Improved deuterium bromide 1-0 band molecular constants from heterodyne frequency measurements

Heterodyne frequency measurements have been made on selected deuterium bromide 1-0 band transitions ranging from P(20) to R(17). Difference frequency beat notes between a tunablediode laser whose frequency was locked to the DBr absorption lines and a CO laser whose frequency was either locked or adjusted to a reference synthesized from CO₂ laser frequency standards were measured. The beat note frequency was then combined with the measured CO laser frequency to give the DBr frequency. For two of the measurements, frequency-doubled CO₂ laser radiation was substituted for the CO laser radiation. The measurements included electric quadrupole split triplets comprising the R(0) and P(1) transitions in the D⁷⁹Br isotope. New DBr constants have been determined, and a table of frequencies is presented for the calibration of spectrometers and tunable lasers in the wavenumber range 1600 to 1990 cm^?1. A table of far-infrared frequencies is also given for DBr covering the range from 50 to 206 cm^?1.     

The need for organic reference materials in marine science

Summary The reference materials (RMs) available for organic trace analysis (OTA) and the development programmes of the RM producers are reviewed. The need for a wider range of determinants, matrices and classes of RMs, particularly the more widespread use of laboratory RMs (LRMs) is discussed. Additional certified RMs should include phenolic surfactant degradation products, chlorophenolics from the wood and paper industries, and organobromines from fire retardants. RMs as molecular markers of geogenic, pyrogenic and biogenic sources; chlorophylls and xanthophylls as a measure of marine productivity and natural shellfish toxins are proposed.

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Notwendigkeit organischer Referenzmaterialien in der Meeresforschung