A first approach using micellar electrokinetic capillary chromatography for the determination of fipronil and fipronil‐sulfone in eggs

Posted on 13 February, 2020 by fqm302

Fipronil is an insecticide that is not approved in the European Union in food. In 2017, fipronil was involved in a European health alert due to its presence in fresh hen eggs because of an illicit use in poultry farms, so reliable methods are needed to determine fipronil and its main metabolites in these matrixes. In this work, we report the first approach to the study of fipronil and two metabolites, fipronil‐sulfone and fipronil‐sulfide by CE. MEKC mode was employed using a solution of 50 mM ammonium perfluorooctanoate pH 9.0 with 10% (v/v) methanol as background electrolyte. The proposed method was combined with a simple sample treatment based on salting‐out assisted LLE (SALLE) using acetonitrile as extraction solvent and ammonium sulfate as salt. The SALLE–MEKC–UV method allowed the simultaneous quantification of fipronil and fipronil‐sulfone. Validation parameters yielded satisfactory results, with precision, expressed as relative SD, below 14% and recoveries higher than 83%. Limits of detection were 90 µg/kg for fipronil and 150 µg/kg for fipronil‐sulfone, so in terms of sensitivity further studies of sample treatments allowing extra preconcentration or the use of more sensitive detection, such as MS, would be needed.

Posted in AGL2015-70708-R, Eggs, Fipronil, MEKC, Pesticides, SALLE, UV-vis | Tagged , , | Comments Off on A first approach using micellar electrokinetic capillary chromatography for the determination of fipronil and fipronil‐sulfone in eggs

Monitoring of cyanotoxins in water from hypersaline microalgae colonies by ultra high performance liquid chromatography with diode array and tandem mass spectrometry detection following salting-out liquid-liquid extraction.

Posted on 10 December, 2019 by fqm302

In this study two different analytical approaches have been developed to determine the presence of several cyanotoxins in saline water samples from a continental salt marsh. A salting-out assisted liquid-liquid extraction (SALLE) has been used in combination with ultra-high performance liquid chromatography-tandem mass spectrometry and UV-diode array detection (UHPLC-MS/MS and UHPLC-DAD). The target analytes are eight microcystins named MC-RR, MC-YR, MC-LR, MC-WR, MC-LA, MC-LY, MC-LW, MC-LF and nodularin (NOD), covering a wide range of polarities. The separation was achieved using a Zorbax Eclipse Plus RRHD C18 column (50 × 2.1 mm, 1.8 μm) in less than 7.5 and 5.5 min for UV and MS/MS detection, respectively. The mobile phase used consisted of water (solvent A) and acetonitrile (MeCN) (solvent B), both containing 0.01% of formic acid for DAD and 0.4% of formic acid for MS/MS detection, at a flow rate of 0.4 mL min−1. The temperature of the column was set at 25 °C and 20 μL of sample were injected. The main parameters affecting the SALLE procedure were studied and the following optimum values were obtained: neutral pH, 2 mL of acetonitrile as extraction solvent and 1.2 g of ammonium sulfate as salting-out agent for 4 mL of water sample. The validation protocols for both methods were accomplished with real water samples obtaining LODs ranging from 1.0 to 3.4 μg L−1 and 0.02 to 0.11 μg L−1 for DAD and MS/MS respectively. Although the SALLE-UHPLC-DAD methodology is easier and cheaper than UHPLC-MS/MS significantly better detection limits were achieved with tandem mass spectrometry as well as allowing for unambiguous identification. Extraction recoveries were higher than 77.0% (except for MC-RR and NOD which were 53.2% and 54.3, respectively) with satisfactory inter-day and intra-day precisions (RSD below 13.3%).

Posted in Cyanotoxins, Mass spectrometry, RTI2018-097043-B-I00, SALLE, UHPLC, UV-vis, Water | Tagged , , , | Comments Off on Monitoring of cyanotoxins in water from hypersaline microalgae colonies by ultra high performance liquid chromatography with diode array and tandem mass spectrometry detection following salting-out liquid-liquid extraction.

Plant-based milks: unexplored source of emerging mycotoxins. A proposal for the control of enniatins and beauvericin using UHPLC-MS/MS

Posted on 3 December, 2019 by fqm302

Mycotoxins have become one of the most common contaminants reported worldwide. Current legislation has established maximum levels only for some well-known mycotoxins; however, there are many other “emerging mycotoxins” for which there is no regulation, as enniatins and beauvericin. An analytical method based on salting-out assisted liquid-liquid extraction followed by ultra-high performance liquid chromatography tandem mass spectrometry is proposed for determination of enniatin A, A1, B, B1, and beauvericin in different plant-based milks, as a possible source of these contaminants, is proposed. The method showed good precision and trueness (RSD <8% and recoveries between 84-97%) with a moderate matrix effect. From a total of 32 samples of plant-based milks of different compositions (including 8 rice milks, 8 oat milks and 16 soy milks), 3 samples were contaminated with the five mycotoxins, while 5 samples were contaminated with four of them, being oat milk the most susceptible for contamination.

Posted in AGL2015-70708-R, Enniatins, Mass spectrometry, SALLE, UHPLC, Vegetable milks | Tagged , , | Comments Off on Plant-based milks: unexplored source of emerging mycotoxins. A proposal for the control of enniatins and beauvericin using UHPLC-MS/MS

Ion mobility spectrometry in food analysis: principles, current applications and future trends.

Posted on 25 July, 2019 by fqm302

In the last decade, ion mobility spectrometry (IMS) has reemerged as an analytical separation technique, especially due to the commercialization of ion mobility mass spectrometers. Its applicability has been extended beyond classical applications such as the determination of chemical warfare agents and nowadays it is widely used for the characterization of biomolecules (e.g., proteins, glycans, lipids, etc.) and, more recently, of small molecules (e.g., metabolites, xenobiotics, etc.). Following this trend, the interest in this technique is growing among researchers from different fields including food science. Several advantages are attributed to IMS when integrated in traditional liquid chromatography (LC) and gas chromatography (GC) mass spectrometry (MS) workflows: (1) it improves method selectivity by providing an additional separation dimension that allows the separation of isobaric and isomeric compounds; (2) it increases method sensitivity by isolating the compounds of interest from background noise; (3) and it provides complementary information to mass spectra and retention time, the so-called collision cross section (CCS), so compounds can be identified with more confidence, either in targeted or non-targeted approaches. In this context, the number of applications focused on food analysis has increased exponentially in the last few years. This review provides an overview of the current status of IMS technology and its applicability in different areas of food analysis (i.e., food composition, process control, authentication, adulteration and safety).

Posted in Food, Ion mobility, Review | Comments Off on Ion mobility spectrometry in food analysis: principles, current applications and future trends.

Occurrence of mycotoxins in swine feeding from Spain.

Posted on 17 June, 2019 by fqm302

A survey including 228 pig feed samples from Spain has been developed, exploring the occurrence of 19 mycotoxins (aflatoxins B1, B2, G1 and G2, ochratoxin A, fumonisins B1 and B2, citrinin, zearalenone, deoxynivalenol, fusarenon X, sterigmatocystin, T-2 toxin, HT-2 toxin, enniatins A, A1, B and B2, and beauvericin). The samples were analysed by solid-liquid extraction followed by liquid chromatography coupled with fluorescence or mass spectrometry detection. Enniatin B was found in 100% of the samples (up to 1200 µg/kg) and beauvericin in more than 90%. Moreover, 40% of samples were contaminated with more than five mycotoxins. This high occurrence is insurmountable and surpasses all previous studies, probably due to the inclusion of emerging mycotoxins, scarcely explored. The majority of the samples (96.9%) were in accordance with EU regulations, which do not address emerging mycotoxins or co-occurrence. These results show that in order to ensure mycotoxin absence, emerging mycotoxins should always be considered.

Posted in AGL2015-70708-R, Animal feed, Mycotoxins, Review | Comments Off on Occurrence of mycotoxins in swine feeding from Spain.

Screening of extraction properties of nanofibers in a sequential injection analysis system using a 3D printed device.

Posted on 15 February, 2019 by fqm302

A novel application of the three-dimensional printing technology for the automation of solid phase extraction procedures in a low-pressure sequential injection analysis system is presented. A 3D printed device was used as a housing for nanofiber membranes in solid phase extraction. The applicability of the device is demonstrated with the extraction of substances of various physical-chemical properties. Pharmaceuticals including non-steroidal anti-inflammatory drugs, antihistaminics, and steroidal structures, as well as emerging pollutants such as bisphenols and pesticide metsulfuron methyl were used as model analytes to study the extraction performance of the nanofibers. Six different nanofiber types comprising polyamide, polyethylene, polyvinylidene fluoride, polycaprolactone combined with polyvinylidene fluoride, and polyacrylonitrile, produced by electrospinning were tested in solid phase extraction. The suitability of specific nanofibers for particular analytes is demonstrated.

Posted in Sequential injection analysis, automated SPE | Comments Off on Screening of extraction properties of nanofibers in a sequential injection analysis system using a 3D printed device.

In-house validation of a rapid and efficient procedure for simultaneous determination of ergot alkaloids and other mycotoxins in wheat and maize

Posted on 26 November, 2018 by fqm302

A fundamental step in addressing the global problem of mycotoxins is the development of highly sensitive, multi-class extraction and detection methods. This constitutes a field of research that has in recent years enjoyed a steady advance. Such methods, generally based on liquid chromatography coupled to mass spectrometry, are widely reported successfully detecting various mycotoxins in different food and feed samples. In this work, an innovative approach to multi-class mycotoxin control is proposed, offering specific advantages: a broader inclusion of more mycotoxin classes, robust and thorough extraction for all target compounds despite their varied chemical properties, and determination of all analytes from a single injection. The method involved the extraction and quantification of the main mycotoxins produced by Aspergillus, Fusarium, and Penicillium fungi, as well as their reported derivatives, together with 12 other compounds most commonly produced by Claviceps purpurea. The popularly reported QuEChERS technique has been reduced to a simple “salting-out liquid-liquid extraction” (SO-LLE) to obtain the most efficient extraction of the aforementioned mycotoxin classes in a very short time. This is in particular extremely important in ensuring correct determination of individual ergot alkaloids, for which short and robust sample preparation as well as short analytical sequences were key for minimizing the epimerization during analysis. The analyses of wheat and maize samples were performed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Matrix-matched calibration curves were established and limits of quantification were below the maximum levels established by the EU regulation. The precision (repeatability and intermediate precision) was lower than 13% in all cases and recoveries ranged between 60 and 98% in maize and between 62 and 103% in wheat, fulfilling the current legislation. The method was applied to study the co-occurrence of these mycotoxins in wheat (n = 13) and maize (n = 15) samples from six European countries. A successful quantification of 23 different mycotoxins, from all major classes, in 85% of wheat and 93% of maize samples was achieved.

Posted in AGL2015-70708-R, Maize, Mass spectrometry, SALLE, UHPLC, Wheat | Tagged , , | Comments Off on In-house validation of a rapid and efficient procedure for simultaneous determination of ergot alkaloids and other mycotoxins in wheat and maize

Collision cross section (CCS) as a complementary parameter to characterize human and veterinary drugs

Posted on 5 November, 2018 by fqm302

In the context of human and veterinary drugs identification, ion mobility spectrometry (IMS) in combination with mass spectrometry (MS) may provide a relevant complementary piece of information to mass-to-charge ratio (m/z), the so-called collision-cross-section (CCS). Up to now, however, the application of CCS as identification parameter has not been fully investigated due to the reduced number of these drugs that have being characterized in terms of CCS. This work proposes a CCS database for 92 human and veterinary drugs, including eighteen benzimidazoles, eleven 5-nitroimidazoles, eleven aminoglycosides, nineteen quinolones, eighteen β-lactams, ten sulfonamides and five tetracyclines. Among them, 37 drugs have been characterized in terms of CCS for the first time. The CCS values of the other 55 compounds have been compared with those from a recently published database in order to evaluate inter-laboratory reproducibility, which is crucial for the implementation of the CCS as identification parameter. CCS values were measured by traveling wave ion mobility spectrometry (TWIMS) under positive ionization conditions. Nitrogen was used as drift gas in the ion mobility cell. The proposed database covers 173 ions including [M+H]+ and [M+Na]+ species. High correlation between m/z and CCS has been observed for [M+H]+ (R2 = 0.9518, n = 91) and [M+Na]+ (R2 = 0.9135, n = 82) ions. As expected, CCS values for sodium adducts are generally greater than for protonated molecules because they exhibit higher molecular weight. However, sodium adducts of aminoglycosides, β-lactams, and of several quinolones and benzimidazoles, were characterized as more compact ions than their related protonated molecule. In addition, this work describes the fragmentation pattern observed for the studied molecules. For the first time, the main fragment ions for most of the compounds have also been characterized in terms of CCS, involving a total of 238 ions. As proof of concept, for the application of this database to biological matrices, eleven veterinary drugs in bovine urine samples were characterized in terms of CCS, showing that this parameter was not influenced by the matrix.

Posted in AGL2015-70708-R, Benzimidazoles, Ion mobility, P12-AGR-1647 | Comments Off on Collision cross section (CCS) as a complementary parameter to characterize human and veterinary drugs

Amino‐functionalized material from a bio‐template for silver adsorption: process evaluation in batch and fixed bed

Posted on 15 October, 2018 by fqm302

The modification of an organic matrix as a bio‐template (grapefruit peel) using urea and melamine was carried out to introduce amino groups on its surface and favor Ag(I) adsorption in aqueous solution for metal recovery. Adsorption capacity in batch mode was proportional to the nitrogen content within the adsorbents, the maximum being the one obtained with the adsorbent functionalized with urea, 72.33 mg g−1, which was tested as a fixed bed in a column to evaluate the metal adsorption in a continuous flow model. The adsorption capacity of the fixed bed was 15.14 mg g−1, and its use was proved over three adsorption–desorption cycles. Amino‐functionalized adsorbent achieved a high Ag+ uptake capacity; from the characterization it is proposed that the adsorption mechanism consists in the formation of the complex R‐NH2Ag+ and R‐COOAg.

Posted in Wastewater | Comments Off on Amino‐functionalized material from a bio‐template for silver adsorption: process evaluation in batch and fixed bed

Effects of different vehiculization strategies for the allium derivative propyl propane thiosulfonate during dynamic simulation of the pig gastrointestinal tract.

Posted on 26 September, 2018 by fqm302

This paper evaluates the bioavailability of allium derivative propyl propane thiosulfonate (PTSO) in the pig gastrointestinal tract by means of an in vitro dynamic gastrointestinal tract simulator system (GITSS). The GITSS is based on a membrane bioreactor comprising a continuous stirred-tank reactor connected in series to a continuous plug-flow tubular reactor. Bioavailability values have been evaluated for different vehiculization strategies, including mere carriers such as polyethylene glycol sorbitan monooleate (a nonionic surfactant also known as Tween 80) and encapsulation matrices (β-cyclodextrin vs. mono- and di-glycerides of edible fatty acids mixed with hydrogenated sunflower oil) and compared with the absorption of free PTSO. The net absorbed amount of PTSO in the GITSS when Tween 80 was used as a carrier was over 3.5 times higher than the one for free PTSO. Neither the encapsulated PTSO in β-cyclodextrin nor by means of mono- and di-glycerides of fatty acids plus a vegetable oil succeeded to improve absorption values for free PTSO. These promising results indicate that Tween 80 provides an interesting and high resistance to the PTSO molecule against the simulated digestive conditions in the stomach, and thus it enables favorably the subsequent absorption process of PTSO along the intestine.

Posted in Animal feed, PTSO | Comments Off on Effects of different vehiculization strategies for the allium derivative propyl propane thiosulfonate during dynamic simulation of the pig gastrointestinal tract.