Page 303 - Tandem Techniques
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passed thorough two broad band interference filters to remove stray light, and then to the
monochromator.
Figure 7.23
The Laser Induced Fluorometric Instrument
Combined with the Liquid Chromatograph
Roach and Harmony employed the tandem system for the separation and trace analysis of amino acids.
The derivatization process (Carlson et al. [9]), employed the reagent 2,3-naphthalenedialdehyde which,
when used in the presence of cyanide, yields adducts of excellent thermal stability and gave high
quantum yields of fluorescent light. An excellent separation was obtained with the desired high
sensitivity. The sensitivity of the tandem system, as defined by the minimum detectable mols ranged
from about 0.2 to 0.4 fmol. of the original acid. Assuming an average molecular weight for the amino
acid of about 150, then this molar sensitivity corresponds to a mass sensitivity range (minimum
detectable mass) of 3 x 10-13 to 6 x 10-13 g (0.3-0.6 pg).
