Rapid and direct detection of artificially aged papers employing easy ambient sonic-spray ionization mass spectrometry.

RATIONALE: The effort to make fake documents look real leads to the use of crickets and beverages to produce artificially aged papers, as land titles, based on yellowing caused by the use of these methods. An old practice in Brazil, called "cricketing", has led to the misappropriation of Brazilian land using these documents. We propose a rapid, simple, instantaneous and non-destructive method to identify artificially aged papers by easy ambient sonic-spray ionization mass spectrometry (EASI-MS) analysis. METHODS: Three typical aging procedures were used to obtain artificially aged papers using coffee, cola drink, and crickets, with the papers being analyzed by EASI-MS. Multivariate statistical analyses were performed on the data to find the sample groups and to study the most relevant ions of each ageing procedure. High-resolution MS (HRMS) was used to obtain the exact masses and attribute formulae to relevant ions present in the samples. RESULTS: The combination of EASI-MS and multivariate statistical analyses allowed us to identify the most relevant ions to classify the adulteration of documents and HRMS identified most of these relevant ions. TMS fingerprinting in combination with multivariate analysis also demonstrated that this approach can qualitatively differentiate all the examined paper samples. CONCLUSIONS: We developed a cheap, fast and easy method that can help to elucidate counterfeit documents that have been artificially aged, helping to identify chemical additives and one that can be used in forensic laboratories.

Interference of Seasonal Variation on the Antimicrobial and Cytotoxic Activities of the Essential Oils from the Leaves of Iryanthera polyneura in the Amazon Rain Forest.

The essential oils (EOs) obtained from the leaves of Iryanthera polyneura Ducke trees was chemically Assessed and tested for the ability of inhibiting the growth of Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans and S. sanguinis. The oil was also tested against breast (MCF-7) and prostate (PC-3) cancer cell lines. Minimum bactericidal concentrations (MBCs) and 50 % inhibition concentrations (IC50 ) values were obtained. EOs were active against Gram-positive bacteria. Spathulenol, α-cadinol and τ-muurolol were major components of EOs. The oils showed a higher cytotoxicity against PC-3 than MCF-7 cells, although the oils were active against both cell types. Oils obtained from leaves collected in the dry season were more active against E. faecalis, S. aureus and PC-3, while the oils obtained from leaves collected in the rainy season were more active against S. mutans, S. sanguinis and MCF-7. The antibacterial and cytotoxic activities of the essential oils from the leaves of I. polyneura are related to the seasonal climate variation and are influenced by compounds that are minor components of the oils.

Novel natural food colourant G8000 benefits LDL- and HDL-cholesterol in humans.

The aim of this study was to investigate the phenolic composition of a natural food colourant (G8000™) as well as its effects on plasma markers after 28-day consumption by healthy individuals at a dietary dose (70 g). Parameters of total cholesterol and its fractions, triglycerides and plasma enzymes biomarkers of muscle injury were measured. Major compounds identified in G8000™ by ESI-MS showed the presence of anthocyanins, organic acids, phenolic acids as well as monosaccharides. HDL levels significantly increased from 43 ± 10.2 mg/dL to 95 ± 16.9 mg/dL. LDL levels significantly decreased from 110 ± 40.9 mg/dL to 69 ± 39 mg/dL (p < 0.001). No significant statistical differences (p > 0.05) were observed for total cholesterol, triglycerides and VLDL. After the intake, plasma enzyme CK-MB decreased from 20 ± 12.1 U/L to 10 ± 1.9 U/L while LDH levels increased from 275 ± 124.4 U/L to 317 ± 114.7 U/L (p < 0.005). No significant differences were observed for CK levels. Taken together, dietary intake of natural colourant G8000™ was able to exert beneficial effects on atherosclerosis biomarkers.

Phenolic diversity and antioxidant potential of different varieties of bamboo leaves using LC-ESI-QTOF-MS/MS and LC-ESI-QqQ-MS/MS.

Bamboo is a highly sustainable plant with a wide variety of leaves, yet little is known about its bioactive composition. Therefore, this study aims to characterize the phenolic profile and antioxidant capacity of 11 different varieties of bamboo leaves using liquid chromatography coupled with mass spectrometry. As a result, 81 phenolic compounds were tentatively identified, 29 of which were identified for the first time in the literature for bamboo leaves. The tentatively identified compounds fell into five classes (hydroxybenzoic and hydroxycinnamic acids, flavones, flavanones, and flavonols). The concentration of phenolic compounds ranged from 103 to 1291 mg/100 g. Among the provisionally identified compounds, there was a predominance of derivatives from the luteolin and apigenin group, with orientin and schaftoside being the majority in each group, respectively. The leaves also showed significant variation in antioxidant activity, highlighting the potential bioactive composition of bamboo leaves for future applications in the food industry.

Determination of Drugs of Abuse in Hair by LC-MS-MS: Application to Suicide Attempts Investigation.

Considering that the use of psychoactive substances (PSs) is a risk factor to either higher intensity or frequency of suicidal behavior, hair analysis was conducted to investigate the most consumed PSs (opiates, amphetamine stimulants, marijuana, cocaine and heroin) in patients who attempted suicide and received urgent care at emergency service. Hair samples were extracted using methanol and sonicated under heating and then analyzed using liquid chromatography-tandem mass spectrometry. During validation, the method complied with international recommended criteria, with limits of detection between 0.0025 and 0.05 ng/mg and linearity between 0.1 and 4 ng/mg for methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), morphine, amphetamine, 6-acetylmorphine, 3,4-methylenedioxyamphetamine (MDA), fenproporex, diethylpropion and codeine; between 0.025 and 1 ng/mg for tetrahydrocannabinol (THC), benzoylecgonine and cocaethylene and between 0.25 and 10 ng/mg for cocaine and mazindol. A total of 109 hair samples were analyzed and segmented in 404 parts. Among all analyzed samples, 30.3% were positive for at least one PS (n = 33), such as cocaine (90.9%), codeine (12.1%), morphine (3.0%), MDMA (3.0%) and THC (3.0%). In segmental analysis of cocaine positive samples (n = 30), 76.7% of the samples indicated recent exposure to cocaine (<1 month). This same behavior was observed when analyzing codeine (n = 4) and morphine (n = 1). THC positive samples indicated exposure dated ∼4 months prior. In conclusion, the method was validated following international recommendations for the 12 most consumed PSs in Brazil, as well as two of the most common found metabolites.

Prenatal exposure to Cannabis smoke induces early and lasting damage to the brain.

Cannabis is the most widely used illegal drug during pregnancy, however, the effects of gestational exposure to Cannabis smoke (CS) on the central nervous system development remain uncharacterised. This study investigates the effects of maternal CS inhalation on brain function in the offspring. Pregnant mice were exposed daily to 5 min of CS during gestational days (GD) 5.5-17.5. On GD 18.5 half of the dams were euthanized for foetus removal. The offspring from the remaining dams were euthanized on postnatal days (PND) 20 and 60 for evaluation. Brain volume, cortex cell number, SOX2, histone-H3, parvalbumin, NeuN, and BDNF immunoreactivity were assessed in all groups. In addition, levels of NeuN, CB1 receptor, and BDNF expression were assessed and cortical primary neurons from rats were treated with Cannabis smoke extract (CSE) for assessment of cell viability. We found that male foetuses from the CS exposed group had decreased brain volume, whereas mice at PND 60 from the exposed group presented with increased brain volume. Olfactory bulb and diencephalon volume were found lower in foetuses exposed to CS. Mice at PND 60 from the exposed group had a smaller volume in the thalamus and hypothalamus while the cerebellum presented with a greater volume. Also, there was an increase in cortical BDNF immunoreactivity in CS exposed mice at PND 60. Protein expression analysis showed an increase in pro-BDNF in foetus brains exposed to CS. Mice at PND 60 presented an increase in mature BDNF in the prefrontal cortex (PFC) in the exposed group and a higher CB1 receptor expression in the PFC. Moreover, hippocampal NeuN expression was higher in adult animals from the exposed group. Lastly, treatment of cortical primary neurons with doses of CSE resulted in decreased cell viability. These findings highlight the potential negative neurodevelopmental outcomes induced by gestational CS exposure.

Development and Validation of a Method for Quantification of 28 Psychotropic Drugs in Postmortem Blood Samples by Modified Micro-QuEChERS and LC-MS-MS.

The development of new sample preparation alternatives in analytical toxicology leading to quick, effective, automated and environmentally friendly procedures is growing in importance. One of these alternatives is the QuEChERS, originally developed for the analysis of pesticide residues, producing cleaner extracts than liquid-liquid extraction, and easier separation of aqueous and organic phases. However, there are few published studies on the miniaturization of this technique for forensic toxicology, especially in postmortem analysis. We developed and validated a modified micro-QuEChERS and LC-MS-MS assay to quantify 16 antidepressants, 7 antipsychotics and 3 metabolites and semi-quantify norfluoxetine and norsertraline in postmortem blood. The calibration curve was linear from 1 to 500 ng/mL, achieved an r > 0.99, with all standards quantifying within ±15% of target except ±20% at the limit of quantification of 1 ng/mL for 26 substances. The F test was applied to evaluate if the variance between replicates remained constant for all calibrators. Six weighting factors were analyzed (1/x, 1/x2, 1/x0,5, 1/y, 1/y2 and 1/y0,5), with the weighting factor with the lowest sum of residual regression errors (1/x2) selected. No endogenous or exogenous interferences were observed. Method imprecision and bias were <19.0% and 19.7%, respectively. Advantages of this method include a low sample volume of 100 µL, simple but effective sample preparation and a rapid 8.5-min run time. The validated analytical method was successfully applied to the analysis of 100 authentic postmortem samples.

LC-MS/MS screening and identification of bioactive compounds in leaves, pulp and seed from Eugenia calycina Cambess.

The Eugenia calycina Cambess, also known as pitanga-do-cerrado, is an unexplored Brazilian fruit used by native people for the treatment of diabetes. The aim of this study was to identify the phenolic compounds from the leaves, pulp and seed of Eugenia calycina by using LC-MS-based targeted and untargeted analysis. The LC-MS-based targeted quantitative analysis showed a high phenolic content in all plant parts in which the ellagic acid was the main phenolic compound with values of 8244.53 µg/g dw (leaves), 5054.43 µg/g dw (pulp) and 715.42 µg/g dw (seed). The leaves, pulp and seed showed a high total phenolic content of 20371.96, 7139.70 and 2204.75 µg/g dw, respectively. In addition, the LC-MS-based targeted analysis showed ellagic acid, myricitrin and epicatechin gallate as the main phenolic compounds in the Eugenia calycina. The LC-MS-based untargeted analysis showed the phytochemical profile of the leaves, pulp and seed in which 153 phytochemicals from different chemical classes were annotated, including organic acids, phenolic acids, flavonoids, and other compounds. The Eugenia calycina has high potential as a plant-based food due to its phytochemical profile and high phenolic content.

Mutamba (Guazuma ulmifolia Lam.) fruit as a novel source of dietary fibre and phenolic compounds.

This study covers the proximate and phytochemical composition of mutamba (Guazuma ulmifolia Lam.) fruit. This fruit showed high dietary fibre (36.9%) and low moisture (10.0%) contents which justify its hardness and dryness. Nevertheless, this fruit is very appreciated due to its sweet pulp (high sucrose content, 16.3%) and attractive taste. The soluble and insoluble-bound phenolic compounds from mutamba fruit were analysed by using liquid chromatography coupled to tandem mass spectrometry (LC-MS). LC-MS identified 26 compounds. Mutamba fruit was composed mainly by soluble flavonoids (1385.9 µg/g dw), namely proanthocyanidins, and aglycones and glycosylated flavonoids. Procyanidin trimer C1 (972.8 µg/g dw) followed by procyanidin dimer B2, rutin, epicatechin, and hyperoside were the main soluble phenolics, accounting 1435.5 µg/g dw. Conversely, the main cell wall bound phenolics (228.8 µg/g dw) were catechin, followed by protocatechuic acid, epicatechin, and gallic acid. In conclusion, mutamba fruit may be a novel source of dietary fibre and bioactive phenolic compounds.

Triple quadrupole-mass spectrometry protocols for the analysis of NBOMes and NBOHs in blotter papers.

NBOMe and NBOH are new psychoactive substances with potent activity on serotonin 5-HT2a receptors causing serious toxic effects, including serotonin toxidrome and death. The aim of this work was to develop a comprehensive MS/MS protocol, using triple quadrupole mass spectrometers coupled to LC and GC, for rapid screening and quantitation of NBOMes and NBOHs in seized blotter papers. Different scan methods (neutral loss, precursor ion or multiple reaction monitoring) were used to obtain structural information of phenylethylamine class. The developed protocol was validated for qualitative and quantitative analysis, showing a satisfactory limit of detection (1 ng/mL), with excellent selectivity, imprecision (intra and interday imprecision lower than 1.2 % RSD) and accuracy (between -7.1 and +5.6 %, n = 15), as well as bias values. The analysis of real samples shown that NBOH compounds were the most frequently detected, with concentrations ranging from 0.1 to 1,929 µg per blotter sample. Triple quadrupole mass spectrometers can be a useful tool for identification of new psychoactive substances. A comprehensive protocol using both LC-MS/MS and GC-MS/MS, with different scanning modes, have been developed and showed to be useful to screening NBOMe and NBOH in blotter papers.

[Different lipid extraction methods on fatty acids composition in cow milk]. / Avaliação de diferentes métodos de extração lipídica sobre a composição de ácidos graxos poliinsaturados em leite de vaca.

Different lipid extraction methods on fatty acids composition in cow milk. Comparative studies among 4 (four) different methods of total lipids extraction were carried out to evaluate the lipid extraction efficiency and fatty acids contents in cow milk. Total lipids extraction methods were Bligh e Dyer (BD), Folch et al. (FLS), Roese-Gottlieb (RG) and Gerber (GB). There were non-significant (p < 0.05) difference, in total lipids content among the extraction methods. The smallest concentrations of omega-3 (n-3) fatty acids and polyunsaturated fatty acids (PUFA) were observed on method GE, possibly due degradation of PUFA immersed in sulfuric acid used during analysis of total lipids. The highest concentrations of n-3 PUFA were observed by BD method, especially to omega-3/omega-6 ratio and alpha-linolenic acid (LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3), significant differences were observed among the methods. The results demonstrate that the different extractions influenced decisively on quantitative fatty acids composition and evaluations indicated the methods BD as better and GE as the worst to polyunsaturated fatty acids determination.

Amazon climatic factors driving terpene composition of Iryanthera polyneura Ducke in terra-firme forest: A statistical approach.

Iryanthera polyneura (Myristicaceae) is popularly known as cumala-colorada, and can be found in the Amazon rain forest. The present study aimed the evaluation of the chemical composition of the essential oils (EOs) obtained from the leaves of I. polyneura throughout a two-year period in order to correlate chemical findings with seasonality and climatic variation. Leaves from I. polyneura were collected 15 times from three different individuals, identified as 22EO, 80EO and 530EO, between the years of 2009 and 2011. The EOs were obtained and tested by gas-chromatography-mass spectrometry techniques. ANOVA and multivariate analyses were used to assess the relationship between the percentage of terpenes and seasonal/climatic variations. Fifty-nine compounds were detected in the EOs, of which 44 were identified (74.5%). The main components of the EOs were spathulenol (6.42 ± 1.02%), α-cadinol (5.82 ± 0.40%) and τ-muurolol (5.24 ± 0.03%). Higher levels of spathulenol were observed in 22EO during rainy season, while τ-muurolol occurred in high amounts during the dry season, as did α-cadinol in 22EO and 80EO. Correspondence analysis revealed a distinction between two groups of EOs based on seasonality, whereas a canonic correspondence analysis and ANOVA determined how the major compounds were related to both seasonality and climatic factors. Non-metric multidimensional scaling in association with an analysis of similarities showed that the abundance and composition of terpenes in the samples varied moderately among the three Iryanthera individual plants. Present findings have shown that there is variation in the occurrence of the major compounds spathulenol, τ-muurolol and α-cadinol produced by I. polyneura and that the pattern of variation is related to season and climatic changes.

Characterization of the lipid profile from coconut (Cocos nucifera L.) oil of different varieties by electrospray ionization mass spectrometry associated with principal component analysis and independent component analysis.

Coconut oil (CO) from fifteen different varieties of coconuts (Cocos nucifera L.) and one CO processed on an industrial scale were analyzed by electrospray ionization mass spectrometry (ESI-MS) and the data processed using the chemometric tools principal component analysis and independent component analysis. ESI-MS fingerprinting of lipid compounds showed predominance of diacylglycerols and triacylglycerols, as confirmed by high-resolution MS measurements. Chemometric processing of the ESI-MS data differentiated the coconut oil samples, showing that different coconut varieties/cultivars produce oils with distinguishable abundances of lipidic compounds. Thus ESI-MS analysis followed by data treatment using chemometric tools offers a tool able to classify the industrial coconut oils in a fast, simple and effective way, as well as serving as a potential method to identify the coconut varieties by the CO origin, and the occurrence of any adulteration. The procedure may also be applied for quality control of the industrial processes.

Determination of free, esterified, glycosylated and insoluble-bound phenolics composition in the edible part of araticum fruit (Annona crassiflora Mart.) and its by-products by HPLC-ESI-MS/MS.

Phenolics present in the free, esterified, glycosylated and insoluble-bound forms of araticum pulp, peel and seed were for the first time characterized and quantified using HPLC-ESI-MS/MS. Levels of total phenolics, flavonoids, condensed tannins and antioxidant activities from araticum fruit followed the order peel > pulp > seed. Overall, insoluble-bound and esterified phenolics were the dominant forms of phenolics from araticum fruit parts and the highest contributors to their antioxidant activities. Extracts were found to contain contrasting levels of phenolics that were specific to each fruit part. From 10 phenolics quantified in araticum fruit, catechin and epicatechin were the major ones from pulp and peel, whereas seed displayed caffeic acid, catechin and epicatechin as its main phenolics. Araticum fruit was found to provide a good source of phenolics, and the full exploitation of this fruit may find applications in the food, cosmetic and pharmaceutical industries.

Carbohydrates, volatile and phenolic compounds composition, and antioxidant activity of calabura (Muntingia calabura L.) fruit.

Soluble carbohydrates, volatile and phenolic compounds from calabura fruit as well as its antioxidant activity were assessed. The low amount of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and similar amount of glucose and fructose allow us to classify the calabura berry as low-FODMAPs. The terpenes ß-Farnesene and dendrolasin identified by SPME-GC-MS were the major volatile components. UHPLC-MS/MS analysis revelled gallic acid (5325 µg/g dw) and cyanidin-3-O-glucoside (171 µg/g dw) as the main phenolic compounds, followed by gentisic acid, gallocatechin, caffeic acid and protocatechuic acid. In addition, gallic acid was found mainly in esterified (2883 µg/g dw) and insoluble-bound (2272 µg/g dw) forms. Free and glycosylated forms showed however the highest antioxidant activity due to occurrence of flavonoids (0.28-27 µg/g dw) in these fractions, such as catechin, gallocatechin, epigallocatechin, naringenin, and quercetin. These findings clearly suggest that calabura is a berry with low energy value and attractive colour and flavour that may contribute to the intake of several bioactive compounds with antioxidant activity. Furthermore, this berry have great potential for use in the food industry and as functional food.

Grape skin extract mitigates tissue degeneration, genotoxicity, and oxidative status in multiple organs of rats exposed to cadmium.

The aim of this study was to investigate whether grape skin extract can mitigate the noxious activities induced by cadmium exposure in multiple organs of rats. For this purpose, histopathological analysis for the liver, genotoxicity, and oxidative status in the blood and liver were investigated in this setting. A total of 20 Wistar rats weighing 250 g, on average, and 8 weeks of age were distributed into four groups (n=5) as follows: control group (nontreated group); cadmium group (Cd); and grape skin extract groups (Cd+GS) at 175 or 350 mg/l. Histopathological analysis in liver showed that animals treated with grape skin extract showed improved tissue degeneration induced by cadmium intoxication. Genetic damage was reduced in blood and hepatocytes as indicated by comet and micronucleus assays in animals treated with grape skin extract. Copper-zinc superoxide dismutase and cytochrome c gene expression increased in groups treated with grape skin extract in liver cells. Grape skin extract also reduced the 8-hydroxy-2'-deoxyguanosine levels in liver cells compared with the cadmium group. Taken together, our results indicate that grape skin extract can mitigate tissue degeneration, genotoxicity, and oxidative stress induced by cadmium exposure in multiple organs of Wistar rats.

Effect of flaxseed oil in diet on fatty acid composition in the liver of Nile tilapia (Oreochromis niloticus).

This study analyzed the effects of different concentrations of flaxseed oil (FO) on the proximate composition and the contents of alpha-linolenic acid (LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), and docosahexaenoic (DHA, 22:6n-3) fatty acids in the liver of cultured Nile tilapia (Oreochromis niloticus). During the five-month culture period, tilapias were given diets with incremental concentrations of FO (0.00%; 1.25%; 2.50%; 3.75%, and 5.00%) as a replacement of sunflower oil (control). There was no significant difference in moisture and ash content in the liver between treatments. Protein values ranged from 12.1% (treatment II) to 13.9% (treatment V) and total lipids ranged from 5.6% (treatment V) to 7.2% (treatment II). There was no significant difference between most treatments. Fatty acid methyl esters (FAMEs) were quantitatively analyzed by capillary gas chromatography against a C(23:0), internal standard. Variations in concentrations (in mg g(-1) of total lipids) of fatty acids between treatment I and treatment V ranged from 4.2 to 51.2 (LNA), from 0.2 to 2.3 (EPA), and from 10.6 to 56.2 (DHA), respectively. This experiment demonstrated that increasing amounts of LNA in feed may markedly increase the amounts of LNA, EPA, and DHA in the liver of Nile tilapia.

EASI-IMS an expedite and secure technique to screen for 25I-NBOH in blotter papers.

The increasing number of new psychoactive substances (NPS) and their quick worldwide spreading, often only slightly modified in the form of new derivatives and analogues, have brought the need for fast, wide-ranging, and unequivocal identification methods in clinical and forensic investigations. Because it usually provides secure results, gas chromatography coupled to mass spectrometry (GC-MS) has been routinely employed as the standard technique for the detection of NPS in blotter papers. For 25I-NBOH (N-(2-hydroxybenzyl)-2-(4-iodo-2,5-dimethoxyphenyl)ethan-1-aminium), however, GC-MS analysis of an blotter paper extract leads to incorrect results. In this work, we investigated whether easy ambient sonic-spray mass spectrometry imaging (EASI-IMS), and ambient ionization MS method can be applied directly to the surface of the sample requiring therefore no extraction or sample preparations, would serve as an efficient, sensitive, and secure alternative for 25I-NBOH screening.

A single administration of fish oil inhibits the acute inflammatory response in rats.

OBJECTIVE: To investigate the antiinflammatory effects of a single administration of fish oil (FO) on the acute inflammatory response. METHODS: The paw edema and pleurisy models were used to evaluate the effects of FO dissolved in olive oil (FOP) orally administered in a single dose in rats. Nitric oxide (NO) concentrations in the pleural exudate were performed according to the Griess method and the cytokine concentrations were determined by Luminex bead-based multiplex assay. RESULTS: FOP treatment (30 and 300 mg/kg) significantly reduced paw edema. FOP treatment at 18.75, 37.5, 75.0, 150.0, and 300 mg/kg decreased both the volume of pleural exudate and cellular migration into the pleural cavity and each of these doses presented the same effectiveness. Treatment with FOP (300 mg/kg) reduced NO, TNF-α, IL-1ß, and IL-6 concentrations in the pleural exudate. CONCLUSIONS: The present data provide evidence that FO has inhibitory effects on the acute inflammatory response when administered in a single dose in rats. This effect might be attributable to a direct inhibitory effect of FO on the production or release of inflammatory mediators that are involved in the pathological processes evaluated herein.

A dopant for improved sensitivity in easy ambient sonic-spray ionization mass spectrometry.

Recently, 3-nitrobenzonitrile (3-NBN) has been used to improve sensitivity of sonic-spray ionization mass spectrometry. Easy ambient sonic-spray ionization (EASI) is one of the simplest, gentlest and most used spray-based desorption/ionization ambient techniques, but limited sensitivity has been commonly taken as its major drawback. Herein we investigate the use of 3-NBN as a dopant in EASI-MS for improved sensitivity. Using a few typical EASI samples as test cases, the presence of 10 ppm (µg ml(-1) ) of 3-NBN in the spray solvent showed two to fourfold gains in EASI-MS sensitivity as measured both by total ion current and S/N ratios, accompanied with significant reductions in chemical noise. Sensitivity for DESI using 3-NBN as a dopant also improved and dopant DESI versus dopant EASI sensitivities were compared. The use of solvent dopants seems therefore to be a promising strategy to improve sensitivity for spray-based ambient MS techniques. Copyright © 2015 John Wiley & Sons, Ltd.