Simple and efficient method for the determination of fipronil and two main metabolites in eggs by capillary liquid chromatography.

Posted on 16 July, 2021 by fqm302

Capillary liquid chromatography (CLC) with UV-diode array detection has been proposed for the first time to determine fipronil and two metabolites, fipronil-sulfide and fipronil-sulfone in hen egg samples. Under optimum conditions, analytes eluted in less than 12 min. Despite the complexity of egg samples, a simple and fast sample preparation method based on salting-out assisted liquid–liquid extraction (SALLE) was developed using acetonitrile as extraction solvent and ammonium sulfate as salting out reagent. To obtain satisfactory extraction efficiencies for the target compounds, several parameters affecting the procedure were optimized, including the nature and amount of the extraction solvent and the type and amount of salting-out reagent, among others. Validation parameters of the proposed SALLE-CLC-UV method yielded satisfactory results with repeatability and intermediate precision, expressed as relative standard deviation (RSD), below 9% and 11%, respectively and recoveries above 80%. Good linearity was obtained (R2 > 0.990) with limits of detection (LOD) below 5 μg·kg−1. The advantages of a miniaturized technique such as CLC in terms of reduced sample and solvent consumption, combined with simplicity of the SALLE procedure, make this method an attractive green alternative to traditional LC for the monitoring of these residues in egg samples.

Posted in Capillary HPLC, Eggs, Fipronil, Pesticides, RTI2018-097043-B-I00, SALLE, UV-vis | Tagged , , | Comments Off on Simple and efficient method for the determination of fipronil and two main metabolites in eggs by capillary liquid chromatography.

Determination of the main ergot alkaloids and their epimers in oat-based functional foods by ultra-high performance liquid chromatography tandem mass spectrometry.

Posted on 18 June, 2021 by fqm302

An ultra-high performance liquid chromatography coupled to tandem mass spectrometry method is proposed for the determination of the major ergot alkaloids (ergometrine, ergosine, ergotamine, ergocornine, ergokryptine, ergocristine) and their epimers (ergometrinine, ergosinine, ergotaminine, ergocorninine, ergokryptinine, and ergocristinine) in oat-based foods and food supplements. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure was applied as sample treatment, reducing the consumption of organic solvent and increasing sensitivity. This method involved an extraction with acetonitrile and ammonium carbonate (85:15, v/v) and a clean-up step based on dispersive solid-phase extraction, employing a mixture of C18/Z-Sep+ as sorbents. Procedural calibration curves were established and limits of quantification were below 3.2 μg/kg for the studied compounds. Repeatability and intermediate precision (expressed as RSD%) were lower than 6.3% and 15%, respectively, with recoveries ranging between 89.7% and 109%. The method was applied to oat-based products (bran, flakes, flour, grass, hydroalcoholic extracts, juices, and tablets), finding a positive sample of oat bran contaminated with ergometrine, ergosine, ergometrinine, and ergosinine (total content of 10.7 μg/kg).

Posted in Ergot alkaloids, Mass spectrometry, Mycotoxins, Oat, QuEChERS, RTI2018-097043-B-I00, UHPLC | Tagged , , | Comments Off on Determination of the main ergot alkaloids and their epimers in oat-based functional foods by ultra-high performance liquid chromatography tandem mass spectrometry.

Occurrence of ergot alkaloids in barley and wheat from Algeria

Posted on 28 April, 2021 by fqm302

The natural occurrence of six major ergot alkaloids, ergometrine, ergosine, ergotamine, ergocornine, ergokryptine and ergocristine, as well as their corresponding epimers, were investigated in 60 cereal samples (barley and wheat) from Algeria. Ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and a QuEChERS extraction method were used for sample analysis. The results revealed that 12 out of 60 samples (20%) were contaminated with ergot alkaloids. Wheat was the most contaminated matrix, with an incidence of 26.7% (8 out of 30 samples). The concentration of total ergot alkaloids ranged from 17.8 to 53.9 μg/kg for barley and from 3.66 to 76.0 μg/kg for wheat samples. Ergosine, ergokryptine and ergocristine showed the highest incidences in wheat, while ergometrine was the most common ergot in barley.

Posted in Barley, Ergot alkaloids, Mass spectrometry, Mycotoxins, QuEChERS, RTI2018-097043-B-I00, UHPLC, Wheat | Tagged , , | Comments Off on Occurrence of ergot alkaloids in barley and wheat from Algeria

A novel approach based on capillary liquid chromatography for the simultaneous determination of neonicotinoid residues in cereal samples

Posted on 18 December, 2020 by fqm302

A simple and effective method using solid–liquid extraction followed by capillary liquid chromatography with diode array detection (CLC-DAD) has been established for the extraction and determination of seven neonicotinoid insecticides commercially available (imidacloprid, thiacloprid, clothianidin, thiamethoxam, acetamiprid, nitenpyram and dinotefuran) in cereal samples. The separation was achieved in less than 19 min using a Zorbax XDB-C18 column (150 mm × 0.5 mm i.d, 5 µm) at a 25 °C, with a mobile phase consisting of ultrapure water and acetonitrile at a flow rate of 10 µL/min. Detection wavelengths of 254 or 270 nm were used, depending on the analyte. Variables affecting the extraction efficiency were optimized, such as type and volume of extraction solvent, and extraction and centrifugation time. Under the optimal conditions, the proposed method was characterized according to SANTE/12682/2019 guideline, in terms of linearity ( ≥ 0.9901), repeatability (RSD ≤ 7.6%), reproducibility (RSD ≤ 10%) and trueness (recoveries ≥ 80%). The limits of detection and quantification were in the ranges of 3–5 and 9–18 µg/kg, respectively, being adequate for the determination of these compounds in cereal samples at levels below its maximum residue limits (MRLs) established by the European legislation. The advantages of a miniaturized technique such as CLC in terms of high mass sensitivity and reduced solvent consumption, combined with the simplicity of the solid–liquid extraction procedure, make this method a useful alternative for the monitoring of these residues at trace level in cereal samples.

Posted in AGL2015-70708-R, Barley, Capillary HPLC, Maize, Oat, Rice, Solid-liquid extraction, UV-vis, Wheat | Tagged , | Comments Off on A novel approach based on capillary liquid chromatography for the simultaneous determination of neonicotinoid residues in cereal samples

Capillary liquid chromatography as an effective method for the determination of seven neonicotinoid residues in honey samples

Posted on 23 October, 2020 by fqm302

A new analytical method based on capillary liquid chromatography with diode array detection has been developed for the simultaneous quantification of seven neonicotinoid insecticides commercially available (imidacloprid, thiacloprid, clothianidin, thiamethoxam, acetamiprid, nitenpyram, and dinotefuran) in honey samples. The separation was achieved in a Zorbax XDB-C18 column (150 × 0.5 mm id, 5 μm), with a mobile phase consisting of ultrapure water (solvent A) and acetonitrile (solvent B) at a flow rate of 10 μL/min. Capillary column was thermostated at 25◦C during the analysis and 254 or 270 nm was established as detection wavelength, depending on the analyte. Furthermore, full loop injection mode (8 μL) was selected, using water as injection solvent. Finally, the optimized method was applied to the analysis of neonicotinoid residues in honey of different floral origins using dispersive liquid–liquid microextraction as sample treatment. Variables affecting the extraction efficiency were optimized, choosing methanol and dichloromethane as dispersive and extraction solvents, respectively. The method was characterized in terms of linearity (𝑅2 ≥ 0.9948), repeatability, reproducibility (relative standard deviation below 4.5 and 6.3% respectively), and recoveries (≥80.5%). Detection and quantification limits were lower than 6.6 and 22.0 μg/kg for the studied analytes, respectively.

Posted in AGL2015-70708-R, Capillary HPLC, DLLME, Honey, Neonicotinoids, UV-vis | Tagged , , | Comments Off on Capillary liquid chromatography as an effective method for the determination of seven neonicotinoid residues in honey samples

Micellar electrokinetic chromatography as efficient alternative for the multiresidue determination of seven neonicotinoids and 6-chloronicotinic acid in environmental samples

Posted on 27 August, 2020 by fqm302

A simple, sensitive, and efficient method has been developed for the determination of the seven neonicotinoid insecticides commercially available (imidacloprid, thiacloprid, clothianidin, thiamethoxam, acetamiprid, nitenpyram, and dinotefuran) and the main metabolite 6-chloronicotinic acid. Micellar electrokinetic chromatography (MEKC) mode was applied, using 48.5 cm of total length capillary (50 μm i.d.) with an extended light-path capillary (150 μm). The running electrolyte consisted of 25 mM sodium tetraborate buffer (pH 9.2) containing 120 mM of sodium dodecyl sulfate and 15% of methanol (v/v). A voltage of 27 kV and a temperature of 25 °C were applied. Samples dissolved in deionized water were hydrodynamically injected at 50 mbar for 12 s, achieving the analysis in less than 12 min. Diode array detection (DAD) was performed at 220, 254, and 270 nm, depending on the analyte. Two different methodologies as sample treatments were developed; for water samples, solid-phase extraction was checked using different cartridges (C18, Oasis® HLB, Oasis® HLB Prime, and Strata-X), being the best option Oasis® HLB for preconcentration and cleanup. In the case of soil samples, a simple solid–liquid extraction was applied using a mixture of 1:3 (v/v) acetonitrile/dichloromethane. Satisfactory linearity, trueness, and precision were achieved, with detection limits in the range of 0.1–0.4 μg L−1 for river water and 1.0–2.9 μg kg−1 for soil samples. Recoveries in the range of 80–107% for all of the assayed neonicotinoids in water samples of different origin and 73–92% for soil samples were achieved.

Posted in AGL2015-70708-R, MEKC, Neonicotinoids, SPE, Soil, Solid-liquid extraction, UV-vis, Water | Tagged , , | Comments Off on Micellar electrokinetic chromatography as efficient alternative for the multiresidue determination of seven neonicotinoids and 6-chloronicotinic acid in environmental samples

Determination of sulfonylurea pesticide residues in edible seeds used as nutraceuticals by QuEChERS in combination with ultra-high-performance liquid chromatography-tandem mass spectrometry

Posted on 13 April, 2020 by fqm302

This work proposes a novel Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method in combination with ultra-high performance liquid chromatography-tandem mass spectrometry for the determination of sulfonylurea residues in edible seeds. The chromatographic separation of nine sulfonylureas was accomplished in less than 5.5 min, using a Luna Omega C18 column (50 × 2.1 mm, 1.6 µm). Mobile phase was supplied at 0.55 mL min-1 and consisted of 0.01% (v/v) aqueous acetic acid as eluent A and a mixture methanol/acetonitrile (80/20, v/v) as eluent B. Column temperature was established at 25 °C. A QuEChERS procedure was investigated as sample treatment for sulfonylureas extraction and sample clean-up. Different clean-up agents (i.e. PSA, Z-Sep+, EMR-Lipid and C18) were evaluated, selecting Z-Sep+ (25 mg) as the best option. The proposed method provided an extraction efficiency greater than 86.2%, while absolute matrix effect was lower than 50.1%. Matrix-matched calibration curves were required for analyte quantification. The analytical method was characterized according to SANTE/11813/2017 guideline, and including limits of detection and quantification, precision, and trueness. Linear dynamic ranges were established from 5 to 150 µg kg−1 for all analytes. Linearity (R2 ≥ 0.9974) and precision in terms of repeatability and intermediate precision (relative standard deviation ≤ 14.7%) are reported. The reporting limit was established at 5 µg kg−1, which is above the limits of quantification of the proposed method (≤ 1.64 µg kg−1) and below the maximum residue levels currently established by European legislation. In general, trueness is within the range of 70–120%. Despite greater recoveries were obtained at the reporting limit (i.e. 120–138%), relative standard deviations lower than 20% were obtained at this concentration level, so fulfilling the requirements of SANTE/11813/2017 guideline. This work represents the first analytical method intended for the analysis of sulfonylureas in sunflower, pumpkin and chia seeds, which are complex matrices due to their high content of fat as well as of growing interest due to their current commercialization as nutraceuticals.

Posted in AGL2015-70708-R, Mass spectrometry, QuEChERS, Seeds, Sulfonylurea, UHPLC | Tagged , , | Comments Off on Determination of sulfonylurea pesticide residues in edible seeds used as nutraceuticals by QuEChERS in combination with ultra-high-performance liquid chromatography-tandem mass spectrometry

Multi-mycotoxin occurrence and exposure assessment approach in foodstuffs from Algeria

Posted on 19 March, 2020 by fqm302

A survey on 120 cereal samples (barley, maize, rice and wheat) from Algerian markets has
been carried out to evaluate the presence of 15 mycotoxins (ochratoxin A, deoxynivalenol, fumonisin B1 and B2, T-2 and HT-2 toxins, zearalenone, fusarenon X, citrinin, sterigmatocystin, enniatins A, A1, B and B1, and beauvericin). With this purpose, a QuEChERS-based extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) were used. Analytical results showed that 78 cereal samples (65%) were contaminated with at least one toxin, while 50% were contaminated with three to nine mycotoxins. T-2 toxin, citrinin, beauvericin and deoxynivalenol were the most commonly found mycotoxins (frequency of 50%, 41.6%, 40.8% and 33.3%, respectively). Fumonisins (B1 + B2), enniatins B and B1, deoxynivalenol and zearalenone registered high concentrations (289–48878 µg/kg, 1.2–5288 µg/kg, 15–4569 µg/kg, 48–2055 µg/kg and 10.4–579 µg/kg, respectively). Furthermore, concentrations higher than those allowed by the European Union (EU) were observed in 21, 8 and 1 samples for fumonisins, zearalenone and deoxinivalenol, respectively. As a conclusion, the high levels of fumonisins (B1 + B2) in maize and deoxynivalenol, zearalenone and HT-2 + T-2 toxins in wheat, represent a health risk for the average adult consumer in Algeria. These results pointed out the necessity of a consistent control and the definition of maximum allowed levels for mycotoxins in Algerian foodstuffs.

Posted in AGL2015-70708-R, Barley, Maize, Mass spectrometry, Mycotoxins, QuEChERS, Rice, UHPLC, Wheat | Tagged , | Comments Off on Multi-mycotoxin occurrence and exposure assessment approach in foodstuffs from Algeria

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.