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Phenol is a toxic compound present in a wide variety of foundry resins. Its quantification is important for the characterization of the resins as well as for the evaluation of free contaminants present in foundry wastes. Two chromatographic methods, liquid chromatography with ultraviolet detection (LC-UV) and gas chromatography with flame ionization detection (GC-FID), for the analysis of free phenol in several foundry resins, after a simple extraction procedure (30 min), were developed. Both chromatographic methods were suitable for the determination of phenol in the studied furanic and phenolic resins, showing good selectivity, accuracy (recovery 99-100%; relative deviations <5%), and precision (coefficients of variation <6%). The used ASTM reference method was only found to be useful in the analysis of phenolic resins, while the LC and GC methods were applicable for all the studied resins. The developed methods reduce the time of analysis from 3.5 hours to about 30 min and can readily be used in routine quality control laboratories. [ABSTRACT FROM AUTHOR]

Abstract: Two chromatographic methods, gas chromatography with flow ionization detection (GC–FID) and liquid chromatography with ultraviolet detection (LC–UV), were used to determine furfuryl alcohol in several kinds of foundry resins, after application of an optimised extraction procedure. The GC method developed gave feasibility that did not depend on resin kind. Analysis by LC was suitable just for furanic resins. The presence of interference in the phenolic resins did not allow an appropriate quantification by LC. Both methods gave accurate and precise results. Recoveries were >94%; relative standard deviations were ≤7 and ≤0.3%, respectively for GC and LC methods. Good relative deviations between the two methods were found (≤3%). [Copyright &y& Elsevier]

A multiresidue analytical methodology based on a solid-phase microextraction (SPME), followed by gas chromatography-ion trap mass spectrometry (GC-IT/MS), has been developed for trace analysis of 20 known or suspected endocrine-disrupting pesticides. The SPME conditions are optimized considering several key parameters to obtain the maximum sensitivity. After the optimization, the method validation is performed, and the limits of detection (ranged from 2-150 ng/L) and the coefficient of determination (above 0.990) of studied compounds are determined for all the analytes. A robust sampling of twenty sampling points of surface water samples from the north and center of Portugal is performed, and the validated methodology is applied. In total, 20 compounds from four chemical families (13 organochlorine, 1 organophosphorus, 2 dicarboximide, and 4 pyrethroids) are studied, and the pesticides most frequently detected are eight organochlorine pesticides (α-, β-HCHs, lindane, HCB, o,p'-DDT, p,p'-DDE, p,p'-DDD, α-endosulfan), cypermethrin, and vinclozolin. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles (MNPs) with different sizes and characteristics were synthesized to be used as a QuEChERS sorbents for the determination of seven organophosphorus pesticides (OPPs) in strawberries by gas chromatography analysis with flame photometric and mass spectrometry detection. To achieve the optimum conditions of modified QuEChERS procedure several parameters affecting the cleanup efficiency including the amount of the sorbents and cleanup time were investigated. The results were compared with classical QuEChERS methodologies and the modified QuEChERS procedure using MNPs showed the better performance. Under the optimum conditions of the new methodology, three spiking levels (25, 50 and 100 μg kg −1 ) were evaluated in a strawberry sample. The results showed that the average recovery was 93% and the relative standard deviation was less than 12%. The enrichment factor ranged from 111 to 145%. The good linearity with coefficients of determination of 0.9904–0.9991 was obtained over the range of 25–250 μg kg −1 for 7 OPPs. It was determined that the MNPs have an excellent function as sorbent when purified even using less amount of sorbents and the magnetic properties allowed non-use of the centrifugation in cleanup step. The new methodology was applied in strawberry samples from conventional and organic farming. The new sorbents were successfully applied for extraction and determination of OPPs in strawberries. [ABSTRACT FROM AUTHOR]

The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was applied to the extraction of 14 organochlorine pesticides (OCPs) residues from commercial fruit pulps available in supermarkets in Fortaleza, Northeastern Brazil. The analyses were carried out by gas chromatography (GC), coupled to an electron-capture detector (ECD), and were confirmed by GC-tandem mass spectrometry (MS). The parameters of the analytical method, such as accuracy, precision, linear range, limits of detection and quantification, were determined for each pesticide. The results showed good linearity (R2≥ 0.9916) and the overall average recoveries were considered satisfactory obtaining values between 69 and 110%, RSD of 2–15 %, except for hexachlorobenzene (HCB) in açai, acerola and guava pulp samples. The OCPs were detected in guava (α–HCH; lindane) and soursop (α, β–HCH isomers) samples. The QuEChERS method and GC–ECD were successfully used to analyze OCPs in commercially available Brazilian fruit pulps and can be applied in routine analytical laboratories. [ABSTRACT FROM AUTHOR]

In this study a citrate-buffered version of QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method for determination of 14 organochlorine pesticides (OCPs) residues in tamarind peel, fruit and commercial pulp was optimized using gas chromatography (GC) coupled with electron-capture detector (ECD) and confirmation by GC tandem mass spectrometry (GC–MS/MS). Five procedures were tested based on the original QuEChERS method. The best one was achieved with increased time in ultrasonic bath. For the extract clean-up, primary secondary amine (PSA), octadecyl-bonded silica (C 18 ) and magnesium sulphate (MgSO 4 ) were used as sorbents for tamarind fruit and commercial pulp and for peel was also added graphitized carbon black (GCB). The samples mass was optimized according to the best recoveries (1.0 g for peel and fruit; 0.5 g for pulp). The method results showed the matrix-matched calibration curve linearity was r 2 > 0.99 for all target analytes in all samples. The overall average recoveries (spiked at 20, 40 and 60 μg kg −1 ) have been considered satisfactory presenting values between 70 and 115% with RSD of 2–15 % (n = 3) for all analytes, with the exception of HCB (in peel sample). The ranges of limits of detection (LOD) and quantification (LOQ) for OCPs were for peel (LOD: 8.0–21 μg kg −1 ; LOQ: 27–98 μg kg −1 ); for fruit (LOD: 4–10 μg kg −1 ; LOQ: 15–49 μg kg −1 ) and for commercial pulp (LOD: 2–5 μg kg −1 ; LOQ: 7–27 μg kg −1 ). The method was successfully applied in tamarind samples being considered a rapid, sensitive and reliable procedure. [ABSTRACT FROM AUTHOR]

Abstract: A multiresidue gas chromatographic method for the determination of six fungicides (captan, chlorthalonil, folpet, iprodione, procymidone and vinclozolin) and one acaricide (dicofol) in still and fortified wines was developed. Solid-phase microextraction (SPME) was chosen for the extraction of the compounds from the studied matrices and tandem mass spectrometry (MS/MS) detection was used. The extraction consists in a solvent free and automated procedure and the detection is highly sensitive and selective. Good linearity was obtained with correlation coefficients of regression (R 2)>0.99 for all the compounds. Satisfactory results of repeatability and intermediate precision were obtained for most of the analytes (RSD⩽20%). Recoveries from spiked wine ranged from 80.1% to 112.0%. Limits of quantification (LOQs) were considerably below the proposed maximum residue limits (MRLs) for these compounds in grapes and below the suggested limits for wine (MRLs/10), with the exception of captan. [Copyright &y& Elsevier]

A SPME-GC-MS/MS method for the determination of eight organophosphorus pesticides (azinphos-methyl, chlorpyriphos, chlorpyriphos-methyl, diazinon, fenitrothion, fenthion, malathion, and methidathion) in still and fortified wine was developed. The extraction procedure is simple, solvent free, and without any sample pretreatment. Limits of detection (LOD) and quantitation (LOQ) values in the range 0.1-14.3 µg/L and 0.2-43.3 µg/L, respectively, were obtained. The LOQ values are below the maximum residue levels (MRLs) established by European Regulation for grapes, with the exception of methidathion. Coefficients of correlation (R2) higher than 0.99 were obtained for the majority of the pesticides, in all different wines analyzed. [ABSTRACT FROM AUTHOR]

Seven pyrethroids (bifenthrin, fenpropathrin, λ-cyhalothrin, permethrin, α-cypermethrin, fenvalerate, and deltamethrin) were extracted from water using C18 solid-phase extraction disks, followed by gas chromatography with an electron capture detector (GC-ECD) analysis. The limits of detection in water samples ranged from 0.5 ng L-1 (fenpropathrin) to 110 ng L-1 (permethrin), applying the calibration graph. The effects of different numbers of (re)utilizations of the same disks (up to four times with several concentrations) on the recoveries of the pyrethroids were considered. The recoveries were all between 70 and 120% after four utilizations of the same disk. There was no difference between these recoveries at a confidence level of 95%. [ABSTRACT FROM AUTHOR]

• New extraction method of xenobiotics from human adipose tissue. • Good sensitivity was achieved by GC-MS and GC-FPD. • The LOD were between 4 to 9 ng/g for synthetic musks • The LOD were between 1 to 7 ng/g for organophosphorus pesticides • Galaxolide was found in all the analyzed human adipose tissue samples. Synthetic musks and organophosphorus pesticides represent a potential risk to the human health since exposure can lead to distinct types of carcinogenesis and endocrine disorders. These are lipophilic compounds as such, prone to deposit and persist in fat tissues, mainly in adipose tissue. Very few studies have reported on the occurrence and accumulation profile of these contaminants in human adipose tissue. Analytical methods for the detection and quantification of synthetic musks and organophosphorus pesticides in adipose tissue are lacking. In this study, the efficacy of different extraction with ultrasonic homogenizer and dispersive solid-phase extraction (d-SPE) clean-up methods were evaluated in human adipose tissue. The relative sample clean-up was assessed by measurement of total lipid content. The quantification of four synthetic musks and six organophosphorus pesticides were performed by gas chromatography (GC) mass spectrometry (MS) and flame photometric detection (FPD), respectively. The d-SPE clean-up with 50 mg PSA, 150 mg MgSO 4 , 100 mg C18EC and 50 mg Z-Sep provided the most effective clean-up, removing the greatest amount of interfering substances including lipids and simultaneously ensuring good chromatographic separation and recoveries. Method detection limits were between 4 to 9 ng/g for synthetic musk and 1 to 7 ng/g for organophosphorus pesticides in adipose tissue. The proposed method was applied to adipose tissue of obese patients and positive samples were confirmed with GC tandem mass spectrometry. Galaxolide was found in all the samples tested with concentrations ranging from 0.08 to 0.5 μg/g of adipose tissue. No other synthetic musk studied was detected. Organophosphorus pesticides were not found in the analysed samples. The developed analytical procedures were successful and can easily be applied to biomonitoring these compounds in human adipose tissue. [ABSTRACT FROM AUTHOR]