碱性微波提取-ICP/MS法测定土壤中六价铬

采用碱性微波提取法处理土壤样品,用电感耦合等离子体质谱（ICP/MS）法测定试样中的六价铬,以标准物质测定相对误差的绝对值作为试验指标建立正交模型,确定碱性微波消解的提取温度95 ℃、提取时间30 min、氯化镁用量005 g、提取液体积6 mL为最佳试验条件,采用He碰撞池技术和在线内标分别消除基体带来的质谱和非质谱干扰。条件优化后,方法检出限为0.10 mg/kg,实际样品6次测定结果的RSD分别为13.0%和5.7%,加标回收率为120%和106%。将该方法用于有证标准土壤样品的测定,测定结果均在标准值范围内。     

电感耦合等离子法测定环境积尘中铅的研究

用细毛刷清扫收集普通居民房顶积尘,参照土壤样品预处理方法-普通酸分解法处理样品,以国标样品、不确定度实验、加标回收实验为质控手段,探索采用电感耦合等离子法测定环境积尘中铅的含量。实验结果表明,该法能将积尘样品完全消解,且电感耦合等离子法测试方法性能稳定、快速、准确,优于其他方法。     

Speciation of mercury in South African coals

Total mercury (Hg_TOT) concentrations were determined by inductively coupled plasma mass spectrometry (ICP MS) for South African Highveld coals. The distribution of Hg in coals was investigated using a four-stage sequential leaching protocol and isotope dilution/gas chromatography coupled to ICP MS (ID-GC-ICP MS). The results show that Hg_TOT ranged from 144 to 303?µg?kg^?1 with a mean of 199?±?26?µg?kg^?1, while Hg_TOT leached from coals using different solvents ranged between 103 and 310?µg?kg^?1 (mean: 218?±?60?µg?kg^?1). Hg leaching rates of 53–78% were achieved in crushed coals. Hg⁰, Hg²⁺, and CH₃Hg⁺ were identified in all coals. CH₃Hg⁺ in studied coals ranged between 0.1 and 0.4 (mean: 0.2) µg?kg^?1. GC ICP MS chromatograms also showed unknown Hg peaks which were identified as other organomercury species such as ethylmercury. Modes of occurrence of Hg in coals were variable with the organic-bound (37–40%) and the sulfide-bound (37–39%) being the dominant mercury forms. Increasing the HCl concentration in the used protocol increased the amount of Hg leached (16%) during this step.     

Monitoring of heavy metals and butyltin compounds in coastal waters of Ligurian Sea: Results of a mussel watch project

From December 1994 up to October 1995 a “Mussel Watch Project”; was carried out to assess the quality of water of the Ligurian Sea and to identify the possible sources of heavy metal pollution. Several metals and organotin compounds were measured in mussels (Mytilus galloprovincialis, Lam) transplanted in different months from a marine farm to eight sites of the Ligurian coast.

Spatial differences and temporal trends in tissue concentrations of Zn, Cu, Ni, Cr, Fe, Al, V, Cd and Mn were evaluated. Concentrations resulted in the same range as those obtained in a previous Mussel Watch Project carried out in the same area. In general, areas of known pollution display high concentrations of these metals, but also some areas not greatly influenced by human activities showed high concentrations of some metals.

Data from this study show little evidence of any overall seasonal pattern except for Cu, Zn and V, concentrations of which were a function not only of sampling site, but also of reproductive cycle.

Organotin compounds show differences in terms of both concentration and speciation between the investigated sites.     

Cadmium and chromium in human lung tissue in relation to smoking and lung cancer

The pulmonary Cd and Cr content was determined from 53 lung cancer patients operated for cancer and from 39 patients who died of non‐malignant diseases. The results were correlated with smoking habits, pulmonary emphysema and occupational history. Both the pulmonary Cd and Cr increased with the amount of smoking. In ex‐smokers the Cr content in lung tissue did not diminish with the time since stopping smoking, but the Cd did follow the half‐life of about 9 years. The pulmonary Cd, compared with smoking habits, behaved similarly in both the lung cancer and control patients, whereas Cr in the lung cancer patients could not be explained solely by smoking, but some of the cancer patients may have been occupationally exposed to Cr. Speciation was not studied.     

利用修改的震级—频度关系研究扬—铜地震带的未来地震

本文对修改的震级-频度关系进行了全面的统计检验。结果表明,修改的震级-频度关系从整体上讲拟合精度是令人满意的,可用于预测。本文根据扬—铜带修改的震级-频度关系,以及极值方法的结果,预测扬—铜带未来可能发生一次6.5—6.8级地震。     

Simpson—Golabi—Behmel syndrome: Disproportionate fetal overgrowth and elevated maternal serum alpha-fetoprotein

Simpson—Golabi—Behmel (SGB) syndrome is an X-linked condition with pre- and postnatal overgrowth, characteristic facies, and visceral and skeletal anomalies. We report an affected male who presented at 16 weeks' gestation with elevated maternal serum α-fetoprotein (MSAFP). Fetal measurements at 20 and 31 weeks' gestation were disproportionate, with marked macrosomia but a low head to abdominal circumference ratio and normal femur length. Fetal overgrowth with elevated MSAFP may prove to be useful markers for the prenatal diagnosis of SGB syndrome.     

石墨炉原子化机理研究方法评述

评述了近年来石墨炉原子化机理研究中用得较多的研究方法,包括热力学方法、动力学方法、原子吸收光谱法、X射线衍射法、X射线光电子能谱法、俄歇电子能谱法、扫描电镜法、分子吸收光谱法和质谱法.每种方法均有其优缺点,综合运用多种研究方法,特别是理论研究与实验研究相结合,更好地阐明原子化机理.     

母乳与牛乳中微量元素的比较

用ＩＣＰ－ＡＥＳ法对母乳和牛乳中Ｋ、Ｎａ、Ｃａ、Ｍｇ、Ｐ、Ｆｅ、Ａｌ、Ｚｎ、Ｓｒ、、Ｐｂ、Ｍｎ、Ｂａ和Ｃｕ等１３种元素含量进行了测定。结果发现母乳与牛乳的营养成分差异较大。研究了深入探讨微量元素在人体内重要的生理功能提供了有用的参考数据。     

沉淀分离富集-电感耦合等离子原子发射光谱测定土壤中可溶态稀土元素

研究电感耦合等离子体原子发射光谱测定土壤中微量可溶态稀土元素的方法。在适宜的ｐＨ＝１０－１１条件下,以ＭｇＣｌ２为载体沉淀分离除去浸提液中的大部分基体杂质如Ｎａ＾＋,Ａｃ＾－,Ｃａ＾２＋,Ｍｇ＾２＋等,有效地消除了这些杂质的干扰,提高了测定方法的准确度;同时,待测可溶态稀土元素被沉淀集,样品中总稀土及单一稀土加标回收率为８８％－１１０％,样品测定结果满意,方法简便快速。