毛细管区带电泳用于分离分析砷化合物的研究

采用毛细管区带电泳，以磷酸盐为缓冲溶液分离了5种砷的化合物：As（Ⅲ）、DMA、ANA、MMA和As（Ⅴ）．用紫外吸收法在191nm波长下，对实验条件进行了优化；使用扩展光程毛细管研究了实验方法的重现性；测定了各种砷化合物的峰面积与浓度的关系，在最大进样量时测定了检出限，并将该方法用于合成样品的分析．     

毛细管电泳-电感耦合等离子体质谱法测定藻类中6种不同形态的砷化合物

建立了一种利用毛细管电泳与电感耦合等离子体质谱联用技术(CE-ICP-MS)分析检测6种不同形态砷化合物的方法。详细研究了缓冲溶液的种类、pH值和浓度,分离电压以及进样时间等因素对6种砷化合物的分离度、灵敏度和重现性等的影响。结果表明,在最佳条件下,三价砷(As3+)、一甲基砷(MMA)、二甲基砷(DMA)、五价砷(As5+)、砷胆碱(AsC)和砷甜菜碱(AsB)6种化合物在25 min内得到完全分离。6次平行测定中,6种砷化合物峰面积的相对标准偏差(RSD)为3%～5%,检出限(以As计)(3倍信噪比)为0.08～0.12 μg/L。应用该方法成功地对海带中6种砷化合物进行了分析,回收率为90%～103%。该方法具有耗时短、灵敏度高、样品消耗量少、稳定性好等优点,可用于藻类样品中不同形态砷化合物的分析。     

毛细管电泳紫外吸收法分离检测海洋生物样品中不同形态的砷化合物

本研究建立了对亚砷酸盐As(Ⅲ)、二甲基砷(DMA)、对甲基苯砷酸(p-As)、一甲基砷(MMA)、砷酸盐(As(Ⅴ)) 5种不同形态的砷化合物的毛细管区带电泳(CZE)分离紫外检测方法,研究了检测波长、缓冲体系种类、pH值及其浓度、分离电压、温度、进样时间等因素对5种形态砷化合物的分离度、灵敏度、重现性等的影响.结果表明,在25 ℃、195 nm、20 mmol/L NaH2PO4-5 mmol/L Na2B4O7(pH=6.25)缓冲溶液、20 kV运行电压、3.0 kPa压力进样10 s条件下,5种不同形态砷化合物在11 min内取得完全分离,5种不同形态砷化合物的迁移时间和峰面积的RSD为0.50%～1.51%和1.65%～3.36%,检出限(3S/N)为0.004～0.30 mg/L.本法成功地应用于虾米中不同砷形态含量的测定,其回收率在93%～106%之间.     

高效液相色谱-电感耦合等离子体质谱联用测定鸡肉及鸡肝中10种砷形态化合物

建立了一种有效分离检测鸡肉及鸡肝样品中洛克沙砷(ROX)、阿散酸(ASA)、硝苯胂酸(NPAA)、卡巴胂(CBS)、砷酸(AsⅤ)、亚砷酸(AsⅢ)、一甲基胂酸(MMA)、二甲基胂酸(DMA)、砷甜菜碱(As B)和砷胆碱(As C)共10种砷形态化合物的高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析方法。采用10%甲醇为提取液,碳酸铵溶液为流动相,以阴离子分析柱将样品提取液进行分离,最后进行ICP-MS测定。10种砷形态化合物在0.1~100μg/L范围内线性关系良好,相关系数(r2)均大于0.999,检出限为0.3~1.5μg/kg,定量下限为1.0~5.0μg/kg,加标回收率为81.3%~97.7%,相对标准偏差为0.1%~3.5%。该法重现性好、灵敏度高,且采用组织研磨仪机械振荡5 min即可成功提取10种砷形态化合物,与常规水浴加热振荡提取相比更加简便、高效。该法适用于鸡肉及鸡肝样品中10种砷形态化合物的同时检测,通过对实际样品的分析测定,在鸡肝样品中检出阿散酸和亚砷酸。     

离子色谱／氢化物发生／原子吸收法测定天然水中的砷形态

砷酸盐(As(Ⅴ))、亚砷酸盐(As(Ⅲ))、甲基胂酸盐(MMAA)和二甲基胂酸盐(DMAA),是天然水中砷的主要存在形态。本文用离子色谱分离这些砷形态,继以KBH_4还原、原子吸收法检测。分离用国产YSA-Ⅱ型阴离子交换色谱柱来完成。按上述砷形态的顺序,检出限以砷计是0.8μl、0.2μl、0.4μl和0.4μg/L。湖水样及市售矿泉水样的加标回收率为93.2％～107.5％。给出上述水样中砷形态的分析结果。     

高分辨ICP-MS测定涂料中痕量砷形态分布的研究

为建立高分辨率电感耦合等离子体质谱法(HR-ICP-MS)测定涂料中砷化合物形态分布的分析方法,应用离子交换树脂和溶剂萃取相结合的分离技术分离涂料中As(Ⅲ)、As(Ⅴ)、MMA(甲基胂酸)、DMA(二甲基胂酸)等4种砷化合物,试液直接用HR-ICP-MS法同时测定上述4种砷化合物,在高分辨质谱测量模式下避免了大量的质谱干扰,考察了采用内标元素对基体效应的校正,应用标准加入法进行定量分析,确定了实验的最佳测定条件。结果表明,方法的检出限为0.002μg/g,样品的加标回收率为98.2%～104.2%,相对标准偏差为0.72%～2.61%。该法具有简单、快速、准确等优点,应用涂料中砷化合物的4种不同形态砷的测定,结果满意。     

水生生物中砷的提取和形态分析的研究进展

综述了水生生物中不同形态砷(包括无机砷、甲基砷、砷甜菜碱、砷胆碱、砷糖、砷脂)的提取方法、分离方法(包括气相色谱法、高效液相色谱法、毛细管电泳法等)和检测方法(包括原子吸收光谱法、原子发射光谱法、原子荧光光谱法、电感耦合等离子体质谱法等)的研究进展,并对其前景进行了简要展望(引用文献74篇)。     

树脂分离-氢化物发生-原子荧光光谱法测定食品中无机砷、一甲基胂和二甲基胂

建立了用阴离子交换树脂分离-氢化物发生原子荧光光谱法测定食品中无机砷、一甲基胂和二甲基胂的方法.分别从样品上样条件及二甲基胂、一甲基胂、 As(Ⅲ)和As(Ⅴ)分离条件进行了优化.研究了树脂处理程序对分离的影响,并探讨了共存离子对测定砷的干扰和消除的方法.对方法的适用范围做了研究.本方法具有操作简便、快速、灵敏度高等优点.检出限(以砷计)分别为: 无机砷0.34 μg/L,一甲基胂0.57 μg/L,二甲基胂0.46 μg/L.     

毛细管电泳法同时测定化妆品中氢醌、苯酚和防腐剂

采用毛细管电泳法对化妆品中氢醌、苯酚、山梨酸和苯甲酸进行了分离研究,考察了缓冲溶液的种类和pH值对分离的影响.以15 mmol/L硼砂(pH 9.2)为电泳缓冲液,采用压力进样方式,在20 kV恒压下进行分离,并在波长240 nm处检测,各组分可达到基线分离.4种标样在0.5～ 100.0 mg/L范围内呈良好线性关系...     

高效液相色谱-电感耦合等离子体-串联质谱法同时测定饲料中As(Ⅲ)、As(Ⅴ)、氨苯胂酸和洛克沙胂

建立了饲料中As(Ⅲ)、As(Ⅴ)、氨苯胂酸(p-ASA)和洛克沙胂(ROX)不同形态砷的高效液相色谱-电感耦合等离子体-串联质谱(HPLC-ICP-MS/MS)检测方法。样品经甲醇-水(1∶1,V/V)超声提取,用Shiseido MGⅡC18色谱柱(250×4.6 mm,5μm)对4种砷形态进行分离,以pH=4.7的6mmol/L四丁基氢氧化铵(TBAH)-甲醇(92∶8,V/V)溶液及pH=1.9的0.05%三氟乙酸(TFA)-甲醇(92∶8,V/V)溶液为流动相进行梯度洗脱。然后通过电感耦合等离子体质谱进行监测,外标法定量。结果表明,在优化的实验条件下,各形态砷在0~50μg/L范围内线性良好(R≥0.9999),As(Ⅲ)、As(Ⅴ)、氨苯胂酸(p-ASA)和洛克沙胂(ROX)的检测限分别为0.05、0.10、0.08、0.60μg/L,4种形态砷的加标回收率范围在85.9%~104.6%之间,相对标准偏差(RSD)均小于5%。通过对实际样品的检测,该方法适用于饲料中常见形态砷的检测。     

Advances in arsenic speciation techniques

The present review describes the speciation techniques of arsenic. The principal advanced techniques discussed are gas chromatography, reversed-phase liquid chromatography, ion chromatography, capillary electrophoresis. Some other techniques are also mentioned. The extraction procedures of arsenic species from unknown samples are also discussed. Arsenic speciation is summarized in tabular form and optimizing parameters are also discussed.     

Separation of arsenic species by capillary electrophoresis with sample-stacking techniques

A simple capillary zone electrophoresis procedure was developed for the separation of arsenic species (AsO(2)(2-), AsO(4)(2-), and dimethylarsinic acid, DMA). Both counter-electroosmotic and co-electroosmotic (EOF) modes were investigated for the separation of arsenic species with direct UV detection at 185 nm using 20 mmol L(-1) sodium phosphate as the electrolyte. The separation selectivity mainly depends on the separation modes and electrolyte pH. Inorganic anions (Cl(-), NO(2)(-), NO(3)(-) and SO(4)(2-)) presented in real samples did not interfere with arsenic speciation in either separation mode. To improve the detection limits, sample-stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were investigated for the preconcentration of As species in co-CZE mode. Less than 1 micromol L(-1) of detection limits for As species were achieved using FASI. The proposed method was demonstrated for the separation and detection of As species in water.     

土壤中砷形态分析研究进展

本文评述了近年来国内外土壤中砷形态分析的主要研究方法,包括联用分析法、分级提取法和同步辐射X-射线线吸收光谱法。联用分析法包括气相色谱联用法、毛细管电泳联用法和高效液相色谱联用法。重点介绍了目前应用范围较广的高效液相色谱-等离子体质谱(HPLC-ICP-MS)联用法和高效液相色谱-氢化物发生-原子荧光光谱(HPLC-HG-AFS)联用法。同步辐射X-射线线吸收光谱法近几年发展迅速,是最具发展潜力的形态分析方法。     

Field Enhanced Sample Injection for the CE Determination of Arsenic Compounds Using Successive Multiple Ionic Polymer Layer Coated Capillaries

A capillary electrophoresis method using indirect UV detection has been applied to the determination of arsenate [As(V)], arsenite [As(III)], monomethylarsonic acid and dimethylarsinic acid. The arsenic species were successfully separated in a successive multiple ionic polymer layer coated capillary. On-line sample preconcentration of arsenic compounds were performed by employing field enhanced sample injection. A baseline separation was achieved in a basic background solution of 10 mM 2,6-pyridinedicarboxylic acid at pH 10.3. The precision of migration time was 1.2–2.4% RSD and peak height was 8.1–12.9% RSD. The limits of detection at a S/N ratio of 3 for the four arsenic compounds were found to be 20–70 ppb, which are comparable to other on-line preconcentration techniques. The enhancement factor was improved by 230–1,500-fold.

     

Field Enhanced Sample Injection for the CE Determination of Arsenic Compounds Using Successive Multiple Ionic Polymer Layer Coated Capillaries

A capillary electrophoresis method using indirect UV detection has been applied to the determination of arsenate [As(V)], arsenite [As(III)], monomethylarsonic acid and dimethylarsinic acid. The arsenic species were successfully separated in a successive multiple ionic polymer layer coated capillary. On-line sample preconcentration of arsenic compounds were performed by employing field enhanced sample injection. A baseline separation was achieved in a basic background solution of 10 mM 2,6-pyridinedicarboxylic acid at pH 10.3. The precision of migration time was 1.2–2.4% RSD and peak height was 8.1–12.9% RSD. The limits of detection at a S/N ratio of 3 for the four arsenic compounds were found to be 20–70 ppb, which are comparable to other on-line preconcentration techniques. The enhancement factor was improved by 230–1,500-fold.     

Analysis and Speciation of Traces of Arsenic in Environmental,Food and Industrial Samples by Voltammetry: a Review

Voltammetric approaches for the determination of arsenic and speciation at trace levels are critically appraised in a review covering the literature from 1970 to 2002. Special attention is devoted to stripping modes and to issues related to the choice of working material and supporting electrolyte. A section is dedicated to the management of real samples and aspects of sample preparation. An extensive compilation, organized by real sample type, gathers essential experimental conditions. Potentiometric stripping analysis is introduced for sake of comparison. The coupling of voltammetric detection or preaccumulation with FIA, chromatography, capillary electrophoresis and ICP techniques is also addressed.     

Speciation of arsenic compounds in fish and oyster tissues by capillary electrophoresis-inductively coupled plasma-mass spectrometry

A capillary electrophoresis-inductively coupled plasma-mass spectrometric (CE-ICP-MS) method for the speciation of six arsenic compounds, namely arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid, dimethylarsinic acid, arsenobetaine and arsenocholine is described. The separation has been achieved on a 70 cm length x 75 microm ID fused-silica capillary. The electrophoretic buffer used was 15 mM Tris (pH 9.0) containing 15 mM sodium dodecyl sulfate (SDS), while the applied voltage was set at +22 kV. The arsenic species in biological tissues were extracted into 80% v/v methanol-water mixture, put in a closed centrifuge tube and kept in a water bath, using microwaves at 80 degrees C for 3 min. The extraction efficiencies of individual arsenic species added to the sample at 0.5 microg As/g level were between 96% and 107%, except for As(III), for which it was 89% and 77% for oyster and fish samples, respectively. The detection limits of the species studied were in the range 0.3-0.5 ng As/mL. The procedure has been applied for the speciation analysis of two reference materials, namely dogfish muscle tissue (NRCC DORM-2) and oyster tissue (NIST SRM 1566a), and two real-world samples.     

毛细管电泳用于形态分析

一种元素的生物可给性、环境行为和迁移性在很大程度上取决于它的形态。如不同的键合形式或氧化态，因此，作为元素物种鉴别和含量测定的形态分析变得越来越重要。毛细管电泳作为一种分离分析技术有许多优点可以满足形态分析的要求。本文从样品的预处理、毛细管电泳的修饰、进样方式、分离模式和检测等几个方面评述了毛细管电泳在形态分析中的应用。     

Fast separations by capillary electrophoresis hyphenated to electrospray ionization time-of-flight mass spectrometry as a tool for arsenic speciation analysis

Fast capillary electrophoresis (CE) hyphenated to time-of-flight mass spectrometry (TOF-MS) of four organoarsenic species (glycerol oxoarsenosugar, sulfate oxoarsenosugar, arsenobetaine, arsenocholine) are presented using short length CE capillaries under high electric field strengths of up to 1.3 kV cm(-1) with small inner diameter (ID). The separation of arsenosugars by CE is demonstrated for the first time. An aqueous formic acid solution was employed as the background electrolyte (BGE) for the separation. Various acid concentrations were evaluated for their influence on migration times, separation efficiency as well as with regard to controlling the charge of the arsenic species. A 0.1 M formic acid/ammonium formate buffer (pH 2.8) proved to be suitable for the separation of the four species. A non-aqueous BGE was tested as an alternative buffer system for fast speciation analysis. Separation of arsenobetaine and arsenocholine could even be achieved within 10 s by pressure-assisted CE. Application of the optimized method for the analysis of extracts of a seagrass and a Wakame algae sample as well as the brown algae homogenate reference material IAEA-140/TM revealed a clear signal for the glycerol arsenosugar.     

Determination of arsenic species in Solanum Lyratum Thunb using capillary electrophoresis with inductively coupled plasma mass spectrometry

A simple and highly efficient interface to couple capillary electrophoresis with inductively coupled plasma mass spectrometry by a microflow polyfluoroalkoxy nebulizer and a quadruple ion deflector was developed in this study. By using this interface, six arsenic species, including arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, and arsenocholine, were baseline‐separated and determined in a single run within 11 min under the optimized separation conditions. The instrumental detection limit was in the range of 0.02–0.06 ng/mL for the six arsenic compounds. Repeatability expressed as the relative standard deviation (n = 5) of both migration time and peak area were better than 2.5 and 4.3% for six arsenic compounds. The proposed method, combined with a closed‐vessel microwave‐assisted extraction procedure, was successfully applied for the determination of arsenic species in the Solanum Lyratum Thunb samples from Anhui province in China with the relative standard deviations (n = 5) ≤4%, method detection limits of 0.2–0.6 ng As/g and a recovery of 98–104%. The experimental results showed that arsenobetaine was the main speciation of arsenic in the Solanum Lyratum Thunb samples from different provinces in China, with a concentration of 0.42–1.30 μg/g.