     

电感耦合等离子体质谱法测定坚果中Se含量的不确定度评估

目的对电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定坚果中硒元素含量的不确定度进行评估。方法根据JJF 1059.1—2012《测量不确定度评定与表示》和JJG196—2006《常用玻璃量器》的规定和要求,通过对整个实验过程产生的不确定度分析,建立数学模型,计算食品中硒元素的不确定度。结果对坚果中硒元素进行测定,得到扩展不确定度为0.103mg/kg,测定结果表示为(1.631±0.103)mg/kg。结论整个实验过程中工作曲线引入的不确定度影响较大,因此应注意工作曲线配制、检测的准确性,确保检测结果的可靠。     

电感耦合等离子体发射光谱法测定奶粉中微量元素含量的不确定度评定

目的评定电感耦合等离子体发射光谱法测定奶粉中微量元素含量的不确定度。方法对电感耦合等离子体发射光谱法测定奶粉中锌、铁、锰、铜、钙、镁、钠、钾8种微量元素的整个实验过程可能引入的各种不确定度来源进行分析,建立不确定度数学模型,计算各不确定度分量及扩展不确定度。结果在置信区间为95%的范围内,奶粉中钙、镁、钠、钾、锌、铁、锰、铜的扩展不确定度分别为0.07330、0.1136、0.07380、0.07340、0.05598、0.05272、0.08542、0.05190。结论标准溶液配制带来的不确定度对钙、钠、钾、锌、铁、铜元素的贡献率最大,由标准曲线拟合带来的不确定度对镁元素的贡献率最大,测量结果重复性带来的不确定度对锰的贡献率最大。     

微波消解-电感耦合等离子体质谱法同时测定椴树蜂蜜中23种元素

椴树蜂蜜是我国东北地区特色蜜种,为了解椴树蜂蜜中元素含量分布,本文建立了微波消解-电感耦合等离子体质谱（ICP-MS）同时测定椴树蜂蜜中B,Na,Mg,P,K,Ca,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Ga,As,Rb,Sr,Mo,Cd,Ba,Pb和U等23种元素的分析方法。结果表明,该方法加标回收率（n=6）在86.5%¹09.8%之间,选择国家标准物质菠菜（GBW10015）和茶叶（GBW10016）验证方法的可靠性,待测元素测定值基本在标准值允许范围内,日内相对标准偏差（n=3）在0.3%⁸.7%之间,日间相对标准偏差（n=5）在1.2%¹0.4%之间。应用该方法测定了吉林省不同采样点的10个椴树蜂蜜,结果发现K的含量最高,As,Cd和Pb含量均符合蜂蜜中相关限量标准要求。根据测定结果,建立了吉林省椴树蜂蜜中元素指纹图谱,发现不同产地的10个椴树蜂蜜样品中元素分布具有共同特征,可为椴树蜂蜜蜜种鉴别提供判别依据。      

电感耦合等离子体发射光谱法测定土壤中镉的含量

目的 建立电感耦合等离子体发射光谱法(inductively coupled plasma optical emission spectrometer, ICP-OES)测定土壤中镉含量的方法。方法 将土壤样品在微波消解仪中用混酸体系中完全消化, 选用二壬基萘磺酸-煤油体系(dinonylnaphthalenesulfonic acid-kerosene, DNNSA-kerosene)作为浓缩样液中镉的萃取剂, 上机测定。结果 萃取剂体积与消解后定容体积之比为1:10时检测效果最好, 标准曲线的线性范围为0.005~0.100 mg/kg, 线性相关系数为0.9999, 检出限为0.01 mg/kg, 在0.05、0.2、0.5 μg 3个加标水平下, 平均加标回收率为96.8%~104.9%, 相对标准偏差(relative standard deviation, RSD)为0.9%~3.0%。结论 本方法操作简单、实验结果准确可靠, 适用于土壤中镉的测定。     

Adulteration detection of argan oil by inductively coupled plasma optical emission spectrometry

The singularity of the trace element profile of argan oil has been demonstrated by means of inductively coupled plasma optical emission measurement in combination with different chemometric approaches. The ability of multivariate analysis methods; such as hierarchical cluster analysis (HCA), principal component analysis (PCA), classification trees using Chi-squared Automatic Interaction Detector (CHAID) and discriminant analysis (DA) to achieve edible oils classification based on its type or variety from their elemental content have been investigated. The calculations were performed using 16 variables (contents of Na, Mg, Al, K, Ca, Ti, Fe, Co, Ni, Cu, Zn, Cd, Pr, Sm, Er and Bi at μg g⁻¹ level determined by ICP-OES). HCA is able to differentiate sunflower oil samples from the rest, however the discrimination of argan oil from olive, seeds and soya oils based on their different trace element composition is hard to achieve. The PCA analysis shows three different classes in the multidimensional space (PC1-3) representing sunflower, argan and a third group comprising olive, seeds and soya oils. CHAID method allows separating the entire vegetable oil dataset, providing a correct re-substitution rate of 94.12% for argan oil using only the concentration of K. DA performed using the same variables, provides also an acceptable average accuracy results of 93.65%, by the re-substitution method. DA has been successfully applied to the analysis adulterated argan oil by addition of cheaper vegetable oils.     

电感耦合等离子体质谱法测定黑果枸杞中的 微量元素

目的建立电感耦合等离子体质谱法(inductively coupled plasma-mass spectrometry,ICP-MS)测定黑果枸杞中镓、锗、锡、铊等元素的分析检测方法。方法黑果枸杞样品经微波消解处理后用电感耦合等离子体质谱法直接分析,在消解之前加入标准混合溶液进行加标实验计算黑果枸杞中镓、锗、锑、铊的回收率。采用内标元素In和Bi消除信号漂移和基体干扰。结果黑果枸杞中的镓、锗、锑、铊的检出限分别为0.006、0.002、0.003、0.0002 mg/kg,加标回收率在105.5%~118.5%之间,相对标准偏差0.2%~5.5%之间。在镓、锗、锑、铊四种微量元素的含量上,黑果枸杞要明显比红枸杞高3~5倍。结论此方法操作简便高效、灵敏度高、准确可靠、适合黑果枸杞中镓、锗、锑、铊四种微量元素的同时测定。     

Multi-element determination in acid-digested soy protein formulations by inductively coupled plasma–optical emission spectrometry

The concentrations of major (Ca, K, Mg, Na and P) and trace elements (Al, Cu and Fe) in soy protein formulations sold in Bahia (Brazil) were determined by inductively coupled plasma–optical emission spectrometry (ICP–OES). Liquid and powdered soy protein formulation samples, both whole and light, were digested using a conventional heating program on a hot-plate. The powdered samples were prepared according to the label instructions for human consumption. A 5.0-ml aliquot of the soy protein emulsion was transferred to a borosilicate Erlenmeyer and concentrated nitric and sulfuric acid added. After a digestion time of ～50 min, hydrogen peroxide was added and heating continued to give a final volume of ～5 ml; the colorless digests were then made up to 15.0 ml with deionised water. Residual acid content was determined by acid-base titration. Good agreement between measured and certified values for all analytes in a non-fat milk powder (NIST SRM 1549) indicated that the method was suitable for major and trace elements determination in soy protein formulations.     

Element fractionation analysis for infant formula and food additives by inductively coupled plasma optical emission spectrometry

Fractionation analyses are essential to investigate the effects of dietary constituents on bioavailability of elements. A sequential separation procedure has been applied for elemental fractionation patterns in infant formula, coffee cream, milk powder, whey powder and rice flour. The protein, lipid and serum fractions were separated successfully, and fractions were analysed for various essential (Fe, Cu, Zn, Mn, Mg, Ca, Cr and Co) and nonessential (Ni, V, Al, Mo, Pb, Sn, Ba and Cd) elements by ICP‐OES. Basically, three main fractions namely protein, lipid and serum were separated. Organically bounded fraction was calculated from the sum of the element contents in protein and lipid fractions. The organically bounded fraction can be retained longer in the body than the other fractions, and its percentages of whole elements are between 3.8% and 92.2% in the samples. Additionally, the distribution tendency of each studied metal was variable, which is based on the sample characteristics and complexation reactivity of the metal. The organically bounded fraction for Fe, Cu, Zn and Mn is higher than the other elements in whole samples except whey powder. Investigated elements are basically included in ionic forms in whey powder. Additionally, Mg and Ca are usually observed as uncomplexed structures in the samples.     

Determination of silver in nano-plastic food packaging by microwave digestion coupled with inductively coupled plasma atomic emission spectrometry or inductively coupled plasma mass spectrometry

The detection of silver in nano-plastic food packaging by microwave digestion coupled with either inductively coupled plasma atomic emission spectrometry (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS) was investigated. Microwave digestion was optimised by trialling different acid mixtures. Both ICP-AES and ICP-MS showed good reproducibility, repeatability and recovery. For ICP-AES the limit of detection of the method (LODm) was 25.0?μg?g(-1), the limit of detection of the instrument (LODi) was 30.0?ng?ml(-1), the linear range was 0.10-10.0?μg?ml(-1). The average recoveries for blank samples spiked with silver at 100, 250 and 500?μg?g(-1) ranged from 82.53% to 87.60%, and the relative standard deviations (RSDs) were from 1.79% to 8.30%. For ICP-MS analysis the LODm was 0.75?μg?g(-1), the LODi was 0.04?ng?ml(-1), the linear range was 0.20-500.0?ng?ml(-1), the RSDs were 2.26-4.79%, and the recoveries were 78.09-92.72% (spiked concentrations of 2.5, 5.0 and 10.0?μg?g(-1)). These results indicate that the proposed method could be employed to analyse silver in nano-plastic food packaging.     

ICP-OES法测定坚果中微量元素的研究

采用微波辅助消解样品,建立了轴向观测电感耦合等离子体发射光谱（ICP-OES）法同时测定坚果中B、Na、Mg、Al、Si、S、K、Ca、Mn、Fe、Ni、Cu、Zn、Sr、Mo、Ba等16种微量元素的分析方法。样品采用硝酸+双氧水混合酸微波辅助消解,优化了仪器的最佳测定条件,确定了各待测元素合适的分析谱线。采用国家一级标准物质（芹菜,GBW10048）进行方法验证,测定结果与标准物质所提供的参考值一致,所有待测元素的检出限为0.31～18.38μg/L,方法具有良好的精密度和准确度。      

ICP-MS法测定肉制品中铅含量的不确定度评定

为更合理、科学地表示用电感耦合等离子体质谱(ICP-MS)法测定食品中铅含量的测量结果,按照<测量不确定度评定与表示>(JJF1059--1999)和<化学分析测量不确定度评定>(JJF1135--2005)的要求和方法, 分析试验过程中的不确定度来源,评定各标准不确定度分量,得出测量结果的扩展不确定度.在该肉制品样品铅含量的测定中,铅含量为0.083 mg/kg,其扩展不确定度为0.008 mg/kg(置信概率为0.95,包含因子为2).     

湿法消解-电感耦合等离子体质谱法同时测定水生蔬菜中5种元素

目的　建立湿法消解/电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry, ICP-MS）测定8种水生蔬菜中5种元素的方法。方法　样品在混合酸（硝酸+高氯酸=4+1, V/V）介质中消解,消解后,将消化液用水转移至25 mL容量瓶,并用ICP-MS同时测定水生蔬菜中总As、Cd、Cr、Ni和Pb这5种元素的含量。结果　5种元素的标准曲线线性范围可达0μg/L~200μg/L,相关系数：0.9992~0.9998,检出限：0.009 μg/L~0.025μg/L,定量限：0.030μg/L~0.083μg/L,回收率：89.4%~112.6%,RSD(n=11)：1.20%~1.86%。80份水生蔬菜样品中5种元素的含量均低于国家标准规定的食品中污染物限量。水生蔬菜不同种类间,5种元素的含量有显著差异。结论　湿法消解/ICP-MS方法直观、快速、准确、可靠,适于水生蔬菜中多元素同时测定。