Electron spectroscopy. Ultraviolet photoexcitation

Abstract

The period covered in this review is from late 1971 to late 1973. During that time, the Journal of Electron Spectroscopy and Related Phenomena has been introduced and become established. A non-mathematical guide to the technique and simplified approach to photoelectron spectroscopy (19), as well as a massive and invaluable conference proceedings (262) have been published. Many of the papers in the conference proceedings have been published separately, in which case we give the journal reference with a crospreference to the proceedings. A recent discussion of the Faraday Society was devoted to photoelectron spectroscopy. There have been comparatively few general reviews (33,73, 103,175, 197), but that of Hamnett, Orchard, and Cox is outstanding (161). It is detailed, critical, and deals with difficulties which are often glossed over or ignored, but unfortunately its coverage of the literature is only through 1970. A review of inorganic aspects has been prepared by DeKock and Lloyd ( 1 1 I ) .In general, it has been a period of consolidation during which many earlier ideas (especially those of D. W. Turner) have been re-examined and exploited, and many more compounds have been run. Taking a bird's eye view of the publications since the last review (32) we note the following trends: Several new instruments have been described and others are in the advanced design stage. Most permit heating of the sample and so many more compounds are accessible to the technique.The various branches of electron spectroscopy which were developed separately are now being used in combination. The Vacuum Generators' ESCA 3 has been specifically designed to allow the same sample to be examined readily in situ by UPS, X-ray photoelectron spectroscopy, Auger spectroscopy, and LEED.UPS has been applied to solids and surfaces. It has become increasingly common for UPS studies of a molecule to be complemented by several types of MO calculation.Simplified methods of interpretation of spectra based on the identification of characteristic localized orbitals have been critically examined and found valuable.The angular distribution of photoelectrons has attracted a lot of attention.On the negative, side, we feel that there has been an undue concentration of a few groups of compounds-uit., substituted benzenes, alkyl alcohols and halides, and simple silicon compounds. In several of these studies, there is a great deal of overlap and lack of reference to published work.A number of papers have been published in which the spectral data are limited to either a portion of the spectrum, showing just one or two bands, or a table of ionization potentials. Such limited information is rarely able to support the author's arguments. TECHNIQUEInstrumentation. There are a number of commercially available UV photoelectron spectrometers. Perkin-Elmer has developed the Turner design from the PS 15 prototype to the PS 18, which enables samples to be heated. The ESCA instruments of AEI, McPherson and Vacuum Generators, can be adapted to UPS, the last of these being ...

Flow injection analysis. New tool for old assays. New approach to analytical measurements

“…These simple concepts have proved extremely successful in the development of analytical systems for a wide variety of analytes. FIA has been used with many different types of detectors, including colorimetric, fluorimetric, flame emission, atomic absorption, inductively coupled plasma, refractive index, chemiluminescence, thermochemical, and a variety of electrochemical detectors (1)(2)(3)(4)(5)(6)(7)(8). It is probable that any detector that can be used with HPLC systems can be used with FIA systems.…”

“…FIA assay systems have been described for many different compounds (1)(2)(3)(4)(5)(6)(7)(8) for use in wide variety of areas, such as clinical chemistry, agricultural chemistry, environmental chemistry, biochemistry, and immunological chemistry. Enzyme assay systems were some of the earliest FIA systems described (11,15) and the precision of the FIA assays makes them quite attractive for enzyme determinations.…”

Flow Injection Analysis

“…the method of choice for many automated and semiautomated assays. A number of reviews (1)(2)(3)(4)(5), one textbook (6), and two views of its early history (7,8) have appeared. Papers on all aspects of FIA are appearing with increasing frequency in the literature.…”

“…These simple concepts have proved extremely successful in the development of analytical systems for a wide variety of analytes. FIA has been used with many different types of detectors, including colorimetric, fluorimetric, flame emission, atomic absorption, inductively coupled plasma, refractive index, chemiluminescence, thermochemical, and a variety of electrochemical detectors (1)(2)(3)(4)(5)(6)(7)(8). It is probable that any detector that can be used with HPLC systems can be used with FIA systems.…”

“…FIA assay systems have been described for many different compounds (1)(2)(3)(4)(5)(6)(7)(8) for use in wide variety of areas, such as clinical chemistry, agricultural chemistry, environmental chemistry, biochemistry, and immunological chemistry. Enzyme assay systems were some of the earliest FIA systems described (11,15) and the precision of the FIA assays makes them quite attractive for enzyme determinations.…”