Qualitative Analysis of Alkyl Nitrite Esters Based on Raman Spectroscopy

In this study, we focused on the rapid detection of alkyl nitrite esters in “Rush poppers”, and constructed qualitative detection methods based on Raman spectroscopy. Raman spectra of six nitrite esters, including butyl nitrite, isobutyl nitrite, amyl nitrite, isoamyl nitrite, tert-butyl nitrite and hexyl nitrite, were determined. For the liquid (the main form of seized samples) and solid adsorption (5%) forms, two analytical strategies, “capillary direct injection-532 nm benchtop detection” and “isobutanol extraction-1064 nm portable detection”, were developed to achieve rapid detection typically within 2 minutes. The practical application showed that the intensity of the characteristic peak (1650 cm^-1, N=O) of the liquid sample is positively correlated with the concentration without pretreatment. Validation of 10 seized samples (6 liquids and 4 solids) showed that the Raman screening results were in complete agreement with GC-MS, and the detection time of portable devices was significantly reduced than that of laboratory analysis. This method solves the pain point that commonly used GC-MS is not applicable in the field, and provides in-situ and rapid technical support for the frontline of drug control.