Browsing by Author "Rodrigues, Manuela J.E."
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- Analysis of pharmaceutical adulterants in plant food supplements by UHPLC-MS/MSPublication . Paíga, Paula; Rodrigues, Manuela J.E.; Correia, Manuela; Amaral, Joana S.; Oliveira, Beatriz; Delerue-Matos, CristinaA method based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was successfully developed and validated for the analysis of 26 pharmaceutical compounds belonging to different therapeutic classes (anorexics, stimulants, anxiolytics, antidepressants and laxatives), which are all prone to be illegally added into weight-loss plant food supplements (PFS) for their pharmacological activity. Internal standard calibration with six isotopically labelled compounds rendered good linearity in the range of 5 to 1000 μg/l, depending on the compound, and good sensitivity with limits of quantification in the range of 0.02–9.80 μg/l. Recoveries were assessed for all the 16 samples analysed and were found between 70% and 120% for over 90% of the analytes. The average recovery value was 90.8%, for the different studied matrices (liquids, liquid ampoules, tablets and capsules), with RSD values lower than 10% for all forms. The changes introduced to the QuEChERS procedure maintained the good performance characteristics of the extraction method while preserving the chromatographic system for the introduction of unwanted matrix compounds. Synephrine was the only compound detected and quantified in one sample, but at a very low concentration (768 μg/l) and its presence may be due to the plant extracts used in the formulation, as synephrine is known to be a natural constituent of Citrus aurantium amara. Despite none of the 16 evaluated samples were found to be adulterated by the illegal addition of the drugs included in this work, the developed methodology can be very useful for monitoring the adulteration of weight-loss PFS.
- Assessment of plant food supplements adulteration with psychopharmaceutical drugsPublication . Rodrigues, Manuela J.E.; Paíga, Paula; Santos, Lúcia H.M.L.M.; Amaral, Joana S.; Oliveira, Beatriz; Correia, Manuela; Delerue-Matos, CristinaThe purpose of this study was to compare three different extraction methods (two based on ethanol extraction and one on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERs) method) to assess the possible addition of psychopharmaceutical drugs (fluoxetine, sertraline, citalopram, venlafaxine, paroxetine, trazodone, and diazepam) as adulterants in St. John's wort (Hypericum perforatum) based plant food supplements (PFS). Methodology: Analysis was performed in a Nexera Ultra-High Performance Liquid Chromatograph (UHPLC) coupled to a triple-quadrupole mass spectrometer (LCMS-8030 Shimadzu) with an electrospray ionization source (ESI), operating in positive ion mode, using a Kinetex C18 fused core column (150 × 2.10 mm i.d.; 1.7 m) (Phenomenex). Multiple reaction monitoring mode (MRM) was selected and pharmaceuticals were quantified by internal standard calibration method. Calibration curves were constructed in the range 10 – 1000 g/L. The three different extraction methods were compared based on the analysis of spiked samples.
- Determination of psychopharmaceutical adulterants in plant food supplements using UHPLC-MS/MSPublication . Rodrigues, Manuela J.E.; Paíga, Paula; Santos, Lúcia H.M.L.M.; Amaral, Joana S.; Oliveira, Beatriz; Correia, Manuela; Delerue-Matos, CristinaIn the last decades, medicinal plants and derived products have become increasingly available on the EU market as components of formulations sold as plant food supplements (PFS). Such products are legally considered as foods under the Directive 2002/46/EC [l] and do not require any kind of authorization to be placed on the market. The legal responsibility for its safety relies on the business operators. Among the several issues that may aíFect the safety of PFS, adulterations including the addition of illegal substances represent an increasing public health concern. In this context, the adulteration by the addition of psychopharmaceuticals should be investigated. Chromatographic methods, especially LC, coupled to various detectors are commonly used for the detection of fraudulent addition of pharmaceuticals in complex mixtures such as PFS. Among them, LC-MS/MS provides accurate and sensitive detectíon ofthe target compounds [2]. The purpose of this study was to assess the presence of psychopharmaceutical adulterants namely, fluoxetine, sertraline, citalopram, venlafaxine, paroxetine, trazodone, and diazepam in St. Johns wort (Hypericum perforatum) based PFS since this plant and/or extracts are traditionally used for its antidepressive properties. Analysis was performed in a Nexera Ultra-High Performance Liquid Chromatograph coupled to a triple-quadrupole mass spectrometer (LCMS-8030 Shimadzu) with an electrospray ionization source (ESI), operating in positive ion mode, using a Kinetex C18 fused core column (150 x 2.10 mm i.d.; 1.7 [im) (Phenomenex). Multiple reaction monitoring mode (MRM) was selected and pharmaceuticals were quantified by internai standard calibration method. Prior to analysis PFS samples were extracted with methanol. The methodology was applied to a set of20 St. Johns wort based PFS commercially available in the Portuguese market.