萃取-缝式石墨管原子捕集火焰原子吸收法测定水样中痕量锑(Ⅲ)和锑(Ⅴ)

研究了锑(Ⅲ)和锑(Ⅴ)在DDTC—MIBK体系中的萃取和反萃取行为，用缝式石墨管原子捕集技术结合火焰原子吸收法测定了水样中的痕量锑(Ⅲ)和锑(Ⅴ)，线性范围为2．0—60μg／L，检出限为0．4μg／L，特征浓度为1．5μg/L／1％吸收，相对标准偏差为2．6％，锑回收率为93．0％一105．0％。     

ICP-AES法测定玻璃器皿中铅、镉、砷、锑溶出量的研究

采用ICP-AES法同时测定玻璃器皿中铅、镉、砷、锑的溶出量,对ICP-AES法测定4％乙酸浸泡液时分析线的选择和射频功率、载气压力的影响,以及基体和共存离子的干扰情况等进行了研究。4种元素的检出限分别为铅0．012mg／L,镉0．0009mg／L,砷0．015mg／L,锑O．015mg／L,加标回收率为97．3％～102．0％,测定结果的相对标准偏差为0．45％～1．36％（n=6）.     

氢化物发生-原子荧光光谱法同时测定水中砷和锑

建立在硝酸介质中用氢化物发生-原子荧光光谱法同时测定水中砷和锑的方法。优化了仪器工作条件、酸度、硼氢化钾及还原剂浓度。砷、锑的线性范围为0～10．0μg／L;检出限分别为0．02,0．01μg／L;测定结果的相对标准偏差分别为1．77％～3．72％,2．95％～4．87％（n=6）;加标回收率分别为98％106％,96％105％。该法操作简便,灵敏度高,快速,便于推广,适用于水中砷和锑的同时测定。     

氢化物发生电感耦合等离子体原子发射光谱法同时测定水和生物样品中砷、铋、锑和硒

研究了一种小型同心氢化物发生器配置一个气液分离器后与多道ICP－AES联用，同时测定水和生物样品中砷、铋、锑、硒的方法。检出限为砷0.4μg/L，铋0.5μg/L，锑1．4μg／L，硒0.5μg／L，相对标准偏差为砷2.7％，铋1．5％，锑2．7％，硒1．9％。用本法测定美国和国家标准物质中的氢化元素，结果满意。     

纳米二氧化钛富集石墨炉原子吸收光谱法测定环境水样中痕量锑

研究了纳米二氧化钛对锑(Ⅲ)和锑(Ⅴ)的吸附性能。研究结果表明：在pH1～lO范围内,纳米二氧化钛对锑(Ⅲ)和锑(Ⅴ)的吸附率均可达98％以上。建立了纳米二氧化钛富集锑(Ⅲ)和锑(Ⅴ),石墨炉原子吸收光谱法测定环境水样中痕量总锑的方法。该法的检出限(3d,n=6)为0．73μg／L,相对标准偏差(RSD)小于2．94％,回收率在92％～95％之间。     

氢化物发生-双道原子荧光光谱法同时测定钢中砷和锑

建立了一种氢化物发生双道原子荧光光谱法同时测定钢中痕量砷和锑的方法．对实验条件进行了优化,在最佳工作条件下,砷和锑的检出限分别为0．012ng／g和0．034ng／g,RSD分别为1．24％和1．97％．将本法应用于钢中的砷和锑的测定,采用加标回收实验控制方法的准确性,砷的回收率为96％～98％,锑的回收率98％～102％．     

阻抑速差催化光度法测定痕量色氨酸和酪氨酸

研究了色氨酸、酪氨酸在硫酸环境中抑制碘对亚砷酸与硫酸铈氧化还原反应的催化作用及动力学条件。在0．001mol／L Ce(SO4)2,0．00125mol／L As2O3,0．013mg／L KI,0．025g／L和0．25g／L NaCl溶液中测定色氨酸和酪氨酸,其线性范围分别为0．0～0．65mg／L,0．0～4．0mg／L和0．0～1．3mg／L。0．10～4．0mg／L,用联立方程分别求出各自含量。用此法对醇溶蛋白质和混合氨基酸溶液中色氨酸和酪氨酸进行测定,混合氨基酸的色氨酸、酪氨酸测量值为0．8037g／L,3．591g/L;蛋白质的色氨酸、酪氨酸测量值为1．8g/kg、3．43g/kg;回收率在88％～109％;色氨酸和酪氨酸的RSD分别为4．8％和5．2％,结果满意。     

FCC催化剂中锑含量的测定

用火焰原子吸收法测定催化剂中锑含量，考察了消解温度、消解时间、酸度等对测量结果的影响，优选出了最佳分析测试条件．所建方法简便、灵敏、准确，该方法回收率在95％-99％之间，变异系数小于2．5％，最小检出限为0．092mg／L.     

锑(Ⅲ)-溴邻苯三酚红导数示波极谱法测定锌浸出液中的锑

在pH2．5的硫酸介质中，锑(Ⅲ)与溴邻苯三酚红生成的络合物产生一个灵敏的导数极谱波，其导数波峰值电位为-0．56V(vs．SCE)，线性范围0．0l～0．5μg／mL，许多离子不干扰测定，不需要分离与富集，直接测定锌浸出液中不同含量的锑。     

氢化物－原子吸收光谱法测定六味地黄丸中砷和锑

本文建立了氢化物原子吸收光谱法测定六味地黄丸中砷和锑的方法。方法的相对标准偏差砷为１．３％、锑为１．６％，回收率在９０％～１１０％之间，检出限分别为砷０．０６ｎｇ／ｍＬ、锑０．１ｎｇ／ｍＬ。本方法可用于中成药中砷和锑的测定。     

锑铅阳极泥中金的分析方法研究

针地用活性炭富集，原子吸收法测定锑铅阳极泥中金存在的主要问题，通过改进制样方法，抑制锑铅水解，选择合适的洗涤剂浓度，获得了满意的分析结果。与火试金法相比，显著地缩短了分析时间，降低了劳动强度及分析成本、消除了铅的挥发污染，实用性强，具有较高的精密度和准确度。     

电感耦合等离子体质谱法检测农作物土壤中的镉、锡、锰、锑、钒、钛、锶金属污染物残留

建立全自动石墨消解- 电感耦合等离子体质谱(ICP-MS)法检测农作物土壤中的镉、锡、锰、锑、钒、钛、锶金属污染物残留的分析方法.随机采集农作物土壤,取约200 g,置于烘箱中烘干,烘干后的样品用粉碎机粉碎,精密称取粉碎后的样品约0.25 g,置于聚四氟乙烯材质的消解罐内,按既定消解程序进行自动消解处理,得样品溶液,上...     

玩具、铅笔中可溶性砷、锑、硒的形态分析

对玩具、铅笔中可溶性砷、锑、硒的形态分析方法进行了研究,对原子荧光光谱法测定不同价态砷、锑、硒的方法进行了优化,建立了砷、锑、硒的原子荧光光谱形态分析方法。该方法样品加标回收率为82.0%~110.0%,测定结果的相对标准偏差为1.35%~2.22%(n=10)。     

空气 - 乙炔火焰原子吸收法连续测定铜粉中微量Fe、Pb、Sb、Zn和Ni

用HNO3-HCl溶解试样,在几个相同量的试液中,分别加入质量浓度依次递增的5种元素的标准溶液,用火焰原子吸收法连续测定了Fe、Pb、Sb、Zn和Ni的含量,建立了优化的仪器测定条件,并对可能存在的元素进行了干扰试验。结果表明,Fe、Pb、Sb等5种元素的回收率为98.0%～102.3%,相对标准偏差为1.4%～2.5%。     

王水密闭溶矿-电感耦合等离子体原子发射光谱法测定锑矿石中的锑

建立了王水密闭溶矿-电感耦合等离子体原子发射光谱法测定锑矿石中锑的方法。研究了溶矿时间、溶矿温度、溶液的酸度、基体效应对测定的影响。样品的相对误差在1.10%~13.33%,11次独立测定的相对标准偏差均小于2%。经标准物质验证,结果满意。     

Relative Stability of Multiple Bonds between Germanium and Stibium. A Theoretical Study

Substituent effects on the potential energy surface of XGeSb (X=H, Li, Na, BeH, MgH, BH₂, AlH₂, CH₃, SiH₃, NH₂, PH₂, OH, SH, F, and Cl) were investigated by using B3LYP/Def2‐TZVP, B3PW91/Def2‐ TZVPP CCSD (T)//B3LYP/Def2‐TZVP methods. The isomers include structures with formal double (Ge=SbX) and triple (Xge=Sb) bonds to germanium‐stibium, so a direct comparison of these types of species is possible. Our model calculations indicate that electropositively substituted Ge=SbX species are thermodynamically and kinetically more stable than their isomeric Xge=Sb molecules. Moreover, the theoretical findings suggest that only the organic substitutions (such as CH₃) can make triply bonded Xge=Sb molecule more stable than the doubly bonded Ge=SbX species.     

Density functional studies on the thermal aryl migration in beta-dicarbonyl ylides and related compounds

The potential energy surfaces for the unimolecular rearrangement reactions of beta-dicarbonyl ylides and beta-carbonylimidoyl ylides have been studied using the density functional method. All of the stationary points were determined at the B3LYP/LANL2DZdp level of theory. Four kinds of beta-dicarbonyl ylide species containing fluorine, chlorine, bromine, and iodine have been chosen in this work as model reactants. Also, five beta-carbonylimidoyl ylide molecules bearing nitrogen, phosphorus, arsenic, stibium, and bismuth have been used in the present study. In the latter reactions, two different reaction pathways have been proposed: (1) a 1,2-aryl shift to the pnicogen element and (2) A 1,2-aryl shift to the oxygen atom. That is, path 1 is reactant-->TS-1-->Pro-1 and path 2 is reactant-->TS-2-->Pro-2. Our theoretical findings strongly suggest that all intramolecular aryl migration reactions proceed via a one-step (concerted) reaction path. For the beta-dicarbonyl ylide species, the smaller the atomic number of the halogen atom, the lower the barrier height, the larger the reaction enthalpy, and, in turn, the easier it is to undergo the intramolecular aryl migration under thermal conditions. Alternatively, the heavier the pnicogen element in the beta-carbonylimidoyl ylides, the smaller the barrier height, and the larger the migration reaction enthalpy, even under thermal conditions. The results obtained allow a number of predictions to be made.     

Production of ginseng saponin and polysaccharide by cell cultures ofPanax notoginseng andPanax ginseng

The effects of various combinations of the two kinds of phytohormones, auxin and cytokinin, on cell growth and production of ginseng saponin and polysaccharide were investigated in suspension cultures ofPanax notoginseng. It was found that a high concentration of kinetin (KT) (7 mg/L) seriously inhibited cell growth, but that of benzyl adenine (BA) did not. Under 0.7 mg/L of cytokinin (i.e., KT and BA), 2,4-dichlorophenoxy acetic acid (2,4-D) at 0.2 mg/L was better for the cell cultures than that at 2 or 20 mg/L; and for both naphthalene acetic acid (NAA) and indole acetic acid (IAA), 20 mg/L was their best level for the cell cultures. The highest cell concentration of 11.9 g/L (by dry wt) was obtained with the combination of 0.2 mg/L of 2,4-D and 0.7 mg/L of BA. The highest saponin content of 13.9% was achieved under 2.0 mg/L IAA and 0.07 mg/L KT; its highest production, i.e., 1.13 g/L, was obtained at 0.2 mg/L of 2,4-D and 0.7 mg/L of KT. Under 20 mg/L NAA and 0.7 mg/L KT, the highest polysaccharide content and production were reached, i.e., 16.4% and 1.86 g/L, respectively. In this work, the effects of phytohormones onP. ginseng cell cultures were also studied. A high saponin production of 1.78 g/L was observed at 10 mg/L of indole butyric acid and 0.1 mg/L of BA, and the highest production of polysaccharide (1.95 g/L) was reached with the combination of 10 mg/L NAA and 0.1 mg/L KT.     

Fed-Batch production of glucose 6-Phosphate dehydrogenase using recombinant saccharomyces cerevisiae

The strain Saccharomyces cerevisiae W303-181, having the plasmid YEpPGK-G6P (built by coupling the vector YEPLAC 181 with the promoter phosphoglycerate kinase 1), was cultured by fed-batch process in order to evaluate its capability in the formation of glucose 6-phosphate dehydrogenase (EC.1.1.1.49). Two liters of culture medium (10.0 g/L glucose, 3.7 g/L yeast nitrogen broth (YNB), 0.02 g/L L-tryptophan, 0.02 g/L L-histidine, 0.02 g/L uracil, and 0.02 g/L adenine) were inoculated with 1.5 g dry cell/L and left fermenting in the batch mode at pH 5.7, aeration of 2.2 vvm, 30 degrees C, and agitation of 400 rpm. After glucose concentration in the medium was lower than 1.0 g/L, the cell culture was fed with a solution of glucose (10.0 g/L) or micronutrients (L-tryptophan, L-histidine, uracil, and adenine each one at a concentration of 0.02 g/L) following the constant, linear, or exponential mode. The volume of the culture medium in the fed-batch process was varied from 2 L up to 3 L during 5 h. The highest glucose 6-phosphate dehydrogenase activity (350 U/L; 1 U=1 micromol of NADP/min) occurred when the glucose solution was fed into the fermenter through the decreasing linear mode.     

电荷注入检测器电感耦合等离子体光谱仪测定非金属元素的分析性能

研究了电荷注入检测器ICP光谱仪测定非金属元素的分析性能。以S、P、As、Se为代表的非金属元素在170－800nm波段内最灵敏的谱线均处于175－200nm远紫外区内。在此区内等离子体有很低的光谱背景发射和良好的谱线测量和背景测量的光度精度。标准曲线线性动态范围在4个数量级。给出了As,Se,S,P主要分析线的灵敏度、线背比、背景等效浓度及检出限。在纯水溶液中的检出限分别为：As 189.142nm 0.003mg/L,P213.618nm 0.005mg/L,S 180.731nm 0.01mg/L,Se 196.090nm 0.009mg/L.