氯代十六烷基吡啶存在下钯与1，4－双肼酞嗪新显色反应的研究

本文研究了１，４－双肼酞嗪（ＤＨＰＨ）与钯的配合显色反应，在阳离子型表面活性剂氯代十六烷基吡啶存在下，在０．１～０．２ｍｏｌ／ＬＨＣｌ溶液中，试剂与钯形成１：１的稳定的黄绿色配合物，最大吸收峰在４００ｎｍ处，表观摩尔吸光系数为２．６×１０￣４，钯量在０～５０μｇ／２５ｍＬ范围内股从比尔定律，方法简便快速，选择性好，已用于催化剂中钯的测定，结果满意。     

Flame atomic absorption spectrometric determination of cadmium and copper in biological reference materials using on-line sorbent extraction preconcentration

Summary Cadmium and copper at the g/g to ng/g level in plant and animal tissue reference materials, and at the g/l level in urine were determined by flame atomic absorption spectrometry using on-line sorbent extraction preconcentration based on flow injection techniques. Bonded silica reversed phase sorbent with octadecyl functional groups (RP-C 18), packed in a 100 l column, was used to collect the diethylammonium-N,N-diethyldithiocarbamate (DDTC) complex formed on-line in the sample digests at low pH. Methanol was used to elute the analyte chelates directly into the nebulizer-burner system of the spectrometer. Small air segments introduced before and after elution prevented the eluent from mixing with the sample solution and increased the sensitivity. A sampling frequency of 85/h could be obtained with a sample loading time of 30 s at a flow rate of 4.0 ml/min. The enrichment factor for both elements was 20 and the enhancement factors, including the effect of the organic solvent and with the flow spoiler removed, were 126 and 114 for cadmium and copper, respectively. The detection limits (3) were 0.15 g/l for cadmium and 0.2 g/l for copper. The precision was 2.3% and 1.4% r.s.d. for 10 g/l Cd and 45 g/l Cu, respectively (n=11). Results for the determination of cadmium and copper in various biological reference materials were typically in good agreement with certified values. Low recoveries were observed, however, for cadmium in samples containing high levels of copper and/or iron, such as bovine liver.On leave from Flow Injection Analysis Research Center, Institute of Applied Ecology, Academia Sinica, Shenyang, China     

反相高效液相色谱分离-安培法检测酚类化合物

本文报道了RP-HPLC-安培法检测测定酚类化合物的条件。在Shim-pack CLC-C_8柱上用含0.05mol/L NaH_2PO_4缓冲溶液的5％甲醇水溶液洗脱分离,于E+1.0V处检测。线性范围在0～7μg/ml,检测限达ng/ml。     

FT-IR evidence for the participation of protonic sites in the heterolytic cleavage of C?H bonds of methane over HZSM-5 zeolite

It has been observed by FT-IR spectroscopy that both kinds of Brönsted acid protons present in HZSM-5 zeolite may be involved in the adsorption of methane at low temperature (173 K) and exchange with CH₄ or CD₄ at high temperature (>500°C). The sites which can adsorb methane at low temperature are the active sites for methane conversion at high temperature. Over HZSM-5 zeolite, the activation of methane is suggested to occur via a heterolytic cleavage of C–H bond with the assistance of protons.     

茶碱抗体的制备及鉴定

茶碱在临床上是一种非常有用的药剂。本文报道一种新的茶碱抗血清的制各及鉴定方法．用混合酸酐法合成抗原，借助于紫外光谱对其进行定性和定量分析。用混合免疫法免疫兔子，用免疫扩散法对抗血清进行鉴定。     

自制环糊精衍生物毛细管柱气相色谱法分离氯苯甲醛和苯系物位置异构体

研究了自制的4根不同环糊精毛细管色谱柱对氯苯甲醛异构体的分离特性，结果表明环糊精类毛细管柱对氯苯甲醛异构体有特殊的分离性能，其中硅烷化乙酰化环糊精柱对其分离效果最佳。此外，全甲基环糊精色谱柱对酚类体系显示了很好的分离性能，硅烷化乙酰化环糊精柱对卤代甲苯体系也取得了令人满意的分离效果。     

青蒿素及其一类物结构和合成的研究——Ⅸ.全合成青蒿素中若干关键化合物的合成

青蒿素是一个含有过氧基团的新型倍半萜内酯~([1]),它具有突出的抗疟作用~([2])。本文报道     

三缺位α-9钨镓杂多酸盐的合成与性质

本文报道了一种新的三缺位杂多阴离子α-[GaW_9O_(34)H_2]~(9-)的钠、钾、四甲基铵盐的合成方法,并通过元素分析、红外、紫外、极谱、热分析等方法对它进行了表征。α-[GaW_9-O_(34)H_2]~(9-)是一具有三个空位的杂多阴离子,它能与过渡金属离子反应生成具有Keggin结构的三取代钨镓杂多阴离子[GaW_9O_(37)M_3(H_2O)_3]~(R-)。     

Comparison of 6Mo/MCM-22 and 6Mo/ZSM-5 in the MDA process

A comparison of methane dehydroaromatization (MDA) on 6Mo/MCM-22 and 6Mo/ZSM-5 was carried out using a gas mixture of 90%CH₄, 2%CO₂ and 8%Ar as the feed. The results indicate that the stability of 6Mo/MCM-22 is better than that of 6Mo/ZSM-5. A detailed study reveals that the ability for coke accommodation and the retention of the shape selectivity for aromatics formation is responsible for the stability of a MDA catalyst. This revised version was published online in August 2006 with corrections to the Cover Date.     

A copper- and amine-free sonogashira reaction employing aminophosphines as ligands

An efficient Pd-catalyzed Sonogashira coupling reaction was achieved in the absence of a copper salt or amine with an inorganic base and easily prepared, air-stable aminophosphine ligands in commonly used organic solvents; good to excellent yields were obtained. Under optimized reaction conditions, the Sonogashira coupling reaction occurred selectively when an enyne substrate was employed and no Heck reaction product was detected; acetone-masked acetylene and trimethylsilylacetylene can also be efficiently coupled, providing a method to make terminal alkynes.