Laser-induced fluorescence spectroscopy of plant-based drugs: Opium and hashish provoking at 405 nm

Shamsi, Ehsan; Parvin, Parviz; Ahmadinouri, Fatemeh; Khazai, Samaneh

doi:10.1016/j.saa.2023.123055

Cited by 3 publications

(1 citation statement)

References 47 publications

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“…This is caused by the fact that E100 (Eosin-Y) and E20/E40 (Nile red) are based on different fluorescent dyes. The dye concentration of 4.69 mg/L is the upper linearity limit of emission measurements in the cuvette due to strong absorption along the laser path and signal reabsorption (see references [24,61]). The linear function shows that all dye-fuel mixtures studied can be considered as dilute up to 4.69 mg/L.…”

Section: Emissionmentioning

confidence: 99%

Spectral Investigations of Fluorescence Tracers in Automotive and Aviation Fuels under Cryogenic Conditions

Koegl,

Vogler,

Zigan

2024

Sensors

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This study investigated spectral laser-induced fluorescence signals of dyes in fuels for automotive and aerospace applications under low temperatures and cryogenic conditions down to 183 K. For this purpose, a fluorescence chamber was developed based on cooling with liquid nitrogen. The design enabled a minimal inner chamber temperature of 153 K. Furthermore, the applicability of two-color LIF for liquid thermometry was evaluated under these conditions. The temperature determination was based on the temperature-sensitive fluorescence intensity ratio of the special dyes doped into the fuels determined in suitable spectral regions, which represented common bandpass filters. For this purpose, the fluorescence signals of the dye doped into the gasoline and jet fuel surrogate isooctane were tested as well as blends of isooctane and the ethanol biofuels E20 (comprising 80 vol.% isooctane and 20 vol.% ethanol), E40, and E100. Additionally, a realistic multi-component fuel Jet A-1 mixed with a suitable fluorescence dye was investigated. E100 was doped with Eosin-Y, and the remaining fuels were doped with Nile red. Temperature-dependent spectral LIF intensities were recorded in the range of 183 K–293 K, which simulate extreme environments for aerospace and automotive applications. Frozen fuel–dye mixtures cause significant extinction effects and prevent sufficient signal detection at low and cryogenic temperatures, defining the detection limit. A temperature decrease led to a spectral shift in the emission peaks of E100 doped with Eosin-Y toward shorter wavelengths, while the spectra of mixtures doped with Nile red were shifted toward longer wavelengths. The suggested bandpass filters produced the temperature-sensitive intensity ratio (the average over the temperature interval) of the dyes with the largest sensitivity for Jet A-1 (5.2%/K), followed by E100 (4.95%/K), E40 (4.07%/K), E20 (3.23%/K), and isooctane (3.07%/K), even at cryogenic temperatures.

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Section: Emissionmentioning

confidence: 99%