1,721,024 research outputs found
Development and validation of a solid-phase extraction method coupled to high-performance liquid chromatography with ultraviolet-diode array detection for the determination of sulfonylurea herbicide residues in bovine milk samples
No full textThis study proposes a fast, simple and sensitive liquid chromatography diode array detector (LC/UV-DAD)-based method for the simultaneous determination of eight sulfonylurea herbicides (bensulfuron methyl, chlorsulfuron, metsulfuron methyl, primisulfuron methyl, rimsulfuron, thifensulfuron methyl, triasulfuron and tribenuron methyl) in bovine whole milk at concentrations lower than the default limit of 0.01mgkg-1 allowed by current legislation (Regulation EC/396/2005 and following Annexes). An effective one-step solid phase extraction (SPE) and clean up procedure was defined with use of Chem Elut cartridges, providing good recoveries for all the analytes tested and with no matrix effects affecting method accuracy. Separation of herbicides was obtained on a C18 column by acetonitrile- water gradient elution. Method validation has been performed according to European Commission Decision 2002/657/EC criteria, in terms of linearity, recovery, precision, specificity, decision limit (CC??) and detection capability (CC??). Typical recoveries ranged between 78.4% and 99.7%, at the maximum residue limits (MRLs) levels established by Regulation EC/396/2005, with relative standard deviations (RSD) no larger than 10%
Monitoring of bisphenols in canned tuna from Italian markets
No full textMonitoring of food contamination from bisphenols is a necessary process for the consumers' risk assessment. A method for the quali-quantitative analysis of Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol A Diglycidyl Ether (BADGE), and Bisphenol F Diglycidyl Ether (BFDGE), by liquid chromatography with fluorescence detection (LC-FD), was performed and validated for their determination in 33 samples of tuna fish, canned in either oil or aqueous medium. Samples were collected in Italian markets. Tuna and the correspondent preservation medium were analyzed separately. Detected levels of bisphenols ranged from 19.1 to 187.0 ng/g in tuna matrix and from 6.3 to 66.9 ng/mL in oil medium. No bisphenols were found in aqueous medium. At least one of the analytes was found in 83% of the tuna samples in oil medium, whereas tuna samples in aqueous medium showed BPA alone in 67% of samples. 21% of the oil medium samples resulted positive for at least one bisphenol. On the basis of measured concentrations and general daily ingestion rate of canned tuna fish, the probable daily intake of BPA for Italian population was calculated
Determination of bisphenol A and bisphenol B residues in canned peeled tomatoes by reversed-phase liquid chromatography
No full textBisphenol A (BPA) and bisphenol B (BPB) concentrations were determined in peeled canned tomatoes of different brands bought in Italian supermarkets. Tomato samples analyzed were packaged in cans coated with either epoxyphenolic lacquer or low BADGE enamel. A solid phase extraction (SPE) was performed on C-18 Strata E cartridge followed by a step on Florisil cartridge. Detection and quantitation were performed by a reversed phase high-performance liquid chromatography (RP-HPLC) method with both UV and fluorescence detection (FD). On the total of 42 tested tomato samples, BPA was detected in 22 samples (52.4%), while BPB was detected in 9 samples (21.4%). BPA and BPB were simultaneously present in 8 of the analyzed samples. The levels of BPA found in this study are much lower than the European Union migration limits of 3 mg/kg food and reasonably unable to produce a daily intake exceeding the limit of 0.05 mg/kg body weight, established by European Food Safety Authority
Development and validation of a solid-phase extraction method coupled to high-performance liquid chromatography with ultraviolet-diode array detection for the determination of sulfonylurea herbicide residues in bovine milk samples
No full textThis study proposes a fast, simple and sensitive liquid chromatography diode array detector (LC/UV-DAD)-based method for the simultaneous determination of eight sulfonylurea herbicides (bensulfuron methyl, chlorsulfuron, metsulfuron methyl, primisulfuron methyl, rimsulfuron, thifensulfuron methyl, triasulfuron and tribenuron methyl) in bovine whole milk at concentrations lower than the default limit of 0.01 mg kg(-1) allowed by current legislation (Regulation EC/396/2005 and following Annexes). An effective one-step solid phase extraction (SPE) and clean up procedure was defined with use of Chem Elut cartridges, providing good recoveries for all the analytes tested and with no matrix effects affecting method accuracy. Separation of herbicides was obtained on a C(18) column by acetonitrile- water gradient elution. Method validation has been performed according to European Commission Decision 2002/657/EC criteria, in terms of linearity, recovery, precision, specificity, decision limit (CC(α)) and detection capability (CC(β)). Typical recoveries ranged between 78.4% and 99.7%, at the maximum residue limits (MRLs) levels established by Regulation EC/396/2005, with relative standard deviations (RSD) no larger than 10%
A Simple and Selective Analytical Procedure for the Extraction and Quantification of Lutein from Tomato By-Products by HPLC-DAD
No full textLutein, a yellow dihydroxylated carotenoid, is
present in many dietary supplements due to its biological
properties. Currently, lutein is extracted from marigold
flowers by expensive and time-consuming processes. Since
tomatoes contain significant levels of lutein, in this study we
have examined the feasibility of using tomato by-products as
an alternative, low-cost source of this carotenoid. The
determination of this carotenoid was performed by highperformance
liquid chromatography???diode array detection,
after selective extraction from tomato waste product
samples. Lutein levels ranged from 9.9 to 10.5 ??g/g dry
weight. Tomato waste products may be indicated as an
alternative commercial source of lutein for food fortification
and/or dietary supplements
Chemistry of Verongida Sponges- I. Constituents of the Caribbean Sponge Pseudoceratina crassa
No full text
A GC-FID Method to Determine Styrene in Polystyrene Glasses
Full text linkThe styrene levels of polystyrene (PS) glasses from the most consumed brands of disposable glasses intended for water and coffee in Brazil were determined. A GC-FID method was developed and validated, showing good precision and accuracy. The method was successfully used to determine styrene in 11 PS glass brands. The styrene levels ranged from 1.68 to 43.69 mg/100 g glass, depending on the kind of polymer, thickness, and glass brand. It could be used to control the content of styrene in the polymer. The migration of styrene from the glasses into water and 20 % ethanol was not detected.São Paulo State Univ, Sch Pharmaceut Sci, Dept Food & Nutr, BR-14801902 Araraquara, SP, BrazilUniv Naples Federico II, Dipartimento Chim Farmaceut & Tossicol, I-80131 Naples, ItalySão Paulo State Univ, Sch Pharmaceut Sci, Dept Food & Nutr, BR-14801902 Araraquara, SP, Brazi
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