RÉSUMÉ
Sulforaphane is a chiral phytochemical with chemopreventive properties. The presence of a stereogenic sulfur atom is responsible for the chirality of the natural isothiocyanate. The key role of sulfur chirality in biological activity is underscored by studies of the efficacy of individual enantiomers as chemoprotective agents. The predominant native (R) enantiomer is active, whereas the (S) antipode is inactive or has little or no biological activity. Here we provide an enantioselective high-performance liquid chromatography (HPLC) protocol for the direct and complete resolution of sulforaphane and its chiral natural homologs with different aliphatic chain lengths between the sulfinyl sulfur and isothiocyanate group, namely iberin, alyssin, and hesperin. The chromatographic separations were carried out on the immobilized-type CHIRALPAK IH-3 chiral stationary phase with amylose tris-[(S)-methylbenzylcarbamate] as a chiral selector. The effects of different mobile phases consisting of pure alcoholic solvents and hydroalcoholic mixtures on enantiomer retention and enantioselectivity were carefully investigated. Simple and environmentally friendly enantioselective conditions for the resolution of all chiral ITCs were found. In particular, pure ethanol and highly aqueous mobile phases gave excellent enantioseparations. The retention factors of the enantiomers were recorded as the water content in the aqueous-organic modifier (methanol, ethanol, or acetonitrile) mobile phases progressively varied. U-shaped retention maps were generated, indicating a dual and competitive hydrophilic interaction liquid chromatography (HILIC) and reversed-phase liquid chromatography retention mechanism on the CHIRALPAK IH-3 chiral stationary phase. Finally, experimental chiroptical studies performed in ethanol solution showed that the (R) enantiomers were eluted before the (S) counterpart under all eluent conditions investigated.
Sujet(s)
Amylose , Isothiocyanates , Isothiocyanates/composition chimique , Chromatographie en phase liquide à haute performance/méthodes , Stéréoisomérie , Amylose/composition chimique , Amylose/analogues et dérivés , Technologie de la chimie verte/méthodesRÉSUMÉ
Rosuvastatin (RSV) is a well-established lipid-lowering drug. RSV is susceptible to degradation under various stress conditions and forms two cyclic derivatives by a radical-mediated photolytic mechanism. On a structural basis, these epimeric compounds (reported as FP-B in the European Pharmacopeia monograph Rosuvastatin tablets) retain the configuration of the stereogenic carbons of RSV (3R,5S) and have opposite absolute configurations at the third stereogenic center. Herein, we report the kinetics of formation and the complete structural characterization, including the assignment of the absolute configuration, of each epimer collected after HPLC separation on a chiral stationary phase. The stereochemistry of the epimers was determined by comparison of the experimental circular dichroism data with the corresponding theoretical values. Kinetic studies revealed that RSV degrades completely to FP-B within 3 h at room temperature. Furthermore, through a multi-disciplinary approach involving chromatography (HPLC and UHPLC), circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), it was demonstrated that FP-B in turn degrades to the lactones under the mild acidic conditions of the chromatographic mobile phase. The ability of RSV to form multiple degradation products may affect the quantification of RSV-related substances and draw attention to potentially toxic RSV-like species in the environment.
Sujet(s)
Rosuvastatine de calcium , Cinétique , Spectrométrie de masse , Chromatographie en phase liquide à haute performance/méthodes , Dichroïsme circulaire , StéréoisomérieRÉSUMÉ
Normal-phase and reversed-phase high-performance liquid chromatography methods for the separation of the active pharmaceutical ingredient escitalopram from its (R)-enantiomer impurity have been developed on the cellulose-based Chiralcel OJ-H chiral stationary phase. Both methods share two features: they use ethanol as a cosolvent and are able to give a complete enantioseparation without interference from other associated chiral impurities. With the green eluent mixture ethanol-water-diethylammine 70:30:0.1 (v/v/v), the resolution between escitalopram and (R)-enantiomer was 2.09 at 30°C. The limits of quantification for the (S) and (R) enantiomers were 4.5 and 3.8 µg mL-1 , respectively.
Sujet(s)
Cellulose , Escitalopram , Cellulose/composition chimique , Chromatographie en phase liquide à haute performance/méthodes , Oxalates , StéréoisomérieRÉSUMÉ
Sulforaphane and iberin are promising chemopreventive chiral phytochemicals. The chirality of these organic isothiocyanates is due to the presence of a stereogenic sulfur atom. Investigations of the effectiveness of single enantiomers as chemoprotective agents highlight the key role played by sulfur chirality on biological activity. The predominant native (R)-enantiomer is active whereas the (S)-counterpart is inactive or poorly active. Here, we provide an enantioselective method for the direct and complete resolution of both chiral sulfoxides by high-performance liquid chromatography on immobilized amylose-derived chiral stationary phases. A set of five different columns was investigated utilizing normal-phase, polar organic and aqueous conditions. The effect of the composition of mobile phase on enantioselectivity and retention was carefully evaluated. U-shape retention maps, which are indicative of a double and competitive hydrophilic interaction liquid chromatography and reversed-phase liquid chromatography retention mechanism, were established by recording the retention factors of the enantiomers of sulforaphane on the Chiralpak IA-3 and Chiralpak IG-3 chiral stationary phases varying progressively the water content in the water-acetonitrile mobile phases.
RÉSUMÉ
The marketing of new argan-based products is greatly increased in the last few years and consequently, it has enhanced the number of control analysis aimed at detecting counterfeit products claiming argan oil as a major ingredient. Argan oil is produced in Morocco and it is quite expensive. Two simple methods for the rapid screening of pure oil and argan-oil based products, focused on the analysis of the triacylglycerol profile, have been developed. A three-minute-run by UHPLC-PDA allows the identification of a pure argan oil, while the same run with the MS detector allows also the analysis of products containing the oil down to 0.03%. On the other hand, by HPTLC the simultaneous analysis of twenty samples, containing argan oil down to 0.5%, can be carried out in a forty-five-minute run. The triglyceride profile of the most common vegetable fats such as almond, coconut, linseed, wheat germ, sunflower, peanut, olive, soybean, rapeseed, hemp oils as well as shea butter used either in cosmetics or commonly added for the counterfeiting of argan oil, has been also investigated. Over sixty products with different formulations and use have been successfully analyzed and argan oil in the 2.4-0.06% concentration range has been quantified. The methods are suitable either for a rapid screening or for quantifying argan oil in different formulations.
Sujet(s)
Chromatographie en phase liquide à haute performance/méthodes , Chromatographie sur couche mince/méthodes , Huiles végétales/analyse , Triglycéride/analyse , Huiles végétales/composition chimique , Huiles végétales/normes , Spectrométrie de masse ESI/méthodes , Facteurs temps , Triglycéride/composition chimiqueRÉSUMÉ
A deeper knowledge of the chemical composition of coffee silverskin (CS) is needed due to the growing interest in its use as a food additive or an ingredient of dietary supplements. Accordingly, the aim of this paper was to investigate the metabolic profile of aqueous extracts of two varieties of CS, Coffee arabica (CS-A), Coffee canephora var. robusta (CS-R) and of a blend of the two (CS-b) and to compare it to the profile of Coffee arabica green coffee (GC). Chlorogenic acids, caffeine, furokauranes, and atractyligenins, phytotoxins not previously detected in CS, were either identified or tentatively assigned. An unknown compound, presumably a carboxyatractyligenin glycoside was detected only in GC. Caffeine and chlorogenic acids were quantified while the content of furokauranes and atractyligens was estimated. GC and CS were also characterized in terms of total polyphenols and antioxidant capacity. Differences in the metabolites distribution, polyphenols and antioxidant capacity in GC and CS were detailed.
Sujet(s)
Antioxydants/analyse , Chromatographie en phase liquide à haute performance , Coffea/composition chimique , Analyse d'aliment/méthodes , Métabolomique/méthodes , Composés phytochimiques/analyse , Graines/composition chimique , Spectrométrie de masse ESI , Toxines biologiques/analyse , Atractyloside/analogues et dérivés , Atractyloside/analyse , Caféine/analyse , Acide chlorogénique/analyse , Coffea/classification , Graines/classificationRÉSUMÉ
Commission regulation (EU) No 358/2014 amending the new regulation (EC) No 1223/2009 on cosmetics has prohibited the use of isopropyl-, isobutyl-, phenyl-, benzyl- and pentylparaben. Furthermore, Commission regulation (EU) No 1004/2014 has lowered the maximum permitted concentration of butyl- and propylparaben in cosmetics and it has also banned them in leave-on products designed for application on the nappy area of children under three years of age. A HPLC-PDA-ESI/MS method has been developed herein for the detection of seventeen preservatives, both the most utilised and the recently forbidden by the new EU regulations. The separation of these compounds, including benzoic acid and its derivatives in a 1.10 - 3.04 log Pow range, has been performed with a gradient elution on a Symmetry(®) C18 column (250×4.6mm i.d., particle size 5µm) with water and acetonitrile (0.1% formic acid) as mobile phase. Quantification has been carried out by HPLC-PDA. The method has been validated and successfully applied to the analysis of a large number of cosmetics with different functions like rinse-off and leave-on, or composition like skin, hair, face and oral products.
Sujet(s)
Chromatographie en phase liquide à haute performance/méthodes , Cosmétiques/analyse , Spectrométrie de masse ESI/méthodes , Union européenneRÉSUMÉ
The aim of this study was to get a rapid metabolic fingerprinting and to gain insight into the metabolic profiling of Arctostaphylos pungens H. B. K., a plant morphologically similar to Arctostaphylos uva-ursi (L.) Spreng. (bearberry) but with a lower arbutin (Arb) content. According to the European Pharmacopoeia the Arb content in the dried leaf of A. uva-ursi (L.) Spreng. must be at least 7% (wt/wt) but other species, like A. pungens, are unintentionally or fraudulently marketed instead of it. Therefore, methanolic leaf extracts of nine A. uva-ursi and six A. pungens samples labeled and marketed as "bearberry leaf" have been analyzed. A five-minute gradient with a UHPLC-PDA-ESI-TOF/MS on an Acquity BEH C18 (50×2.1 mm i.d.) 1.7 µm analytical column has been used for the purpose. A comprehensive assignment of secondary metabolites has been carried out in a comparative study of the two species. Among twenty-nine standards of natural compounds analyzed, fourteen have been identified, while other fifty-five metabolites have been tentatively assigned. Moreover, differences in both metabolic fingerprinting and profiling have been evidenced by statistical multivariate analysis. Specifically, main variations have been observed in the relative content for Arb, as expected, and for some galloyl derivative like tetra- and pentagalloylglucose more abundant in A. uva-ursi than in A. pungens. Furthermore, differences in flavonols profile, especially in myricetin and quercetin glycosilated derivatives, were observed. Based on principal component analysis myricetrin, together with a galloyl arbutin isomer and a disaccharide are herein proposed as distinctive metabolites for A. pungens.
Sujet(s)
Arctostaphylos , Arbutoside/analyse , Arctostaphylos/composition chimique , Arctostaphylos/génétique , Arctostaphylos/métabolisme , Ericaceae/composition chimique , Flavonoïdes/analyse , Tanins hydrolysables/analyse , Métabolomique , Méthanol , Résonance magnétique nucléaire biomoléculaire , Phénols/analyse , Extraits de plantes/composition chimique , Feuilles de plante/composition chimique , Quercétine/analyseRÉSUMÉ
Statins, widely used for treatment of hypercholesterolemia, have been demonstrated to exert pleiotropic beneficial effects independently of their cholesterol-lowering action, such as anti-inflammatory activity. A gender disparity has been observed in their cholesterol lowering activity as well as in response to these "off label" effects. Monocytes play a central role in atherosclerotic disease and, more in general, in inflammatory responses, through their chemotactic function and cytokine production. On these bases, in the present work, we examined the effect of statins on homeostasis and migration properties of freshly isolated monocytes from male and female healthy donors. Two prototypic natural and synthetic statins with different polarity, that is, type 1 and type 2 statins, have been considered: simvastatin and atorvastatin. Freshly isolated monocytes from peripheral blood of male and female healthy donors were treated with these drugs in the absence or presence of lipopolysaccharide (LPS) stimulation. Results obtained indicated that the polar statin efficiently inhibited chemotaxis of monocytes more than the apolar statin and that this effect was more significantly induced in cells from females than in cells from males. Dissecting the mechanisms involved, we found that these results could mainly be due to differential effects on: (i) the release of key cytokines, for example, MCP-1 and TNF-α; (ii) the maintenance of the redox homeostasis; (iii) a target activity on microfilament network integrity and function. All in all these results could suggest a reappraisal of "off-label" effects of statins taking into account either their chemical structure, that is, molecular polarity, or the gender issue.
Sujet(s)
Athérosclérose/traitement médicamenteux , Inflammation/traitement médicamenteux , Monocytes/effets des médicaments et des substances chimiques , Caractères sexuels , Athérosclérose/anatomopathologie , Atorvastatine , Mouvement cellulaire/effets des médicaments et des substances chimiques , Femelle , Volontaires sains , Acides heptanoïques/administration et posologie , Humains , Inflammation/génétique , Inflammation/anatomopathologie , Lipopolysaccharides/toxicité , Mâle , Pyrroles/administration et posologie , Simvastatine/administration et posologie , Facteur de nécrose tumorale alpha/métabolismeRÉSUMÉ
Spent coffee grounds (SCG) were extracted with an environmentally friendly procedure and analyzed to evaluate the recovery of relevant natural antioxidants for use as nutritional supplements, foods, or cosmetic additives. SCG were characterized in terms of their total phenolic content by the Folin-Ciocalteu procedure and antioxidant activity by the DPPH scavenging assay. Flavonoid content was also determined by a colorimetric assay. The total phenolic content was strongly correlated with the DPPH scavenging activity, suggesting that phenolic compounds are mainly responsible for the antioxidant activity of SCG. An UHPLC-PDA-TOF-MS system was used to separate, identify, and quantify phenolic and nonphenolic compounds in the SCG extracts. Important amounts of chlorogenic acids (CGA) and related compounds as well as caffeine (CAF) evidenced the high potential of SCG, a waste material that is widely available in the world, as a source of natural phenolic antioxidants.
Sujet(s)
Antioxydants/composition chimique , Café/composition chimique , Caféine/analyse , Calibrage , Acide chlorogénique/analyse , Chromatographie en phase liquide à haute performance , Flavonoïdes/analyse , Spectrométrie de masse , Phénols/analyseRÉSUMÉ
Herbal species different from the official bearberry, Arctostaphylos uva-ursi, are sold through conventional markets and also through non-controlled Internet websites, putting consumer safety at risk owing to the lack of quality control. Recently, Arctostaphylos pungens has become one of the most used species as a raw material for herbal medicines and dietary supplements in the place of official bearberry, a plant used for the treatment of various urinary disorders. A fingerprint identification based on an integrated application of different analytical techniques (HPTLC, NMR, HPLC-DAD and LC-ESI-MS) is here described to distinguish A. uva-ursi from A. pungens. The HPTLC and HPLC-DAD fingerprints resulted the simplest methods to differentiate the two species, whereas LC-ESI-MS was more useful to quantify arbutin, the main component of bearberry, and to evaluate its different content in the two species. This multidisciplinary study showed for the first time a specific phytochemical fingerprint of the new species A. pungens.
Sujet(s)
Arctostaphylos/composition chimique , Chromatographie en phase liquide à haute performance , Chromatographie sur couche mince , Flavonoïdes/isolement et purification , Science des plantes médicinales/normes , Spectroscopie par résonance magnétique , Spectrométrie de masse ESIRÉSUMÉ
Methylprednisolone (MP) released by poly(d,l-lactide-co-glycolide) microspheres (PLGA MS) was monitored in plasma after intra-articular (i.a.) administration into rat joint. A validated LC-ESI-MS/MS method was used to quantify the plasmatic concentrations of MP. The calculated pharmacokinetic parameters were compared to those obtained after the i.a. administration of a commercially available suspension of MP acetate (MPA). Different pharmacokinetic profiles were observed in the two formulations, and a lower peak level (C(max) = 13.7 ± 4.3 ng · mL(-1)) and AUC(0-72 h) (198 ± 45 ng · mL(-1) · h) were observed for MP-PLGA MS than MPA (C(max) = 18.4 ± 2.7 ng · mL(-1)) and AUC(0-72 h) (943 ± 249 ng · mL(-1) · h). The administration of MP-PLGA MS resulted in a rapid increase in the MP concentration at 30 min, with a t(max) at 0.8 ± 0.3 h. Instead, for the MPA suspension the t(max) was 32.0 ± 13.9 h. These differences were indirectly confirmed by the evaluation of the extra-articular effects, namely, carrageenan-induced paw edema, since MP-PLGA MS showed a lower anti-inflammatory activity than MPA.
Sujet(s)
Anti-inflammatoires/administration et posologie , Acide lactique/composition chimique , Méthylprednisolone/administration et posologie , Acide polyglycolique/composition chimique , Animaux , Anti-inflammatoires/pharmacocinétique , Aire sous la courbe , Chromatographie en phase liquide , Préparations à action retardée , Articulations , Méthylprednisolone/pharmacocinétique , Microsphères , Copolymère d'acide poly(lactique-co-glycolique) , Rats , Spectrométrie de masse ESI , Spectrométrie de masse en tandemRÉSUMÉ
A study on urinary metabolites of methylprednisolone acetate (MPA) has been performed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) in precursor ion scanning (PIS) and neutral loss (NL) modes. Patients suffering from joint inflammation have been treated with Depo-Medrol® (MPA marketed suspension, 40 mg) intra-articularly (IA) and after a wash-out period, intramuscularly (IM) at the same dose. Urine samples have been collected after both the administration routes. Metabolites were identified in PIS mode by setting the fragment ion at m/z 161 which is specific for MPA, methylprednisolone (MP), methylprednisolone hemisuccinate, and in NL mode by selecting the losses of 54, 72, 176 and 194 Da. The MP-related structure of each target ion detected in both the MS modes was then confirmed by MS/MS acquisitions, and by accurate mass experiments. By using this approach, 13 MPA metabolites (M1-M13) have been identified, nine already reported in the literature and four unknown and for which the chemical structures have been proposed. No differences in the metabolic pattern of MPA when administered IM or IA were observed. The relative abundances of metabolites compared with the internal standard (MP-D2) were monitored by multiple reaction monitoring analysis for 19 days after both the administration routes.
Sujet(s)
Méthylprednisolone/analogues et dérivés , Adulte , Chromatographie en phase liquide à haute performance , Humains , Injections articulaires , Injections musculaires , Méthylprednisolone/administration et posologie , Méthylprednisolone/urine , Acétate de méthylprednisolone , Adulte d'âge moyen , Arthrose/traitement médicamenteux , Spectrométrie de masse ESI , Spectrophotométrie UV , Spectrométrie de masse en tandemRÉSUMÉ
A new, simple, sensitive and specific liquid chromatography/electrospray ionization tandem mass spectrometric (LC/ESI-MS/MS) method in precursor ion scanning (PIS) mode has been developed for the rapid detection of methylprednisolone acetate (MPA) and its metabolites in rat urine. A suitable product ion specific for methylprednisolone (MP) and MPA was selected after a fragmentation study on 20 (cortico)steroids at different collision energies (5-40 eV). Urine samples were simply treated with acetonitrile then dried in a SpeedVac system. The method was validated and compared with other PIS methods for detecting corticosteroids in human urine. It was more sensitive, with limit of detection (LOD) and lower limit of quantitation (LLOQ), respectively, of 5 and 10 ng mL(-1). The method was applied for the analysis of rat urine collected before and after (24, 48, 72 h) intra-articular (IA) injection of a marketed formulation of MPA (Depo-Medrol(R)). MS/MS acquisitions were taken at different collision energies for the precursor ions of interest, detected in PIS mode, to verify the MP-related structure. Six different metabolites were detected in rat urine, and their chemical structures were assigned with a computational study.
Sujet(s)
Méthylprednisolone/analogues et dérivés , Spectrométrie de masse ESI/méthodes , Spectrométrie de masse en tandem/méthodes , Animaux , Humains , Mâle , Méthylprednisolone/composition chimique , Méthylprednisolone/métabolisme , Méthylprednisolone/urine , Acétate de méthylprednisolone , Structure moléculaire , Rats , Rat Wistar , Sensibilité et spécificitéRÉSUMÉ
A rapid, sensitive and specific liquid chromatography-electrospray-tandem mass spectrometric (LC-ESI-MS/MS) method for the simultaneous detection and quantitation of methylprednisolone acetate (MPA) and methylprednisolone (MP) in rat plasma, using a triple-stage quadrupole, has been developed and validated. MP-D(2) was used as internal standard (IS) and acetonitrile was added to plasma samples for protein precipitation. After extraction with dichloromethane, the analytes were separated on a C-12 reversed-phase column by isocratic elution (6min at a flow rate 0.2mLmin(-1)) with water containing 0.01% formic acid (A) and acetonitrile (B) (50:50, v/v). Quantitation was performed in positive ion multiple reaction monitoring (MRM) mode by applying the following precursor-to-product ion transitions: MPA m/z 417-->135+161+253; MP m/z 375-->135+161+253; IS m/z 377-->135+161+253. The method, validated over the concentration range 6-600ngmL(-1), has been shown to meet the current requirements of bioananalytical validation, providing satisfactory results in terms of linearity, recovery, intra-day and inter-day precision and accuracy. The lower limit of quantitation (LLOQ) was 6ngmL(-1) for both the analytes (0.080 and 0.072pmol injected for MP and MPA, respectively). The method was successfully applied to monitor the plasma levels of MPA and MP following intra-articular (IA) injections of a low MPA (Depo-Medrol((R))) dose in rats.
Sujet(s)
Méthylprednisolone/analogues et dérivés , Méthylprednisolone/administration et posologie , Méthylprednisolone/sang , Spectrométrie de masse ESI/méthodes , Animaux , Chromatographie en phase liquide/méthodes , Injections articulaires , Mâle , Acétate de méthylprednisolone , Rats , Rat Wistar , Spectrométrie de masse en tandem/méthodes , Facteurs tempsRÉSUMÉ
Glutathionylated hemoglobin (Hb-SSG) is now recognized as a promising biomarker of systemic oxidative stress. Aim of this study is to gain a mechanistic insight into its formation. The ability of GSSG to form Hb-SSG through a thiol-disulfide exchange mechanism was firstly examined. For this purpose, GSSG (ranging from 0.23 to 230micromol/g Hb, 15microM-15mM final concentrations) was incubated with 1mM Hb and the relative content of Hb-SSG determined by direct infusion mass spectrometry (Orbitrap as analyzer). No detectable Hb-SSG was observed at a GSSG concentration range found in physiopathological conditions (0.13-0.23micromol/g Hb). To reach a detectable Hb-SSG signal, the GSSG concentration was raised to 2.3micromol/g Hb (0.5% relative abundance). The relative content of Hb-GSSG dose-dependently increased to 6% and 11% at 77 and 153micromol/g Hb, respectively. The second step was to demonstrate whether Hb-SSG is formed through a sulfenic acid intermediate, a well-recognized mechanism of S-protein glutathionylation. Cys beta93 sulfenic acid was found to be formed by oxidizing Hb with 1mM H(2)O(2), as demonstrated by direct infusion and LC-ESI-MS/MS experiments and using dimedone as derivatazing agent. When H(2)O(2)-treated Hb was incubated with physiological concentrations of GSH (9micromol/g Hb), the corresponding Hb-SSG form was detected, reaching 15% of relative abundance. In summary, we here demonstrate that Hb glutathionylation can occur through a Cys sulfenic acid intermediate which is formed in oxidizing conditions. Hb glutathionylation is also mediated by a thiol-disulfide transfer mechanism, but this requires a concentration of GSSG which is far to be achieved in physiopathological conditions.
Sujet(s)
Cystéine/analogues et dérivés , Disulfure de glutathion/composition chimique , Hémoglobines/composition chimique , Spectrométrie de masse ESI/méthodes , Acides sulféniques/composition chimique , Cystéine/composition chimique , HumainsRÉSUMÉ
A rapid and simple LC-ESI-MS method for the simultaneous detection and quantitation of six preservatives in homeopathic syrups has been developed. Counterfeit homeopathic syrups are suspected to contain preservatives that are not declared in label. For this reason a method to ascertain the absence of sorbic and benzoic acids, methyl-, ethyl-, propyl- and butyl-parabens, as the most frequently utilised preservatives, has been developed. Analytes were eluted with a linear gradient of acetonitrile-5mM ammonium acetate in 12 min using 2,4-dichlorobenzylalchol as Internal Standard. The HPLC separation was performed on an Eclipse XDB-C18 (2.1 mm x 50 mm-5 microm) column and the ESI-MS detection was performed in negative ion mode. Linearity of the method was studied in the range of 2 pg to 10 ng injected and correlation coefficients r2 > or =0.9992 were obtained. LOD ranged from 0.04 to 0.4 ng mL(-1).
Sujet(s)
Étiquetage de médicament/normes , Escroquerie/prévention et contrôle , Homéopathie , Parabènes/analyse , Préparations pharmaceutiques/normes , Chromatographie en phase liquide/méthodes , Humains , Reproductibilité des résultats , Spectrométrie de masse ESI/méthodes , Spectrométrie de masse en tandem/méthodes , Facteurs tempsRÉSUMÉ
A simple high-performance liquid chromatography (HPLC) method with both ultraviolet (UV) and electrospray ionisation mass spectrometry (ESI-MS) detection has been developed for the determination of seven pharmaceuticals in counterfeit homeopathic preparations. Naproxen, Ketoprofen, Ibuprofen, Diclofenac, Piroxicam, Nimesulide and Paracetamol were separated by reversed phase chromatography with acetonitrile-water (0.1% acetic acid) mobile phase, and detected by UV at 245 nm and by ESI-MS in negative ionisation mode with the exception of Paracetamol which was detected in positive ionisation mode. Benzoic acid was used as internal standard (IS). This method was successfully applied to the analysis of homeopathic preparations like mother tinctures, solutions, tablets, granules, creams, and suppositories. Linearity was studied with UV detection in the 50-400 microg mL(-1) range and with ESI-MS in the 0.1-50 microg mL(-1) range. Good correlation coefficients were found in both UV and ESI-MS. Detection limits ranged from 0.18 to 41.5 ng in UV and from 0.035 to 1.00 ng in ESI-MS.
Sujet(s)
Anti-inflammatoires non stéroïdiens/analyse , Chromatographie en phase liquide à haute performance/méthodes , Escroquerie/prévention et contrôle , Homéopathie , Préparations pharmaceutiques/normes , Spectrométrie de masse ESI/méthodes , Spectrophotométrie UV/méthodes , Reproductibilité des résultatsRÉSUMÉ
A high performance liquid chromatography electrospray mass spectrometry (HPLC-ESI-MS) method, for the detection of corticosteroids in cosmetics has been developed. A water-acetonitrile linear gradient on a C-18 reversed-phase column was found to be suitable in separating triamcinolone and its main derivatives, which greatly differ in lipophilicity. Detection was performed in negative electrospray ionisation mode. Good correlation between peaks areas and solutions concentration was found in the range 0.05-10.0 micro g ml(-1) and the detection limits resulted in the range of 20-45 pg injected. The method was successfully applied to the analysis of real samples of shampoo.