Application Note & Pubblicazioni Scientifiche
Per esigenze di studio o di aggiornamento professionale.
Per esigenze di studio o di aggiornamento professionale.
This application note describes a rapid analytical method for the detection of 20 perfluoroalkyl substances (PFAS) in human hair within 10 minutes. Solid phase extraction (SPE) using the Agilent Bond Elut ENV cartridge was used to extract the sample. The extract was then separated using liquid-chromatography (Agilent 1290 Infinity II LC) coupled to a quadrupole time-of-flight mass spectrometer (Agilent 6545 LC/Q-TOF) for accurate mass measurement of PFAS in hair. The limits of quantitation (LOQ) were in the range of 0.07 to 0.5 ng/g, demonstrating the sensitivity of the method. Linearity was 0.1 (or 0.2 or 0.5) to 10 ng/g, and relative standard deviations (RSDs) were 1 to 16%. To verify the applicability of the method for the determination of PFAS in hair, 11 samples obtained from adults in the general population were tested.
The marine ecosystem is monitored through the analysis of some sentinel species, that is, fishes and bivalves, also in consideration that seafood is reported as the primary dietary source of human exposure to PFAS. In this frame, the utility of using different shellfish as indicator species in biomonitoring studies has been investigated by analysing mussels, clams, oysters and scallops collected at the North-East coast of the Mediterranean Sea and from Pacific and Atlantic Ocean. These filter-feeding organism has long been exploited for their ability to accumulate xenobiotics from the surrounding environment, thus to reflect the xenobiotics presence of their proximity environment. The different distribution of PFAS between water and sediments observed especially for branched isomers and long-chain molecules highlighted in a number of studies in marine settings may also be reflected into biota. In fact, in case of PFAS, both chemical structure and the characteristic of the environment are considered to influence the degree of accumulation into an aquatic organism. On this base, mussels, oysters, scallops and clams, which differently thrive in water or sediments, might reflect also a different spatial distribution of the PFAS presence in the same area. To this aim, a method for the target and untargeted detection of PFAS in bivalves has been proposed by liquid chromatography coupled to accurate mass spectrometry (LC-QTOF). The target analytes were enlisted in the EPA 533 regulation, which is currently applied for PFAS determination in drinking water and comprised legacy, emerging, branched and precursors of PFAS. The untargeted analysis was carried out in accurate scan mode, and data were mined against an in-house database of 150 entries of PFAS substances. Potential compounds with the highest detection frequency (DF) were then confirmed by reference material.
Biomonitoring of perfluoroalkyl substances (PFASs) in hair is conventionally achieved by SPE extraction and
liquid chromatography-triple quadrupole analysis, with sensitivities in the range of ng/g. The aim of this study
was to develop and validate a rapid method to detect 20 perfluoroalkyl substances (PFASs) in human hair from
general populations by SPE purification and liquid-chromatography coupled to accurate mass measurement (LCQTOF).
The obtained sensitivities (LOQ), linearity and RSD accuracies were respectively in the range of 0.07–0.5
ng/g, 0.1 (or 0.2 or 0.5)-10 ng/g, 1–16%. To verify the applicability of the method, 11 hair samples from volunteers
were tested. The detected PFAS were PFBA (range 0.24–14.6 ng/g), PFBS (0.496 ng/g), PFOA (range
0.08–0.178 ng/g) and PFOS (
N-acylethanolamines (NAEs) comprise a family of bioactive lipid molecules present in animal and plant tissues, with N-palmitoylethanolamine (PEA) having received much attention owing to its antiinflammatory, analgesic and neuroprotective activities. 2-Pentadecyl-2-oxazoline (PEA-OXA), the oxazoline of PEA, reportedly modulates activity of Nacylethanolamine-hydrolyzing acid amidase (NAAA), which catabolizes PEA. Because PEA is produced on demand and exerts pleiotropic effects on non-neuronal cells implicated in neuroinflammation, modulating the specific amidases for NAEs (NAAA in particular) could be a way to preserve PEA role in maintaining cellular homeostasis through its rapid on-demand synthesis and equally rapid degradation. This study provides the first description of PEA-OXA in both green and roasted coffee beans and Moka infusions, and its synthesis. In an established model of carrageenan (CAR)-induced rat paw inflammation, PEA-OXA was orally active in limiting histological damage and thermal hyperalgesia 6 h after CAR intraplantar injection in the right hindpaw and the accumulation of infiltrating inflammatory cells. PEA-OXA appeared to be more potent compared to ultramicronized PEA given orally at the same dose (10 mg/kg). PEA-OXA markedly reduced also the increase in hindpaw myeloperoxidase activity, an index of polymorphonuclear cell accumulation in inflammatory tissues. NAAA modulators like PEA-OXA may serve to maximize availability of NAEs (e.g. PEA) while providing for recycling ofthe NAE components for further resynthesis
Inflammatory bowel disease (IBD) is a chronic disorder characterized by inflammation of the gastrointestinal (GI) tract, and it is associated with different neurological disorders. Recent evidence has demonstrated that the gut-brain-axis has a central function in the perpetuation of IBS, and for this reason, it can be considered a possible therapeutic target. N-Palmitoylethanolamine-oxazoline (PEA-OXA) possesses anti-inflammatory and potent neuroprotective effects. Although recent studies have explained the neuroprotective properties of PEA-OXA, nothing is known about its effects on the gut-brain axis during colitis. The aim of this study is to explore the mechanism and the effect of PEA-OXA on the gut-brain axis in rats subjected to experimental colitis induced by intracolonic administration of dextran sulfate sodium (DSS). Daily oral administration of PEA-OXA (10 mg/kg daily o.s.) was able to decrease the body weight loss, macroscopic damage, colon length, histological alteration, and inflammation after DSS induction. Additionally, PEA-OXA administration enhanced neurotrophic growth factor release and decreased the astroglial and microglial activation induced by DSS. Moreover, PEA-OXA restored intestinal permeability and tight junctions (TJs) as well as reduced apoptosis in the colon and brain. In our work, we demonstrated, for the first time, the action of PEA-OXA on the gut-brain axis in a model of DSS-induced colitis and its implication on the “secondary” effects associated with colonic disturbance.
The Agilent IDP-15 Oil free scroll pump was evaluated and compared for analytical performance against the conventional Edwards 5 Pump in two independent studies. Both studies used Agilent 7000 Triple Quadrupole Mass Spectrometers (GC/MS-MS). Parameters assessed included vacuum readings and tune reports. The studies concentrated on two different sets of compounds and examined the chromatograms, calibration curves, qualifier ratios, repeatability and S/N produced when using the two different configurations.
The Agilent IDP-10 Dry Scroll pump was evaluated and compared for analytical performance against the conventional oil roughing pump in the multi-residue pesticides analysis in food. This study used Agilent Intuvo 9000 GC coupled to 7010B Triple Quadrupole Mass Spectrometers (GC/MS-MS). Parameters assessed included vacuum readings and tune reports. The analysis was focused on 30 pesticides in a lemon matrix and examined the chromatograms, calibration curves, repeatability and S/N produced when using two different configurations.
The present study was aimed at the investigation, through HPLCDAD-ESI-MS/MS, of polyphenols in seven autochthonous C. intybus varieties, already known from literature to contain various substances with antioxidant properties, from the Veneto region of Italy, namely 'Castelfranco', 'Chioggia', 'Rosa di Gorizia', 'Rosa di Verona', 'Treviso Precoce', 'Treviso Tardivo' and 'Verdon da Cortèl'. Thirteen polyphenols, belonging to hydroxycinnamic acid, ﬂavone, ﬂavonol and anthocyanin classes, were detected in most samples. The developed analytical methodwas validatedinagreementwithICHguidelines.Thetotalamountofpolyphenols rangedfrom52to386 (mean: 254)mg/100g freshweight (F.W.).Theresultswere furtherconﬁrmedbyPrincipal CompositionAnalysis (PCA), which highlighted peculiar features and similarities among analysed samples for each variety (except for 'Chioggia' samples). The developed method is suitable for routine analyses, as well as geographical characterization, selection of diﬀerent C. intybus varieties and for the determination of related polyphenols dietary recommended intakes.
The regulatory governing the controls and the legal limits for the analysis of volatile organic compounds (VOC’s) in water and soil are becoming more and more stringent. In particular the Italian DLGS 152/2006 and upgrades set the detection limits for some compounds, in the order of 1 ppt. Typically, these analyses met EPA (Environmental Protection Agency) methods guidelines. In particular, EPA method 8260 requires the use of the GC-MS as separation-detection technique, and EPA method 5030 for the Purge & Trap extraction technique. The addition of a cryofocusing step, after the concentration of the sample through the P&T technique, is often used in order to achieve the above limits. Cryofocusing involves the use of liquid nitrogen, which is expensive and not easily handled. The goal of this work is to achieve the limit of 1 ppt, for the compounds 1,2-Dibromoethane and 1,2,3trichloropropane in aqueous matrices avoiding the Cryofocusing step.
Acrylamide (C3H5NO) is a polar, low MW molecule and its analysis by direct GC/MS is not an easy task, mainly because of low peak efficiency in chromatographic separation and no significant, low mass fragmentation in MS detection. With regard to these difficulties, direct GC/MS acrylamide analysis has never become a routine method and therefore, acrylamide is normally analyzed by GC/MS after derivatization (brominated) to limit strong peak broadening and increase the identification power of ion fragments. The aim of this study was to demonstrate the possibility of carrying out reliable direct GC analysis of acrylamide, by employing Ultra Inert technology and different chemically bonded GC columns. As reliable and sensitive MS/ MS detection was used, there was no need for derivatization. Standard solutions were prepared both in ethyl acetate and methanol so as to be easily coupled to SPE sample preparation. Studies were conducted on acrylamide standard solutions in the concentration range of 1-1000 ng/mL. A GC/MS method was developed and four different chemically bonded GC columns were tested in terms of peak shape, linearity, S/N, absolute areas, absolute RTs and carry over.
Adulteration of botanical food supplements with undeclared synthetic drugs is becoming a widespread and mostly uncontrolled problem in many countries [1-5]. Among them, slimming functional food are commercially readily available to a vast unaware population. At the moment, there are no established analytical protocols for the systematic detection of synthetic adulterants in these products but a large body of literature is converging to the target screening approach, either by liquid chromatography or gas chromatography [6, 7]. However, this approach may not be suitable due to the sheer number of chemicals. For this reason, high-resolution high-accuracy mass spectrometry (HRMS), enabling accurate-mass determination of ionic species (and metabolites), offers the potential to overcome the limitations of multi-target screening.
Crizotinib (C21H22Cl2FN5O, MW 449.12) is an anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI)3 that leads to responses in most patients with NSCLC (non-small cell lung cancer) harboring ALK translocations. Crizotinib showed promising results in the treatment of NSCLC patients with ALK translocations and therefore received accelerated approval for ALK positive NSCLC in August 2011 by the FDA. Due to its relatively recent introduction into pharmacological practice, very few analytical methods are available in literature for crizotinib determination so its therapeuticalmonitoring (TDM) is hampered and in-vivo metabolic studies limited [1-2].
In order to improve the economic sustainability of the Jatropha-biofuel chain, seed cake detoxification and utilization of ‘non toxic’ Jatropa curcas accessions are the main activities pursued with the aim of using J. curcas seed cake in animal feed. Given this growing interest, a robust and reliable method for phorbol esters (PEs) determination is necessary. HPLC-UV is a well-established method to detect and quantify the PEs content in Jatropha seeds and related products, but it seems to be unsuitable for more complex matrices like Jatropha leaves and animal tissues, due to the presence of interfering compounds. The objective ofthis work was to develop and optimize a LC–MS/MS method for the quantitative determination of PEs in seeds and leaves of J. curcas L. plants from Ghana and Mexico and in liver (as an organ with the function of accumulation) from goats fed with PEs in their diet. The HPLC-UV analysis evidenced five chromatographic peaks in the toxic seed kernels corresponding to the factors C1, C2, C3, C6 and C4–C5, respectively, with a PEs concentration of about 5100 g/g (as TPA equivalent). No PEs related peaks were detected in Mexican kernel seeds while in the case of leaves and liver the analysis was hampered by the presence of interfering compounds. The toxic kernel seed extract was used as a standard solution for the PEs quantitation in leaves and liver samples by LC–MS/MS, with the standard addition method. The most intense MRM transitions used to quantify and qualify the PEs were: 675→311, 693→311, and 293→265 m/z. The LC–MS/MS method with a LOD and a LOQ of 0.07 and 0.21 g/g, respectively, resulted in more sensitivity and selectivity than the HPLC-UV method. All three MRM transitions were present in Ghanaian toxic kernel seed, while no peaks were present in the supposed non-toxic Mexican kernel seed. PEs concentration in the leaves of toxic Ghanaian accession resulted in about 1/10 of that in the kernel, while no PEs peaks were found in the J. curcas leaves from Mexico and in liver samples
SOLID PHASE EXTRACTION OF ORGANOPHOSPOROUS PESTICIDES IN WATER WITH AGILENT BOND ELUT PPL
The growing market of herbal remedies worldwide could pose severe problems to consumers’ health due to the possible presence of potentially harmful, undeclared synthetic substances or analogues of prescription drugs. The present work shows a simple but effective approach to unequivocally identify synthetic anorectic compounds in allegedly ‘natural’ herbal extracts, by exploiting Q-TOF LC/MS technology, with the help of the Agilent’s Forensic Accurate Mass Library (Forensic PCDL AM), Agilent’s Auxiliary Softwares, MFG (Molecular Formula Generator) and MSC (Molecular Structure Correlator).