Fast DLLME-GC-MS Method for Determination of Pesticides in Carmelite Drops and Evaluation of Matrix Effects in Related Medicinal Products.

The production of nutraceuticals is a growing trend, as many consumers consider them an important part of the modern active lifestyle. Others rely on the use of nutraceuticals instead of prescribing pharmaceuticals to improve their health more naturally. One of the major concerns in the nutraceutical industry is the potential presence of contaminants.

Determination of fipronil and its three degradates in water using stir bar sorptive extraction-thermal desorption-gas chromatography-tandem mass spectrometry.

A method was developed for determination of fipronil (FIP) pesticide and its three major degradates (fipronil desulfinyl, fipronil sulfide, fipronil sulfone) in water at the levels required by the EU Commission in the Decision 2022/1307. The method combines solvent-free stir bar sorptive extraction (SBSE) with thermal desorption-gas chromatography-tandem mass spectrometry (TD-GC-MS/MS). Simple sample processing involves 16 h of stirring a 100 mL water sample with a polydimethylsiloxane-coated sorptive stir bar, followed by TD of the trapped analytes into the GC.

Dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry for the determination of pesticide residues in nutraceutical drops.

An economical and rapid method has been developed using dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry to extract and determine forty pesticides in nutraceutical drops containing alcohol. Parameters affecting the DLLME performance, such as solvent selection and volume of extractive and dispersive solvent, salt effect, pH, mixing type and extraction time, were studied. Tetrachloroethane was the selected extraction solvent.

Development of fast, efficient and ecological method employing vortex-assisted dispersive liquid-liquid microextraction combined with fast gas chromatography-mass spectrometry for pesticide residues analysis in alcohol-content samples.

A fast, ecological, and efficient method employing vortex-assisted dispersive liquid-liquid microextraction (DLLME) method for isolation and preconcentration of selected endocrine disrupting pesticides from beverages containing some degree of alcohol was developed. The effect of several extraction parameters, such as selection of extractive solvent, its volume and extraction time, the salt addition was investigated. Four different extractive solvents (chloroform, tetrachloroethane, tetrachloromethane and toluene) and their combinations were evaluated for DLLME.

Occurrence of pesticide residues and transformation products in different types of dietary supplements.

The purpose of this study was to evaluate the presence of pesticide residues and transformation products in dietary supplement products. Thirty-two samples were analysed to determine 177 pesticides by gas chromatography-tandem mass spectrometry (GC-MS/MS) and 333 pesticides by liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Pesticides were extracted from different kinds of dietary supplements by the use of a modified QuEChERS extraction method.

Multifamily determination of pesticide residues in soya-based nutraceutical products by GC/MS-MS.

An analytical method based on a modified QuEChERS extraction coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS) was evaluated for the determination of 177 pesticides in soya-based nutraceutical products. The QuEChERS method was optimised and different extraction solvents and clean-up approaches were tested, obtaining the most efficient conditions with a mixture of sorbents (PSA, C18, GBC and Zr-Sep(+)). Recoveries were evaluated at 10, 50 and 100 μg/kg and ranged between 70% and 120%.

Analysis of endocrine disrupting pesticides by capillary GC with mass spectrometric detection.

Endocrine disrupting chemicals, among them many pesticides, alter the normal functioning of the endocrine system of both wildlife and humans at very low concentration levels. Therefore, the importance of method development for their analysis in food and the environment is increasing. This also covers contributions in the field of ultra-trace analysis of multicomponent mixtures of organic pollutants in complex matrices.

Combination of QuEChERS and DLLME for GC-MS determination of pesticide residues in orange samples.

A new method combining QuEChERS (quick, easy, cheap, effective, rugged and safe) and DLLME (dispersive liquid-liquid microextraction) followed by gas chromatography-mass spectrometry with selected ion monitoring (SIM) was developed for the simultaneous determination of 19 pesticides from nine chemical groups exhibiting or suspected to exhibit endocrine-disrupting properties in orange samples. Acetonitrile extract obtained from QuEChERS extraction was used for DLLME as dispersive solvent and carbon tetrachloride as extractive solvent to increase the enrichment factor of the extraction procedure. The effect of several extraction parameters, such as volume extract achieved by the QuEChERS method and subsequently used for DLLME, selection of extractive solvent and its volume, was tested.

Analysis of pesticide residues by fast gas chromatography in combination with negative chemical ionization mass spectrometry.

A combination of fast GC with narrow-bore column and bench top quadrupole mass spectrometer (MS) detector in negative chemical ionization (NCI) mode (with methane as reagent gas) is set up and utilized for the ultratrace analysis of 25 selected pesticides. The observed pesticides, belonging to the endocrine disrupting chemicals (EDCs), were from different chemical classes. A comparative study with electron impact (EI) ionization was also carried out (both techniques in selected ion monitoring (SIM) mode).

Possibilities and limitations of quadrupole mass spectrometric detector in fast gas chromatography.

In this work the application and limitations of a common bench top quadrupole mass spectrometer was evaluated for the qualitative and quantitative measurement of n-alkanes and pesticides of a wide range of volatilities and polarities with fast GC separations using 0.15 mm I.D.