RESUMO
This review gives an overview of current knowledge about 3-monochloropropane-1,2-diol (3-MCPD) formation and detection. Although 3-MCPD is often mentioned with regard to soy sauce and acid-hydrolysed vegetable protein (HVP), and much research has been done in that area, the emphasis here is placed on other foods. This contaminant can be found in a great variety of foodstuffs and is difficult to avoid in our daily nutrition. Despite its low concentration in most foods, its carcinogenic properties are of general concern. Its formation is a multivariate problem influenced by factors such as heat, moisture and sugar/lipid content, depending on the type of food and respective processing employed. Understanding the formation of this contaminant in food is fundamental to not only preventing or reducing it, but also developing efficient analytical methods of detecting it. Considering the differences between 3-MCPD-containing foods, and the need to test for the contaminant at different levels of food processing, one would expect a variety of analytical approaches. In this review, an attempt is made to provide an up-to-date list of available analytical methods and to highlight the differences among these techniques. Finally, the emergence of 3-MCPD esters and analytical techniques for them are also discussed here, although they are not the main focus of this review.
Assuntos
Compostos Alílicos/análise , Pão , Grão Comestível/química , Glicerol/análogos & derivados , Proteínas de Vegetais Comestíveis/química , Alimentos de Soja , Compostos Alílicos/química , Queijo , Café/química , Glicerol/análise , Glicerol/química , Hidrocarbonetos Clorados , Estrutura Molecular , Alimentos de Soja/análise , alfa-CloridrinaRESUMO
Sugars and stearates (composed of fatty acids) are both frequent components used in the production of ecstasy tablets. Their analysis can therefore provide supplementary information useful for drug intelligence. Links established using these substances would be very significant as they should give us information about the manufacturer of the tablets. Two methods have been developed for the analysis of sugars and fatty acids by GC-MS and were applied to 109 ecstasy tablets. Characterisation of the samples should allow the differentiation of a certain number of them and furthermore their classification into groups. This is obtained by analysing the raw data using chemometric methods. Several pre-treatments have been tested together with six similarity measures on a small number of ecstasy samples in order to determine which combination would best characterise one ecstasy sample and differentiate it from the others at the same time. Normalisation followed by the fourth square and applied together with the squared cosine function appeared to give the best results and has been applied to all samples. The correlation values obtained of each sample with all others express the probability of a presence of a link between two samples. In order to verify the signification of these values, and thus of a link, all samples have been compared considering the data visually according to three selected criterions. The 109 examined samples could be divided into 67 groups, with 43 of them containing only one sample. Considering the distribution of their correlation values, sample pairs showing a value below 0.23 can be considered as linked. As the excipients are necessarily related to the blending, which also includes the active substance, and variation in the excipient content has been proven by the grouping of the samples, a low similarity value does indicate a link with regard to the producer. In conclusion, it appears that the result obtained with the excipients is certainly very valuable, but all other available information has to be taken into account as well before making any conclusions.
RESUMO
Cellulose and lactose are the most frequently used excipients in illicit ecstasy production. The aim of this project was to use near infrared reflectance spectroscopy (NIRS) for the determination of the different chemical forms of these two substances, as well as for the differentiation of their origin (producer). It was possible to distinguish between the different chemical forms of both compounds, as well as between their origins (producers), although within limits. Furthermore, the possibilities to apply NIR for the analysis of substances such as found in illicit tablets were studied. First, a few cellulose and lactose samples were chosen to make mixtures with amphetamine at three degrees of purity (5, 10 and 15%), in order to study the resulting changes in the spectra as well as to simultaneously quantify amphetamine and identify the excipient. A PLS2 model could be build to predict concentrations and excipient. Secondarily, the technique was to be applied to real ecstasy tablets. About 40 ecstasy seizures were analysed with the aim to determine the excipient and to check them against each other. Identification of the excipients was not always obvious, especially when more than one excipient were present. However, a comparison between tablets appeared to give groups of similar samples. NIR analysis results in spectra representing the tablet blend as a whole taking into account all absorbing compounds. Although NIRS seems to be an appropriate method for ecstasy profiling, little is known about intra- and intervariability of compression batches.
RESUMO
Fatty acids are the basis of so-called stearates which are frequently used as lubricants in the production of ecstasy tablets. Being a product added at the initial tablet production step its composition does not change once the compression is performed. The analysis of fatty acids can therefore provide useful information for a drug intelligence purpose. In this context an appropriate analytical method was developed to improve results already obtained by routine analyses. Considering the small quantity of such fatty acids in ecstasy tablets (approximately 3%) the research focussed on their extraction and concentration. Two different procedures were tested: (1) liquid/liquid extraction using dichloromethane followed by derivatisation and (2) in situ transesterification using bortrifluoride. Analyses were performed by GC-MS. The two procedures were optimized and applied to eight ecstasy seizures, in order to choose one of the procedures for its application to a large ecstasy sample set. They were compared by considering the number of peaks detected and sample amount needed, reproducibility and other technical aspects.