Optical assessment of heroin using laser-induced fluorescence spectroscopy based on modified Beer-Lambert formalism

Heroin as a derivative of morphine contains the alkaloids and flavonoids with plenty of three to five aromatic rings. The latter is known as the main source of fluorescence emission after laser excitation. Here, laser induced fluorescence (LIF) spectroscopy at excitation line of 405 nm with the solvent densitometry method is introduced based on modified Beer-Lambert (MBL), for the rapid and reliable identification of street heroin samples. Not only this hybrid method is cost effective, portable and easy to operate, but also it demonstrates an accurate technique based on the four unique parameters of the concentration at peak (C_p), self-quenching (K), and extinction coefficients (α) as well as the Stocks shift (S_S).