比值光谱导数法同时测定铝合金中铁,铜,锌

用比值光谱－导数分光光度法，在ｐＨ５．５缓冲溶液中，利用金属－２－（５－溴－２－吡啶偶氮）－５－二乙氨基酚（５－Ｂｒ－ＰＡＤＡＰ）－ＯＰ三元络合物显色体系，对混合物中铁，铜，锌三组分进行了同时测定。合成试样５次测定回收率在９７．３％－１０４．４％之间。应用于铝合金中铁，铜，锌的测定，各６次测定的ＲＳＤ分别为３．６６％，１．３８％，２．０３％。     

空气—C2H2火焰原子吸收光谱法测定中草药（鸦胆子,补骨脂）中…

用空气－Ｃ２Ｈ２火焰原子吸收光谱法测定了中草药中的Ｆｅ、Ｍｇ含量，讨论了测定条件，结果令人满意，方法的回收率：Ｆｅ９８．２０％－１０４．９％，ＣＶ１．０６％－１．０７％，Ｍｎ９９．４％－１０１％，ＣＶ＝０．５２％－１．９４％。     

乙基磺原酸钾—MIBK萃取原子吸收测定重晶石中铅,镉

本文较详细地研究了以乙基磺原酸钾作为金属分离的溶剂萃取试剂测定重晶石中铅，镉的条件，并确定了测定方法，铅和镉与乙基磺原酸钾反应生成白色络合物，该络合物在水相溶液中能定量地萃入甲基异丁基甲酮中。它们的回收率分别为９７％－１０３％和９６％－１０１％。铅和镉分别在０－６μｇ／ｍＬ和０－０．８μｇ／ｍＬ呈线性关系。本法可测定０．０００ｘ％－０．ｘ％Ｐｂ，０．０００ｘ％－０．０ｘ％Ｃｄ．     

溶剂萃取-火焰原子吸收法测定银杏叶提取物中铅镉

提出了用硝酸消解，KI－MIBK系统萃取，火焰原子吸收光谱法测定银杏叶提取物中痕量铅，镉的方法，铅，镉的相对标准偏差均小于4．5％，回收率分别在96．0％－100．0％和97．0％－102．0％之间。测定结果满意。     

动力学—两次标准加入法同时测定钼和钨

本文提出了动力学－两次标准加入法双组份同时测定的新方法，讨论了测定的基本原理；用停流ＦＩＡ光度法研究了钼和钨共同催化的Ｈ２Ｏ２－Ｉ＾－动力学反应体系，并建立了钼和钨同时测定的条件，用本法测定了钢样和模拟样品中的钼、钨含量，结果满意，钼和钨的回收率分别为９７％－１０２．６％和９８．２％－１０３％；相对标准偏差分别为２．８％－３．２％和２．１％－３．５％。     

SDM—1型耐硫催化剂甲烷化反应动力学：I.本征动力学模型

本文研究了ＳＤＭ－１型城市煤气耐硫甲烷化催化剂的本征动力学，在５７３－６７３Ｋ，０．３０－１．２０ＭＰａ的反应条件下，原料气的组成为Ｈ２ ４２－４５％，ＣＯ１１－２４％，ＣＨ４ １．８－１５％，ＣＯ２５．８－１７％，余者为Ｎ２气，采用幂函数模型回归的动力学方法为：     

微型镉柱还原分光光度法测定血清中一氧化氮

建立了微型镉柱还原法间接测定血清中一氧化氮的新方法。本方法还原硝酸根所需时间短，还原率达９５％以上，用于测定混合血清中一氧化氮。检测范围为０－１０００μｍｏｌ／Ｌ，相对标准偏差为１．７０％－２．４９％，对ＮＯ＾－３的回收率为９５．８％－１０４．０％，对ＮＯ＾－２的回收率为９３．６％－９６．８％。     

乳化剂OP存在下微分电位溶出法同时测定铅铜的研究

在乳化剂ＯＰ存在下及０．３ｍｏｌ／Ｌ ＨＣｌ介质中，铅，铜在峰电位－０．５５Ｖ及－０．３４Ｖ处分别有一灵敏的溶出峰。详细探讨了溶出分析的最佳条件。本方法已用于发酵酒，配制酒，蒸馏酒及饮料中铅，铜的直接测定，回收率为９０．６％－１１０％，ＲＳＤ为０．２％－８．２％，检出限为０．０２５－０．００５４μｇ／２０ｍＬ范围。     

控温消解-冷原子吸收方法测定水果蔬菜中微量汞

应用程序控温－湿法消解－氢化物发生－冷原子吸收光谱法对水果蔬菜中的汞的定量方法进行了研究和探讨。对程序控温消解仪的消解条件、氢化物－冷原子吸收的测定条件进行了探讨。在本文选择的条件下，回收率为86．99％－108．00％，相对偏差为4．6％－10．8％。该方法与国家标准方法相对照，无明显差异。     

比光谱导数-零交点法同时测定铜、锌、镍

在ｐＨ＝８的硼砂－ＨＣｌ缓冲溶液中，以乳化剂ＯＰ作增溶剂，Ｃｕ＾２＋，Ｚｎ６２＋，Ｎｉ＾２＋分别与５－Ｂｒ－ＰＡＤＡＰ形成稳定的配合物，用比光谱导数－零交点法同时测定铜，锌，镍，合成试样６次测定的相对标准偏差小于５％，铜，锌，镍的回收率分别为９７．０％－１０３．２％，９６．３５－１０４．８％和９５．２％－１０１．９％。     

Simultaneous determination of trace amounts of borate, chloride and fluoride in nuclear fuels employing ion chromatography (IC) after their extraction by pyrohydrolysis

An accurate and sensitive method based on the combination of pyrohydrolysis-ion chromatography (PH-IC) is proposed for the simultaneous separation and determination of boron as borate, chloride and fluoride in nuclear fuels such as U(3)O(8), (Pu,U)C and Pu-alloys. The determination is based on the initial pyrohydrolytic extraction of B, Cl and F from the samples as boric acid, HCl and HF, respectively, which are subsequently separated by ion chromatography (IC). The proposed method significantly improves the existing analytical methodology as it combines the determination of boron, a critical trace constituent in nuclear materials, along with F(-) and Cl(-) for chemical quality control measurements. Various experimental parameters were optimized to achieve maximum recoveries of the analytes during the pyrohydrolysis and to get better ion chromatographic (IC) separation of borate, F(-) and Cl(-) along with other anions such as CH(3)COO(-), NO(2)(-), NO(3)(-), Br(-), PO(4)(3-) and SO(4)(2-). Recoveries of more than 93% could be obtained for all the analytes in the sample (0.5-1.5 g) at 1200+/-25K and distilled with pre-heated steam at the flow rate of 0.3 mL/min. An isocratic elution with a mobile phase of 0.56 M d-mannitol in 6.5mM NaHCO(3) was used for the IC separation. The detection limits for B (as borate), F(-) and Cl(-) were 24, 13 and 25 microgL(-1), respectively. Precision of about 5% was achieved for determination of boron, Cl(-) and F(-) in the samples containing 1-5 ppm(w) of boron, and 10-25 ppm(w) of Cl and F. The method was validated with reference materials and successfully applied to the nuclear fuels. The methodology is easy to adapt on routine basis.     

Chemical control on the coordination mode of benzaldehyde semicarbazone ligands. synthesis, structure, and redox properties of ruthenium complexes

Reaction of benzaldehyde semicarbazone (HL-R, where H is a dissociable proton and R is a substituent (R = OMe, Me, H, Cl, NO(2)) at the para position of the phenyl ring) with [Ru(PPh(3))(3)Cl(2)] and [Ru(PPh(3))(2)(CO2)Cl2] has afforded complexes of different types. When HL-NO(2) and [Ru(PPh(3))(3)Cl2] react in solution at ambient temperature, trans-[Ru(PPh(3))(2)(L-NO2Cl] is obtained. Its structure determination by X-ray crystallography shows that L-NO2 is coordinated as a tridentate C,N,O-donor ligand. When reaction between HL-NO2 and [Ru(PPh(3))(3)Cl2] is carried out in refluxing ethanol, a more stable cis isomer of [Ru(PPh(3))(2)(L-NO2)Cl] is obtained. The trans isomer can be converted to the cis isomer simply by providing appropriate thermal energy. Slow reaction of HL-R with [Ru(PPh(3))(2)(CO2)Cl2] in solution at ambient temperature yields 5-[Ru(PPh(3))(2)(L-R)(CO)Cl] complexes. A structure determination of 5-[Ru(PPh(3))(2)(L-NO2)(CO)Cl] shows that the semicarbazone ligand is coordinated as a bidentate N,O-donor, forming a five-membered chelate ring. When reaction between HL-R and [Ru(PPh(3))(2)(CO2Cl2] is carried out in refluxing ethanol, the 4-[Ru(PPh(3))(2)(L-R)(CO)Cl] complexes are obtained. A structure determination of 4-[Ru(PPh(3))(2)(L-NO2)(CO)Cl] shows that a semicarbazone ligand is bound to ruthenium as a bidentate N,O-donor, forming a four-membered chelate ring. All the complexes are diamagnetic (low-spin d(6), S = 0). The trans- and cis-[Ru(PPh(3))(2)(L-NO2)Cl] complexes undergo chemical transformation in solution. The 5- and 4-[Ru(PPh(3))(2)(L-R)(CO)Cl] complexes show sharp NMR signals and intense MLCT transitions in the visible region. Cyclic voltammetry of the 5-[Ru(PPh(3))(2)(L-R)(CO)Cl] and 4-[Ru(PPh(3))(2)(L-R)(CO)Cl] complexes show the Ru(II)-Ru(III) oxidation to be within 0.66-1.07 V. This oxidation potential is found to linearly correlate with the Hammett constant of the substituent R.     

Determination of 36Cl in biological shield concrete using pyrohydrolysis and liquid scintillation counting

A method for the determination of 36Cl in biological shield concrete of nuclear reactors was developed. Cl in the concrete sample was extracted quantitatively by pyrohydrolysis at 900 degrees C and recovered in Na2CO3 solution for subsequent measurement of 36Cl by liquid scintillation counting. WO3 was used as an accelerator in the pyrohydrolysis. The Cl extraction procedure was optimized by investigating experimental conditions with the use of ion chromatography and its recovery was evaluated by the analysis of the geochemical reference samples. The detection limit of 36Cl was 0.02 Bq g(-1) for a sample weight of 2 g. The relative standard deviation was 3-7% for the samples containing 0.5 Bq g(-1) levels of 36Cl. The method was applied to determine 36Cl in biological shield concrete of the Japan Power Demonstration Reactor.     

The analysis of phosphorus and chlorine in natural waters by alpha-particle activation

Using activation by 16 MeV α-particles quantitative analysis has been carried out for P and Cl in natural waters with a reproducibility of ±5%. Limits of detection of 0.1 and 0.4 ppm were obtained for the two elements, respectively. The method is applied to the determination of P and Cl in water samples taken in the environment of Amsterdam.     

Chloride-enhanced atmospheric pressure chemical ionization mass spectrometry of polychlorinated n-alkanes

The use of high-performance liquid chromatography combined with chloride-enhanced atmospheric pressure chemical ionization for the determination of polychlorinated n-alkanes (PCAs, also called chlorinated paraffins or CPs) is described as an alternative to gas chromatographic methods. Atmospheric pressure chemical ionization in the negative ion mode formed exclusively [M+Cl](-) adduct ions and suppressed fragmentation when a chlorinated solvent was added. Limits of detection were 1-2 ng/microL for technical PCA mixtures. Response factors for single short-chain PCA homologues with different degrees of chlorination varied by not more than a factor of 6.5. The developed method was applied for the determination of the composition of technical PCA mixtures as well as for the analysis of PCAs in household commodities. Medium-chain PCAs were found in paint samples at concentrations of 8.2-11.5% (w/w), compared with 7.4-11.5% obtained by gas chromatography combined with electron ionization tandem mass spectrometry.     

Improvements in the N,N-diethyl-p-phenylenediamine method for the determination of free and combined residual chlorine through the use of FIA

In the determination of free and combined chlorine, the reaction of permanganate standards with N,N-diethyl-p-phenylenediamine (DPD) exhibits nonlinearity presumably because both the colored semiquinoid product and the colorless quinoid product are both formed. The titrimetric DPD method titrates both of the products while the colorimetric method monitors only the colored semiquinoid products. This results in a nonlinear response for the colorimetric method above 1.0 mg/l. as Cl(2). Under FIA conditions, the nonlinearity of the DPD colorimetric method is eliminated in the 0.1-5.0 mg/l. (as Cl(2)) range and the linear range is expanded to 0.1-8.0 mg/l. as Cl(2). Also, relative standard deviations are improved by 0.5-11% relative to the colorimetric method and 1.5-4.0% relative to the titrimetric method. The FIA method was developed further to sequentially determine both free and combined chlorine, since chloramine was found to have a negligible interference in the free chlorine determination.     

Simultaneous determination of bisphenol A and its halogenated derivatives in river water by combination of isotope imprinting and liquid chromatography-mass spectrometry

A restricted access media-molecularly imprinted polymer (RAM-MIP) for [2H16]bisphenol A (BPA-d16) was prepared by a multi-step swelling and polymerization method using 4-vinylpyridine as a functional monomer and ethylene glycol dimethacrylate as a cross-linker, followed by hydrophilic surface modification using glycerol dimethacrylate and glycerol monomethacrylate as hydrophilic monomers. The obtained RAM-MIP showed excellent molecular recognition abilities for BPA and BPA-d6 as well as BPA-d16 used as the template molecule, and good ones for tetrachlorobisphenol A (Cl4-BPA) and tetrabromobisphenol A (Br4-BPA). Next, the RAM-MIP was utilized for selective on-line pretreatment and enrichment of BPA, Cl4-BPA and Br4-BPA in a river water sample, followed by their separation and determination by LC-MS. The calibration graphs of BPA, Cl4-BPA and Br4-BPA, constructed using BPA-d6 as an internal standard, showed good linearity in the range of 12.5-200 pg/mL (r > 0.999) with a 2-mL injection of a river water sample. The inter-day precision data for the assay of BPA, Cl4-BPA and Br4-BPA at 25 pg/mL were 1.08, 3.67 and 1.58%, respectively. Furthermore, this method was successfully applied for the simultaneous determination of BPA and its halogenated derivatives in river water.     

Determination of mepiquat chloride residues in cotton and soil by liquid chromatography/mass spectrometry

A liquid chromatographic/mass spectrometric (LC/MS) method is reported for the determination of the onium-type plant growth regulator mepiquat chloride in cotton and soil. The pesticide was extracted from the sample with ethanol and water containing 2% NH4Cl. The extract was cleaned up on a solid-phase extraction C18 column, and the pesticide was determined by LC/MS. The average recoveries were 85.9-93.8, 81.3-91.7, and 78.1-94.7%, with corresponding relative standard deviations of 3.4-9.6, 3.7-12.3, and 4.0-9.8%, from soil, cotton leaves, and cotton seeds, respectively. A coefficient of determination of R2 = 0.9964 was obtained for the analyte calibration graph, from 0.05 to 100 microg/mL. Decision limits, CCalpha, and detection capability, CCbeta, were calculated. Electrospray ionization LC/MS in the positive-ion mode (ESI+) was used to detect mepiquat chloride in extracts of soil, cotton leaves, and cotton seeds. The ion at m/z 114 in the mass spectrum was monitored.     

Br2+Cl2=2BrCl反应机理的理论和实验研究

用(U)MP2方法, 取6-311G*基组, 研究了反应Br2+Cl2=2BrCl的机理, 求得四中心和三中心的过渡态, 通过比较反应通道的活化能的大小, 得到如下结论: 双分子基元反应的最小活化能小于Cl2和Br2的离解能, 在没有光引发的条件下, 标题反应将以分子与分子作用形式完成; 若有光引发, Br2或Cl2先解离成原子, 再经过Br原子与Cl2反应或Cl原子与Br2反应, 能较快完成标题反应. 分别测定了光照和避光两种条件下的反应体系在412 nm处吸光度的变化, 证实了理论研究的结果.     

The determination of sulphur in copper,nickel and aluminium alloys by proton activation analysis

The ³⁴S(p, n)^34mCl reaction induced by 13-MeV protons is used for the determination of sulphur in copper, nickel and aluminium alloys. The ^34mCl is separated by repeated precipitation as silver chloride. The results obtained were 3.08 ± 0.47, 1.47 ± 0.17 and <1μg g^-1 for copper, nickel and aluminium alloys, respectively.