内标和快速共沉淀-火焰原子吸收光谱法测定食盐中的镉   总被引：3，自引：0，他引：3  

苏耀东  秦立俊李静 陈龙武 《岩矿测试》2005,24(3):201-204

探讨了用火焰原子吸收法测定以（2-吡啶偶氮）-2-萘酚-Ni（Ⅱ）为共沉淀体系，以Mn（Ⅱ）为内标，在pH=9．0的条件下快速共沉淀分离富集食盐中的痕量Cd。当试液为100mL时，方法的检出限为5．7μg/L，加标回收率为96％～101％，相对标准偏差（RSD，n=6）〈5％，基本消除了基体干扰。  相似文献   

贵州都匀牛角塘富镉锌矿同位素地球化学研究   总被引：2，自引：0，他引：2  

叶霖  潘自平  李朝阳  刘铁庚  厦斌 《矿物岩石》2005,25(2):70-74

通过对牛角塘富镉锌矿的硫和铅同位素研究发现，该矿床同位素组成与其他含镉铅锌矿床明显不同，其硫同位素组成以富重硫为特征，δ^34S值变化范围不大，集中在 22‰～ 30‰；硫化物单矿物、矿石和乌训组地层岩石具有极其相近的铅同位素组成和高μ值(9．66～9．884)。表明该矿床的硫主要来源于寒武系地层硫酸盐或油田卤水，成矿物质铅主要来自铀钍相对富集的上部地壳岩石即清虚洞组白云岩(含矿地层)下伏地层乌训组页岩夹薄层灰岩，因此，牛角塘富镉锌矿成矿物质主要来源于上地壳即乌训组地层岩石，成矿时代为加里东运动的中晚期。  相似文献   

Mechanism of cadmium resistance and adsorption of a yeast strain Rhodotorula sp. Y11     

YUAN Hongli  LI Zhijian  WANG Nengfei  HUANG Huaizeng 《中国科学D辑(英文版)》2005,48(Z2)

The mechanism of cadmium resistance of a yeast strain Rhodotorula sp. Y11 isolated from mine soil was investigated. We found that the yeast cells treated with different methods showed different cadmium-adsorption models. Grown in medium supplied with 100 mg/L of cadmium, 3.29% of the cell-absorbed cadmium was accounted in the cytoplasm. However, only 1% was taken into the cytoplasm and 99% was bound to the cell wall using the lyophilized biomass to adsorb cadmium in double distilled water. Treatments with alkali, ethanol-chloroform and proteinase showed different influences on the biosorption of whole cells and isolated cell walls. FT-IR analysis showed that acetyl of chitin was the active compound in the cells to absorb cadmium. The production of Metallothioneins, proteins related to the resistance to heavy metal in yeast, was evidently induced by cadmium, achieving 638.8 μg/g wet weight, which was about 85 folds higher than that in the uninduced biomass and was also much higher than that reported previously. The molecular weight of Metallothioneins was 6500 Da estimated by SDS-PAGE.  相似文献   

恩施州富硒区儿童发镉的调查     

邵器行  毛大钧  苏宏灿 《矿物岩石地球化学通报》1998,(2)

恩施州富硒区儿童发镉的调查邵器行（中国地质大学,武汉４３００７４）毛大钧苏宏灿（恩施州卫生防疫站,湖北恩施４４５０００）（恩施州妇幼保健院,湖北恩施４４５０００）关键词镉元素的组合效应儿童富硒区湖北恩施Ｃｄ是对人体有害的微量元素。在铅锌多金属硫化物矿...  相似文献   

Mobilization and attenuation of metals downstream from a base-metal mining site in the Mátra Mountains, northeastern Hungary     

László Ódor  Richard B Wanty  István Horváth  Ubul Fügedi 《Journal of Geochemical Exploration》1998,65(1):47-60

Regional geochemical baseline values have been established for Hungary by the use of low-density stream-sediment surveys of flood-plain deposits of large drainage basins and of the fine fraction of stream sediments. The baseline values and anomaly thresholds thus produced helped to evaluate the importance of high toxic element concentrations found in soils in a valley downstream of a polymetallic vein-type base-metal mine. Erosion of the mine dumps and flotation dump, losses of metals during filtering, storage and transportation, human neglects, and operational breakdowns, have all contributed to the contamination of a small catchment basin in a procession of releases of solid waste. The sulfide-rich waste material weathers to a yellow color; this layer of `yellow sand' blankets a narrow strip of the floodplain of Toka Creek in the valley near the town of Gyöngyösoroszi. Contamination was spread out in the valley by floods. Metals present in the yellow sand include Pb, As, Cd, Cu, Zn, and Sb. Exposure of the local population to these metals may occur through inhalation of airborne particulates or by ingestion of these metals that are taken up by crops grown in the valley. To evaluate the areal extent and depth of the contamination, active stream sediment, flood-plain deposits, lake or reservoir sediments, soils, and surface water were sampled along the erosion pathways downstream of the mine and dumps. The flood-plain profile was sampled in detail to see the vertical distribution of elements and to relate the metal concentrations to the sedimentation and contamination histories of the flood plain. Downward migration of mobile Zn and Cd from the contaminated upper layers under supergene conditions is observed, while vertical migration of Pb, As, Hg and Sb appears to be insignificant. Soil profiles of ¹³⁷Cs which originated from above-ground atomic bomb tests and the Chernobyl accident, provide good evidence that the upper 30–40 cm of the flood-plain sections, which includes the yellow sand contamination, were deposited in the last 30–40 years.  相似文献   

胁迫时间和胁迫浓度对超积累植物印度芥菜细胞中镉分布的影响   总被引：2，自引：0，他引：2  

杨红霞  张惠娟  高津旭  刘崴  李冰 《岩矿测试》2014,33(5):723-729

超积累植物对重金属的区隔化作用能有效降低细胞质内金属离子的浓度,是对重金属重要的解毒机制之一,而细胞内各组织的区隔化作用大小并未取得一致性结论。本文研究了胁迫浓度和胁迫时间对超积累植物印度芥菜(Brassica juncea)细胞及亚细胞中镉分布的影响。印度芥菜幼苗分别用0.5、1.0、2.0、3.0、5.0mg/L镉胁迫1、5、7、10、14天后收获,采用电感耦合等离子体质谱法测定印度芥菜根系和叶片亚细胞中镉的含量。结果表明:镉在细胞壁中的比例占50%~64%,细胞液占22%~38%,细胞器占7%~17%,镉在细胞壁中所占比例显著高于细胞液和细胞器,证明细胞壁区隔化在镉的解毒机制中具有重要的作用。随着胁迫时间和胁迫浓度的增加,根系和叶片中亚细胞各组织中镉含量持续增加,超过7天,镉含量显著升高,说明镉对植物的危害是一个缓慢过程。印度芥菜对镉胁迫浓度的最大耐受量为1.0 mg/L,超过此浓度,植物细胞的破坏症状加重;细胞超微结构研究也表明,镉胁迫浓度超过1.0 mg/L后,细胞结构发生了不同程度的损坏,出现质壁分离、液泡增大甚至空泡化、质膜粗糙等现象,继而影响到细胞的正常功能。因此,在考察重金属对植物的危害时,要充分考虑时间和浓度梯度两个参数的协同作用。  相似文献   

石墨炉原子吸收法测定钛铁矿中的微量镉     

姜云 《山东地质》2014,(1):61-63

研究了石墨炉原子吸收测定钛铁矿中微量元素 Cd 的方法,探索了在高含量的 Fe,Ti 基体干扰下以NH4H2PO4-H2NCSNH2-EDTA为混合基体改进剂的最佳仪器工作条件。在取样0．2000g,定容25 mL的条件下,方法检出限为0．006μg/g,用国家标准物质验证,其准确度（犚犈％）＜10％,12次测定精密度（犚犛犇％）＜10％,加标回收率90％～110％之间,符合国家相关要求。  相似文献   

向日葵根分泌物对针铁矿吸附Cd2+的抑制效应   总被引：1，自引：0，他引：1  

黄承玲  张道勇  潘响亮 《地理科学》2009,29(3)

向日葵根分泌物明显抑制针铁矿吸附Cd2+。随着pH的升高,针铁矿对Cd2+的吸附量升高,针铁矿对Cd2+的平衡吸附量pH在3~6时增长的幅度较大,pH>7后,对Cd2+的吸附量的增长趋于稳定。在溶液初始pH为3~8的范围内,向日葵根分泌物抑制针铁矿对Cd2+的吸附。针铁矿等温吸附Cd2+符合Langmu ir方程和Freund lich方程,吸附动力学符合二级速率方程。根分泌物的存在明显抑制针铁矿对Cd2+的吸附强度和吸附速率。表明针铁矿对Cd2+的吸附是一个熵增的吸热反应;根分泌物的存在则降低了吸附反应的自发性。  相似文献   

Effect of cadmium on the defense response of Pacific oyster Crassostrea gigas to Listonella anguillarum challenge     

丛明  吕家森  吴惠丰  赵建民 《中国海洋湖沼学报》2013,31(5):1002-1009

Heavy metal pollution can affect the immune capability of organisms.We evaluated the effect of cadmium(Cd) on the defense responses of the Pacific oyster Crassostrea gigas to Listonella anguillarum challenge.The activities of several important defensive enzymes,including superoxide dismutase(SOD),glutathione peroxidase(GPx),acid phosphatase(ACP),Na+,K+-ATPase in gills and hepatopancreas,and phenoloxidase-like(POL) enzyme in hemolymph were assayed.In addition,the expression levels of several genes,including heat shock protein 90(HSP90),metallothionein(MT),and bactericidal/permeability increasing(BPI) protein were quantified by fluorescent quantitative PCR.The enzyme activities of SOD,ACP,POL,and GPx in hepatopancreas,and the expression of HSP90 were down-regulated,whereas GPx activity in the gill,Na+,K+-ATPase activities in both tissues,and MT expression was increased in Cdexposed oysters post L.anguillarum challenge.However,BPI expression was not significantly altered by co-stress of L.anguillarum infection and cadmium exposure.Our results suggest that cadmium exposure alters the oysters’ immune responses and energy metabolism following vibrio infection.  相似文献   

Behavior of Cu, Ni and Cd during nutrient depletion in a spring bloom in Funka Bay     

Isao Kudo  Katsuhiko Matsunaga 《Journal of Oceanography》1998,54(6):619-627

The concentrations of Cu, Ni and Cd were determined in Funka Bay during a spring phytoplankton bloom, consisting of diatoms. Just after the bloom, both dissolved Cd and nutrients were removed in the euphotic zone. However, the removal ratio of Cd to phosphate was very different from that in seawater. The removal of Cd took place at a Cd/phosphate ratio of 0.07×10⁻³, which was lower than in seawater before the bloom (0.25×10⁻³), leading to an increase in this ratio in seawater exceeding 0.7×10⁻³ at the end of the bloom. Elevated concentrations of Cd and phosphate were observed in the deeper layer after the bloom due to the decomposition of detrital materials produced in the bloom. The ratio of Cd/phosphate in the regeneration step was 0.24×10⁻³ which was different from the removal ratio of 0.07×10⁻³. These observations suggest that the high Cd/phosphate ratio in the regeneration would reflect a relatively high regeneration rate of Cd than that of phosphate. No significant decrease in Cu and Ni concentrations was observed during the development of the bloom, suggesting that biological removal of these metals was not so significant during the spring bloom. The concentrations of Cd, Cu and silicate in surface waters increased after the bloom with decreasing salinity due to the influence of a spring thaw.  相似文献