土壤中重金属检测样品前处理技术现状分析

土壤中重金属检测样品前处理是一个复杂且关键的步骤,对最终分析结果有重要的影响。文章对目前主要采用湿法消解(盐酸-硝酸-高氯酸-氢氟酸、王水/王水回流、反王水)、干灰化法消解与微波消解技术及其现状进行介绍,指出其各自的优势与存在问题,为土壤中重金属检测样品前处理技术的进一步探索研究提供参考。     

超高斯（分布）随机振动HALT试验剖面建立要点解析

本文介绍了超高斯（分布）随机振动HALT技术,对超高斯（分布）随机振动HALT试验剖面的建立提出了方法和建议,主要包括试验顺序的选择、应力强度的确定、步进量级的选择、驻留时间确定和试验停止原则等五方面,并总结了现场试验的要求和注意事项。     

The toxicity of composted sediments from Mediterranean ports evaluated by several bioassays

This work investigates the ecotoxicological evaluation of contaminated dredged sediments from French Mediterranean navy harbour (A), commercial port (B) and two composite specimens (C) and (D) coming from the mixture of A and B with other port sediments. The toxicity of elutriates from these sediments is estimated using embryo-toxicity test, Microtox® solid phase test, LuminoTox, phytotoxicity tests and genotoxicity test. Bioassay responses are not clearly correlated with chemical contamination in the whole sediment and vary as a function of tested organisms. The highest contaminated samples (A and C) are almost always more toxic than the less contaminated samples (B and D). Among composite sediments, the mixture effect with other sediments is not efficient to decrease toxicity in sample C, suggesting that other parameters influence toxicity level such as particle size or organic matter content. These parameters should be taken into consideration in order to improve the efficiency of the mixture process and produce composite sediments with low toxicity.     

双层管用于发光细菌检测水样毒性时的色度修正

阐述了应用发光细菌检测有色水样毒性时,水样色度会引起附加发光抑制的原因,提出应用同心双层检测玻管,可以对有色水样色度引起的附加发光抑制加以修正.通过比较单层管和双层管测定标准曲线间的差异、设置阴性对照和阳性对照评价该方法的可靠性,以及用该方法检测有色水样活性黑KN-B溶液的急性毒性实验,结果表明,用同心双层检测玻管可以有效修正由水样色度引起的附加发光抑制.     

Standardizing the Methodology of Sperm Cell Test with Paracentrotus Lividus

The sperm cell toxicity test with Paracentrotus lividus is widely used in Italy to assess the quality of complex aqueous matrices, but at present there is a shortage of standardized methodologies for the bioassay performance. In this work several critical points were considered, in order to verify the reliability of this bioassay and to improve its standardization.In particular, we have studied the differences in EC50 values at different sperm: egg ratios and with different quantities of gametes; the influence of sperm and eggs on fertilization rate and the influence of different recipients materials (plastic or glass). At the same time, it was evaluated if the obtained EC50 values were in accordance with those reported in literature.Experiments performed yielded EC50 values for copper ranging from 16.54 μ g/l to 69.59 μ g/l, with a total mean value ± SD of 39.79 μ g/l ± 11.17. These data fit with those found in literature for other echinoid species. According to the same authors, poor fertilization was probably due to the effects on sperm and not on eggs, and moreover the linear regression analysis performed on each experiment suggested that the best amount of eggs to use in the test was 1000.Results from the comparison between the performance of the test in plastic or glass tubes showed an higher success in fertilization rate using borosilicate glass tubes.     

室内空气中甲醛测定比对试验的探讨

为了检验化学酚试剂比色法与便携式甲醛测定仪测定室内空气中甲醛方法间有无显著性差异,用2种方法做了比对试验,并对2种方法的相关性、精密性进行了分析。结果表明,2种分析方法无显著性差异。便携式甲醛分析仪具有操作简单、携带方便、直观性强等优点,有利于民用建筑室内环境中甲醛的测定。     

Epiphytic lichen diversity in central European oak forests: Assessment of the effects of natural environmental factors and human influences

We investigated lichen diversity in temperate oak forests using standardized protocols. Forty-eight sites were sampled in the Czech Republic, Slovakia and Hungary. The effects of natural environmental predictors and human influences on lichen diversity (lichen diversity value, species richness) were analysed by means of correlation tests. We found that lichen diversity responded differently to environmental predictors between two regions with different human impact. In the industrial region, air pollution was the strongest factor. In the agricultural to highly forested regions, lichen diversity was strongly influenced by forest age and forest fragmentation. We found that several natural factors can in some cases obscure the effect of human influences. Thus, factors of naturality gradient must be considered (both statistically and interpretively) when studying human impact on lichen diversity.     

Variability of sediment-contact tests in freshwater sediments with low-level anthropogenic contamination - Determination of toxicity thresholds

Freshwater sediments with low levels of anthropogenic contamination and a broad range of geochemical properties were investigated using various sediment-contact tests in order to study the natural variability and to define toxicity thresholds for the various toxicity endpoints. Tests were performed with bacteria (Arthrobacter globiformis), yeast (Saccharomyces cerevisiae), nematodes (Caenorhabditis elegans), oligochaetes (Lumbriculus variegatus), higher plants (Myriophyllum aquaticum), and the eggs of zebrafish (Danio rerio). The variability in the response of some of the contact tests could be explained by particle size distribution and organic content. Only for two native sediments could a pollution effect not be excluded. Based on the minimal detectable difference (MDD) and the maximal tolerable inhibition (MTI), toxicity thresholds (% inhibition compared to the control) were derived for each toxicity parameter: >20% for plant growth and fish-egg survival, >25% for nematode growth and oligochaete reproduction, >50% for nematode reproduction and >60% for bacterial enzyme activity.     

一株氧化亚铁硫杆菌的筛选及生长条件研究

从广东省大宝山矿区尾矿中分离纯化得到一株嗜酸细菌,对其进行DNA提取和16S rRNA扩增后测序,将测序结果与国际基因数据库Genbank中已有相关菌株序列进行相似性比对后,发现该菌株与氧化亚铁硫杆菌(Acidithiobacil-lus ferrooxidans)Tf-49菌位于系统发育树的同一分支中,二者相似度高达99%以上,确定其为氧化亚铁硫杆菌并命名为DBS-8菌。另外,通过设计5因素4水平的正交实验,研究了接种量、培养温度、硫酸铵浓度、初始pH和初始亚铁浓度对该菌株生长状况的影响。结果表明适宜该菌株生长的最佳初始条件为:20%的接种量、3.0 g/L硫酸铵、9.0 g/L初始亚铁、pH=2.0和28℃培养,各初始条件对细菌生长影响的顺序为:pH初始亚铁浓度接种量温度硫酸铵浓度。     

通海阀箱消声器环境试验研究

目的验证通海阀箱消声器的环境适应性。方法分析通海阀箱消声器的结构组成、工作原理、使用环境。综述环境试验的相关标准,并对GJB 150A军用装备实验室环境试验办法中有关水面船舶部分进行剪裁,依据GJB 150A开展倾斜摇摆试验、振动试验、冲击试验,确定上述试验的方法、相关参数,并设计模拟海水环境的工装。结果消声器在施加了上述试验的环境应力后,外观结构无明显变形,紧固件无松脱、断裂等。通海阀箱消声器声学性能无明显下降,插入损失保持大于8 dB。结论通海阀箱消声器在恶劣的环境条件下具有较高的可靠性。GJB 150A部分试验参数设计过于保守,对船舶非电子设备影响较小,可依据实测应力量值进行试验。