Fiber Optic Coupled Raman Based Detection of Hazardous Liquids Concealed in Commercial Products

Abstract

Raman spectroscopy has been widely proposed as a technique to nondestructively and noninvasively interrogate the contents of glass and plastic bottles. In this work, Raman spectroscopy is used in a concealed threat scenario where hazardous liquids have been intentionally mixed with common consumer products to mask its appearance or spectra. The hazardous liquids under consideration included the chemical warfare agent (CWA) simulant triethyl phosphate (TEP), hydrogen peroxide, and acetone as representative of toxic industrial compounds (TICs). Fiber optic coupled Raman spectroscopy (FOCRS) and partial least squares (PLS) algorithm analysis were used to quantify hydrogen peroxide in whiskey, acetone in perfume, and TEP in colored beverages. Spectral data was used to evaluate if the hazardous liquids can be successfully concealed in consumer products. Results demonstrated that FOC-RS systems were able to discriminate between nonhazardous consumer products and mixtures with hazardous materials at concentrations lower than 5%.

Stability of Studtite in Saline Solution: Identification of Uranyl–Peroxo–Halo Complex

“…This is indicative of the stretching of the O–O bond. 56 , 57 In the solution containing 20 mM U(VI) and 20 mM H 2 O 2 (sky blue dots), a studtite suspension is formed. The Raman spectrum for this system has one uranyl–aquo complex peak and two new peaks at 821 and 735 cm –1 .…”

Raman Scattering Techniques for Defense and Security Applications

“…Raman spectroscopy is a good candidate for applications for detection at a distance, thanks to its ability to be able to acquire signals over potentially very long distances using intrinsically collimated lasers and the ability to be coupled with fiber optics. The examples for biohazard detection remotely using optical fibres are limited though. , This could be due to the high background from silica based optical fibers but recent hollow core fiber technologies offer hope. , Nevertheless, technologies such as portable Raman spectrometers permit the design of compact robotic devices that can be mounted on unmanned ground vehicles (UGVs). , Raman is not without drawbacks for such applications, however. The greatest issue for fielding Raman as a stand-off or proximal detection system is the collection of the signal from the sample.…”

“…The examples for biohazard detection remotely using optical fibres are limited though. 141,142 This could be due to the high background from silica based optical fibers but recent hollow core fiber technologies offer hope. 143,144 Nevertheless, technologies such as portable Raman spectrometers permit the design of compact robotic devices that can be mounted on unmanned ground vehicles (UGVs).…”

Chemometrics-enhanced fiber optic Raman detection, discrimination and quantification of chemical agents simulants concealed in commercial bottles

“…Vibrational techniques such as infrared spectroscopy (IRS) and Raman spectroscopy (RS), which have played a crucial role in chemical and biological threat characterization in past years, promise continue to play central roles in the standoff detection of these threats [9]. As a powerful technique for chemical analysis, RS is a non-invasive procedure that provides high spectral resolution [10].…”

“…In 2011, Ramírez-Cedeño et al utilized optical-fiber-coupled RS (OFC-RS) to detect hazardous liquids concealed in commercial products at 785 and 532 nm [9]. They proved that optical-fibercoupled Raman probes were able to discriminate hazardous liquids from common drinks inside consumer product bottles.…”