湖南省主要稀有稀土金属矿床特征

湖南省主要有铌、钽、铷、铯、锂、铍、锆等稀有金属及稀土金属矿床.矿床类型以岩浆晚期分异交代型、气成热液型、伟晶岩型、风化壳型和砂矿型为主.稀有稀土金属矿床在空间分布与成因上,与燕山期花岗岩体密切相关,往往具有水平分带和垂向分带规律.     

面向全球战略新兴资源时代 探寻中国三稀矿产发展之路

正"三稀矿产"是稀土、稀有金属和稀散元素矿产的统称,具体包括镧、铈、镨、钕、钷、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥、钪、钇17种稀土元素;铌、钽、锂、铍、锆、铪、锶、铷、铯9种稀有金属;镓、锗、铟、铊、铼、镉、硒、碲8种稀散元素。这34个矿种产量不大,     

铷和铯的应用前景及其制约因素

文章对铷和铯的资源特征、用途、发展前景及制约因素进行了分析。铷和铯在地壳中分布并不稀少,因赋存状态而造成的提取困难是其稀贵的主要原因,由于其应用领域特殊以及价高的原因,整个社会的需求量并不大,其应用前景取决于应用领域的拓展和低成本提取技术的发展。通讯、化工、环保、能源以及深部钻井领域发展会增加对这两种金属及其化合物的需求,离子交换法和溶剂萃取法的发展可望降低其提取成本,能够促使其应用于更广泛的领域。     

某地铯榴石的形成条件及找矿标志

本文研究了某地含铯榴石伟晶岩的分布规律及特征后,认为铯在伟晶岩浆晚期的富集,是由于挥发组分的集中、岩脉局部膨大、致密围岩的作用等条件而引起的。因此,分异晚期形成的锂云母微斜长石纳长石伟晶岩、岩脉的膨大部位、致密块状围岩是寻找铯榴石的重要标志。     

原子吸收光谱法测定土壤及钾素肥料中的钾

钾是植物三大必需元素之一,土壤中钾的测定多用火焰光度法,钾素肥料中钾的测定一般以四苯硼钾重量法测定。钾的原子吸收光谱法测定多通过稀释并加入铯盐做电离抑制剂后测定,这样,可以增加分析手续和试剂消耗,同时大倍量的稀释也引入分析误差,     

中国食管癌与土壤环境中元素的相关性

利用土壤元素资料 2 0 6 94 4 8个数据 ,食管癌死亡调查资料 1750 80例 ,研究了食管癌死亡率与人群生存的土壤环境中元素的相关性。结果表明 ,铅、硒、铷、铯、镁、钙、镓、铊、钍、铀、锡、铪、铋、钼、溴、碘元素与食管癌死亡率有相关性     

中国大肠癌与土壤环境中元素的相关性研究

利用土壤元素资料2069448个数据,大肠癌死亡调查资料42480例,研究了大肠癌死亡率与土壤环境中砷、镉、钴、铬、铜、氟、汞、锰、镍、铅、硒、钒、锌、锂、钠、钾、铷、铯、银、铍、镁、钙、锶、钡、硼、铝、镓、铟、铊、钪、钇、镧、铈、镨、钕、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥、钍、铀、锗、锡、钛、锆、铪、锑、铋、钽、碲、钼、钨、溴、碘、铁等61个元素的相关性.结果表明.砷、钒、铯、铊、铀、锑元素与大肠癌死亡率有相关性.等级相关分数分别为-0.5123(p＜0.005),-0.3179(p＜0.05),-0.3190(p＜0.05),-0.4552(p＜0.01),-0.4857(p＜0.005),-0.3232(p＜0.05)     

全差示光度法测定化探样品中痕量铀

文本所述的是测定化探样品中微量铀的方法。试样经酸分解,制备为盐酸、氯化钠溶液,通过742阴离子交换树脂分离Th、TR、Zr、Ti和V等干扰元素,用水解脱铀,在pH=7.9,以Br-PADAP显色,全差示光度法测定铀。方法灵敏度为0.0004μg/ml/0.005A′。     

水中痕量铬(总铬及六价铬)的催化极谱测定

本文提出了在 CYDTA.α,α—联吡啶、亚硝酸钠、氯化铵、氢氧化铵体系中测定水中痕量铬的方法。由于在底液中加入了少量的 CYDTA.,不但消除了铁的严重干扰,而且保持了铬催化波灵敏度的特点。并进行了测定条件试验和其它离子的干扰试验,选择了最佳测定条件,拟定了可不经分离直接测定总铬的方法。此方法快速、简便,重现性好,其检测限为0.2ppb。六价铬的测定,采用阳离子树脂交换分离三价铬后,按测定总铬的方法进行。     

矿化期同位素年龄测定初探

矿化期同位素年龄测定工作的成败,室内选样和元素分离测试技术是关键。根据我们多年的工作实践,本文着重总结、讨论了以下几个问题:根据铷锶的化学和矿物学特征确定含铷锶的样品;研究矿体围岩蚀变的特征、期次,并从中选出满足Rb-Sr等时线年龄方法所要求的样品;对铷锶封闭体系作辩证的分析与处理;室内元素的分离和测试技术如何达到低本底,高灵敏度,高精度。     

Extraction of organochlorine pesticides in sediments using soxhlet,ultrasonic and accelerated solvent extraction techniques

The application of soxhlet, ultrasonic and accelerated solvent extraction techniques to the analysis of six organochlorine pesticides (α-HCH, β-HCH, γ-HCH, o, p'-DDT, p,p'-DDT and p, p'-DDE) in Taihu Lake sediment samples is described. It was found that the limits of quantification ranged from 0.002μgg-1 to 0.004μgg-1, and the recoveries of organochlorine pesticides with the three extraction techniques were acceptable (>80.7%). With a mass selective detector, better results were obtained by accelerated solvent extraction using hexane-acetone (1:1) as compared with soxhlet and ultrasonic extraction. It was shown that the accelerated solvent extraction was the optimum technique for the analysis of organochlorine pesticides in sediments. The general features of the three extraction techniques are also presented.     

Evaluating the performances of accelerated-solvent extraction, microwave-assisted extraction, and ultrasonic-assisted extraction for determining PCBs, HCHs and DDTs in sediments

Three extraction techniques have been recently used for the quantitative extraction of semi-volatile organic pollutants in sediments, i.e. accelerated solvent extraction (ASE), microwave assisted extraction (MAE) and ultrasonic assisted extraction (UAE). However, their extraction efficiencies have rarely been quantitatively compared using rigorous mathematical methods. In this paper, one-way analysis of variance (ANOVA) was employed to evaluate the performance of ASE, MAE and UAE in the overall extraction of PCBs, DDTs and HCHs by analysis of their recoveries from the Standard Reference Material IAEA-417, a sediment sample certified by many international laboratories. Conclusions were drawn at a significance level of P ≤ 0.05. No significant differences were found among the mean values for method recoveries using ASE, MAE and UAE. The mean values for real recoveries using ASE and MAE were nearly identical, but the real recovery using UAE was much lower. The concentrations of all PCBs, DDTs and HCHs except for CB52 and o,p′-DDT using UAE were the lowest. Comparing the results obtained using ASE with MAE, the concentrations of CB28, CB52, CB138, α-HCH, β-HCH, p,p′-DDE and p,p′-DDD were nearly identical, while the concentrations of other compounds were significantly different. Based on the low recoveries, it was concluded that UAE is a relatively inefficient extraction method, while ASE and MAE are equivalent methods. Taking into consideration the relative standard deviation (RSD) values, solvent volume, extraction time, and purchasing costs of the apparatus, MAE was considered superior to ASE for extraction of PCBs, DDTs and HCHs.     

矿石中红柱石含量的化学法测定

运用化学法测定矿石中红柱石含量,关键是溶剂的选择。当矿样中存在黑云母、石榴石、石英等矿物时,可采用NH_4F—HNO_3作选择溶剂,经对试样20次测定,其RSD(%)=5.30%。当矿样中存在有十字石时,可采用NH_4HF_2—HNO_3作选择溶剂,通过十字石和红柱石不溶解率的差异将二者分离开,然后用联立方程和经验公式运算求出红柱石的含量。本法对试样8次测定,其RSD(%)=3.86%。     

海水介质中漂白珍珠长麻率研究

以海水为溶剂进行珍珠漂白,探讨双氧水浓度、漂白液pH值和漂白时间与珍珠长麻情况之间的关系。结果表明:从抑制珍珠长麻方面考虑,最佳双氧水的浓度为5%,漂白液pH值为8.60,漂白时间为3d。     

Metabolomic Fingerprint of the Model Ciliate,Tetrahymena thermophila Determined by Untargeted Profiling Using Gas Chromatography-Mass Spectrometry

The ciliate Tetrahymena is a valuable model organism in the studies of ecotoxicology. Changes in intracellular metabolism are caused by exogenous chemicals in the environment. Intracellular metabolite changes signify toxic effects and can be monitored by metabolomics analysis. In this work, a protocol for the GC-MS-based metabolomic analysis of Tetrahymena was established. Different extraction solvents showed divergent effects on the metabolomic analysis of Tetrahymena thermophila. The peak intensity of metabolites detected in the samples of extraction solvent Formula 1(F1) was the strongest and stable, while 61 metabolites were identified. Formula 1 showed an excellent extraction performance for carbohydrates. In the samples of extraction solvent Formula 2(F2), 66 metabolites were characterized, and fatty acid metabolites were extracted. Meanwhile, 57 and 58 metabolites were characterized in the extraction with Formula 3(F3) and Formula 4(F4), respectively. However, the peak intensity of the metabolites was low, and the metabolites were unstable. These results indicated that different extraction solvents substantially affected the detected coverage and peak intensity of intracellular metabolites. A total of 74 metabolites(19 amino acids, 11 organic acids, 2 inorganic acids, 11 fatty acids, 11 carbohydrates, 3 glycosides, 4 alcohols, 6 amines, and 7 other compounds) were identified in all experimental groups. Among these metabolites, amino acids, glycerol, myoinositol, and unsaturated fatty acids may become potential biomarkers of metabolite set enrichment analysis for detecting the ability of T. thermophila against environmental stresses.     

Isolation,Identification, and Quantitative Determination of Saponin in Apostichopus japonicus by HPLC-DAD

Apostichopus japonicus is an important invertebrate that is widely used as a tonic food in Asian countries.The purpose of this study is to purify and identify a class of compound,the saponins,from the body wall of A.japonicus,and to establish a new me-thod to determine the quantity of saponins in the sea cucumber.In this study,the saponins of A.japonicus,cladoloside A(CA),were ob-tained from 80%ethanol extract by column chromatography for the first time and were characterized using the spectral method.The resulting purified saponins were then profiled using ¹HNMR,¹³CNMR,and ESI-MS,which revealed the CA molecular formula of C₅₃H₈₂O₂ and contained a triterpenoid backbone,a methylglucopyranosyl moiety,a quinovopyranosyl,and two xylopyranosyls.A me-thod for the quantitative determination of CA,comprising microwave-assisted extraction,high-performance liquid chromatography,and diode array detector method,was established.Extraction efficiency was optimized by changing microwave power,extraction sol-vent,volume,time,and temperature.Results showed that under the optimum conditions(extraction time of 10 min,temperature of 45℃,and solvent of 25 mL 70%ethanol under 400 W),the detection limit of CA was 0.0015 mg mL^?1,and the recoveries of CA from samples at spiking levels of 10,20,and 50μg g^?1 ranged from 90.1%-104%.The proposed method was successfully applied to ana-lyze the saponins in different tissues of A.japonicus collected in different seasons.The method developed in this study can provide quantitative technical support for the quality control of A.japonicus.     

Culture of yeast cells immobilized by alginate-chitosan microcapsules in aqueous-organic solvent biphasic system

Immobilization biocatalysis is a potential technology to improve the activity and stability of biocatalysts in nonaqueous systems for efficient industrial production. Alginate-chitosan(AC) microcapsules were prepared as immobilization carriers by emulsification-internal gelation and complexation reaction,and their contribution on facilitating the growth and metabolism of yeast cells were testified successfully in culture medium-solvent biphasic systems. The cell growth in AC microcapsules is superior to that in alginate beads, and the cells in both immobilization carriers maintain much higher activity than free cells,which demonstrates AC microcapsules can confer yeast cells the ability to resist the adverse effect of solvent.Moreover, the performance of AC microcapsules in biphasic systems could be improved by adjusting the formation of outer polyelectrolyte complex(PEC) membrane to promote the cell growth and metabolic ability under the balance of resisting solvent toxicity and permitting substrate diffusion. Therefore, these findings are quite valuable for applying AC microcapsules as novel immobilization carriers to realize the biotransformation of value-added products in aqueous-solvent biphasic systems.     

利用小杂鱼、低值鱼提取浓缩鱼蛋白

以小杂鱼、低值鱼为原料,采用溶剂萃取法研究了溶剂种类、温度、时间和溶剂量对鱼蛋白提取过程中脱水、脱脂、脱色和脱腥的影响,筛选出提取浓缩鱼蛋白的最佳工艺条件。结果表明,在该工艺条件下制得的浓缩鱼蛋白,其蛋白质含量高达９２．２８％,脂肪含量仅为０．０９２％。     

Dissolved copper, lead and cadmium in Pingtan waters, East China Sea

mODUCTIONTheislandsOfHaitan,Yuo,Dalian,DowiangandCaoguinPingtanCoUntyofFu-jianProvincearetogetherthewhtoasPingtan(25'l5'-25o45'E,l19"32'-12o"lo'N,EaStChinaSea).AmngthemHaitangIslanisthedrinoneinPingtanCotmty,andthelargestinFuianProvince.RngtanhaSanatuIalfishinggroUn(SeduMOUntaln)beingrenownedboghoutthecOUnnyandawelldeVfoPedaqUacultUreindusny.Pingtanwa-tersresotirceswerestirveyedforthefirsttimebytheauthorssothattheknowedgegainedcanbeaPPliedforbettereaploitahon,PIDechon,andde…     

CTAB对改善Cr(VI)萃取的研究

以煤油为溶剂,TBP为萃取剂,研究了CTAB对于Cr(VI)萃取率的影响。结果表明,CTAB能够有效改善Cr(VI)迁移效果,且在一定条件下,可使Cr(VI)萃取率提高到98%,应用于实际电镀废液,回收率在90%以上。