微波消解-火焰原子吸收光谱法测定油脂样品中的9种金属元素

为建立一种能对油脂样品中9种金属元素含量进行准确测定的方法,以5种食用油和2种地沟油为试材,采用微波消解法对样品进行前处理,利用火焰原子吸收光谱仪进行测定,并对微波消解油脂样品时的程序和条件进行了设计和优化,最终建立了包含5个步骤的微波消解新程序,其中最大消解压力为35 atm,最大温度为190 ℃,保持时间为20 min。方法性能考察表明:9种待测金属元素在各自的浓度范围内均具有良好的线性关系,决定系数为0.9982~0.9994,检出限为0.0013~0.0122 μg/mL,样品的加标回收率范围在98.94%~101.45%之间,RSD≤4%（n=6）。采用所建方法对7种油脂样品中的9种金属元素进行了含量测定,检测结果表明:5种食用油中含有丰富的营养元素,而Cr、Cd、Pb元素未检出,初步判断油脂的营养价值和安全性较高。而地沟油样品由于检出含有Cr、Cd、Pb,且Pb的含量远超国家标准限定值,已不适宜食用。实际应用表明:所建方法具有操作简便、准确度高等优点,能满足各类油脂中金属元素的检测需要。     

北京市场常见食用菌重金属含量测定及评价

目的对北京市场常见食用菌重金属污染情况进行测评。方法调查选取北京大、中型超市常见食用菌5个品牌的4种食用菌共20个样品,进行清洁、烘干、磨粉、过筛和硝酸高氯酸湿法消解,采用原子荧光光谱法测定重金属As、Pb、Cd含量。结果所测样品As、Pb、Cd的平均含量分别为国家标准的32%、60%和NY/T 749-2003的81%,总体上是安全的;其中,金针菇超标率为26.7%,杏鲍菇为13.3%,平菇为6.7%,蟹味菇未检测到超标;20个检测样品中,3个Pb超标、4个Cd超标,超标率分别为15%和20%。结论北京市场常见食用菌As、Pb、Cd污染较轻,总体安全,但个别样品Pb、Cd含量超标,需引起重视。     

应用ICP-MS/MS准确测定紫苏籽油中的重金属元素

紫苏籽油中重金属元素的准确测定仍然是食品安全的重要分析任务。本研究基于电感耦合等离子体串联质谱(ICP-MS/MS)建立了快速准确测定紫苏籽油中Cr、As、Cd、Hg、Pb的分析方法。对于测定过程中Cr和As所面临的严重干扰,在MS/MS模式下,采用O_2为反应气,通过质量转移反应将Cr~+和As~+转移为CrO~+和AsO~+实现无干扰测定,而对于Cd、Hg、Pb测定过程中存在的干扰轻微可以忽略不计,仍然可以在MS/MS模式下使用无气方式使待测离子运行的质谱通道更加畅通,提高待测离子的传输效率。采用建立的方法,所有元素在0～50μg/L的范围内具有良好的线性关系(R~2≥0.999 7),应用三水平加标回收实验评估了方法的准确性,各元素的加标回收率在92. 5%～108. 0%之间,相对标准偏差(RSD)≤4. 1%。Cr、As、Cd、Hg、Pb的检出限分别为3. 56、1. 91、0. 84、2. 25、0. 89 ng/L,方法已应用于紫苏籽油中重金属元素的测定。实际样品的ICP-MS/MS分析结果表明,紫苏籽油中Cr、As、Cd、Hg、Pb的含量极低,不会对人体构成潜在危害。     

微波消解-火焰原子吸收光谱法测定百里香中微量元素

采用微波消解-火焰原子吸收光谱法(FAAS法),连续测定雷山县乌东村的百里香中的Zn,Fe,Cu,Mn,Ni,Cd,Cr,Pb含量。待测元素的最佳测试条件经过正交试验设计优化组合确定。结果表明,供试样品中微量元素Zn,Fe,Cu,Mn的含量分别为154.6,331.4,1.86,342.6mg/kg,而重金属元素Ni,Cd,Cr,Pb未检出。用此法节省时间和试剂,环境污染少,操作简便,精密度和准确度较高。     

炭化-湿法消解-石墨炉原子吸收光谱法测定植物油中铅、镉和铬的研究

为了快速、准确、低成本地消解植物油,检测Pb、Cd和Cr含量,通过对比消解用酸和取样量,优化石墨炉原子吸收光谱仪(GFAAS)灰化温度和原子化温度,对比消解方法及ICP-OES、ICPMS和GFAAS等方法的精密度,采用炭化-湿法消解-GFAAS测定了12类219件植物油(134件食用油和85件调味油)Pb、Cd和Cr含量,同时利用加标回收进行质量控制。结果表明:取样量为0.200 0 g,消解用酸为硝酸13 m L、过氧化氢5 m L时,可将植物油消解彻底;采用氘灯背景校正法测定Pb和Cd,塞曼背景校正法测定Cr;测定Pb、Cd和Cr的灰化温度和原子化温度分别为400、300、1 400℃及1 100、800、2 000℃;加标回收率范围为94.6%~109.3%;食用油Pb、Cd和Cr含量平均值为0.052 2、0.001 0、0.331 7 mg/kg,调味油的Pb、Cd和Cr含量平均值为0.192 5、0.003 7、1.813 8 mg/kg。调味油Pb、Cd和Cr的含量普遍高于食用油中的含量;炭化-湿法消解-GFAAS测定Pb、Cd和Cr的精密度较高、方法可靠,是批量检测植物油Pb、Cd和Cr的优选方法。     

“食品分析样品前处理方法研究”专题征稿函

<正>食品安全检测是每个人都重视的问题,其中食品分析的样品前处理是影响检测结果的重要步骤。前处理是样品的制备和对样品中待测组分进行提取、净化和浓缩的过程。在整个食品检测分析中,前处理常常需要整个检测时间的70%～80%,而且实验中的误差很多时候来自样品的前处理过程。鉴于此,本刊特别策划了"食品分析样品前处理方法研究"专题,主要围绕食品检测中样品制备方法、样品中待测组分提取、净化、浓缩等方面或您认为有意义的相关领域展开论述和研究,综述及研究论文均可。鉴于您在该领域丰富的     

ICP-OES法测定果冻中微量重金属元素

采用电感耦合等离子体发射光谱(ICP-OES)法同时测定果冻中Cr、Co、Ni、Cu、As、Cd、Sb、Sn、Hg、Pb等重金属元素。样品用硝酸+双氧水分解后,试液直接用ICP-OES法同时上述10种元素。对分析谱线、基体效应和等离子体参数等进行了讨论,确定了仪器的最佳工作条件。结果表明,10种待测元素的检出限在0.44～3.80μg/L之间,各待测元素的浓度与信号强度的线性关系良好,线性相关系数R2≥0.9997,各待测元素的精密度良好,RSD<2.98%,回收率为92.6%～106.8%。该方法简便、快速、准确,可以用来进行果冻的质量控制和安全评价。     

食品级SiO2中有害元素的发射光谱分析

建立了用电感耦合等离子体发射光谱(ICP-OES)法测定食品添加剂SiO2中Cr、Co、Ni、As、Cd、Sb、Hg、Pb等有害元素的分析方法。样品用硝酸+氢氟酸分解后,试液直接用ICP-OES法同时测定上述8种元素。研究了基体硅对分析元素的光谱干扰情况和基体效应的影响,确定了仪器的最佳工作参数,通过选择灵敏度高且不受干扰的待测元素谱线为分析线。结果表明:8种待测元素的检出限在1.69~8.33μg/L之间,各待测元素的浓度与信号强度的线性关系良好,线性相关系数R2≥0.999 8,各待测元素的精密度良好,RSD<2.95%,三水平加标回收率为93.3%~102.3%。     

“食品分析样品前处理方法研究”专题征稿函

<正>食品安全检测是每个人都重视的问题,其中食品分析的样品前处理是影响检测结果的重要步骤。前处理是样品的制备和对样品中待测组分迚行提取、净化和浓缩的过程。在整个食品检测分析中,前处理常常需要整个检测时间的70%～80%,而且实验中的误差很多时候来自样品的前处理过程。鉴于此,本刊特别策划了"食品分析样品前处理方法研究"专题,主要围绕食品检测中样品制备方法、样品中待测组分提取、净化、浓缩等方面或您认为有意义的相兲领域展开论述和研究,综述及研究论文均可。鉴于您在该领域丰富的     

“食品分析样品前处理方法研究”专题征稿函

正食品安全检测是每个人都重视的问题,其中食品分析的样品前处理是影响检测结果的重要步骤。前处理是样品的制备和对样品中待测组分进行提取、净化和浓缩的过程。在整个食品检测分析中,前处理常常需要整个检测时间的70%～80%,而且实验中的误差很多时候来自样品的前处理过程。     

Development and validation of a method for Cd, Pb and As analysis in bovine, equine and poultry liver by inductively coupled plasma mass spectrometry

A method for the determination of As, Cd and Pb in bovine, equine and poultry liver by ICP-MS was developed and validated. Samples were digested in a microwave oven using a 10% HNO(3) solution. A set of experiments was made according to a central composite design (CCD) for optimisation of the plasma argon flow, nebuliser argon flow and radiofrequency power applied to the plasma. During the validation, Rh and Ru were evaluated as internal standards and, after validation, the best was Rh for Pb and Cd analysis, but for As better results were obtained without an internal standard. The method allowed As, Cd and Pb determination with a 3.3% HNO(3) solution for the calibration curves ranging from 0 to 40 μg l(-1) for As and from 0 to 20 μg l(-1) for Cd and Pb. The recovery values obtained showed averages of 100%, 106% and 96% for As, Cd and Pb, respectively. Limits of quantification obtained were 85 μg kg(-1) for As, 6.5 μg kg(-1) for Cd and 12.5 μg kg(-1) for Pb. Repeatability and within-laboratory reproducibility were evaluated through the indicators HORRAT(r) and HORRAT(R), and the results were less than 0.30. The method is simple, fast and showed adequate precision and accuracy for the determination of As, Cd and Pb in bovine, equine and poultry liver. The precision, recovery, uncertainties, and limits of detection and quantification for each analyte were in accordance to European Union Commission Regulation 2007/333/EC.     

微波消解-电感耦合等离子体质谱法同时测定 橄榄油中的18种金属元素

目的建立微波消解-电感耦合等离子体质谱(ICP-MS)法同时快速测定进口橄榄油中18种微量金属元素(锂、铍、钛、钴、镍、铜、锌、钼、银、镉、锡、锑、钡、汞、铅、铁、锰、砷)的分析方法。方法橄榄油经微波消解进行样品前处理,采用ICP-MS测定,外标法定量。结果本方法测定18种金属元素的线性范围宽,线性关系良好(r0.999),检出限低,各元素的加标回收率在82.3%~110.5%之间,相对标准偏差均小于5%。结论本方法具有简单、快速、灵敏度高、准确度高、回收率高等特点,能够同时对橄榄油中18种元素进行分析。     

Dithizone-modified graphene oxide nano-sheet as a sorbent for pre-concentration and determination of cadmium and lead ions in food

Graphene oxide nano-sheet was modified with dithizone as a novel sorbent for selective pre-concentration and determination of Cd(II) and Pb(II) in food. The sorbent was characterised by various analytical methods and the effective parameters for Cd(II) and Pb(II) adsorption were optimised during this work. The high adsorption capacity and selectivity of this sorbent makes the method capable of fast determinations of the Cd(II) and Pb(II) content in complicated matrices even at μg l^?1 levels using commonly available instrumentation. The precision of this method was < 1.9% from 10 duplicate determinations and its accuracy verified using standard reference materials. Finally, this method was applied to the determination of Cd(II) and Pb(II) ions in common food samples and satisfactory results were obtained.     

电感耦合等离子体原子发射光谱法测定食品 添加剂硫酸锌中铁、锰、铅、镉

目的建立一种用电感耦合等离子体原子发射光谱法(ICP-OES)测定食品添加剂硫酸锌中铁、锰、铅、镉的方法。方法试样用水溶解后,采用电感耦合等离子体发射光谱法测定试液中铁、锰、铅、镉的含量,标准曲线法定量。结果试样中铁、锰、铅、镉的检测限分别为0.5 mg/kg、0.1 mg/kg、0.1 mg/kg、0.1 mg/kg。重复性和精密度好,RSD5%,回收率在90%~120%,符合国标要求。样品检测结果与国家标准方法的结果基本一致。结论本方法操作简便,结果准确可靠。适用于食品添加剂硫酸锌中多种杂质元素的高通量、快速检测。     

Monitoring of Zn(II), Cd(II), Pb(II) and Cu(II) During Refining of Some Vegetable Oils Using Differential Pulse Anodic Stripping Voltammetry

In this study, a novel approach has been developed using differential pulse anodic stripping voltammetry (DPASV) for the simultaneous determination of Zn(II), Cd(II), Pb(II) and Cu(II) in edible oils at hanging mercury drop electrode. The microwave digestion of oil samples was carried out with concentrated HNO₃ and H₂O₂. KNO₃ was used as a supporting electrolyte. The experimental conditions optimized such as deposition time, stirring rate and size of mercury drop were 300 s, 600 rpm and 10 mm², respectively. The method was applied to quantify Zn(II), Cd(II), Pb(II) and Cu(II) in crude and refined hazelnut, corn, sunflower and olive oils. During refining of different vegetable oils, the removal efficiencies of Zn(II), Cd(II), Pb(II) and Cu(II) were calculated as 98.20–99.91, 98.50–99.90, 95.26–99.76 and 95.93–99.92 %, respectively. The limits of detection for Zn(II), Cd(II), Pb(II) and Cu(II) were 2.1?×?10^?8, 8.7?×?10^?10, 7.1?×?10^?9 and 3.4?×?10^?9 and the limits of quantification were 6.8?×?10^?8, 2.9?×?10^?9, 2.3?×?10^?8 and 1.1?×?10^?8 M with linear regression coefficients (R ²) of 0.9930, 0.9928, 0.9893 and 0.9931, respectively. It was observed that the above metals in crude and refined vegetable oils could be determined simultaneously by the DPASV method.     

微波消解-电感耦合等离子体质谱法测定高钙基体中As、Pb、Cu、Cd

研究溶液中高钙基体效应及降低基体干扰的方法,建立微波消解一电感耦合等离子体质谱法9n,4定高钙基体中As、Pb、cu、cd含量的分析方法。样品采用微波消解,通过研究功率和载气流速在不同钙基体含量时对As、Pb、cu、Cd测定的影响,结合调谐液优化仪器工作参数,选择合适的内标元素对钙基体干扰进行校正。结果：高钙基体中钙基体含量在不超过0．1％,90rain内连续进样引起的基体干扰基本上得到克服。各元素加标回收率均在89％～104％,标准偏差均低于4．0％。方法准确可靠,适用于高钙基体中As、Pb、Cu、Cd含量的同时测定。     

茶叶中镉、铅、砷的浸出规律及快速测算方法研究

为明确茶叶中镉、铅、砷的浸出规律,探索茶叶中相应重金属元素的快速测算方法,分别采用微波消解和沸水浸提方法进行前处理,运用电感耦合等离子体质谱仪(ICP-MS)测定了茶叶、茶水和茶渣中的镉、铅、砷的含量,研究了3种元素的浸出规律及快速测算方法。结果表明,所测茶叶中镉、铅、砷的含量均未超过国家限定标准。在本研究提取条件下,镉、铅、砷三种元素在浸提20min茶水中的含量与其在茶叶中的含量均呈线性关系,镉的线性方程为Y=7.40623X+0.0235(r=0.9999),铅的线性方程为Y=5.44998X+0.03008(r=0.9935),砷的线性方程为Y=2.25405X+0.01115(r=0.9822)。因此,可以通过测定茶水中的镉、铅、砷含量来评估茶叶中的镉、铅、砷总量,以实现对茶叶中镉、铅、砷含量的快速测算;本研究明确了镉、铅、砷的浸出规律,提供了一种快速提取和检测茶叶镉、铅、砷含量的新方法。     

中药渣及袋栽平菇中重金属含量的研究

用原子吸收分光光度法对药渣及用药渣栽种的平菇中重金属元素铅、铜、镉含量进行了测定,并用单项累积污染超标倍数Pe进行评价。结果表明:药渣中铜、铅、镉均被检出,铜的平均含量为14.32 mg/kg,镉的平均含量为0.212 5 mg/kg,均低于中国药典2005版和绿色行业标准的限量标准;铅平均含量为8.356 mg/kg,高于中国药典2005版和绿色行业标准1.67倍,其单项累积污染超标倍数Pe为0.67。用药渣栽种的平菇(试验组)中重金属铅、镉均未检出,说明平菇对药渣中的铅未产生富集现象,铜平均含量为9.199 mg/kg,低于国家食品(蔬菜、食用菌)卫生限量标准,平菇中铜、铅、镉含量是安全的。     

A Nafion-coated bismuth film electrode for the determination of heavy metals in vegetable using differential pulse anodic stripping voltammetry: An alternative to mercury-based electrodes

Mercury electrodes have been traditionally employed for achieving high reproducibility and sensitivity of the stripping technique. However, new alternative electrode materials are highly desired because of the toxicity of mercury. Bismuth is an electrode material characterized by its low toxicity and its ability to form alloys with some metals such as cadmium, lead and zinc, allowing their preconcentration at the electrode surface. In this work, we reported the simultaneous determination of Pb(II), Cd(II) and Zn(II) at the low μg/l concentration levels by differential pulse anodic stripping voltammetry (DPASV) on a Nafion-coated bismuth film electrode (NCBFE) plated in situ, and investigated the application of NCBFE to heavy metals analysis in vegetable samples. The analytical performance of NCBFE was evaluated for simultaneous determination of Pb(II), Cd(II) and Zn(II) in non-deaerated solution, with the limits of determination of 0.30 μg/l for Zn, 0.17 μg/l for Cd and Pb at a preconcentration time of 180 s. High reproducibility for NCBFE was indicated from the relative standard deviations of 2.4% for Pb, 2.0% for Cd and 3.4% for Zn at the 15 μg/l level (n = 15). The NCBFE was successfully applied to determine Pb and Cd in vegetable samples, and the results were in agreement with those of graphite furnace atomic absorption spectrometry (GFAAS).