Search results for "RESIDUES"
showing 10 items of 147 documents
Evaluation of a solid-phase extraction system for determining pesticide residues in milk.
1993
Abstract A simple and rapid procedure based on reversed solid-phase extraction with octadecylsilica was developed for determining chlorinated pesticide residues in milk. The need for an agent that breaks the fat globules was first investigated and the method variables were optimized on whole homogenized milk (3.6% fat content). Recovery experiments performed for 26 organochlorine pesticides at levels of 3–40 μg/l gave > 80% recoveries for all the compounds. The method was validated and evaluated by comparison with two widely used liquid-liquid extraction methods. The performance was checked by analysis of a certified standard with natural low endogenous levels (CMR 187) and different kinds …
Analysis of Pesticide Residues in Milk, Eggs, and Meat
2009
This handbook provides a systematic description of the principles, procedures, and technology of the modern analytical techniques used in the detection, extraction, clean up, and determination of pesticide residues present in the environment. This book provides the historical background of pesticides and emerging trends in pesticide regulation. The text discusses various techniques for analysis, including supercritical fluid extraction, disposable electrochemical biosensors, matrix solid-phase dispersion, volatmetric methods, and liquid chromatography. The authors also address the scope and limitation of NEEM products in plant protection as well as the analysis of medicinal plants.
Metodo per la realizzazione di un’opera costruttiva modulare per la protezione del territorio e detta opera
2017
The patent consists of an advanced technique for the modular elements construction, made with organic waste materials. These elements are used for land protection within the Soil and Water Bioengineering works. The linear work with anti-erosion function, consolidating and stabilizing of slopes, consists of modules (Roll Modular Fascine, RFM) made with the residues of vine pruning and with the residues of a marine plant, Posidonia oceanica beached. The work is made with waste materials. The material to make the module consists of vine prunings, collected with specialized agricultural machines. The fascines have a diameter of 40 cm and a length of 60 cm. Their density can be varied by acting …
Food Contaminants
2014
Chemical contaminants may occur in our food from various sources. Contaminants can be present in foods mainly as a result of the use of agrochemicals, such as residues of pesticides and veterinary drugs, contamination from environmental sources (water, air or soil pollution), cross-contamination or formation during food processing, migration from food packaging materials, presence or contamination by natural toxins or use of unapproved food additives and adulterants. They typically pose a health concern, resulting in strict regulations of their levels by national governments and internationally. Therefore, analysis of relevant chemical contaminants is an essential part of food safety testin…
Application of solid-phase microextraction for determining phenylurea herbicides and their homologous anilines from vegetables.
2004
Abstract Residues of metobromuron, monolinuron and linuron herbicides and their aniline homologous were analyzed in carrots, onions and potatoes by solid-phase microextraction (SPME) performed with a polyacrylate fiber. A juice was obtained from food samples that were further diluted, and an aliquot was extracted after sodium chloride (14%) addition and pH control. At pH 4 only the phenylureas were extracted. A new extraction at pH 11 allowed the extraction of phenylureas plus homologous aniline metabolites. Determination was carried out by gas chromatography with nitrogen–phosporus detection (NPD) the identity of the determined compounds was studied by gas chromatography–mass spectrometry.…
Pesticide analysis in coffee leaves using a quick, easy, cheap, effective, rugged and safe approach and liquid chromatography tandem mass spectrometr…
2017
An analytical method using a quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure for multi-residue determination of 52 pesticides in coffee leaf extractshas been developed and validated according to SANTE/11945/2015 guidelines. Different sorbent combinations for dispersive solid phase extraction (d-SPE) clean-up as well as dispersive liquid-liquid microextraction (DLLME) were tested. The relative standard deviations (RSDs) for the recovery of 87-94% of pesticides added to coffee leaf extracts,was ≤20% for samples spiked at concentrations up to 50ng*g-1 depending on the clean-up procedures. However, samples spiked with a 100ng*g-1 pesticide mixture gave RSDs>20% for most pest…
Determination of macrolide antibiotics in meat and fish using pressurized liquid extraction and liquid chromatography–mass spectrometry
2008
We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using pressurized liquid extraction (PLE) and liquid chromatography-mass spectrometry with electrospray ionization (LC-(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, extraction time and number of cycles. The optimum conditions were: methanol as the extraction solvent; a temperature of 80 degrees C; a pressure of 1500psi; an extraction time of 15min; 2 cycles; a flush volume of 150% and a purge time of 300s. All recoveries for macrolide antibiotics were over 77% at 200mug/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on d…
Multi-residue analysis of 30 currently used pesticides in fine airborne particulate matter (PM 2.5) by microwave-assisted extraction and liquid chrom…
2009
A confirmatory and rapid procedure has been developed for the determination of 30 currently used pesticides (CUP) in fine airborne particulate matter (PM 2.5) at trace level. The proposed method includes extraction of PM 2.5-bound pesticides by microwave-assisted extraction (MAE) followed by a direct injection into LC-MS/MS. The main parameters affecting the MAE extraction (time, temperature and volume of solvent) were optimised using statistical design of experiments (DoE). The matrix effect was also evaluated. Recoveries ranged from 72 to 109% and the limit of quantification (LoQ) was 32.5 pg m(-3) for chlorpyrifos, 13.5 pg m(-3) for fenhexamid, imazalil and prochloraz, and 6.5 pg m(-3) f…
Optimization of a matrix solid-phase dispersion method for the analysis of pesticide residues in vegetables
1996
A multiresidue method based on matrix solid-phase dispersion (MSPD) is studied to determine chlorfenvinfos, chlorpyrifos, fenarimol, iprodione, procimydone, propiconazole, tetradifon, triadimefon and vinclozolin in artichokes, green beans, lettuces and tomatoes. Alumina, silica and Florisil were assessed as extracting phases, and the extracts from Florisil were the cleanest. To facilitate manual extraction, sand was added to the sample together with the dispersing phase. Three eluting systems were then studied, and dichloromethane proved to be the best. Further purification can be performed using solid-phase cleanup after diluting extracts with aqueous solutions. Octyl- and octadecyl-silica…
Profiling of compounds and degradation products from the postharvest treatment of pears and apples by ultra-high pressure liquid chromatography quadr…
2010
This study deals with a simple strategy to pinpoint potential unknown compounds in full scan mass spectrometry (MS) experiments. Forty samples of apples and pears intended for human consumption were analyzed by ultra-high performance liquid chromatography quadrupole-time-of-flight (UPLC–QqTOF-MS), after extraction of the possible contaminants by rinsing the peel of the fruit with ethyl acetate. The peaks were visually recognized in the total ion chromatogram (TIC). Two major types of postharvest treatments were detected in this set of samples: imazalil (IMZ)/ethoxyquin (EQ) and thiabendazole (TBZ)/diphenylamine (DPA). The present work also describes the metabolites formed by degradation of …