Calibration for the determination of 19 trace elements in serum and urine

A fast, high-throughput and accurate method was developed for determination of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Se, U, Zn, Sb, Sn, I and Hg in urine and serum by inductively coupled plasma mass spectrometry. The samples were directly analyzed after 1/20 (v/v) dilution in 0.4% (v/v) HNO₃ and 0.005% Triton X-100. Three calibration modes were tested: aqueous and matrix matching with urine and serum. The accuracy was tested using reference materials of serum, urine and spiking. Results showed that the use of matrix matching calibration reduced the interferences and improved the recoveries for Al, Co, Pb and I in urine. The matrix matching did not affect the results considerably for serum. When serum was spiked with As, Co, Cs, Pb, U, Hg, I, Ba, Al, Cr and Ni, only matrix matching presented good recoveries. Helium was used as a collision cell gas reducing effectively polyatomic interferences for Al, Mn, Cu, Ni, Cr, Zn, As and Fe. Selection of the best internal standard was carried out for each element. The use of diluted HNO₃ improved the limit of detection. Finally, the method was applied successfully in samples of urine from workers occupationally exposed.     

电感耦合等离子体—质谱法测定成人脏器样品中痕量稀土元素的研究

本文采用ＩＣＰ－ＭＳ法对成人脏器样品中痕量稀土元素进行了研究，选择了测定的最佳仪器参数，检查了测定中的各种干扰和影响；用铼（Ｒｅ）为内标元素补偿基体抑制效应和灵敏度的漂移。方法对稀土元素各分量的检出限为０．００５－０．０２６ｎｇ．ｍ１＾－１，标准回收率为９２．９－１１１．３％，精密度为０．９６－３．０７％。在严格分析质量控制的基础上用混合酸消解样品，不须分离富集，直接对成人的心、脾、肝、肾、肺肉中     

Partition of iodine (¹²⁹I and ¹²⁷I) isotopes in soils and marine sediments

Natural organic matter, such as humic and fulvic acids and humin, plays a key role in determining the fate and mobility of radioiodine in soil and sediments. The radioisotope ¹²⁹I is continuously produced and released from nuclear fuel reprocessing plants, and as a biophilic element, its environmental mobility is strongly linked to organic matter.Due to its long half-life (15.7 million years), ¹²⁹I builds up in the environment and can be traced since the beginning of the nuclear era in reservoirs such as soils and marine sediments. Nevertheless, partition of the isotope between the different types of organic matter in soil and sediment is rarely explored. Here we present a sequential extraction of ¹²⁹I and ¹²⁷I chemical forms encountered in a Danish soil, a soil reference material (IAEA-375), an anoxic marine sediment from Southern Norway and an oxic sediment from the Barents Sea. The different forms of iodine are related to water soluble, exchangeable, carbonates, oxides as well as iodine bound to humic acid, fulvic acid and to humin and minerals. This is the first study to identify ¹²⁹I in humic and fulvic acid and humin. The results show that 30-56% of the total ¹²⁷I and 42-60% of the total ¹²⁹I are associated with organic matter in soil and sediment samples. At a soil/sediment pH below 5.0-5.5, ¹²⁷I and ¹²⁹I in the organic fraction associate primarily with the humic acid while at soil/sediment pH > 6 ¹²⁹I was mostly found to be bound to fulvic acid. Anoxic conditions seem to increase the mobility and availability of iodine compared to oxic, while subaerial conditions (soils) reduces the availability of water soluble fraction compared to subaqueous (marine) conditions.     

Speciation of methylmercury in rice grown from a mercury mining area

Monomethylmercury (CH₃Hg⁺ and its complexes; MeHg hereafter) is a known developmental neurotoxin. Recent studies have shown that rice (Oryza sativa L.) grain grown from mercury (Hg) mining areas may contain elevated MeHg concentrations, raising concerns over the health of local residents who consume rice on a daily basis. An analytical method employing high performance liquid chromatography (HPLC) - inductively coupled plasma mass spectrometry (ICP-MS) following enzymatic hydrolysis was developed to analyze the speciation of MeHg in uncooked and cooked white rice grain grown from the vicinity of a Hg mine in China. The results revealed that the MeHg in the uncooked rice is present almost exclusively as CH₃Hg-l-cysteinate (CH₃HgCys), a complex that is thought to be responsible for the transfer of MeHg across the blood-brain and placental barriers. Although cooking does not change the total Hg or total MeHg concentration in rice, no CH₃HgCys is measurable after cooking, suggesting that most, if not all, of the CH₃HgCys is converted to other forms of MeHg, the identity and toxicity of which remain elusive.     

ICP-MS测定地表水中多个元素的分析方法研究

研究并提出了用ICP-MS测定地表水中多个元素的分析方法。由于利用ICP-MS测定地表水中多个元素的国家标准方法还未形成,所以本文以灵敏度、氧化物产率、信背比、双电荷为考察指标优化仪器参数设置,从曲线、检出限、准确度、精密度等方面对ICP-MS测定地表水中多种元素的分析方法进行了研究和探讨,并按照该方法对实际样品进行了分析,由结果可知,该方法具有快速、简便,能同时分析多个元素等优点。其中Li、Al、Cr、Mn、Sr、Ba六个元素在测定中加标回收还需要进一步研究。     

我国东北地区土壤铀同位素水平、分布和来源

系统采集了我国东北地区132个表层土壤样品,采用混合酸全溶分解样品,使用UTEVA萃取色谱分离样品溶液中的铀,应用串联四极杆电感耦合等离子体质谱（ICP-MS/MS）测量样品溶液中²³⁸U、²³⁵U、²³⁴U,获得了研究区域表层土壤中3种铀同位素浓度水平和分布.首次大范围报道该地区表土中²³⁴U水平,发现在部分土壤中²³⁴U发生明显的同位素分馏.²³⁵U/²³⁸U原子比值分布显示区域大气核武器试验的放射性颗粒物在山脉迎风坡有明显沉积,导致大兴安岭等山脉的西侧²³⁵U/²³⁸U原子比值较高.但该区域铀同位素整体上处于环境本底水平,受人类核活动影响较小.来源分析表明研究区域表土中铀主要来源于成土母岩的岩石风化以及人类的工业和农业活动.     

电感耦合等离子体质谱法测定大气颗粒物中微量元素及铂族元素

大气颗粒物样品采集量较少,一般只有5~10mg左右,其中铂族元素含量很低并且受到Cu、Ni、Cd、Zr、Hf等元素的严重干扰,直接测定误差很大,必须要进行分离富集。因此,同时测定其中的微量元素及铂族元素非常困难。本文利用HF和HNO3在封闭溶样装置中对大气颗粒物样品进行消解,样品完全消解后,分取约1/4的样品溶液,以Ir作为内标元素等离子体质谱法测定微量元素,然后将剩余样品通过Dowex,50W X8阳离子树脂和P507萃淋树脂混合交换柱,分离基体元素及干扰元素,以Ir为内标等离子体质谱法测定Pt、Pd、Rh三个铂族元素以及Re和Au。实现了一次溶样同时测定大气颗粒物中的微量元素、稀有分散元素及铂族元素。国际标样结果稳定可靠。     

成都绕城高速两侧土壤重金属含量测定及健康风险评价

成都绕城高速公路属于成都市主要交通干线,为成都市带来巨大经济及社会效益,但是,也不可避免给环境带来污染。因此,研究成都绕城高速两侧土壤污染情况具有重要意义。采用"梅花点法"和"四分法"采集得到成都绕城高速公路两侧表层土壤(0~20cm)样品24个,电感耦合等离子体质谱法(ICP-MS)测得土壤样品中铬(Cr)、镍(Ni)、铜(Cu)、锌(Zn)、砷(As)、镉(Cd)和铅(Pb)含量的平均值分别为46.81、192.48、28.24、111.79、4.74、2.79和51.68 mg/kg。讨论重金属分布特点,采用污染指数法对土壤重金属污染进行评价;应用美国环境保护局风险评价方法对成都绕城高速两侧土壤重金属通过直接摄入、皮肤接触和呼吸摄入3种途径进入人体的危害进行了风险计算和初步评价。结果表明:成都绕城高速公路两侧土壤未受到重金属污染(Ni除外),且7种重金属对人体均不存在明显健康风险。     

铊在黄铁矿中的相态分布及碳酸盐在其释放过程中的作用

采用分级提取-电感耦合等离子体质谱法,对黄铁矿中铊的相态分布进行了考察.结果表明,黄铁矿中的铊主要以存在于硅酸盐相中和以酸可交换的形式存在于矿物结构中的铊为主,这部分铊分别占到58.3%和25.1%;以可氧化态形式结合在黄铁矿(FeS2)中的铊次之,占11.2%;以易还原态形式存在于铁氧化物相中的铊最少,为5.4%.自然条件下铊的释放主要是酸可交换态铊和可氧化态铊的释放迁移过程.漫反射红外光谱表征发现,黄铁矿在表面氧化过程中其表面羟基增多,表明存在表面溶解及表面酸化现象.进一步的释放机理探讨认为,铊在黄铁矿表面存在一种"溶解-吸附沉淀"平衡,这一平衡由碳酸盐中和作用和黄铁矿表面氧化共同控制,并决定了铊的释放迁移.     

上海近海(洋山)海水主要成分及微量元素分析

为研究人为活动等因素对近海海水成分和海洋环境的影响,本文使用离子色谱(IC)和电感耦合等离子体质谱技术(ICP-MS)分别对上海沿海(洋山)海域海水中的主要成分和43种微量元素含量进行了分析。通过钠度和富集因子等参数将测量值与全球海水平均值进行了比较分析。结果显示:上海近海海水受长江等陆地河流的冲淡作用,主成分浓度整体下降,但主成分之间的比例变化不大;人为活动对近海海水微量元素的含量有显著影响,在海水被冲淡的背景下,40种所测微量元素发生不同程度的富集,富集的可能来源有海事航运活动、沿海及长江流域工业废弃物排放及沿海河流水土流失等。