A Raman- and XRD study of the crystal chemistry of cobalt blue

The aim of this research project was to synthesise both the normal and inverse cobalt aluminate spinels by various methods and characterise them mainly by Raman spectroscopy with the support of X-ray powder diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), energy disperse spectroscopy (EDS), and scanning electron microscopy (SEM). Four different synthesis methods (glycine-gel, citrate-gel, polyol and solid-state) were used to synthesise the cobalt aluminate powders with the general formula CoIICoIIIxAl2-xO4 (where x = 0-2). The gel or powder precursors were annealed at various temperatures ranging from 350ºC - 1000ºC. The properties of the intermediate and final products, influenced by the synthesis method, processing temperature, processing time and particle size, were compared. Raman spectra and XRD patterns indicating the presence of both normal and inverse cobalt aluminate spinel were observed. The inverse spinel was identified both as a transitional phase as well as a final phase, depending on the synthesis method and annealing temperature used. The various synthesis methods were also used to gain further insight into the crystal chemistry of cobalt aluminate. The solid-state method is the more traditional synthesis method. Solution techniques (glycine-gel, citrate-gel and polyol) were used in an attempt to synthesise blue cobalt aluminate at relatively low temperatures and processing times in order to obtain homogeneous, nanosized crystals with broad applicability. The polyol method was found to be most favourable for the synthesis of blue cobalt aluminate with regard to processing temperature and processing time. The various characterisation methods used, show that the intensity of the colour of the powders produced are strongly related to the degree of material crystallinity as well as Al/Co ratio. Inverse (Co2AlO4) and Co3O4 spinels are formed at lower temperatures or when the Co/Al ratio is greater than 0.5. The normal spinel (CoAl2O4) is produced at higher temperatures or when the Co/Al ratio is 0.5. The XRD patterns of CoAl2O4, Co2AlO4 and Co3O4, are very similar because they share the same spinel cubic structure (space group Fd3m) differing only slightly in the lattice size. It has been demonstrated that Raman and XRD can be used to distinguish between inverse and normal spinels while FT-IR and EDS are useful for assessing the purity of the powders produced. As predicted by group theory, five Raman and four IR active vibrations were evident in the results.Dissertation (MSc)--University of Pretoria, 2009.Chemistryunrestricte

Simultaneous detection of controlled substances in waste water

This study presents a method of simultaneous detection of both traditional and newly emerged drugs of abuse in wastewater. The method is based on solid phase extraction and gas chromatography-mass spectrometry analysis. This analytical method separates 25 drugs from different classes including amphetamines, cathinones, tropane alkaloids, piperazines plus ketamine, amitriptyline, diazepam and morphine. In addition, newer compounds (methcathinone, mephedrone, butylone), and isomers (1-(2-methoxyphenyl) piperazine, 1-(4-methoxyphenyl) piperazine; 1-(2-flurophenyl) piperazine, 1-(4-flurophenyl) piperazine; 1-(3-trifluoromethylphenyl) piperazine, 1-(4-trifluoromethylphenyl) piperazine) have been separated, with greater sensitivity (×100 order of magnitude). This work reports the detection of butylone, mephedrone, 1-(4-methoxyphenyl) piperazine, 1-(2-flurophenyl) piperazine and 1-methyl-4-benzylpiperazine for the first time in waste water. This suggests that with changes in drug use patterns, constant monitoring of waste water entering treatment plants should be carried out and treatment processes need to be put in place for their removal

Chemical profiling of the street cocktail drug ‘Nyaope’ in South Africa using GC-MS II: Stability studies of the cannabinoid, opiate and antiretroviral components during sample storage

Nyaope is a mixture of low grade heroin, cannabis products, antiretroviral drugs and other materials added as bulking agents. It is a highly physically additive mixture which is smoked by users. As part of the development of a method for the analysis and profiling of nyaope this study evaluates the stability of the cannabinoid, opiate and antiretroviral components of nyaope during storage following seizure. Conditions used were those typically used for storage of drug seizures: in a desiccator in a refrigerator, in a desiccator in the dark at room temperature, in a desiccator in daylight at room temperature and ambient room temperature in the dark in a cabinet used for storage of drug seizures. Street samples of cannabis (Δ9-tetrahydrocannabinol) and heroin were mixed with efavirenz and nevirapine tablets to mimic a nyaope sample. The samples were homogenized and transferred into glass bottles and extracted with tertiary butyl alcohol (tBuOH) and analysed by gas chromatography – mass spectrometry (GC-MS) after the powdered drugs had been stored for intervals of 0 and 24 hours under each storage condition. The data obtained indicates that the target drug components in nyaope samples decompose and that for comparison purposes the drug extracts should be prepared in tBuOH immediately after seizure because of the decomposition of the drug components during storage prior to extraction and analysis. The implications of this work are that law enforcement agencies dealing with nyaope and wanting to compare drug samples may need to change their practice around how the drug is handled after seizure but prior to analysis

A validated method for the analysis and profiling of ‘nyaope’ using gas chromatography – mass spectrometry

Nyaope, a Tswana word for a mixture or ‘mish-mash’, describes a drug cocktail consisting of heroin, cannabis, and on occasion other controlled substances and warfarin. It is highly addictive with extremely unpleasant side effects caused by withdrawal from the drug. It is a problem drug especially in townships in South Africa. However, its prevalence in neighbouring southern African states and further afield is not yet known. There is currently no validated method for the analysis and comparison of nyaope. We describe a validated method for the gas chromatography – mass spectrometry analysis of nyaope so that within-batch and between-batch comparisons of nyaope can successfully be made for the first time. The validated method managed an accuracy within the range 80–120%, the precision was less than 20% for all analytes and managed linearity with R2≥0.99. The detection limits for diamorphine, efavirenz, nevirapine and Δ9-tetrahydrocannabinol were 14.2, 18.6, 18.7 and 9.94 pg on column, respectively, and the limits of quantitation were 43.1, 56.3, 56.6 and 30.1 pg on column, respectively. The simulated and casework samples were successfully discriminated into original batches using the identified nyaope components, the unsupervised chemometric methods principal component analysis and hierarchical clustering, as well as chromatographic profiles

Proceedings of the Salford Postgraduate Annual Research Conference (SPARC) 2011

These proceedings bring together a selection of papers from the 2011 Salford Postgraduate Annual Research Conference(SPARC). It includes papers from PhD students in the arts and social sciences, business, computing, science and engineering, education, environment, built environment and health sciences. Contributions from Salford researchers are published here alongside papers from students at the Universities of Anglia Ruskin, Birmingham City, Chester,De Montfort, Exeter, Leeds, Liverpool, Liverpool John Moores and Manchester

An overview of recent developments in the analytical detection of new psychoactive substances (NPSs)

New psychoactive substances (NPSs), sometimes referred to as “legal highs” in more colloquial environments/ the media, are a class of compounds that have been recently made available for abuse (not necessarily recently discovered) which provide similar effects to the traditional well studied illegal drugs but are not always controlled under existing local, regional or international drug legislation. Following an unprecedented increase in the number of NPSs in the last 5 years (with 101 substances discovered for the first time in 2014 alone) its, occasionally fatal, consequences have been extensively reported in the media. Such NPSs are typically marketed as ‘not for human consumption’ and are instead labelled and sold as plant food, bath salts as well as a whole host of other equally nondescript aliases in order to bypass legislative controls. NPSs are a new multi-disciplinary research field with the main emphasis in terms of forensic identification due to their adverse health effects, which can range from minimal to life threatening and even fatalities. In this mini-review we overview this recent emerging research area of NPSs and the analytical approaches reported to provide detection strategies as well as detailing recent reports towards providing point-of-care/in-the-field NPS (“legal high”) sensors

Simultaneous detection of drugs of abuse in waste water using gas chromatography-mass spectrometry

Sewage epidemiology is increasingly becoming an alternative method of estimating drug usage and consumption patterns for a given population. With the constant emergence of new psychoactive substances such as cathinones and piperazines, versatile, reliable, specific and sensitive analytical methods are needed for their detection in complex matrices such as waste water. This thesis reports the development of an analytical method based on solid phase extraction, derivatization with pentafluoropropionic anhydride and analysis by gas chromatography-mass spectrometry for the simultaneous analysis of 29 illicit and therapeutic drugs of abuse. All 29 drugs could be reliably identified in spiked waste water samples using selected ion monitoring and splitless injection. Recoveries for the majority of the drugs were above 70 %. Linearity varied based on the analyte but was assessed in the range 2.0 x 10-4 to 1.4 μg/mL. Intra-assay and intermediate precision of the instrument was determined at 0.005, 0.1 and 1.0 μg/mL, with the majority of relative standard deviations less than 10 %. Limits of detection and quantification for drugs such as amphetamine and methamphetamine were better than reported values for liquid chromatography-tandem mass spectrometry, a more commonly used technique. Untreated 72 h composite waste water samples from Cambridge, UK, were analysed using a six-point standard addition curve. Eleven drugs of abuse were detected, including amphetamine, methamphetamine, butylone and 4-fluoromethamphetamine. The latter two having been detected for the very first time in waste water. Using the validated method, the consumption of heroin, ketamine, cocaine, methamphetamine and amphetamine, in Cambridge, UK, was estimated to be 399.4 ± 90.8, 2463.5 ± 182.5, 195.5 ± 95.4, 84.3 ± 59.1 and 38.9 ± 24.8 mg/day per 1000 inhabitants. This is the first reported validated method for the detection of both classic drugs of abuse and new psychoactive substances in waste water using gas chromatography-mass spectrometry and derivatization with pentafluoropropionic anhydride

The use of derivatisation to increase method sensitivity and specificity for the detection of drugs of abuse in waste water

research carried out with partners at Anglia Ruskin Universit