磷酸提取-高效液相色谱-氢化物发生原子荧光光谱法分析垃圾焚烧飞灰中无机砷形态

以H3PO4为提取剂,通过微波提取的方法,采用高效液相色谱-氢化物发生原子荧光光谱联用技术(HPLC-HG-AFS)实现了垃圾焚烧飞灰中砷的价态测定.重点探究了H3PO4存在下,使用HPLC-HG-AFS测定无机砷(As(Ⅲ)和As(Ⅴ))价态的色谱条件.结果表明,当使用(NH4)2HPO4为流动相时,H3PO4的存在会对As(Ⅴ)的分析造成不利影响,增大流动相流速对改善这种状况几乎没有效果;而使用Na2HPO4-KH2PO4混合溶液(pH 6.864)作为流动相时,可以显著降低H3PO4对As(Ⅴ)分析的干扰.在优化的色谱条件下,As(Ⅲ)和As(Ⅴ)可在5 min内实现分离,检出限分别为0.063和0.110 μg/L.在标准物质加标回收实验中,各价态回收率良好(86.5％～102.5％).利用本方法对来自4个垃圾焚烧电厂的飞灰样品进行分析,发现垃圾焚烧飞灰中的砷主要以As(Ⅴ)的形式存在.     

氢化物发生原子荧光结合计算法测定大气颗粒物中砷的形态

运用碱式消解法对样品进行前处理,采用氢化物发生-原子荧光光谱数学计算法测定大气颗粒物中As(Ⅲ)和As(Ⅴ)的含量。探讨了还原剂用量、酸介质及其酸度、载气及屏蔽气流量和观测高度等对荧光强度的影响,分析了共存离子对砷测定的干扰。在选定的最佳条件下,得到检出限为0.34μg/L,加标回收率为87.8%～108.2%。方法可用于测定大气颗粒物中不同形态的砷。     

HPLC-HG-AFS测定大气颗粒物中砷的形态

采用高效液相色谱-氢化物发生原子荧光光谱联用测定了北京大气颗粒物中As(III),As(Ⅴ),二甲基砷酸(DMA)和一甲基砷酸(MMA)的含量。研究了仪器条件、流动相组成和梯度洗脱程序对砷形态分离的影响。实验结果显示,在优化的色谱与氢化原子荧光检测条件下,采用pH6.0,浓度为10 mmol/L和200 mmol/L NH4H2PO4为流动相A和B,在1~3 min内用60%的A和40%的B洗脱使砷的4种形态达到最佳分离效。As(III),As(Ⅴ),DMA和MMA的检出限为1.45,1.22,1.91和1.64 mg/L,回收率为90.5%~93.2%,相对标准偏差为0.38%~1.7%。方法适用于大气颗粒物中砷的形态分析研究。     

高效液相色谱-氢化物发生-原子荧光光谱法检测紫菜中的砷形态

测定了4种中国紫菜样品的总砷含量并且分析了紫菜中的砷形态。紫菜经电热消解、ICP-AES测定,总砷含量为14.0～42.1 mg/kg。以高效液相色谱-氢化物发生-原子荧光光谱法(HPLC-(UV)-HG-AFS)测定紫菜中的5种砷形态。紫菜样品都检测出了DMA(0.196～0.668 mg/kg),但没有检测出As(III),As(V),MMA和AsB,紫菜砷的形态主要是砷糖。     

离子色谱-氢化物发生原子荧光光谱联用技术在砷形态分析中的应用

建立了离子色谱-氢化物发生原子荧光光谱联用分离4种常见有毒砷化合物的方法. 二者通过内径0.25 mm的PEEK管直接相连. 实验对影响分离度和测定灵敏度的参数进行了优化. 在优化条件下, 质量浓度均为50 μg/L的4种砷化合物混合标准溶液平行7次进样, 得到DMA、 As(Ⅲ)、 MMA和As(Ⅴ)的色谱峰面积的相对标准偏差(RSD)为2.8～3.0%. 250 μL进样的线性范围为5～1000 μg/L, 检出限为0.8～1.2 μg/L (三倍基线噪音峰高). 用建立的方法测定了砷处理后的水稻木质部伤流液中的砷量, 4种砷化合物的加标回收率为89%～105%. 该装置接口简单, 方法分离度好, 灵敏度高, 可用于实际样品中痕量砷化合物的形态分析.     

HPLC-AFS联用测定海产品中砷的形态

建立了高效液相色谱-原子荧光分光光度法测定海产品中无机砷(As V,AsⅢ)、有机砷(DMA,MMA,AsB)含量的方法.样品经含10％(体积分数)HC1的提取液振荡提取、离心分离、二路形态分析预处理、高效液相色谱分离,用原子荧光光度计检测As(Ⅲ),DMA,MMA,As(v);四路条件(过氧化氢氧化和开启紫外灯)形态分析预处理装置处理,高效液相色谱分离,原子荧光光度计测定AsB.As(Ⅲ)线性范围为0～100.00 μg/L,r2=0.9997;DMA线性范围为0～100.00 μg/L,r2=0.9993;MMA线性范围为0～100.00 μg/L,r2=0.9990;As(Ⅴ)线性范围为0～100.00 μg/L,r2=0.999 1;AsB线性范围为0～200.00 μg/L,,r2=0.9994.3个样品加标回收率为As(Ⅲ)86.7％～89.4％,DMA 111.2％～117.0％,MMA 109.7％～111.6％,As(Ⅴ) 83.8％～90.7％,AsB 88.3％～90.4％.用该方法测定虾仁(干)5个价态测定结果的相对标准偏差为3.07％～9.93％(n=6).5个价态的检出限(S/N=2)为As(Ⅲ)0.29 μg/L,DMA 0.36 μg/L,MMA 0.27 μg/L,As(V) 0.56 μg/L,AsB l.46 μg/L.该方法适用于海产品中As(Ⅲ),DMA,MMA,As(V),AsB含量的测定.     

微波辅助提取-液相色谱-氢化物发生-原子荧光光谱法分析沉积物中砷的形态

采用微波辅助提取-液相色谱-氢化物发生-原子荧光光谱法(LC-HG-AFS)联用技术分析了太湖沉积物中砷的形态[亚砷酸(As(III))、二甲基砷酸钠(DMA)、一甲基砷酸二钠(MMA)和砷酸As(V)]。测得沉积物中以无机砷为主,且以As(V)居多。选定以1mol/L的磷酸和0.1mol/L抗坏血酸为提取液,在微波辅助萃取(功率为60W,时间12min)下,萃取率达79.84%～91.57%,回收率在94.78%～107.6%之间。4种砷的形态在0～160μg/L之间时线性良好,检测限为0.6～2.3μg/L,相对标准偏差RSD为1.62%～2.20%。方法具有简便、快速、灵敏的特点。     

大气颗粒物中砷及其形态的研究进展

大气颗粒物中毒性准金属元素砷及其形态含量变化引起的环境健康问题受到了广泛关注。由于工业生产和煤燃烧等人类活动,砷普遍存在于多种环境介质中。排放到大气中的砷能够随气流进行长距离迁移,致使一些偏远区域大气中的砷含量明显超出欧盟的限制标准(6 ng/m3)。砷的毒性表达很大程度依赖其存在种态,无机砷毒性大于有机砷,且砷(Ⅲ)的毒性明显强于砷(Ⅴ)。本文概述了大气中砷的来源,并选取自2000年来的代表性成果比较了不同国家及不同功能区大气砷的含量变化,同时对1975年来多数关于大气颗粒物中砷形态变化特征的研究进行了评述。     

HPLC–AFS联用测定海产品中砷的形态

建立了高效液相色谱–原子荧光分光光度法测定海产品中无机砷(As V,AsⅢ)、有机砷(DMA,MMA,AsB)含量的方法。样品经含10%(体积分数)HCl的提取液振荡提取、离心分离、二路形态分析预处理、高效液相色谱分离,用原子荧光光度计检测As(Ⅲ),DMA,MMA,As(V);四路条件(过氧化氢氧化和开启紫外灯)形态分析预处理装置处理,高效液相色谱分离,原子荧光光度计测定AsB。As(Ⅲ)线性范围为0～100.00μg/L,r2=0.999 7;DMA线性范围为0～100.00μg/L,r2=0.999 3;MMA线性范围为0～100.00μg/L,r2=0.999 0;As(V)线性范围为0～100.00μg/L,r2=0.999 1;AsB线性范围为0～200.00μg/L,r2=0.999 4。3个样品加标回收率为As(Ⅲ)86.7%～89.4%,DMA 111.2%～117.0%,MMA 109.7%～111.6%,As(V)83.8%～90.7%,AsB 88.3%～90.4%。用该方法测定虾仁(干)5个价态测定结果的相对标准偏差为3.07%～9.93%(n=6)。5个价态的检出限(S/N=2)为As(Ⅲ)0.29μg/L,DMA 0.36μg/L,MMA 0.27μg/L,As(V)0.56μg/L,AsB 1.46μg/L。该方法适用于海产品中As(Ⅲ),DMA,MMA,As(V),AsB含量的测定。     

液相色谱-氢化物发生/原子荧光法测定啤酒中砷的形态

采用液相色谱-氢化物发生/原子荧光(LC-HG/AFS)联用技术测定了啤酒中砷的形态.优化了氢化物发生的实验条件,当以10％的盐酸为载流,3.5％的KBH4为还原剂,流量为500 mL/min的氩气作为载气时,取得了较好的信号强度;以20 mmol/LKH2PO4-K2 HPO4(pH=6.0,流速1 mL/min)为...     

超声萃取-高效液相色谱-串联质谱法测定大气颗粒物中甾醇类化合物

采用超声萃取与液相色谱-串联质谱联用,建立了快速测定大气颗粒物中甾醇类化合物的方法.甾醇类化合物用甲醇超声萃取,浓缩后使用液相色谱-串联质谱分析.采用Waters公司Atlantis C18色谱柱(100mm× 2.1 mm,3μm),以乙腈和水混合流动相梯度洗脱,实现了胆甾醇、豆甾醇、菜油甾醇及β-谷甾醇的分离.并在APCI-MS/MS MRM模式下定量检测.在选取的实验条件下,方法回收率在80.3％～97.7％之间,检出限0.015 ng/m3,相对标准偏差小于15％,日内及日间测定精密度小于20％.本方法具有较好的准确性及精密度,实际样品的测试结果表明,方法可以满足大气颗粒物中甾醇类化合物的定量分析要求.     

鱿鱼丝中砷的形态分析

采用电感耦合等离子体-质谱(ICP-MS)测定了14种鱿鱼丝(Dried Shredded Squid,DSS)中的砷总量,发现14种鱿鱼丝中的砷总量均低于2μg.g-1;用高效液相色谱(HPLC)与ICP-MS联用技术建立了As(Ⅲ)、As(Ⅴ)、二甲基胂酸(DMA)、甲基胂酸(MMA)、砷甜菜碱(AsB)和砷胆碱(AsC)六种砷形态的分离分析方法;采用快速溶剂萃取(ASE)、超声溶剂提取(SON)和盐酸浸提三种不同的前处理方法分析了3种鱿鱼丝中的砷形态,发现鱿鱼丝中的砷主要以AsB形式存在。     

氢化物发生-原子荧光光谱法测定中草药中不同形态的砷

本文建立了氢化物发生-原子荧光光谱法测定中草药方剂原生药、残渣、悬浮态及可溶态中的三价及五价砷的方法。研究了仪器的工作条件、试剂浓度及不同增感剂对砷原子荧光强度的影响和五价砷的还原条件，探讨了共存离子对砷测定的干扰及消除方法。利用本方法成功地对黄连解毒汤中的砷进行了形态分析。方法检出限为89．1ng／L，RSD为1．24％，样品加标回收率为91．1％～109．3％。     

Oxidation State Specific Generation of Arsines from Methylated Arsenicals Based on L- Cysteine Treatment in Buffered Media for Speciation Analysis by Hydride Generation - Automated Cryotrapping - Gas Chromatography-Atomic Absorption Spectrometry with the Multiatomizer

An automated system for hydride generation - cryotrapping- gas chromatography - atomic absorption spectrometry with the multiatomizer is described. Arsines are preconcentrated and separated in a Chromosorb filled U-tube. An automated cryotrapping unit, employing nitrogen gas formed upon heating in the detection phase for the displacement of the cooling liquid nitrogen, has been developed. The conditions for separation of arsines in a Chromosorb filled U-tube have been optimized. A complete separation of signals from arsine, methylarsine, dimethylarsine, and trimethylarsine has been achieved within a 60 s reading window. The limits of detection for methylated arsenicals tested were 4 ng l(-1). Selective hydride generation is applied for the oxidation state specific speciation analysis of inorganic and methylated arsenicals. The arsines are generated either exclusively from trivalent or from both tri- and pentavalent inorganic and methylated arsenicals depending on the presence of L-cysteine as a prereductant and/or reaction modifier. A TRIS buffer reaction medium is proposed to overcome narrow optimum concentration range observed for the L-cysteine modified reaction in HCl medium. The system provides uniform peak area sensitivity for all As species. Consequently, the calibration with a single form of As is possible. This method permits a high-throughput speciation analysis of metabolites of inorganic arsenic in relatively complex biological matrices such as cell culture systems without sample pretreatment, thus preserving the distribution of tri- and pentavalent species.     

Arsenic speciation in natural water samples by coprecipitation-hydride generation atomic absorption spectrometry combination

A speciation procedure for As(III) and As(V) ions in environmental samples has been presented. As(V) was quantitatively recovered on aluminum hydroxide precipitate. After oxidation of As(III) by using dilute KMnO₄, the developed coprecipitation was applied to determination of total arsenic. Arsenic(III) was calculated as the difference between the total arsenic content and As(V) content. The determination of arsenic levels was performed by hydride generation atomic absorption spectrometry (HG-AAS). The analytical conditions for the quantitative recoveries of As(V) including pH, amount of aluminum as carrier element and sample volume, etc. on the presented coprecipitation system were investigated. The effects of some alkaline, earth alkaline, metal ions and also some anions were also examined. Preconcentration factor was calculated as 25. The detection limits (LOD) based on three times sigma of the blank (N: 21) for As(V) was 0.012 μg L⁻¹. The satisfactory results for the analysis of arsenic in NIST SRM 2711 Montana soil and LGC 6010 Hard drinking water certified reference materials for the validation of the method was obtained. The presented procedure was successfully applied to real samples including natural waters for arsenic speciation.     

High performance liquid chromatography hydride generation in situ trapping graphite furnace atomic absorption spectrometry: A new way of performing speciation analysis using GFAAS as detector

A new procedure for the speciation analysis of hydride forming elements using GFAAS as detector is proposed. The separation of the species is performed by HPLC and the eluent flow is merged with HCl and NaBH₄ solutions moved by peristaltic pumps controlled by a flow injection apparatus. As the species emerges from the column, its respective hydride is formed and carried through the autosampler capillary to an Ir treated graphite tube pre-heated at 300 °C, where it is trapped. After the hydride collection, the autosampler arm is moved from the tube and atomization takes place. The sequence is repeated for the next emerging species. The feasibility of the system was evaluated for the speciation of As (III) and As (V) in waste water samples. The retention times were previously determined using a more concentrated mixed analytical solution and a quartz tube as atomizer. The analytical curves obtained by the proposed procedure showed similar slopes for both species as well as coefficient of regression better than 0.99. Limits of detection were 0.2 ng/mL for both species, 50 times better then the same assembly using a quartz tube atomizer. In the analysis of certified reference materials the sum of the As (III) and As (V) species concentrations were in close agreement with the arsenic concentration certified for total arsenic.     

液相色谱分离-氢化物原子吸收测定血清中不同形态的有机砷化合物

建立了一种色谱分离－紫外线消解－氢化物原子吸收光谱测定６种有机砷化合物的方法。这６种砷化合物分别是：甲基胂酸（ＭＭＡ）,二甲基胂酸（ＤＭＡ）,胂三甲胺内酯,胂胆碱,三甲基氧化胂和四甲基胂。由于ＡｓＢ,ＡｓＣ和ＴＭＡｓ＾＋不能直接与ＮａＢＨ４反应产生氢化物,因此在色谱柱与检测器之间增设了一个紫外线消解装置,使这些砷化合物在发生氢化物前先行消解。     

Hydride Generation Atomic Fluorescence Spectrometric Determination of Ultratrace Arsenic in High Purity Indium Oxide

A simple, sensitive, and interference free method was proposed for the determination of total arsenic in high purity indium oxide by hydride generation atomic fluorescence spectrometry (HG-AFS). Preconcentration was carried out by distillation of volatile arsenic trichloride. Hydrazine sulfate was used as a prereductant to reduce As (V) to As (III). The volatile arsenic trichloride generation was based on the reaction between As (III) and hydrochloric acid, and vapors were absorbed with water. The method provides a linear response range of 2 ng/mL–70 ng/mL, a detection limit of 0.1 ng/mL, a recovery of 96%–113%, and an average relative standard deviation of 2.42%. The method was validated by means of interlaboratory comparative analysis with the proposed method HG-AFS, and the comparison of data by using proposed method HG-AFS and reference methods of ICP-OES and spectrophotometry.