联用技术测定富硒农产品中硒的形态研究进展

硒的营养功能与农产品硒的形态息息相关。联用技术作为元素形态分析的有效方法,近年来受到了人们广泛关注。对用联用技术测定富硒农产品中硒的形态研究现状及进展进行了综述,包括前处理技术、色谱分离技术和定量检测方法等3个方面。     

联用技术在植物硒形态分析中的应用

介绍了植物中硒形态分析的意义,植物中硒存在的形式;综述了植物中硒形态分析时,采用的萃取、液相色谱、气相色谱、电泳和毛细管电泳等样品分离技术;电感耦合等离子体质谱、同位素稀释-质谱、电感耦合原子发射光谱及电喷雾质谱分析方法,引用文献51篇.     

农产品中硒元素的提取和形态分析进展

综述了农产品中硒元素形态组分的提取、分离富集以及检测技术的进展。样品前处理提取的方法主要采取水、稀酸等介质提取无机硒，使用有机试剂等介质以及酶法的提取，能较好的提取各种形态有机硒。分离富集技术主要集中在共沉淀法、离子交换法、气相色谱、液相色谱、毛细管电泳等手段。关于硒元素各种形态的检测联用是未来发展的趋势，目前研究主要集中在高效液相色谱-电感耦合等离子体质谱联用技术、高效液相色谱-氢化物发生-原子荧光联用技术、毛细管电泳-电感耦合等离子体质谱联用技术等方面。最后对农产品中硒元素的提取方法及形态分析的发展趋势进行了总结和展望。     

砷形态分析的研究进展

综述了砷的提取、分离和检测方法的研究进展。主要包括超声提取法、微波辅助提取法、固相萃取法等常用的提取方式;分别用于水样和海产品中砷的富集的共沉淀法和毛细管电泳法;以及高效液相色谱-电感耦合等离子体-质谱法、高效液相色谱-氢化物发生-原子吸收光谱法、氢化物发生-电感耦合等离子体-原子发射光谱法等用于砷形态分析的分离和检测方法(引用文献56篇)。     

高灵敏度原子荧光光谱系统应用于砷、硒形态分析的研究

将实验室自制的高灵敏度原子荧光光谱系统与色谱分离、在线紫外光前处理装置联用,实现了元素形态的液相色谱分离、在线紫外消解、蒸气发生及原子荧光光谱测定,并以砷、硒两元素为例对系统的分析性能进行研究。样品通过加热混旋提取、离心、过滤,使用反相色谱柱并以5.0 mmol/L磷酸氢二铵缓冲溶液(pH 5.7)-0.5 mmol/L四丁基溴化铵(TBAB)-1%甲醇为流动相进行分离;三价砷(AsO3-3)、二甲基砷(DMA)、一甲基砷(MMA)、五价砷(AsO3-4)可在7 min内进行分离和测定,硒代胱氨酸(SeCys)、硒代蛋氨酸(SeMet)、四价硒(SeO2-3)、六价硒(SeO2-4)的测定约需11 min。在优化实验条件下,方法检出限(DLs,S/N=3)为0.08~0.74μg/L;相对标准偏差(RSD,n=7)为1.4%~7.9%,实际样品的加标回收率为82.5%~116.5%;砷、硒各形态在0.28~40.0μg/L和0.38~80.0μg/L范围内线性良好。建立的联用系统稳定性好、检出限低,可实现样品中低浓度砷、硒形态的准确测定。     

高效液相色谱-原子荧光光谱联用技术测定富硒鸡蛋中的硒形态

为监测市场上富硒鸡蛋中蛋清及蛋黄中硒形态的种类及分布规律,优化建立了一种高效液相色谱-氢化物发生-原子荧光光谱联用技术测定富硒鸡蛋蛋清及蛋黄粉中硒形态的方法。随机选取富硒鸡蛋样品,进行蛋清蛋黄分离、冷冻干燥及蛋黄脱脂处理,处理后样品经Tris-HCl缓冲液（5 mmol/L, pH=7.5）55 oC恒温振荡、酶解提取,高速离心机（10000 r/min）离心10 min,上清液过0.22 μm有机滤膜后采用高效液相色谱-氢化物发生-原子荧光光谱联用技术进行测定,外标法定量。结果表明,该方法能在11 分钟内实现5种硒形态的基线分离,且各种硒形态的线性相关系数(r)均大于0.9994,其检出限在0.5-3.0 μg/L之间,回收率在81.6%~110.4%之间,可以满足检测需求,按照该实验方法测定市场上富硒鸡蛋中的硒形态,方法灵敏度高、准确性好,且测得的富硒鸡蛋蛋清样品中硒形态主要成分为硒代蛋氨酸,而蛋黄样品主要成分为硒代半胱氨酸,还有少量的硒代蛋氨酸,同时,一些鸡蛋还含有极少量的亚硒酸根,但蛋清及蛋黄中硒代氨基酸的含量总和占总硒含量的83.3-98.4%,适用于富硒鸡蛋中的硒形态提取。由此可见,市场上富硒鸡蛋中的硒主要以硒代氨基酸的形式存在,比较适合日常补硒,且该方法可以对市场上富硒食品起到一定监测作用。     

硒的分析概况

对硒分析方法进行了综述,共分硒的分析分离方法,硒的定量法两大部分。硒的分析和分离方法中,介绍了硒的分析方法及分类,硒样品采集与前处理,分离方法。硒的定量法中介绍了重量法、容量法、分光光度法、荧光法、原子吸收分光光度法、原子发射光谱法、极谱法、中子活化分析法、气相色谱法、液相色谱法等。每一分析法中介绍了测定法研究及应用实例 。本文参考了137篇有关硒与硒分析法资料。     

环境水样中硒形态分析的样品预处理

综述了近几年来测定环境水样中硒的样品前处理方法,主要包括样品消解,加入基体改进剂和分离富集3个方面。消解法中主要使用湿法消解;加入基体改进剂适用于石墨炉原子吸收光谱法的样品预处理,可以提高硒的灰化温度,减少硒的损失以及样品中基体的干扰;固相萃取法是萃取法的主要使用手段。     

植物样品中痕量砷的形态分析研究进展

介绍了近十年来国内外植物样品中包括药用植物中砷的形态分析研究进展。由于植物中的砷含量甚低,其主要的检测手段是:氢化物电感耦合等离子体原子吸收光谱法(HG-ICP-AAS)、高效液相色谱-等离子体质谱法(HPLC-ICP-MS)、氢化物原子荧光光谱法(HG-AFS)。     

铬形态分析的分离富集/原子光谱分析研究进展

综述了铬形态分析的分离富集／原子光谱分析研究进展,详细讨论了铬的存在形态、铬形态分析中的样品前处理方法、分离富集／原子光谱检测技术及应用。     

Pretreatment procedures for characterization of arsenic and selenium species in complex samples utilizing coupled techniques with mass spectrometric detection

Research interest in analyzing arsenic and selenium is dictated by their species-dependent behavior in the environment and in living organisms. Different analytical methodologies for known species in relatively simple chemical systems are well established, yet the analysis of complex samples is still a challenge. Owing to the complex matrix and low concentrations of target species that may be chemically labile, suitable pretreatment of the sample becomes a critical step in any speciation procedure. In this paper, the pretreatment procedures used for arsenic and selenium speciation are reviewed with the emphasis on the link between the analytical protocol applied and the biologically-significant information provided by the results obtained. In the first approach, the aim of pretreatment is to convert the original sample into a form that can be analyzed by a coupled (hyphenated) technique, preventing possible losses and/or species interconversion. Common techniques include different leaching and extraction modes, enzymatic hydrolysis, species volatilization, and so on, with or without species preconcentration. On the other hand, if the speciation analysis is performed for elucidation of elemental pathways and specific functions in a living system, more conscious pretreatment and/or fractionation is needed. The macroscopic separation of organs and tissues, isolation of certain types of cells, cell disruption and separation of sub-cellular fractions, as well as isolation of a specific biomolecules become important. Furthermore, to understand molecular mechanisms, the identification of intermediate—often highly instable—metabolites is necessary. Real life applications are reviewed in this work for aquatic samples, soils and sediments, plants, yeast, and urine.     

HPLC-ICP-MS在食品中硒和砷形态分析及其生物有效性研究中的应用

食品中含有与人体健康密切相关的多种微量元素,微量元素的毒性和生物有效性取决于它们的化学形态。食品中的微量元素形态分析及其生物有效性研究对食品安全控制与营养评价具有至关重要的意义。本文扼要介绍了高效液相色谱与电感耦合等离子质谱（HPLC-ICP-MS）联用情况,该技术以不同的色谱分离柱完成各种分析物的分离,具有高灵敏度、高选择性、线性范围宽、检测限低、多元素同时检测等特点,在微量元素形态分析中占有重要的地位。综述了HPLC-ICP-MS在食品微量元素形态分析及其生物有效性研究中的应用,重点介绍了富硒酵母、蒜类植物、富硒营养保健品等食品中硒形态和海产品、农产品等食品中砷形态的研究,以及其它多种微量元素的形态分析和这些微量元素在生物体内的代谢。     

高效液相色谱/电感耦合等离子体质谱联用技术用于元素形态分析的研究进展

介绍了高效液相色谱与电感耦合等离子体质谱（HPLC－ICP－MS）联用技术在环境、材料和生命科学样品的元素形态分析中的研究进展，着重介绍该联用方法的接口技术及几种与ICP－MS联用的主要色谱类型，阐述了几种样品预处理方法，并对样品引入系统、复杂基体分离和元素形态定量和结构分析等联用技术在元素形态分析中所面临的问题进行讨论。     

Separation and Detection of Arsenic and Selenium Species in Environmental Samples by HPLC-ICP-MS

A method is presented for arsenic speciation analysis of an oyster sample using ion chromatography coupled with an inductively coupled plasma mass spectrometry (ICP-MS) instrument. A strong anion exchange resin was employed with a step gradient elution of 0.1 mM/0.1 M K 2 SO 4 at pH 10.2. Arsenobetaine and dimethylarsinic acid were determined following extraction based on trypsin enzymolysis with 95-100% extraction efficiency. Limits of detection in the range 0.1-0.3 mg kg m 1 of arsenic were obtained for organic arsenic species. No inorganic arsenic was detected. Validation was performed using TORT-2 as a certified reference material. Although high performance liquid chromatography (HPLC) coupled to ICP-MS is an effective method for speciation analysis it is not always necessary to obtain such a detailed picture. A simple liquid chromatographic separation technique based upon mini-column technology is presented. It was developed to obtain a fast, efficient and reliable separation of inorganic from organic, i.e. assumed toxic from non-toxic, arsenic and selenium species suitable for use as an initial screening method for environmental analysis. Two types of strong anion exchange resin were tested. Excellent separation was obtained for both min-column resins and analysis times were within 7 min. Limits of detection obtained for inorganic arsenic, organic arsenic, selenomethionine, Se IV and Se VI were 1.6, 1.8, 66, 32 and 22 µg kg m 1 , respectively.     

Non-chromatographic hydride generation atomic spectrometric techniques for the speciation analysis of arsenic,antimony, selenium,and tellurium in water samples—a review

Hydride generation (HG) coupled with AAS, ICP–AES, and AFS techniques for the speciation analysis of As, Sb, Se, and Te in environmental water samples is reviewed. Careful control of experimental conditions, offline/online sample pretreatment methods employing batch, continuous and flow-injection techniques, and cryogenic trapping of hydrides enable the determination of various species of hydride-forming elements without the use of chromatographic separation. Other non-chromatographic approaches include solvent extraction, ion exchange, and selective retention by microorganisms. Sample pretreatment, pH dependency of HG, and control of NaBH₄/HCl concentration facilitate the determination of As(III), As(V), monomethylarsonate (MMA), and dimethylarsinate (DMA) species. Inorganic species of arsenic are dominant in terrestrial waters, whereas inorganic and methylated species are reported in seawater. Selenium and tellurium speciation analysis is based on the hydrides generation only from the tetravalent state. Se(IV) and Se(VI) are the inorganic selenium species mostly reported in environmental samples, whereas speciation of tellurium is rarely reported. Antimony speciation analysis is based on the slow kinetics of hydride formation from the pentavalent state and is mainly reported in seawater samples.     

A new HG/LT-GC/ICP-MS multi-element speciation technique for real samples in different matrices

An improved speciation technique is presented for metal(loid)organic compounds, enabling identification and quantification of species from twelve elements: germanium, arsenic, selenium, molybdenum, tin, antimony, tellurium, iodine, tungsten, mercury, lead and bismuth. At this time it is possible to identify 29 species with boiling points between –88.5?°C and 250?°C in gaseous, liquid and solid samples in a few minutes. This study shows as an example results from measurements of soil samples from municipal waste deposits. The HG/LT-GC/ICP-MS-(hydride generation/low temperature-gas chromatography/inductively coupled plasma-mass spectrometry) apparatus contains a home-built gas chromatograph that enables satisfactory separation of various species with a boiling point difference of ≥ 14?°C. The absolute detection limits for the elements mentioned above were below 0.7 pg.     

A new HG/LT-GC/ICP-MS multi-element speciation technique for real samples in different matrices

An improved speciation technique is presented for metal(loid)organic compounds, enabling identification and quantification of species from twelve elements: germanium, arsenic, selenium, molybdenum, tin, antimony, tellurium, iodine, tungsten, mercury, lead and bismuth. At this time it is possible to identify 29 species with boiling points between -88.5 degrees C and 250 C in gaseous, liquid and solid samples in a few minutes. This study shows as an example results from measurements of soil samples from municipal waste deposits. The HG/LT-GC/ICP-MS-(hydride generation/low temperature-gas chromatography/inductively coupled plasma-mass spectrometry) apparatus contains a home-built gas chromatograph that enables satisfactory separation of various species with a boiling point difference of > or = 14 degrees C. The absolute detection limits for the elements mentioned above were below 0.7 pg.     

Analysis of selenium species by capillary electrophoresis

The presence of selenium in the form of different species in environmental and biological samples receives an increasing attention due to better understanding of its bioavailability, toxicity and transport mechanism. For many years, gas and liquid chromatography have been extensively explored in speciation analysis of this element. Recently, capillary electrophoresis (CE) has made much progress in this field. This review presents the developments in the application of CE for simultaneous separation and determination of different selenium compounds. Various separation approaches and detection methods as well as pre-concentration techniques are discussed. The speciation performance of CE is illustrated by a number of practically relevant applications.     

Determination of inorganic arsenic species As(III) and As(V) by high performance liquid chromatography with hydride generation atomic absorption spectrometry detection

The paper presents the principles and advantages of a technique combining high performance liquid chromatography and hydride generation atomic absorption spectrometry (HPLC-HGAAS) applied to speciation analysis of inorganic species of arsenic As(III) and As(V) in ground water samples. With separation of the arsenic species on an ion-exchange column in the chromatographic system and their detection by the hydride generation atomic absorption spectrometry, the separation of the analytical signals of the arsenic species was excellent at the limits of determination of 1.5 ng/ml As(III) and 2.2 ng/ml As(V) and RSD of 4.3% and 7.8% for the concentration of 25 ng/ml. The hyphenated technique has been applied for determination of arsenic in polluted ground water in the course of the study on migration of micropollutants. For total arsenic concentration two independent methods: HGICP-OES and HGAAS were used for comparison of results of real samples analysis.