Visualization and LC/MS Analysis of Colorless Pepper Sprays?

Abstract

Pepper sprays are used in a variety of circumstances, including criminal activity, self-defense, and law enforcement. As such, the presence or absence of pepper sprays on evidentiary materials is often important when determining the facts of an incident. When no visible stains are present on evidentiary materials, ascertaining the presence or absence of pepper spray can be a challenge to the forensic analyst. A method, based on a chemical derivatization of capsaicinoids using a diazonium salt, has been developed for the visualization of colorless, ultraviolet (UV) activated fluorescent dye-free pepper sprays on textiles. Identification of both the capsaicinoids and their derivatives is confirmed via extraction of the derivatized capsaicinoids followed by liquid chromatography/mass spectrometry (LC/MS) analysis. LC/MS analysis is conducted using a YMC Basic™ column and elution of the compounds using a gradient of 10 mM ammonium formate, pH 4.2 and methanol at 0.35 mL/min. Full-scan MS data are collected for the full 6.5 min LC analysis. Although this method is qualitative in nature, visual detection of as little as 50 µL of a 0.2% pepper spray (equivalent to ~0.1 mg) on a variety of garments is possible, and more than adequate signal-to-noise is obtained for reconstructed ion chromatograms on LC/MS analysis at these levels.

Development and validation of AccuTOF-DART™ as a screening method for analysis of bank security device and pepper spray components

“…Pepper spray can be used by either the general public as a defense spray or by police officers as a less-than-lethal (LTL) control tactic for subduing riots or stopping assailants [7][8][9][10]. The main active ingredient in most pepper sprays is oleoresin capsicum, which is the oily extract of hot peppers [7][8][10][11][12].…”

“…The main active ingredient in most pepper sprays is oleoresin capsicum, which is the oily extract of hot peppers [7][8][10][11][12]. Although oleoresin capsicum is composed of several capsaicinoids, capsaicin is the most abundant and thus the most appealing for analytical purposes [7][8][10][11][12].…”

Mobility of Heavy Metals from Soil into Hot Pepper Fruits: A Field Study

“…an estimated 80%-95% of the naturally occurring capsaicinoids in peppers (Cavett et al 2004). These compounds exhibit antioxidant activity and potent antimutagenic and anticarcinogenic properties (Surh and Seoul 2002).…”

Fundamental studies of the adhesion of explosives to textile and non-textile surfaces

“…Additionally, when solvent-swabbing a piece of clothing, often only a general swab of the garment is taken, meaning that any sections containing high concentrations of explosives particles may be inadvertently passed over and not sampled [6]. Alternative methods for sampling porous surfaces include vacuum sampling [7,8], solvent extraction [1,9,10] and direct sampling methods such as Raman spectroscopy and DESI-MS [5,[11][12][13][14].…”