小花玄参中微量金属元素分析

采用干式灰化法分解样品,火焰原子吸收光谱法测定小花玄参不同部位中微量金属元素含量.小花玄参不同部位均含有钙、铁、锰、镁、铜和锌等微量金属元素,其中钙、铁、锰的含量较高,锌、镁的含量较低;6种微量金属元素在块根中含量均高于茎叶;加标回收率在95.3%~104.1%之间,相对标准偏差小于2%,具有较高的精密度与准确度.为小花玄参的质量控制和开发利用提供了重要依据.     

火焰原子吸收光谱法连续测定辣椒中的铜、锌、铁、锰

研究了辣椒中金属元素的含量和火焰原子吸收光谱法在同一体系中测定辣椒中微量元素铜、锌、铁、锰的方法,考察了硝酸、过氧化氢的不同用量的影响和在同一体系中铜、铁、锌、锰的相互干扰。为其进一步利用提供了一定依据,取得了较理想的效果。     

广西黑老虎中微量元素测定

采用原子吸收光谱法测定广西黑老虎中锰、铁、铜、锌、镁、钙等6种微量元素,并与笋干和16种蔬菜中6种微量元素含量进行比较,结果发现,黑老虎中锰、铁、铜、锌、镁、钙等6种微量元素含量均较高,其中锰、钙、铜、锌含量高于笋干,锰、铁、铜、锌含量远远高于16种蔬菜中微量元素的含量,钙含量高于部分蔬菜含量。提示广西黑老虎中含有丰富的人体所需微量元素,作为药用植物,具有极高的药用价值。     

铬(Ⅵ)-二乙基二硫代甲酸钠共沉淀-原子吸收光谱法测定环境水样中铁、锰、锌、镉

提出了以二乙基二硫代甲酸钠螯合铬(Ⅵ)作为载体共沉淀富集水体中铁、锰、锌和镉的方法。沉淀经离心分离,甲基异丁酮溶解后,以微量进样300μL火焰原子吸收光谱法测定铁、锰、锌,以石墨炉原子吸收光谱法测定镉。用水样10.0 mL,在pH 4.6的邻苯二甲酸氢钾缓冲介质中加入20 g.L-1重铬酸钾溶液150μL,20 g.L-1DDTC溶液1.0 mL可达到完全共沉淀分离,所得沉淀经离心分离后用甲基异丁酮2.0 mL溶解,并用于AAS分析。在优化的条件下,铁、锰、锌和镉的检出限(3σ)分别为9.0,6.8,1.8,0.03μg.L-1,相对标准偏差(n=6)在1.8%~3.8%之间。方法用于实际水样的测定,用标准加入法测得回收率在93.7%~105.0%之间。     

六种生物制剂中锌、铜、铁、铬、锰、镍含量的测定

利用火焰原子吸收法直接测定生物制剂样品中锌,铜,铁,铬,锰,镍的含量。结果表明,六种生物制剂中以蚂蚁因子注射液中的铜、铜,铁,铬,锰,镍含量最高;不同的生物制剂中六种微量元素的含量有一定差别。     

提取对中药材中金属元素含量的影响

中药材中常因含有一定量的重金属元素而使其质量受到影响。采用火焰原子吸收分光光度法测定几种常用中药材提取前后金属元素铜、铅、镉、锰、锌、铁的含量变化。结果表明,大部分中药材提取后金属元素含量均有不同程度的下降,这为去除中药材中的铅、铜等重金属提供了参考依据。     

碘离子胁迫对绿豆萌发过程4种微量元素的影响

用火焰原子吸收法测定绿豆萌发过程中铜、铁、锰和锌的含量,研究不同含量碘离子胁迫对绿豆萌发过程中生理活动的影响。结果显示,各含量培养液所培养的绿豆芽苗中4种元素含量随培养时间的增加而显著降低,适当质量浓度的碘离子(20~80 mg/L)可以促进绿豆对铜、铁、锌的溶出,但碘离子质量浓度过高(100 mg/L)时将抑制绿豆对铜、铁、锰的溶渗出,培养末期绿豆均能从培养液中重新利用铁、锰、锌3种微量元素。     

微波消解原子吸收光谱法测定鱼肉中14种金属元素

以微波消解法处理鱼肉样品,用火焰原子吸收光谱法测定鲶鱼、胖头鱼、小黄花鱼、鲫鱼4种鱼肉中的钾、钠、镁、钙、铁、钴、镍、铜、锌、锰、锶、铬、镉和铅元素含量。鱼肉样品以5 mL HNO_3和1 mL H_2O_2在一定的温度和时间下经微波消解处理后,在最佳工作条件下测定以上14种金属元素含量,各元素的加标回收率在95.4%~104.6%之间,检出限为0.001 1~0.012 9μg/mL,标准工作曲线的线性相关系数均大于0.999,该方法测定结果的相对标准偏差为0.71%~4.28%(n=10)。该方法适用于鱼肉中钾、钠、镁、钙、铁、钴、镍、铜、锌、锰、锶、铬、镉和铅14种金属元素的含量测定。     

火焰原子吸收光谱法测定感冒灵颗粒中的金属元素含量

目的建立感冒灵颗粒中6种金属元素的火焰原子吸收测定方法。方法采用微波消解样品,利用火焰原子吸收光谱法测定感冒灵颗粒中钙、镁、铁、锌、铜和锰含量。结果该测定方法的回收率在95.11%~106.23%之间,市售感冒灵颗粒中含有一定的金属元素,锰和钙含量较高。结论该法简便、准确,结果令人满意。     

火焰原子吸收光谱法测定温里类中草药中痕量元素

应用火焰原子吸收光谱法测定了6种温里类中草药(即香附子、干姜、肉桂、细辛、高良姜及小茴香)中4种痕量元素铜、铁、锌及锰的含量。样品用硝酸-高氯酸(4+1)混合酸消解后加入过氧化氢,并蒸发至近干,残渣溶于硝酸(1+99)溶液中后用于火焰原子吸收光谱法分析,标准曲线分别用上述4种元素的标准溶液制作。按此方法分析了上述6种中草药中铜、铁、锌及锰4种痕量元素,并在此基础上用标准加入法作了回收试验,测得4种痕量元素的回收率在93.5%~109.0%之间。     

Metal-Directed Formation of Tetra-, Hexa-, Octa-, and Nonanuclear Complexes of Magnesium,Calcium, Manganese,Copper, and Cadmium

Efficacious metal control of self-assembly of dialkylketipinate dianions leads to completely different supramolecular assemblies. The structures of grid 1 , double-decker 2 , triple-decker 3 , and metalla-spherand 4 were characterized by X-ray crystallographic analyses or by NMR spectroscopy.     

Optimization of parameters for semiempirical methods. III Extension of PM3 to Be,Mg, Zn,Ga, Ge,As, Se,Cd, In,Sn, Sb,Te, Hg,Tl, Pb,and Bi

Using a recently developed procedure for optimizing parameters for semiempirical methods,¹ PM3 has been extended to a total of 28 elements. Average ΔH_f errors for the newly parameterized elements are Be: 8.6, Mg: 8.4, Zn: 5.8, Ga: 14.9, Ge: 11.4, As: 8.5, Se: 11.1, Cd: 2.6, In: 11.3, Sn: 9.0, Sb: 13.7, Te: 11.3, Hg: 6.8, Tl: 6.5, Pb: 7.4, and Bi: 10.9 kcal/mol. For some elements the paucity of data has resulted in a method, which, while highly accurate, is likely to be only poorly predictive.     

猪胰脏中铁钙镁铜铅锌镉锰钴镍的测定

采用硝酸－过氧化氢在自动回流消化仪中消化猪胰脏,火焰原子吸收光度法测定铁、钙、镁、铜、锌、铅、镉、锰、钴、镍的含量。,方法简便,快速,结果令人满意,并对猪胰脏食用价值进行了评价。     

Prediction of the enthalpy of vapourisation for anhydrides,formates, acetates,propionates, butyrates,esters, and ethers

Four analytical correlations based on the use of the corresponding states principle were used to calculate the enthalpy of vapourisation of fluids. Three of these correlations require as inputs the critical temperature and the acentric factor. The fourth requires a molecular Lennard–Jones parameter and the acentric factor. Results for 184 polar and non-polar fluids grouped into 9 families are compared with the values accepted by the Design Institute for Physical Property (DIPPR) project. Recommendations are given for the use of each model and for the choice of the adequate model for each family of fluids.     

ICP-AES法测定铝中铁、硅、铜、镓、镁、锌、锰和钛

用 50g L氢氧化钠溶液溶解铝样品 ,硝酸 (1 1 )酸化 ,以ICP AES测定其中铁、硅、铜、镓、镁、锌、锰和钛等 8种杂质元素。     

ICP-MS测定化妆品中铍、镉、铊、铬、砷、碲、钕、铅

目的：建立化妆品中铍、镉、铊、铬、砷、碲、钕、铅8种有害元素的测定方法。方法：采用电感耦合等离子体质谱法,样品采用微波消解,以钇、锂、铟、铋为内标作定量分析。结果：各元素和内标元素在一定浓度范围内的质量数比值均与浓度呈良好的线性关系,线性方程的相关系数均大于0.9998,平均回收率为95%~104%,相对标准偏差(RSD)均小于3%。结论：该方法灵敏度高,准确,可为化妆品中上述元素的限量检查提供参考。     

Thin-layer chromatographic separation of aldrin,dieldrin, γ-hexachlorocyclohexane,malathion, ethyl-parathion,pentachlorophenol, and of chlordane,dieldrin, γ-hexachlorocyclohexane,malathion, ethyl-parathion,and pentachlorophenol from each other

A thin-layer chromatographic method is reported for the separation of aldrin (or chlordane), dieldrin, γ-hexachlorocyclohexane, malathion, ethyl-parathion, and pentachlorophenol from each other. The procedure, however, does not separate aldrin and chlordane from each other although it does separate either pesticide from the other components. The method employs alumina plates with n-hexane:xylene:benzene:toluene:cyclohexane:methyl cyclohexane (50:50:50:50:50:50:) as developing solvent.     

Enthalpies of dilution of aqueous solutions of formamide,acetamide, propionamide,andN,N-dimethylformamide

The enthalpies of dilution of aqueous solutions of formamide, acetamide, propionamide,N,N-dimethylformamide, and sucrose have been measured from about 0.15 to 2.0 moles-kg ^–1 at 25.0°C. The results of the enthalpy measurements were used to calculate the pairwise enthalpies of interaction for each compound with itself. The equation of Savage and Wood together with their interaction parameters are used to predict the experimental results. All of the predictions are within the standard deviation of the original correlation of Savage and Wood (±220 J-kg-mole ^–2 ). Detailed examination of the results shows that specific effects are present but they are less than 220 J-kg-mole ^–2 . Results on urea and substituted ureas are used to determine interaction coefficients for a urea group with itself and with another CH ₂ group. The result,H _U,U =–280 andH _{U,CH 2} =29 J-kg-mole ^–2 , is an improvement on the previous arbitrary assignment of parameters for urea interactions.