摘要:

The electrochemical behavior of 6-MP was studied by cyclic voltammetry at a hanging copper amalgam dropping electrode (HCADE). It was found that 6-MP could form a complex with the Cu(II) stripped from the HCADE, showing a new peak at −0.19V in the medium of 0.1mol/L LiClO4-0.5mol/L HClO4solution. The mechanism of the reaction was proposed. This new peak was sensitive and could be used for the determination of trace 6-MP by differential pulse adsorption cathodic stripping voltammetry (DPAdCSV). The linear range was from 3.6×10−10to 5.3×10−6mol/L, and the detection limit was about 1.2×10−10mol/L (S/N=3). The method was also successfully applied to the determination of 6-MP in pharmaceutical tablets.

ISSN:0003-2719    

DOI:10.1080/00032719608002277

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The preparation of cellulose tribenzoate (CTB) chiral stationary phases coated on a small-particle (5 μ m, 120A°) spherical silica support, according to a process that is reported, is presented. The products of asymmetric hydroesterification of norbornene are resolved on the cellulose tribenzoate chiral stationary phases.

ISSN:0003-2719    

DOI:10.1080/00032719608002278

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The present note deals with the optimization of the combustion of organic materials to CO2in Pyrex and quartz tubes. The influence of temperature and oxidant on the combustion yield was investigated. Different physical forms of CuO and a CuO/MnO2-mixture were used as oxidants. Possible isotopic effects during combustion were tested by gas isotope ratio mass spectrometry (GIRMS) of the CO2. Excellent results were obtained for combustion in Pyrex at 530 °C using CuO rods mixed with 20% MnO2as oxidant. The stable isotope results for CO2prepared with this method were accurate and showed a very good precision of 0.030 %. Applications for which quantitative combustion is a necessity, we suggest the use of CuO powder (< 100 μm) as oxidant and a combustion temperature of 850 °C.

ISSN:0003-2719    

DOI:10.1080/00032719608002279

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608002280

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608002281

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0003-2719    

DOI:10.1080/00032719608002266

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor