Weakly Bound Complexes of γ-Butyrolactone with Water as Observed in Matrix Isolation FTIR and Theoretical Calculations

A computational and spectroscopic analysis of weakly bound complexes of 1:1 γ-butyrolactone with water has been completed. In this work, multiple density-functional theories and perturbation theory were used to explore the energy-landscape of the complex. Four unique structures were identified in this analysis. One structure was characterized by the formation of a water to carbonyl hydrogen bond and the other three were formed from water to ester hydrogen bonds. The carbonyl-bound conformation was found to be the global minimum across a comprehensive panel of calculations. A wave function analysis demonstrated that the structures were additionally stabilized by weak van der Waals interactions. FTIR spectroscopy of matrix-isolated samples indicated the presence of at least two of the calculated geometries. The structures were identified to be a carbonyl-bound and at least one ester-bound structure. The transitions identified for the carbonyl-bound complex were noted to be significantly more intense than those of the ester bound, indicating greater prevalence in the matrix.

Smartphone-based colorimetric determination of gamma-butyrolactone and gamma-hydroxybutyrate in alcoholic beverage samples

Gamma-hydroxybutyrate (GBH) is a popular recreational drug. Its strong sedative and amnesic effects have led to drug-facilitated sexual assaults, poisonings, overdose, and death. As a result, legislation has restricted its availability leading to GHB, consumers switching to its pro-drug, gamma-butyrolactone (GBL). Consequently, there is a growing need for methods capable of their determination in complex samples such as beverages. Previous studies have shown the possibility to colorimetrically qualitatively determine both GBH and GBL by the formation of the lactone and its reaction with hydroxylamine and ferric chloride to give a purple-colored complex. In this present investigation, we have shown the possibility of using this approach to both quantify GBL and GHB using both UV/Vis spectrometry and by the application of the camera of a smartphone to record images of the purple color developed. Via subsequent use of a downloadable free App, to extract the numerical values of the Red, Green, and Blue (RGB) color components, it was shown possible to construct a calibration curve and to quantitatively determine the concentration of the drugs present in fortified alcoholic beverage samples. It was found that by simple mathematical normalization of the RGB values the effects of camera distance and elimination could be readily overcome. Using the smartphone approach, GBL determinations on a sample of lager beer gave a mean recovery of 103% (%CV = 0.70%, n = 5) at a concentration of 0.56 mg/ml indicating the method holds promise for the determination of GBL and GHB in such samples.

Date-rape evidence through fast determination of γ-butyrolactone in adulterated beverages

An infrared spectroscopy (IR) based methodology has been developed to determine γ-butyrolactone (GBL) in adulterated beverages. The proposed method permits the direct screening of GBL in beverages and involves a minimum sample treatment requiring less than 2 min for quantitative determination of GBL. Sensitivity of IR method was improved by using liquid-liquid extraction (LLE) providing detection limits of 0.023 mg g^-1. Accuracy of the proposed methodology was evaluated through the analysis of soft beverages and alcoholic cocktails spiked with GBL at concentration levels ranging from 0.075 to 10 mg g^-1 providing recovery values from 91 to 100%. GBL was determined in twelve blind-spiked beverages, including from mineral water to wine and cocktails. Results obtained were statistically comparable to those provided by a liquid chromatography (LC) reference methodology and consistent with the spiked values. Therefore, the use of LLE-FTIR allowed a simple, sensitive and quantitative determination of GBL in soft beverages and alcoholic cocktails, thus evidencing its use for sex submission intention.

Use of Spectroscopic Methods and Their Clinical Applications in Drug Abuse: A Review

Assurance of substance abuse in plasma and different parts of the body is vital in clinical and legal toxicology. Detection techniques are evaluated for their appropriateness in scientific and clinical sciences, where extraordinary prerequisites must be met. Recognition and affirmation are for the most part done by gas chromatography-Mass spectrometry (GC-MS) or liquid chromatography (LC-MS), Surface-enhanced Raman spectroscopy (SERS), Magnetic resonance imaging, Positron Emission Tomography, Infrared Spectroscopy, and UV Spectroscopy. Progressed spectroscopic techniques provided helpful quantitative or qualitative data about the natural chemistry and science of exploited substances. These spectroscopic techniques are assumed as quick, precise, and some of them are non-damaging investigation apparatus that may be assumed as a substitution for previously used compound investigation. Spectroscopy with its advances in technology is centralized to novel applications in the detection of abused drug substances and clinical toxicology. These techniques have attracted growing interest as forensic tools for the early detection and monitoring of exploited drugs. This review describes the principle, role, and clinical application of various spectroscopic techniques which are utilized for the identification of drug abuse like morphine, cocaine, codeine, alcohol, amphetamines, and their metabolites in whole blood, plasma, hair, and nails.

Detection of ɣ-hydroxybutyric acid (GHB) and ɣ-butyrolactone (GBL) in alcoholic beverages via total vaporization solid-phase microextraction (TV-SPME) and gas chromatography-mass spectrometry

Total Vaporization Solid-Phase Microextraction (TV-SPME) relies on the same technique as standard SPME but completely vaporizes a sample extract, and analytes are sorbed directly from the vapor phase. On-fiber derivatization may also be performed using TV-SPME, where the fiber is first exposed to the headspace of a vial containing the derivatization agent, then exposed to a new vial containing the sample. ɣ-Hydroxybutyric acid (GHB) and ɣ-butyrolactone (GBL) are drugs of concern in that they may be used in drug facilitated sexual assault by surreptitiously spiking them into a victim's beverage. These drugs cause sedation, memory loss, and are difficult to detect in biological samples. One challenge in their analysis is that they can interconvert in aqueous samples, which was demonstrated in samples allowed to stand at room temperature for long periods. A volume study of GBL in water was performed with volumes ranging from 1 to 10,000 µl to compare the efficacy of TV-SPME, headspace SPME, and immersion SPME. Lastly, water, beer, wine, liquor, and mixed drinks were spiked with either GHB or GBL with realistic concentrations (mg/ml) and microliter quantities were analyzed using a TV-SPME Gas Chromatography-Mass Spectrometry method. The GBL volume study demonstrated an increased sensitivity in GBL detection when TV-SPME was utilized. Additionally, GHB and GBL were identified in various beverages at realistic concentrations. Overall, TV-SPME is beneficial because it requires no sample preparation and uses smaller sample volumes than immersion and headspace SPME.

Behind the reactivity of lactones: a computational and spectroscopic study of phenol·γ-butyrolactone

In this work, the intermolecular interaction between phenol and γ-butyrolactone (GBL) has been studied by a combination of spectroscopic and computational techniques. The electronic and vibrational transitions of phenol · GBL were measured in a supersonic jet expansion by resonant two-photon ionization (R2PI) and ion dip IR (IDIR) spectroscopy. The results obtained were compared with calculations carried out with both M06-2X and MP2 molecular orbital methods in order to characterize the intermolecular interactions. The singly detected conformer is stabilized by a relatively strong hydrogen bond in which phenol acts as a proton donor to the carbonyl group of GBL. The phenol · GBL2 cluster has also been studied, finding up to three populated conformers. Nevertheless, in the three species, the main interaction between the phenolic hydroxyl group and the GBL's carbonyl group remains similar to that of phenol · GBL. Furthermore, the C ═ O · · · H interaction is reinforced.

The role of mobile instrumentation in novel applications of Raman spectroscopy: archaeometry, geosciences, and forensics

The applications of analytical Raman spectroscopy in the characterisation of materials associated with archaeologically excavated artefacts, forensic investigations of drugs of abuse, security and crime scenes, minerals and rocks and future astrobiological space missions are now well established; however, these applications have emphasised the need for new developments in the area of miniaturised instrumentation which extends the concept and breadth of the analytical requirement to facilitate the provision of data from 'in field' studies. In this respect, the apparently unrelated themes of art and archaeology, forensic science, geological science and astrobiology as covered by this review are unified broadly by the ability to record data nondestructively and without resorting to sampling and the subsequent transfer of samples to the analytical laboratory. In studies of works of art there has long been a requirement for on-site analysis, especially for valuable paintings held under strict museum security and for wall paintings which cannot physically be removed from their setting; similarly, the use of portable Raman spectroscopy in archaeological and geological field work as a first-pass screening device which obviates the necessity of multiple and wasteful specimen collection is high on the wish-list of practicing spectroscopists. As a first-pass screening probe for forensic crime scenes, Raman spectroscopy has proved to be of inestimable value for the early detection of dangerous and prohibited materials such as drugs of abuse, explosives and their chemical precursors, and banned contraband biomaterials such as ivories and animal products; in these applications the advantage of the Raman spectroscopic technique for the recognition of spectral signatures from mixtures of inorganic and organic compounds is paramount and not afforded by other less portable instrumental techniques. Finally, in astrobiological work, these requirements also apply but with the additional prerequisite for system operation remotely - often over distances of several hundred million kilometres - as part of instrumental suites on robotic spacecraft and planetary landers; this necessitates robust and reliable instrumentation for the observation of unique and characteristic spectral features from the planetary geological surface and subsurface which are dependent on the assignment of both biological and geological band signatures.

Rapid and on-site analysis of illegal drugs on the nano-microscale using a deep ultraviolet-visible reflected optical fiber sensor

A deep ultraviolet-visible (DUV-Vis) reflected optical fiber sensor was developed for use in a simple spectrophotometric detection system to detect the absorption of various illegal drugs at wavelengths between 180 and 800 nm. Quantitative analyses performed using the sensor revealed a high specificity and sensitivity for drug detection at a wavelength of approximately 200 nm. Using a double-absorption optical path length, extremely small sample volumes were used (32 to 160 nL), which allowed the use of minimal amounts of samples. A portable spectrophotometric system was established based on our optical fiber sensor for the on-site determination and quantitative analysis of common illegal drugs, such as 3,4-methylenedioxymethamphetamine (MDMA), ketamine hydrochloride, cocaine hydrochloride, diazepam, phenobarbital, and barbital. By analyzing the absorbance spectra, six different drugs were quantified at concentrations that ranged from 0.1 to 1000 μg mL(-1) (16 pg-0.16 μg). A novel Matching Algorithm of Spectra Space (MASS) was used to accurately distinguish between each drug in a mixture. As an important supplement to traditional methods, such as mass spectrometry or chromatography, our optical fiber sensor offers rapid and low-cost on-site detection using trace amounts of sample. This rapid and accurate analytical method has wide-ranging applications in forensic science, law enforcement, and medicine.

Evaluation of a spectral searching algorithm for the comparison of Raman band positions

Raman spectroscopic identification of unknown materials involves often the comparison of the spectrum of the unknown spectrum with previously recorded reference spectra or data from literature. However, when spectra with many Raman bands or spectra of mixtures are involved, searching can be quite complex. Different chemometrical approaches have been proposed, but these have some drawbacks. Therefore, in this paper a novel approach is proposed, which is based on a multivariate comparison of Raman band positions. Different similarity measures can be used and are evaluated with spectra of test samples that were recorded on different spectrometers, using different laser wavelengths. Moreover, this study evaluates the performances of this algorithm for identifying different compounds in mixtures, by using an iterative approach.

Qualitative analysis and the answer box: a perspective on portable Raman spectroscopy

Miniaturization of Raman instruments has created a new genre of devices for qualitative analysis of materials. These new devices are introducing Raman spectroscopy to a diverse range of applications.