Screening methods laser detection

Separation and detection techniques for antibacterials in food mainly focus on the use of LC coupled to MS or tandem MS. Nevertheless, recent studies have suggested capillary electrophoresis coupled to laser-induced fluorescence (LIE) as a way of improving sensitivity [49], HRLC coupled to microTOF-ESI-MS as a highly selective, sensitive, and quick screening method for 100 veterinary drugs in fish, meat, and egg samples [195], and nanoscale LC coupled to UV or ion trap MS, with LODs in the range 0.01-0.51 pg/L (nanoLC-MS) and the possibility that even lower limits could be achieved by using triple quadrupole MS [59]. 

In the last few years, new procedures were developed for PAH analysis using MS-based detection methods. GC-IT-MS and a laser desorption-IT-MS screening method were applied to the analysis of airborne particulate-associated PAHs. Direct screening of aerosol filter samples were carried out using laser desorption TOF-MS. Isotope dilution techniques using GC-MS were also developed for some PAHs, such as benzo[a]pyrene. 

Therefore, heterogeneous catalysts present a greater potential for the application of HT and Combinatorial methods, because they involve diverse compositional phases that are usually formed by interfacial reactions during their synthesis, which in turn produce a variety of structural and textural properties, often too vast to prepare and test by traditional methods. In this respect the HT and Combinatorial methods extend the capabilities of the R D cycle, which comprises the synthesis, the characterization of physicochemical properties and the evaluation of catalytic properties. The primary screening HT method gives the possibility of performing a rapid test of hundreds or thousands of compounds using infrared detection methods [27-29]. Alternatively, a detection method called REMPI (Resonance Enhanced Multi Photon Ionization) has been used, which consists of the in situ ionization of reaction products by UV lasers, followed by the detection of the photoions or electrons by spatially addressable microelectrodes placed in the vicinity of the laser beam [30, 31]. 

A variation of the LORIA test uses new technology to evaluate the surface quality of Class A automotive body panels, eliminating subjective visual methods. It uses a low-intensity visible laser to detect surface deviations and imperfections. The beam is projected and scanned across the area, reflected on screen and captured by a high-resolution video camera. There is no contact with the surface, no stylus and no damage. 

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