Laser fluorimetric detection

C. Wersig, W, Finke, E. Handler, H-P Josel and E. Schmidt, Performance of commercial laser diodes in fluorimetric detection, in Advances in Fluorescence Sensing Technology (J. R. Lakowicz and R. B. Thompson, eds.), Proc. SPIE 1885, 389-400 (1993). 

Disbold et al. [34] developed a laser fluorimetric method for the determination of zearalenone (6-(10-hydroxy-6-oxo-fra s-l-undcccnyl-/i-resorcylic acid n-lactone))-infected corn. By combining laser fluorimetry with high-pressure liquid chromatography, these workers were able to detect and quantitate the naturally fluorescent mycotoxin zearalenone in contaminated corn samples. 

Desbene, P. L., C. J. Morin, N. L. Mofaddel, R. S. Groult, Fluorescein sodium salt in laser-induced indirect fluorimetric detection application to organic anions, 7. Chromatogr. A, 1995, 716, 279-290. 

A variety of analytical methods has been used for determining trace concentrations of PAHs in environmental samples (Table 6-2). These include GC with various detectors, HPLC with various detectors, and TLC with fluorimetric detectors. Various detection devices used for GC quantification include FID, MS, Fourier transform infrared spectrometer (FT-IR), laser induced molecular fluorescence detector (LIMF), diode array detector (DAD), and gas phase fluorescence detector (GPFDA). GC/MS and HPLC with UV or spectrofluorimetric detectors are perhaps the most prevalent analytical methods for determining concentrations of PAHs in environmental samples. 

Fluorescence spectroscopy plays an important function in modern food analysis as can be seen from its wide use in the determination of numerous food components, contaminants, additives, and adulterants. This technique has made available very sensitive and selective methods that satisfy the requirements of food analysis, which are usually very complex, taking into account the large number of species to be determined, frequently at very low concentrations, and the wide variety of foodstuffs available. Initially, the use of fluorescence spectroscopy in food analysis was limited to the determination of species with intrinsic fluorescence (e.g., vitamins, aflatoxins, and some polycyclic aromatic hydrocarbons (PAHs)), but now it is widely applied to nonfluorescent species, using several physicochemical means such as chemical or photochemical derivatization reactions. Numerous techniques involve fluorescence detection in liquid chromatography (LC), frequently using pre- or postcolumn derivatization. In addition to conventional fluorime-try, which is commonly chosen for this purpose, other fluorimetric techniques such as laser-induced... 

Analytical procedures for foods are generally based on extraction with purified solvents following saponification with alcoholic potash. Purification of the extracts by chromatography on column or plates is followed by analysis of the purified extract using TLC, GLC or HPLC. Spectrophotometric or spectrofluorimetric methods may be used for quantitation of the hydrocarbons a collaborative study of a spectrophotometric method showed it to be applicable at the 2 fig/kg level. HPLC techniques using spectrofluorimetric detection have been described for which improved levels of detection are claimed. Benzo(a)pyrene produces substitution products with nucleic acids. Hydrocarbon deoxyribonucleoside adducts may be isolated from DNA by gel permeation chromatography, and the formation of hydrocarbon epoxides by mammalian enzyme reaction has also been demonstrated . The limit of detection of spectrophotometric and fluorimetric methods has been improved by three orders of magnitude by the use of laser-induced fluorescence procedures for the... 

---