Electrospray Ionization Mass Spectrometry Fingerprinting Research Articles

Specialized natural product analysis and chemophenetics of some Turkish endemic Centaurea L. (Asteraceae) taxa by electrospray ionization mass spectrometry fingerprinting and liquid chromatography-tandem mass spectrometry

Specialized natural product analysis of six Turkish endemic and two narrowly distributed Centaurea L. taxa was performed via electrospray ionization mass spectrometry (ESI-MS) fingerprinting and liquid chromatography-tandem mass spectrometry (LC-MS/MS), which is an effective methodology that is widely used for fast screening of complex natural mixtures such as food extracts, but not has not been used as commonly for plant chemophenetics. This method is preferable when it is aimed to compare a large number of plant extracts for chemophenetic purposes and when it is difficult to provide equally good chromatographic separation in all of the extracts. ESI-MS shows the major compounds in fingerprinting extracts. LC-MS/MS provides identification according to fragmentation with the advantage of MS/MS, and validation can be performed in selected reaction monitoring (SRM) mode with simultaneous precursor and product ion scans. Herein, sixteen flavones, four flavonols, four flavanones, two lignans, three sesquiterpene lactones, and four phenolic acids, a total of thirty three substances, were identified tentatively or unambiguously from the extracts. It was concluded that ESI-MS fingerprinting is a suitable method for plant chemophenetics when coupled and validated with LC-MS/MS. Moreover, it was concluded that sesquiterpene lactones, lignans, and flavonoids are suitable for taxonomic purposes in Centaurea owing to species-specific metabolite profiles.

Application of electrospray ionization mass spectrometry fingerprinting associated with macroscopic and histological analysis for Plantago major herbal infusions quality control

The present study demonstrates the need to conduct an integrative quality control of teas marketed as Plantago major. In the present study, quality control checks were performed through macroscopic, microscopic and chemical analyses of commercial brands. Leaves with parts not allowed for consumption were found in all brands. Six brands showed histological similarity <50% with the authentic P. major. Eight brands demonstrated low chemical similarity (40 to 60%), indicating that they do not have the same compounds from the authentic P. major. All commercial samples are contaminated with aflatoxins, indicative of fungicide contamination and consequent degradation of phenolic compounds and reduction of antioxidant activity from the commercial samples. The difference in the present study is the integrative application of methods for success in the quality control of P. major, which can be applied to other species. Thus, more rigorous inspection actions in the production of teas to guarantee the therapeutic benefit of these products.

Characterization of Royal Jelly by Electrospray Ionization Mass Spectrometry Fingerprinting

Royal jelly is an apicultural product, fed to the queen bee and consumed by humans as a health food and traditional medicine; its beneficial effects on human health have been the subject of several studies. As royal jelly is obtained in small amounts and reaches a high market price, it could be adultered with other cheaper substances. As it is prone to degradation at room temperature, lyophilization is used to prolong its shelf life. Due to the complex composition of royal jelly, several different parameters need to be evaluated to determine of freshness, purity and quality; consuming an appreciable amount of sample and time. Electrospray ionization mass spectrometry (ESI-MS) fingerprinting was carried out in the negative ion mode on a high resolution FT-ICR mass spectrometer; marker compounds were identified by comparison of their high resolution mass with data from literature. ESI-MS fingerprinting was capable of characterizing natural, lyophilized, degraded and adultered samples of royal jelly, and indicate marker compounds for each set of samples, with the aid of Principal Component Analysis. The complete analysis, from a simple extraction procedure to ESI (-)-MS fingerprinting, takes only a few minutes and consumes only 50 mg per sample. Therefore, large numbers of samples can be quickly evaluated for purity and freshness in a single-shot approach, while using small amounts of royal jelly per analysis.

Characterization of Royal Jelly by Electrospray Ionization Mass Spectrometry Fingerprinting

Characterization of Royal Jelly by Electrospray Ionization Mass Spectrometry Fingerprinting

Direct infusion electrospray ionization mass spectrometry applied to the detection of forgeries: Roasted coffees adulterated with their husks

Recognition of samples of coffee adulterated with their own husks has been a challenging task. The quite similar physical aspect of roasted grinded coffee husk when compared to ground coffee hampers a prompt visual distinction among both types of products. Several methodologies that make use of distinct analytical techniques have been developed for the authentication of coffee quality. In the present work, we demonstrate that direct infusion electrospray ionization mass spectrometry (ESI-MS) can be applied to detect counterfeit samples of roasted coffee adulterated by the addition of coffee husks (at a level of 10% w/w) in a quick and reliable way. The ESI-MS fingerprints (in both the negative and positive modes) revealed the presence of diagnostic markers, such as carbohydrates (for instance, saccharose), chlorogenic acids, caffeine, and other components related to the coffee flavor, that characterize each type of sample (coffee and rusk). Furthermore, the PCA (principal component analysis) methodology, applied to the whole set of the ESI-MS data (in the negative mode), grouped the samples into three clearly distinct categories: coffees, husks and blends. The results presented herein describe therefore an innovative and rapid methodology potentially useful in the diagnosis of such hardly-detectable type of adulteration.

Electrospray ionization mass spectrometry fingerprinting of Brazilian cachaças produced in copper alembic and in stainless-steel column stills

Brazilian cachaca can be produced in two different ways: distilled in stainless steel column or in copper alembic stills. We evaluated 36 samples of commercial non-aged cachacas: 18 samples of sweetened cachacas distilled in stainless steel column, and 18 samples distilled in copper alembic stills. Fingerprints were obtained through electrospray ionization mass spectrometry by recording the intensity of the 15 most abundant ions. Principal component analysis was applied to the data and separated the samples in two groups. However, after sample standardization with sugar (20 g L−1), it was not possible to group them by type of distillation. The results showed that the technique applied did not allow differentiation of cachacas based on the distillation system, but for the presence or absence of sugar in them.

Differential analysis of human kidney stone samples using electrospray ionization mass spectrometry

Kidney stones may be caused by many factors, including ingestion of melamine for a relatively long time. The diagnosis of melamine-induced kidney stones and the understanding of how the melamine is involved in the formation of kidney stones are of practical importance. To establish a sensitive method based on widely used electrospray ionization mass spectrometry (ESI-MS) for diagnosis of melamine-induced kidney stones and to probe the differential formation of melamine-induced kidney stones at molecular levels. Human kidney stones were collected in hospital from 6 groups of patients at different ages. ESI-MS was employed as the main technique with the principal component analysis for data processing. Using principal component analysis (PCA) of the ESI-MS fingerprints, a set of 21 melamine-induced kidneystone samples and 21 uric acid derived kidney stone samples were successfully differentiated from the other groups, rendering ESI-MS method a potential platform for differential analysis of the human kidney stones of various causes at molecular levels. The experimental results also indicate that in addition to the melamine, the chemical compounds enwrapped in the melamine-induced kidney stone samples are different from other kidney stone samples. These findings suggest that ESI-MS is a useful tool for diagnosis of melamine-induced kidney stone samples and the melamine-induced kidney stone could be formed by different mechanisms. Key words: Toxicity of melamine, chemical profiling, uric acid, electrospray ionization-mass spectrometry (ESI-MS), kidney stone, melamine, principal component analysis.

The Famous Amazonian Rosewood Essential Oil: Characterization and Adulteration Monitoring by Electrospray Ionization Mass Spectrometry Fingerprinting

Direct infusion of samples via electrospray ionization mass spectrometry (ESI-MS) is shown to characterize unequivocally genuine samples of Amazonian Aniba rosaeodora Ducke (Rosewood) essential oils obtained either from the wood or leafs. The ESI-MS also distinguishes the essential oils from synthetic linalool; hence, adulteration by the synthetic oil is also clearly detected. The analysis requires no pretreatment or preseparation, and the most polar components of the essential oil are extracted with an acidified 1:1 methanol/water solution. This simple extract is then analyzed by direct infusion ESI-MS in the positive ion mode, which provides characteristic fingerprintings of the sample composition. The ESI-MS fingerprinting can be used therefore as a simple and fast (few minutes) method for authenticity and quality control of this famous Amazonian essential oil.

Chemical Fingerprinting of Counterfeits of Viagra and Cialis Tablets and Analogues via Electrospray Ionization Mass Spectrometry

Direct infusion electrospray ionization mass spectrometry (ESI-MS) is shown to provide an efficient tech- nique for the investigation of polar composition of forensic tablets for male erectile dysfunction. ESI-MS fingerprinting of 41 commercial sildenafil samples (Viagra ® , Cialis ® , Lazar ® , Libiden ® , Maxfil ® , Plenovit ® , Potent 75 ® , Rigix ® , V-50 ® , Vimax ® , Pramil 75 ® and Pramil ® ) and 56 counterfeit samples (Viagra and Cialis) were obtained. The spectra for the authentic Viagra ® tablets showed abundant ions exclusively corresponding to the sildenafil (SLD) molecule: [SLD + H] + of m/z 475; [SLD + Na] + of m/z 497; and [2SLD + H] + of m/z 949. The spectra for commercial sildenafil samples also showed predominat SLD ions. Tablets of authentic Cialis ® showed mainly ions of m/z 343, 365 and 707 from the lactose molecule (the excipient); as well as a minor ion of m/z 390 corresponding to the active ingredient tadalafil (TAD) in its protonated form [TAD + H] + . For counterfeit Cialis samples, however, normally TAD ions of much high abundances was observed, together with ions corresponding to sildenafil analogues such as those of m/z 489 (homosildenafil) and 505 (hydroxyhomosildenafil). Principal component analysis was applied to ESI-MS fingerprint data, placing samples according to their contents of active ingredients hence authentic and counterfeit samples are easily recognized.

Flavour characterization of red wines by descriptive analysis and ESI mass spectrometry

Direct infusion electrospray ionization mass spectrometry (ESI-MS) is a new technique that allows for the identification of volatile and non-volatile compounds in foods and beverages, without the need for extraction, isolation and prior chromatographic separation of the sample constituents. The objective of this research was to explore the potential of ESI-MS to identify the acid and phenolic compounds in red wines important for the beverage flavour profile. Thus, descriptive flavour data from red wines elaborated with Vitis labrusca, hybrid and Vitis vinifera grapes was initially generated by a trained panel ( n 1 = 12 panellists; n 2 = 6 repetitions) and subsequently correlated with ESI-MS data collected in the negative ion mode. Considerable variation concerning several acid and polyphenolic compounds identified in the samples was observed amongst the wines. The Principal Component Analysis (PCA) and correlation analyses of the data showed that the succinic acid contents were good predictors of sourness ( r = 0.63, p = 0.05). A negative correlation was also observed between grape flavour and the carbonic acid contents ( r = −0.76, p = 0.02), amongst other findings. Overall, the results indicated ESI-MS fingerprinting as a fast and reliable technique with potential use in wineries for quality control.

Green and roasted arabica coffees differentiated by ripeness, process and cup quality via electrospray ionization mass spectrometry fingerprinting

Direct infusion electrospray ionization mass spectrometry in both the negative ESI(-)-MS and positive ESI(+)-MS ion modes are investigated to differentiate green and roasted Arabica coffees with different stages of ripeness (green, ripe and overripe), post-harvesting process (dry, wet and semi-wet) and coffees with different cup qualities. In the ESI(-)-MS of green coffees, ions from deprotonated fatty acids and chlorogenic acids are the most important for ripeness discrimination. In the ESI(+)-MS, maturity is differentiated by ions from protonated caffeine, chlorogenic acids and K+ adducts of fatty acids. To differentiate between post-harvesting process in both ionization modes, ions from fatty acids, chlorogenic acids, sugars and carboxylic acids generated in the fermentation process are the most representative. Roasted Arabica coffees are also well discriminated: in the ESI(-)-MS, ions from chlorogenic acids and short-chain organic acids derived from sugars are important. In the ESI(+)-MS, discrimination are mainly performed by low m/z ions such as protonated pyridine and alkylpiridines formed via trigonelline degradation. Both ESI(+)-MS and ESI(-)-MS are able to differentiate cup quality for Arabica roasted coffees and the ions used to perform discrimination are the same ones described in ripeness and post-harvesting processes.

Brazilian cachaça: “Single shot” typification of fresh alembic and industrial samples via electrospray ionization mass spectrometry fingerprinting

Abstract Copper pot stills (alembics) and industrial stainless steel columns are the most common distillation devices used in Brazil to produce sugarcane spirit (cachaca). The use of both apparatus originates two distinctive products, the so-called (a) alembic (the most valuable) and (b) industrial cachacas, respectively, with subtle but characteristic chemical compositions and sensorial properties. Herein, we demonstrate that the use of direct infusion electrospray ionization mass spectrometry in the negative mode, ESI(−)–MS, is able to provide fast “single shot” fingerprinting discrimination between these two types of spirits. Representative samples of both spirits show ESI(−)–MS with regular sets of diagnostic ions of m/z 279, 255, 199, 171, 143 (alembic) and of m/z 377, 341 (industrial). Principal component analysis (PCA) of the ESI(−)–MS data consistently split the 34 alembic and the 14 industrial samples into two well-defined groups. Sugar addition to the alembic samples was also easily detected.

Biodiesel Typification and Quality Control by Direct Infusion Electrospray Ionization Mass Spectrometry Fingerprinting

Direct infusion electrospray ionization mass spectrometry (ESI-MS) of aqueous/methanolic extracts of biodiesel samples is shown to permit simple and fast fingerprinting typification, identification of the alcohol used in the trans-esterification process, monitoring of degradation and adulteration, and screening of residual glycerin and mono-, di-, and tri-glycerides. As proof-of-principle cases, ESI-MS fingerprints in both the positive and the negative ion modes were acquired for biodiesel samples derived from soybean oil, sunflower oil, canola oil, olive oil, castor oil, jatropha curcas oil, palm oil, lard, and tallow. In the negative ion mode, characteristic sets of ions corresponding to de-protonated fatty acids were detected for each type of biodiesel, thus allowing their reliable typification via these taxonomic markers. Biodiesel degradation was also monitored by ESI(−)-MS with the detection of degradation markers, mainly oxidized fatty acids. When using ESI(+)-MS, the main diagnostic ions detected were the protonated fatty esters, which reveal therefore both the oil source and the alcohol (methanol or ethanol, or other heavier alcohols) used for trans-esterification. Residual glycerin and mono-, di-, and tri-glycerides are also detected, which makes ESI-MS also applicable for laboratory and on-site screening of biodiesel quality.

Characterization of the variation in the imidazole alkaloid profile of Pilocarpus microphyllus in different seasons and parts of the plant by electrospray ionization mass spectrometry fingerprinting and identification of novel alkaloids by tandem mass spectrometry

Pilocarpus microphyllus (Rutaceae), popularly known as jaborandi, is the only commercial source of an imidazole alkaloid named pilocarpine. In the present study, the variation in the profile of imidazole alkaloids in different seasons and in different parts of the P. microphyllus plant during the summer was analyzed by electrospray ionization mass spectrometry in the positive ion mode [ESI(+)-MS]. The fingerprints of these extracts repeatedly presented similar ions which were mass-selected and studied by tandem mass spectrometry (ESI-MS/MS and ESI-MS/MS/MS) and high-resolution mass spectrometry, resulting in the characterization of eight imidazole alkaloids. The data from the ESI(+)-MS fingerprints were analyzed by principal component analysis (PCA), showing that pilocarpine was present mainly in the summer, whereas in the autumn mainly pilosine and winter anhydropilosine were found. Three alkaloids, reported for the first time in extracts of P. microphyllus, were found. Analysis of the distribution of alkaloids in different parts of the plant during the summer showed that, although pilocarpine was present throughout the plant, 13-nor-8(11)-dihydropilocarpine was found mainly in the stem, pilosine and anhydropilosine were present mainly in the intermediary leaves, and the three new alkaloids were mainly found in the leaflets and petioles. Based on the dissociation patterns of these alkaloids, we observed that there were three structurally related groups of alkaloids differing in their distribution in the plant tissues and responding differently to seasonal variations. These results also indicate that these three groups of alkaloids could belong to intermediate, parallel or competitive pathways for pilocarpine formation biosynthesis.

Electrospray Ionization Mass Spectrometry Fingerprinting of Brazilian Artisan Cachaça Aged in Different Wood Casks

We have investigated the capability of direct infusion electrospray ionization mass spectrometry in the negative ion mode, ESI(-)-MS, to differentiate representative samples of artisan cachaça, a Brazilian sugar cane distillate of large production, aged in four different types of wood casks: amburana (Amburana cearensis), jequitibA (Cariniana estrellensis), balm (Myroxylon peruiferum), and oak (Quercus rubra). The ESI(-)-MS were found to be very characteristic, showing sets of diagnostic ions for each of the four types of samples: amburana (m/z 271, 313, 377), jequitibA (m/z 143, 171, 255), balm (m/z 137, 269, 283, 297), and oak (m/z 197, 301, 307). Furthermore, principal component (PCA) and hierarchical cluster analysis (HCA), applied to the ESI(-)-MS data, divided these samples into four definite categories. The influence of the aging time on the ESI(-)-MS fingerprints of the cachaça samples stored in oak casks was also established. An inversion in the relative intensity of the diagnostic ions of m/z 307 and 301 is detected in the ESI(-)-MS as the aging time increased from 1 to 2 years. The chemical structures of the major cachaça components were proposed on the basis of the following: (a) the comparison of the ESI(-)-MS/MS of the diagnostic anions with those of the authentic anions or (b) the interpretation of the fragmentation patterns of the previously unknown diagnostic anions. Hence, direct infusion ESI(-)-MS allows not only a rapid, simple, and accurate way to distinguish among cachaça samples stored in different wood casks but also monitoring changes in their chemical composition according to the aging time.

Electrospray ionization mass spectrometry fingerprinting of propolis of native Brazilian stingless bees

Stingless bees are found in many tropical and subtropical regions of the word. The knowledge of the composition of their propolis as well as the plants that are visited as sources of resins is therefore of prime importance. Here the negative ion mode electrospray ionization mass spectrometry [ESI(-)-MS] fingerprints of propolis from various species of native stingless bees from different regions in Brazil are compared to determine their composition patterns. The correlation among the propolis samples was investigated via chemometric analysis.

Electrospray ionization mass spectrometry fingerprinting of perfumes: rapid classification and counterfeit detection

A fast procedure to classify perfumes and identify counterfeit samples is described. Dilution of a few microL of the sample in a 1:1 methanol/water solution is followed by detection of its major polar components via direct infusion electrospray ionization mass spectrometry (ESI-MS) in the positive ion mode. As proof-of-principle cases, three famous brands of perfumes were used. The ESI+-MS fingerprints of authentic samples were very characteristic, showing distinctive sets of polar markers for each sample. Principal component analysis (PCA) placed samples of the three perfume brands in well-defined groups. Counterfeit samples were also clearly detected owing to contrasting ESI-MS fingerprints, with PCA placing these samples far away from the authentic samples.

Effect of the maceration time on chemical composition of extracts of Brazilian propolis

SummaryIt is believed that longer maceration times change significantly the ethanolic extract composition of propolis, improving its pharmacological, nutritional and antimicrobial properties. To probe whether such superior composition is indeed obtained, 10 samples of propolis from several regions in Brazil and one sample from North America were left to macerate in 70% ethanol for periods between 20 days and one year. The resultant extracts were evaluated in terms of the yield of extracted material and also analyzed by electrospray ionization mass spectrometry (ESI-MS) fingerprinting. A small increase in the yield of the extracted material over the period analyzed was observed. ESI-MS fingerprints indicate qualitatively the same composition but with a greater incidence of the high-mass components after six months. The extracts of one sample of green Brazilian propolis were also quantified using both gas chromatography mass spectrometry and high performance liquid chromatography. No new components were identified after longer maceration times and the changes in the relative concentrations of the identified components were in line with the results of the yield and ESI-MS fingerprints. Therefore, prolonged extraction periods do not necessarily result in richer propolis extracts.

Electrospray ionization mass spectrometry fingerprinting of essential oils: Spices from the Labiatae family

Polar components of the methanolic extracts of the essential oils of the spices Origanum dictamnus, Origanum vulgare, Origanum majorana and Rosmarinus officinalis, all four belonging to the Labiatae family, were investigated by direct infusion electrospray ionisation mass spectrometry (ESI-MS) both in the negative and positive ion modes. Characteristic ESI mass spectra with many diagnostic ions were obtained for the extracts of all four spices, serving for fast and reliable identification of these species. Tandem mass spectrometry (ESI-MS/MS), which often forms a series of fragment ions, and this additional MS dimension increases selectivity for authenticity and adulteration tests for spice essential oils. The MS technique also provides complementary information of component structures revealing the presence of important bioactive components.

Characterization of Vegetable Oils by Electrospray Ionization Mass Spectrometry Fingerprinting: Classification, Quality, Adulteration, and Aging

An improved approach for the direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis of vegetable oils is described. The more polar components of the oils, including the fatty acids, are simply extracted with methanol/water (1:1) solution and analyzed by direct infusion ESI-MS in both the negative and positive ion modes. This fingerprinting analysis was applied to genuine samples of olive, soybean, corn, canola, sunflower, and cottonseed oil, to admixtures of these oils, and samples of aged soybean oil. ESI-MS fingerprints in the positive ion mode of the extracts divide the oils into well-defined groups, as confirmed by principal component analysis, whereas ESI-MS fingerprints in the negative ion mode clearly differentiate olive oil from the five other refined oils. The method is also shown to detect aging and adulteration of vegetable oils.