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Abstract(s)
As piperazinas são consideradas um novo grupo de drogas de abuso sintéticas que surgiram no mercado ilícito a partir da segunda metade dos anos 90. Os seus efeitos psicoactivos, como por exemplo estados de euforia, são comparáveis aos obtidos por consumo de anfetaminas e ecstasy, sendo por isso consideradas uma alternativa legal, barata e segura.
Deste modo torna-se necessário o desenvolvimento de métodos analíticos rápidos e sensíveis para a quantificação e determinação destas drogas em amostras biológicas.
O objectivo deste trabalho foi o desenvolvimento e validação de um método analítico usando microextracção em seringa empacotada (MEPS) e cromatografia líquida de alta eficiência acoplada a um detector de fotodiodos (UPLC-DAD), para a determinação e quantificação de quatro derivados das piperazinas em amostras de urina. As piperazinas estudadas foram a 1-benzilpiperazina (BZP), 1-(3-trifluorometilfenil)piperazina (TFMPP), 1-(3-clorofenil)piperazina (mCPP) e 1-(4-metoxifenilpiperazina (MeOPP), usando como padrão interno a 1-(2-clorofenil)piperazina (oCPP). É a primeira vez que este tipo de compostos é determinado em amostras de urina com recurso à MEPS.
O método foi totalmente optimizado usando o planeamento factorial, uma poderosa ferramenta estatística que permite avaliar de forma multivariada os diversos factores intervenientes no processo de extracção. As condições finais optimizadas foram: diluição da amostra (1:2), número de aspirações pelo dispositivo (8), activação do mecanismo de troca iónica (1% ácido acético), a quantidade de metanol no solvente de lavagem (10%) e a eluição dos analitos (5% de amoníaco em metanol).
O procedimento foi linear para o intervalo de concentrações de 0.1 (limite inferior de quantificação - LLOQ) até 5 μg/mL, com coeficientes de determinação (R2) superiores a 0.99 para todos os analitos. Os limites de detecção foram de 0.1 μg/mL para a BZP e TFMPP, enquanto para a MeOPP e mCPP foi obtido 0.05 μg/mL. Os valores da precisão intra-dia e intermédia variaram de 1 a 12% enquanto a exactidão está dentro de um intervalo de ±14% para todos os analitos, preenchendo os critérios normalmente aceites para a validação de métodos bioanalíticos. Nas condições optimizadas, obtiveram-se recuperações superiores a 80% para todos os analitos, excepto para a BZP (50%).
A MEPS mostrou ser uma técnica simples e rápida para a determinação de piperazinas em amostras de urina, permitindo poupar tempo e dinheiro. Além disso, o facto de que apenas 0.1 mL de amostra são necessários para efectuar a análise, torna o método uma ferramenta poderosa e valiosa para a monitorização destas drogas em urina, por exemplo em situações de âmbito forense.
Piperazines are considered a new group of synthetic drugs of abuse that emerged in the illicit market from the second half of 1990. Their psychoactive effects, such as states of euphoria, are comparable to those obtained by use of amphetamines and ecstasy, and is therefore considered a legal alternative, inexpensive and safe. Thus it becomes necessary to develop rapid and sensitive analytical methods for quantification and determination of these compounds in biological samples. The goal of this work was to develop and validate an analytical method using microextraction syringe packed (MEPS) and high performance liquid chromatography coupled to detector efficiency photodiodes (UPLC-DAD) for the determination and quantification of four derivatives of piperazines in urine samples. The studied piperazines were: 1-benilpiperazine (BZP), 1-(3- trifluorometilfenil)piperazine (TFMPP), 1-(3-chlorophenyl)piperazine (mCPP) and 1-(4- metoxifenilpiperazine (MeOPP), using as internal standard 1-(2-chlorophenyl)piperazine (oCPP). This is the first time that those compounds are determined in urine samples by means of MEPS. The method was comprehensively optimized using the factorial design approach, and the evaluated parameters were sample dilution (1:2), strokes (8), cathion exchange mechanism enhancement (1% acetic acid), amount of methanol on the washing solvent (10%), and elution of the analytes (5% ammonia in methanol). The procedure was linear at concentrations ranging from 0.1 (lower limit of quantitation – LLOQ) to 5 µg/mL, with correlation coefficients (R2 ) higher than 0.99 for all analytes in all runs. The limits of detection were 0.1µg/mL for BZP and TFMPP, while for MeOPP and mCPP 0.05 µg/mL was obtained. Intra- and interday precision ranged from 1 to 12%, while accuracy was within a ±14% interval for all analytes, fulfilling the criteria normally accepted in bioanalytical method validation. Under the optimized conditions, extraction efficiency was higher than 80% for all analytes, except for BZP (50%). MEPS has shown to be a rapid and robust procedure for the determination of piperazine-type stimulants in human urine, allowing reducing the handling time and costs usually associated to these analyses. Furthermore, the fact that only 0.1 mL of sample is required to accomplish the analysis make this method a valuable and powerful tool for drug monitoring in human urine.
Piperazines are considered a new group of synthetic drugs of abuse that emerged in the illicit market from the second half of 1990. Their psychoactive effects, such as states of euphoria, are comparable to those obtained by use of amphetamines and ecstasy, and is therefore considered a legal alternative, inexpensive and safe. Thus it becomes necessary to develop rapid and sensitive analytical methods for quantification and determination of these compounds in biological samples. The goal of this work was to develop and validate an analytical method using microextraction syringe packed (MEPS) and high performance liquid chromatography coupled to detector efficiency photodiodes (UPLC-DAD) for the determination and quantification of four derivatives of piperazines in urine samples. The studied piperazines were: 1-benilpiperazine (BZP), 1-(3- trifluorometilfenil)piperazine (TFMPP), 1-(3-chlorophenyl)piperazine (mCPP) and 1-(4- metoxifenilpiperazine (MeOPP), using as internal standard 1-(2-chlorophenyl)piperazine (oCPP). This is the first time that those compounds are determined in urine samples by means of MEPS. The method was comprehensively optimized using the factorial design approach, and the evaluated parameters were sample dilution (1:2), strokes (8), cathion exchange mechanism enhancement (1% acetic acid), amount of methanol on the washing solvent (10%), and elution of the analytes (5% ammonia in methanol). The procedure was linear at concentrations ranging from 0.1 (lower limit of quantitation – LLOQ) to 5 µg/mL, with correlation coefficients (R2 ) higher than 0.99 for all analytes in all runs. The limits of detection were 0.1µg/mL for BZP and TFMPP, while for MeOPP and mCPP 0.05 µg/mL was obtained. Intra- and interday precision ranged from 1 to 12%, while accuracy was within a ±14% interval for all analytes, fulfilling the criteria normally accepted in bioanalytical method validation. Under the optimized conditions, extraction efficiency was higher than 80% for all analytes, except for BZP (50%). MEPS has shown to be a rapid and robust procedure for the determination of piperazine-type stimulants in human urine, allowing reducing the handling time and costs usually associated to these analyses. Furthermore, the fact that only 0.1 mL of sample is required to accomplish the analysis make this method a valuable and powerful tool for drug monitoring in human urine.
Description
Keywords
Microextracção em seringa empacotada Piperazines Drogas de abuso Análise de urina
Citation
Publisher
Universidade da Beira Interior