氢化物发生-原子荧光法测定中药中痕量汞

应用AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生技术,采用HNO₃-H₂O₂体系和聚四氟乙烯高压釜消解中药样品,并优化了实验条件,建立了氢化物发生-原子荧光法测定中药中痕量汞。同时,研究了硼氢化钾浓度,光电管负高压,灯电流,原子化器高度,屏蔽气和载气流量等因素对测定结果的影响。在选定实验条件下,汞的检出限为0.021 μg·L-1, 桃叶(GBW08501)验证结果与推荐值一致,6次测定结果相对标准偏差为0.34%。此方法简便、快速、灵敏、准确,以工作曲线法和加入作图法对照,对于实际中药样品的测定得到了满意的结果。     

Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: A review

Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed.     

氢化物发生-原子荧光光谱法研究嗜热四膜虫对阿散酸饲料添加剂及其环境降解物的砷吸收

用以单细胞原生动物嗜热四膜虫对阿散酸及其降解物的砷吸收模型,研究了饲料添加剂阿散酸及其环境降解物对生物体的影响.四膜虫在含有阿散酸及其降解物的培养基中培养72 h后,洗去培养基,收集细胞.将虫体裂解,分离细胞膜和细胞内质液,经消解.用流动注射氢化物发生-原子荧光光谱法(HG-AFS)分别测定了细胞膜上和细胞膜内的砷.结果表明,阿散酸及其环境降解物可被细胞膜吸收并进入细胞内,且降解产生的无机砷比阿散酸更易被吸收,生物体通过细胞的砷吸收引起毒害.     

氢化物发生-原子荧光法测定中药(党参、黄芪、巴戟天)中的铅

应用AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生技术,采用HNO₃-H₂O₂体系和高压釜消解中药样品测定了中药党参、黄芪、巴戟天中的铅。同时,研究了光电管负高压、灯电流、屏蔽气和载气流量、载流的选择,酸度的影响等。在选定实验条件下,铅的检出限为0.08 μg·L-1, 相对标准偏差为0.34%。该方法简便、快速、灵敏,对于实际中药样品的测定得到了满意的结果。     

纳米二氧化钛胶体分离富集-氢化物原子荧光光谱法测定水中超痕量锗

提出了用纳米TiO2胶体富集,氢化物原子荧光光谱法测定水样中超痕量锗的新方法。当溶液的pH为6.0～8.0时,纳米TiO2胶体对Ge((Ⅳ)吸附率为97.0～99.0%,并且吸附速度快。利用纳米TiO2胶体良好的吸附性能对水样中超痕量Ge((Ⅳ)进行富集,离心后,弃去上清液,用少量盐酸将富集了Ge((Ⅳ)的沉积物(纳米二氧化钛)转化成胶体,用氢化物原子荧光光谱法直接测定胶体中的锗。该法检出限(3σ)低(0.060μg.L-1),精密度好(相对标准偏差(RSD)为2.0%),简单、快速(省去了繁琐的过滤和脱附过程),用于实际水样中超痕量锗的测定,结果满意。     

氢化物—原子荧光法测定植物及人发中的痕量硒

本文研究开发了在捕集剂覆盖下低温焙烧富集分离氢化物原子荧光光谱法测定植物和人发样品中的痕量硒，本方法克服了使用混合酸分解样品时，有机物质不能彻底分解而给测定带来的不利影响。其方法精密度和准确度均能满足测定的要求。     

Speciation and detection of arsenic in aqueous samples: A review of recent progress in non-atomic spectrometric methods

Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005–2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been made beyond what is in the officially prescribed compendia (which are included) and recent reviews are available.     

纳米氧化锌分离富集—氢化物原子荧光光谱法测定水中超痕量砷

在中性pH(6.5～7.5)条件下,振荡10 min,As(Ⅲ)在ZnO表面的吸附率即可达到99.5%以上。依据水体中As(Ⅲ)在氧化锌上的高吸附容量和纳米氧化锌在酸性溶液中的良好溶解性质,提出纳米ZnO富集,离心分离,使用盐酸将富集了As(Ⅲ)的ZnO沉淀溶解,利用原子荧光光谱法分析水样中超痕量砷的新方法。该法检出限（3σ）低（0.075 μg·L-1）,精密度好(相对标准偏差(RSD)为1.6%)。用于实际水样中超痕量As(Ⅲ)的测定,其回收率在97.0%～104.5%之间。结果表明该方法具有简单、快速、灵敏度高等优点。