摘要:

It has been more than 22 years from the time of the discovery of pure nuclear quadrupole resonance spectroscopy.1BSince that time the technique has found increased use by scientists in both physics and chemistry for studies dealing with materials in the solid state. Up to a few years ago it was primarily a physicist's tool.1AVarious studies were performed to measure such things as the effect of pressure and temperature on the nuclear quadrupole resonance signal. However, in the last several years it has become more of a chemist's tool2Aand has been used in those analytical applications where it can be used uniquely. It is these kinds of applications that will be covered in this review but before proceeding with that some of the theory will be covered in an elementary way. Then some of the different kinds of instrumentation that can be employed in the examination of materials that give nuclear quadrupole resonance signals will be discussed.

ISSN:0007-8980    

DOI:10.1080/10408347308542662

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Many techniques in modern analytical chemistry involve electron transfer in heterogeneous systems. The most important procedures in this classification are those normally grouped under the heading of electroanalytical methods. The basic principles of these particular systems and their expanding value in chemical analysis are constantly under review, and for this reason receive little comment in this article.

ISSN:0007-8980    

DOI:10.1080/10408347308542663

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

The purpose of this article is to review methods involving gas, thin-layer, paper, and liquid-column chromatography for the analysis of multiresidues and the determination of some individual residues of pesticides in various types of samples. At present, gas chromatography is by far the most widely used method for the qualitative and quantitative analysis of pesticide residues. Paper and thin-layer chromatography are used mainly for confirming identifications of substances tentatively determined by gas chromatography but may also provide cleanup prior to gas chromatography and semiquantitative estimation in cases where gas chromatography is unavailable or not applicable. Liquid column chromatography has been used mostly for the cleanup of sample extracts, but modern high-speed methods have recently been applied to the resolution and determination of compounds not volatile or stable enough for gas chromatography. Ancillary methods used in combination with these chromatographic techniques for pesticide identification will also be reviewed. The attempt has been made to cite only the most widely used and reliable analytical methods available as of spring, 1973. Where possible, the methods have been compared and their limitations and some precautions that should be observed in using them are given.

ISSN:0007-8980    

DOI:10.1080/10408347308542664

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor