Field-portable detection of fentanyl and its analogs: A review.

The need to detect fentanyl and its analogs in the field is an important capability to help prevent unintentional exposure or overdose on these substances, which may result in death. Many portable methods historically used in the field by first responders and other field users to detect and identify other chemical substances, such as hazardous materials, have been applied to the detection and identification of these synthetic opioids. This paper describes field portable spectroscopic methods used for the detection and identification of fentanyl and its analogs.

Monitoring of the interconversion of gamma-butyrolactone (GBL) to gamma hydroxybutyric acid (GHB) by Raman spectroscopy.

Gamma-hydroxybutyric acid (GHB) is a drug-of-abuse that has recently become associated with drug-facilitated sexual assault, known as date rape. For this reason the drug is commonly found 'spiked' in alcoholic beverages. When GHB is in solution it may undergo conversion into the corresponding lactone, Gamma-butyrolactone (GBL).

Characterisation of transmission Raman spectroscopy for rapid quantitative analysis of intact multi-component pharmaceutical capsules.

A detailed characterisation of the performance of transmission Raman spectroscopy was performed from the standpoint of rapid quantitative analysis of pharmaceutical capsules using production relevant formulations comprising of active pharmaceutical ingredient (API) and 3 common pharmaceutical excipients. This research builds on our earlier studies that identified the unique benefits of transmission Raman spectroscopy compared to conventional Raman spectroscopy. These include the ability to provide bulk information of the content of capsules, thus avoiding the sub-sampling problem, and the suppression of interference from the capsule shell.

Transmission Raman spectroscopy as a tool for quantifying polymorphic content of pharmaceutical formulations.

We present the first quantitative study of polymorphic content in a model pharmaceutical formulation using transmission Raman spectroscopy (TRS), and compare the results obtained with those from traditional backscattering geometry. The transmission method is shown to provide a true bulk measurement of the composition, being unaffected by systematic or stochastic sub-sampling issues that can plague traditional backscattering geometries. The accuracy of the quantification of the polymorphs using TRS was shown to surpass considerably that achieved using conventional backscattering mode.

A Raman spectroscopic study of a fulgurite.

A Raman microspectroscopic study of several fulgurites has been undertaken. A fulgurite is an amorphous mineraloid, a superheated glassy solid that is formed when a lightning bolt hits a sandy or rocky ground and thermal energy is transferred. The Raman spectra revealed several forms of crystalline and fused silica and also the presence of polyaromatic hydrocarbons found in an interfacial zone of a glass bubble.

Broadband terahertz time-domain spectroscopy of drugs-of-abuse and the use of principal component analysis.

Terahertz frequency time-domain spectroscopy has been used to analyse a wide range of samples containing cocaine hydrochloride, heroin and ecstasy--common drugs-of-abuse. We investigated real-world samples seized by law enforcement agencies, together with pure drugs-of-abuse, and pure drugs-of-abuse systematically adulterated in the laboratory to emulate real-world samples. In order to investigate the feasibility of automatic spectral recognition of such illicit materials by terahertz spectroscopy, principal component analysis was employed to cluster spectra of similar compounds.

Calculation and measurement of terahertz active normal modes in crystalline PETN.

The terahertz frequency spectrum of pentaerythritol tetranitrate (PETN) is calculated using Discover with the COMPASS force field, CASTEP and PWscf. The calculations are compared to each other and to terahertz spectra (0.3-3 THz) of crystalline PETN recorded at 4 K.

Identification of the date-rape drug GHB and its precursor GBL by Raman spectroscopy.

Gamma hydroxybutyric acid (GHB), also known as 'liquid ecstasy', has recently become associated with drug-facilitated sexual assaults, known colloquially as 'date rape', due to the ability of the drug to cause loss of consciousness. The drug is commonly found 'spiked' into alcoholic beverages, as alcohol increases its sedative effects. Gamma hydroxybutyric acid and the corresponding lactone gamma-butyrolactone (GBL) will reach an equilibrium in solution which favours the lactone in basic conditions and GHB in acidic conditions (less than pH 4).

Vibrational spectroscopic characterisation of salmeterol xinafoate polymorphs and a preliminary investigation of their transformation using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry.

Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting beta-adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry.

In-situ detection of drugs-of-abuse on clothing using confocal Raman microscopy.

This study describes the application of confocal Raman microscopy to the detection and identification of drugs-of-abuse in situ on undyed natural synthetic fibres, and coloured textile specimens. Raman spectra were obtained from drug particles trapped between the fibres of the specimens. Pure samples of cocaine hydrochloride and N-methyl-3,4-methylenedioxy-amphetamine HCl (MDMA-HCl) were used in this study.

Raman spectroscopic investigation of cocaine hydrochloride on human nail in a forensic context.

This study describes the application of Raman spectroscopy to the detection of drugs of abuse and noncontrolled substances used in the adulteration of drugs of abuse on human nail. Contamination of the nail may result from handling or abusing these substances. Raman spectra of pure cocaine hydrochloride, a seized street sample of cocaine hydrochloride (77%), and paracetamol could be acquired from drug crystals on the surface of the nail.

The Rio Tinto Mars analogue site: an extremophilic Raman spectroscopic study.

The Rio Tinto site is recognised as a terrestrial Mars analogue because of the presence of jarosite and related sulfates which have recently been identified by the NASA Mars Exploration Rover "Opportunity" in the El Capitan region of Meridiani Planum on Mars. It has long been known that acidophilic microbial action is responsible for the deep blood-red colour of the water in Rio Tinto, where the pH varies from about 1.5 to 3.