砷形态分析

综述了近几年砷形态分析方法的最新研究进展.以常见砷形态分析方法发展为主线,讨论了不同砷形态分析方法的发展过程和应用情况,对不同方法的优缺点进行了扼要评述.早期的砷形态分析方法主要是以色谱和原子光谱联用为主要手段,随着不同的、更为有效的砷化合物检测手段的出现,砷形态分析方法也不断进行完善、发展.目前,在定量分析方面以液相色谱和电感耦合等离子体质谱联用方法为主要常规分析手段;在砷化合物定性分析方面,色谱-电感耦合等离子体质谱与电喷雾质谱相互补充的联用方法逐渐成为了主要分析手段.砷形态分析在环境健康和毒理学方面的应用是目前该领域的主要研究方向,结合国际上最新的研究进展,讨论了砷形态分析方法在环境毒理学等研究中发挥的重要作用.     

蛋白-蛋白相互作用小分子抑制剂研究进展

蛋白-蛋白相互作用在生物过程中扮有非常重要的角色,并且与人类疾病息息相关.因此,基于蛋白-蛋白相互作用的小分子抑制剂的研究为新药研发提供了更好的思路与方向.对近几年来合成的几类蛋白-蛋白相互作用小分子抑制剂的设计、化学结构、生物活性及研究进展进行了较为详细的综述,对其发展趋势进行了展望.     

HPLC-ICP-MS测定中药中砷的形态

报道了高效液相色谱-电感耦合等离子体质谱（HPLC—ICP-MS）联用技术测定中药中砷的形态，采用阴离子交换柱，以0．2mmol／L EDTA和2mmol／L NaH2PO4的溶液为流动相，pH6．0，流速为1．0mL／min，成功分离了亚砷酸（AsⅢ）、砷酸（AsV）、甲基砷（MMA）和二甲基砷（DMA）。检出限分别为0．67μg／L（AsⅢ），0．85μg／L（DMA），0．43μg／L（MMA），0．70μg／L（AsV）。中药样品经过（1＋1）甲醇和水的溶液超声提取，离心、过滤、氮气吹干甲醇，超纯水定容。样品加标平均萃取回收率分别为：92．8％（AsⅢ），108％（DMA），104％（MMA），101％（AsV），相对标准偏差（RsD，n=7）均小于10％。     

HPLC-ICP-MS测定中药中砷的形态

报道了高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术测定中药中砷的形态.采用阴离子交换柱,以含0.2 mmol/L乙二胺四乙酸(EDTA)和2 mmol/L NaH2PO4的水溶液为流动相,pH 6.0,流速为1.0 mL/min,成功分离了亚砷酸(AsⅢ)、砷酸(AsⅤ)、甲基砷(MMA)和二甲基砷(DMA).检出限分别为0.67 μg/L (AsⅢ),0.85 μg/L (DMA),0.43 μg/L (MMA),0.70 μg/L (AsⅤ).中药样品经过(1 1)甲醇水溶液超声提取,离心、过滤、氮气吹干甲醇,超纯水定容.样品加标平均萃取回收率分别为: 92.8% (AsⅢ),108% (DMA),104% (MMA),101% (AsⅤ),RSD (n=7)均小于10%.     

HPLC-MS/MS测定多宝鱼和紫菜中的砷甜菜碱

建立了多宝鱼和紫菜中砷甜菜碱的高效液相色谱多级质谱联用(HPLC-MS/MS)分析方法.样品以甲醇-水混合液(体积比1 : 1)提取,提取液再经氮吹浓缩.样品溶液在C18柱上以1%(体积分数)甲酸和甲醇梯度洗脱,然后在电喷雾电离正离子模式下进行质谱分析.多反应监测模式下进行检测,标准曲线法定量.定量分析的线性范围为10 ～700 μg/L,检出限为4.1 μg/L,鱼和紫菜中的加标回收率分别为95%和68%.该文同时还研究了砷甜菜碱的碰撞裂解机理.     

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。     

15种中药材中砷的形态分析

利用高效液相色谱(HPLC)与电感耦合等离子体质谱(ICP-MS)联用技术对6种砷形态[砷胆碱(AsC)、砷甜菜碱(AsB)、三价砷As(Ⅲ)、二甲基砷酸(DMA)、甲基砷酸(MMA)和五价砷As(Ⅴ)]进行了分离,测定了0 ～100 μg/L范围内6种砷形态的混合标准工作曲线,相关系数(r2)优于0.990,方法检出限均为0.2 μg/L.采用甲醇-水(体积比1 : 1)超声法提取了15种中药材中的砷形态,用HPLC-ICP-MS进行分析,结果表明,15种中药材中存在的主要砷形态是有毒的As(Ⅴ),另外还有少量的砷甜菜碱和砷胆碱,并且动物用药中的有机砷含量明显高于植物用药.     

鱼露中砷形态分析

采用高效液相色谱-电感耦合等离子体质谱（HPLC-ICP/MS）联用技术对鱼露样品中砷形态进行分析。鱼露样品采用含0.45%H₂O₂的1%HNO₃溶液90℃热浸提3 h,8000 r/min离心过滤后,采用Hamilton PRP-X100阴离子交换柱（250 mm×4.1 mm,10μm）,以（NH₄）₂HPO₄溶液为流动相,梯度洗脱,HPLC-ICP/MS法进行分析。结果显示,在前处理过程中添加H₂O₂可准确测定鱼露样品中一甲基砷（MMA）和无机砷（i As）的含量;同时发现氧化后砷甜菜碱（As B）高的鱼露基质样品中少量的As B会转化为未知砷形态,影响二甲基砷（DMA）的准确测定。     

砷形态分析方法进展

对光变分析法,高效液相色谱法,毛细管电泳法以及气相色谱法在砷形态分析中的应用进行了评述,比较了各种方法的优缺点,引用文献82篇。     

人肝细胞中总砷及砷代谢产物分析方法研究

本工作研究了冷消解、微波消解、高压密闭消解方法对超声破碎后细胞中砷的ICP-MS测定的影响,并与直接进样测定结果作对比.结果表明,微波消解法和高压密闭消解法效果较好,测定的精密度以RSD表示,分别为2.1%和1.2%;日间6次测定的精密度分别为1.2%和2.0%;元素加标回收率均在95.7%～108.1%范围.用4种消解方法对应的ICP-MS方法检出限介于0.74～0.93 μg/l之间,符合痕量分析要求.本工作还建立了高效液相色谱(HPLC)与电感耦合等离子体质谱(ICP-MS)联用技术对1 μmol/L染砷组细胞样品中的砷化学形态进行了初步探讨,发现细胞内除了存在无机砷(As(Ⅲ)和As(Ⅴ))外,同时存在二甲基砷(DMA)和一种甲基砷中间代谢产物.     

Arsenic speciation by coupling capillary zone electrophoresis with mass spectrometry

Summary Capillary zone electrophoresis (CZE) has been coupled with mass spectrometry to enable the identification of mineral and organometallic compounds of arsenic in speciation studies. The electrophoretic effluent was introduced through a concentric interface into the mass spectrometer. Make-up liquid was added to enable electric contact at the outlet of the separation capillary and to assist the electronebulization process. After ionization, the ions were analyzed and quantified with an ion-trap detector. Optimization of the coupling conditions (geometry of the concentric interface, composition and flow rate of the sheath liquid, electronebulization and detection conditions) is described. The results show that the geometry of the concentric interface and the positioning of the outlet of the separation capillary have a critical effect on stability and sensitivity. Programming the electronebulization and detection conditions throughout the analysis enabled identification and quantification of the seven arsenic compounds of interest (neutral, and positively or negatively charged species) in less than 20 min at the ppm level. Limits of detection ranged from 0.5 to 3.3 mg L⁻¹, corresponding to amounts injected ranging from 15 to 60 pg. The linear dependence of mass spectrometric response on arsenic concentration was verified for concentrations ranging from 5 to 200 mgL⁻¹. For the two positively charged species, arsenobetaine and arsenocholine, an on-line preconcentration technique (field-amplified sample injection) enabled reduction of the detection limits by approximately one order of magnitude to 110 and 160 μgL⁻¹, respectively.     

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.     

南极磷虾油中总砷含量及砷形态分析

南极磷虾油富含Omega-3磷脂而具有强大的保健功能,但由于其砷含量较高,在保健品领域的应用受到一定限制.由于南极磷虾油中含有大量的磷脂质,采用常规的提取方法分析难以对其砷形态进行准确定量分析.本研究采用高效液相色谱-电感耦合等离子体质谱((HPLC-ICP-MS)联用技术建立了针对砷甜菜碱(AsB)、二甲基砷酸(DMA)、一甲基砷酸(MMA)、三价砷As(Ⅲ)、五价砷As(Ⅴ)5种砷形态的分析方法.采用C18固相萃取进行样品脱脂前处理,采用阴离子交换色谱IonPac AS9-H阴离子分析柱(250 mm×4 mm),流动相采用38 mmol/L Na2SO4+15 mmol/L乙酸钠;流速0.6 mL/min,流速1 mL/min,进行5种形态砷化合物的分析.结果表明,5种砷化合物的线性范围为0.5～500 μg/L,相关系数R＞0.9993.检出限(LOD)为0.1 ～0.2 μg/L,定量限(LOQ)为1.5 ～2.6 μg/L,RSD＜5％.加标回收率为88.9％ ～ 106.3％.样品的测定结果显示,南极磷虾油中砷形态的主要存在形式为无毒的砷甜菜碱,因此可以安全地应用于食品及保健品.     

高效液相色谱/氢化物发生/原子荧光快速检测尿砷形态

本文对砷形态分析方法进行了评述。提出了人尿中Ａｓ（Ⅲ）、Ａｓ（Ⅴ）、一甲基砷（ＭＭＡ）和二甲基砷（ＤＭＡ）的快速、灵敏的形态分析方法。方法基于在１５ｃｍ长、３μｍ粒径的ＨＰＬＣ柱上快速分离不同形态的砷后以灵敏的氢化物发生／原子荧光检测。常见砷的四种形态的分析只须４ｍｉｎ即可完成,检出限在μｇ／Ｌ级。标准样品尿中砷的形态分析结果与标准值吻合很好。本法已应用于摄取砷糖前、后所采集的尿样中砷的形态分析研     

Ion-Exchange Method for Analysis of Four Arsenic Species and its Application to Tap Water Analysis

Abstract

Arsenic (III), arsenic (V), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were separated by ion-exchange chromatography. The elution sequence was as follows: 1.5 M ammonia followed by 0.12 M hydrochloric acid yielding As(III); 1 M hydrochloric acid followed by water yielding first As(V) and then MMA. Detection was performed by hydride generation-atomic absorption spectrometry.

The possible interferences of 13 metallic ions have been studied and none of them was found to interfere.

The method provides good linearity, precision, accuracy, and sensitivity. It has been applied to the speciation of arsenic in tap water samples from North West of Spain (a region about 29500 Km²).     

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％。     

Arsenic speciation patterns in freshwater fish

Muscle of 16 freshwater fish (9 different species belonging to 4 different families) was analysed for arsenic species using HPLC separation (anion and cation exchange) followed by on-line UV-decomposition, hydride generation and AFS detection. The main arsenic compounds found in the extracts were arsenobetaine (AsB), which accounted for 92–100% of extractable arsenic in species of salmonids (Salmo marmoratus, Oncorhynchus mykiss, Salmo trutta m. fario), and dimethylarsinic acid (DMAA), which accounted for 75% of extractable arsenic in burbot (Lota lota). AsB was also found in lower concentrations in almost all other fish species analysed (Silurus glanis, L. lota, Barbus barbus, Rutilus pigus virgo, Chondrostoma nasus). Arsenite (As(III)) and trimethylarsine oxide (TMAO) were detected in low concentrations in some representatives of Cyprinidae only (R. pigus virgo, C. nasus). Except in salmonids, an unknown cationic compound was present in most of the samples in relatively low concentrations. Cluster analysis of the generated data seems to indicate that there is a correlation between fish family and the arsenic speciation pattern. This is especially clear for the salmonids which show a completely separate cluster and thus a very distinct arsenic speciation pattern.     

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.     

植物中砷的形态分析

应用离子交换树脂静态吸附和溶剂萃取相结合的分离技术，分析了植物中砷的四种形态化合物：无机三价砷和五价砷，一甲基胂和二甲基胂。并用石墨炉原子吸收光谱法（ＧＦＡＡＳ）测定其含量。文中采用ＨＣｌ浸提植物的砷，并对ＨＣｌ的浓度、体积以及浸提时间作了详细的探讨。用２０ｍＬ１ｍｏｌ／ＬＨＣｌ对１．０ｇ干植物２ｄ的浸出量与传统消化法总量的比值为０．８５－１．００。对浸出液进行形态分析，总砷回收率为８６％－９３％     

磷酸超声提取大气颗粒物中砷的多种形态

以H<,3>PO<,4> 为提取剂,利用高效液相色谱与氢化物发生原子荧光光谱联用(HPLC-HG-AFS)实现了大气颗粒物中砷形态的温和提取测定,并通过标准样品的形态加标实验确定了最佳提取方法.在优化的色谱及光谱条件下,As(Ⅲ),As(Ⅴ),MMA(甲基胂酸)和DMA(二甲基胂酸)均可达基线分离,其方法检出限分别为1...