Quechers

This study aimed to optimize and validate a multi-residue method for identifying and quantifying pesticides in honey by using an accurate, rapid and reliable method for the simultaneous determination of 101 pesticide residues in honey by liquid chromatography coupled with tandem mass spectrometry LC–ESI (+)-MS/MS operating in multiple reaction monitoring (MRM) mode. The performance of the analytical method was validated in accordance with EU SANCO guidelines (SANTE/12682/2019). Acceptable values were obtained for the following parameters: linearity, recoveries, precision (reproducibility and repeatability) and measurement uncertainty tests (<50.0%). A highly efficient approach for determining pesticide residues in honey with good recoveries was developed. The recovery values obtained at two fortification levels: 0.01 and 0.1 mgkg−1, were 73.2% and 119.7% respectively, with an average RSD<17% for all the tested compounds. The estimated linearity measured at five concentration l...

In this study was compared the amount of polycyclic aromatic hydrocarbons (PAHs) in meat which had been grilled and baked. The purpose of the study was to determine which kind of preparation of the meat is more harmful by comparing the amounts of PAHs. In the study was tested six samples. Three samples were baked and three were grilled. Methods which have been used are the QuEChERS extraction method and method of gas chromatography-mass spectrometry (GC-MS) to determine the amount of PAHs in samples of meat. The results showed that the baked meat has about seven times larger amount of one of PAHs (naphthalene) than meat from the grill. These results led to the conclusion that the baked meat is more harmful than the grilled one and the reason for this is that the baking takes place indoors.
Keywords: meat, PAH, QuEChERS, GC-MS

The use of pesticides on maize crops during and after harvest constitutes a serious health and environmental risk if its prevalence remains during the consumption line. Therefore, the proper determination of the residues of such substances is critical for minimizing the negative impact of pesticides on health and quality of agricultural products. The aim of this study was to evaluate the multiresidual extraction methodology QuEChERS (“Quick, Easy, Cheap, Effective, Rugged, Safe”) as an economic alternative with easy implementation for the analysis of 10 pesticides in floury white corn (Zea mays). Two variants of this method were tested: the original non-buffered method and the official method AOAC 2007.01 with acetate buffer. Analyzes were carried out by gas chromatography with electron capture detector (GC-ECD). Co-extractives percentage and moisture in the final extract were compared, and a check in terms of accuracy, linearity, accuracy, and sensitivity matrix effect was made. Implementation of the original method permitted to obtain cleaner extracts and more consistent and appropriate (overall average between 71,4 – 111,6% with coefficients of variation less than 9,2%) recovery percentages. Additionally, linearity (r> 0,9892) and limits of detection and quantification below the maximum residue limits established by the European Commission (10 to 50 mg kg-1) were also obtained, which makes this method a good choice to routinely quantify the residual effect of the assessed pesticides in the matrix of work.

In this study was compared the amount of polycyclic aromatic hydrocarbons (PAHs) in meat which had been grilled and baked. The purpose of the study was to determine which kind of preparation of the meat is more harmful by comparing the amounts of PAHs. In the study was tested six samples. Three samples were baked and three were grilled. Methods which have been used are the QuEChERS extraction method and method of gas chromatography-mass spectrometry (GC-MS) to determine the amount of PAHs in samples of meat. The results showed that the baked meat has about seven times larger amount of one of PAHs (naphthalene) than meat from the grill. These results led to the conclusion that the baked meat is more harmful than the grilled one and the reason for this is that the baking takes place indoors

A multiresidue method for detecting and quantifying sulfonamides (sulfapyridine, sulfamerazine, sulfathiazole, sulfamethazine, sulfadimethoxine, sulfamethoxazole, and sulfamethoxypyridazine) and trimethoprim in tilapia fillet () using liquid chromatography coupled to mass spectrometry was developed and validated. The sample preparation was optimized using the QuEChERS approach. The chromatographic separation was performed using a C18 column and 0.1% formic acid in water and acetonitrile as the mobile phase in the isocratic elution mode. Method validation was performed based on the Commission Decision 2002/657/EC and Brazilian guideline. The validation parameters evaluated were linearity ( ≥ 0.99); limits of detection (LOD) and quantification (LOQ), 1 ng·g and 5 ng·g, respectively; intraday and interdays precision (CV lower than 19.4%). The decision limit (CC 102.6-120.0 ng·g and 70 ng·g for sulfonamides and trimethoprim, respectively) and detection capability (CC 111.7-140.1 ng·g an...

Se desarrolló un método multirresiduo<br />para la determinación de 24 plaguicidas<br />de diferentes características fisicoquímicas<br />en tomate. El proceso de extracción<br />se basó en el método QuEChERS y la determinación<br />de los compuestos se realizó<br />mediante cromatografía líquida ultrarrápida<br />acoplada a espectrometría de masas.<br />Los resultados de la validación indicaron<br />que el método presenta porcentajes de<br />recuperación de entre el 71,3 y el 114%,<br />coeficientes de variación inferiores al<br />20%, límites de detección entre 0,002 y<br />0,225 mg/kg, límites de cuantificación<br />entre 0,009 y 0,750 mg/kg. En los estudios<br />de linealidad, para todos los parámetros<br />evaluados, se obtuvieron resultados adecuados en los rangos de trabajo. Para<br />probar la metodología desarrollada, se<br />evaluaron muestras de frutos de tomate<...

In this study, a new method has been developed to determine seven neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam) in bee pollen using ultra-high performance liquid chromatography (UHPLC) coupled to a selective MS detector (qTOF). An efficient sample treatment involving an optimized quick, easy, cheap, effective, rugged and safe (QuEChERS) method was proposed. In all cases, average analyte recoveries were between 91 and 105%, and no matrix effect was observed. Chromatographic analysis (6.5 min) was performed on a core-shell technology based column (Kinetex(®) EVO C18 , 50×2.1 mm, 1.7 μm, 100 Å). The mobile phase consisted of 0.1% formic acid in water and 0.1% of formic acid in acetonitrile, with a flow rate of 0.3 mL/min in gradient elution mode. The fully validated method was selective, linear from LOQ to 500 μg/kg, precise and accurate; relative standard deviation (% RSD) and relative error (% RE) values we...