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排序方式: 共有93条查询结果,搜索用时 46 毫秒
1.
Cavaliere C Foglia P Pastorini E Samperi R Laganà A 《Rapid communications in mass spectrometry : RCM》2005,19(21):3143-3158
A mass spectrometric method for extensive detection and semi-quantitative determination of flavonoid glycosides in stem and leaves of young Triticum durum plants is presented. About 100 g of sample were lyophilized and ground, and the compounds of interest were then extracted, cleaned-up, and fractionated using high-performance liquid chromatography (HPLC). Tandem mass spectrometry analyses were performed using a quadrupole-linear ion trap instrument with an information-dependent data acquisition (IDA) protocol that looped two experiments, enhanced MS scan and enhanced product ion scan. Various glycoconjugates, which are all derivatives of only four flavones, apigenin, luteolin, chrysoeriol and tricin, were identified and belong to the following categories: 7 monoglycosides, 31 diglycosides, 15 triglycosides and 1 tetraglycoside. Among these some acylated glycosides were found. Tricin derivatives are present exclusively as O-glycosides, while apigenin and luteolin are present always as C-glycosides. Semi-quantitative estimation was performed by using the monoglycoside and diglycoside of quercetin as internal standards. 相似文献
2.
Multiresidue determination of UV filters in water samples by solid‐phase extraction and liquid chromatography with tandem mass spectrometry analysis
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Anna Laura Capriotti Chiara Cavaliere Susy Piovesana Roberto Samperi Serena Stampachiacchiere Salvatore Ventura Aldo Laganà 《Journal of separation science》2014,37(20):2882-2891
UV filters, contained in sunscreens and other cosmetic products, as well as in some plastics and industrial products, are nowadays considered contaminants of emerging concern because their widespread and increasing use has lead to their presence in the environment. Furthermore, some UV filters are suspected to have endocrine disruption activity. In the present work, we developed an analytical method based on liquid chromatography with tandem mass spectrometry for the determination of UV filters in tap and lake waters. Sixteen UV filters were extracted from water samples by solid‐phase extraction employing graphitized carbon black as adsorbent material. Handling 200 mL of water sample, satisfactory recoveries were obtained for almost all the analytes. The limits of detection and quantification of the method were comparable to those reported in other works, and ranged between 0.7–3.5 and 1.9–11.8 ng/L, respectively; however in our case the number of investigated compounds was larger. The major encountered problem in method development was to identify the background contamination sources and reduce their contribution. UV filters were not detected in tap water samples, whereas the analyses conducted on samples collected from three different lakes showed that the swimming areas are most subject to UV filter contamination. 相似文献
3.
Cold spray is an innovative coating technology. Very fine particles are accelerated, then sprayed on a substrate in condition very far from material melting. The unique mechanical properties experienced by the sprayed material are due to the severe plastic deformation acting during particle impact. In the present paper, the microstructural and mechanical behavior of Ti- and Ni-based nanocomposites coatings produced via cold spray are presented. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
4.
Chiara Cavaliere Anna Laura Capriotti Andrea Cerrato Laura Lorini Carmela Maria Montone Francesco Valentino Aldo Lagan Mauro Majone 《Molecules (Basel, Switzerland)》2021,26(3)
Polyhydroxyalkanoates (PHAs) are well-known biodegradable plastics produced by various bacterial strains, whose major drawback is constituted by the high cost of their synthesis. Producing PHAs from mixed microbial cultures and employing organic wastes as a carbon source allows us to both reduce cost and valorize available renewable resources, such as food waste and sewage sludge. However, different types of pollutants, originally contained in organic matrices, could persist into the final product, thus compromising their safety. In this work, the exploitation of municipal wastes for PHA production is evaluated from the environmental and health safety aspect by determining the presence of polycyclic aromatic hydrocarbons (PAHs) in both commercial and waste-based PHA samples. Quantification of PAHs by gas chromatography-mass spectrometry on 24 PHA samples obtained in different conditions showed very low contamination levels, in the range of ppb to a few ppm. Moreover, the contaminant content seems to be dependent on the type of PHA stabilization and extraction, but independent from the type of feedstock. Commercial PHA derived from crops, selected for comparison, showed PAH content comparable to that detected in PHAs derived from organic fraction of municipal solid waste. Although there is no specific regulation on PAH maximum levels in PHAs, detected concentrations were consistently lower than threshold limit values set by regulation and guidelines for similar materials and/or applications. This suggests that the use of organic waste as substrate for PHA production is safe for both the human health and the environment. 相似文献
5.
何会海 C.Bacci 包克智 F.Barone B.Bartoli P.Bernardini S.Bussino E. Calloni R. Cardarelli S.Catalanotti S.Cavaliere F.Cesaroni 查敏 P.Creti 单增罗布 B.D''''Ettorre Piazzoli M.DeVincenzi T.DiGirolamo G.DiSciascio 冯振勇 傅宇 高晓宇 庚庆喜 郭宏伟 何瑁 黄庆 M.I 《中国物理 C》2001,(1)
利用羊八井50m2RPC地毯(YBJ-ARGO实验原型)的测试数据对其性能进行了分析研究,包括原初粒子方位角分布、天顶角分布、地毯的角分辨、探测时间系统误差对方位角分布的正弦调制、探测时间系统误差的离线修正、几何不对称的小型地毯探测器上原初粒子到达方向重建误差造成的方位角分布的不均匀性等. 相似文献
6.
Natural estrogens in dairy products: Determination of free and conjugated forms by ultra high performance liquid chromatography with tandem mass spectrometry
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Chiara Cavaliere Anna Laura Capriotti Patrizia Foglia Susy Piovesana Roberto Samperi Salvatore Ventura Aldo Lagan 《Journal of separation science》2015,38(20):3599-3606
Natural estrogens are synthesized by mammals in different amounts depending on the developmental stage and pregnancy/lactation period, and they may pass into milk, where they are mostly present as glucuronated and sulfated forms. In modern dairy practices, about 75% of milk is produced from pregnant cows; therefore, the amount of hormones that may pass into milk could be of concern. While estrogen determination in milk has been investigated in depth, the individual determination of estrogens and their conjugated forms in dairy products has not been fully addressed. The aim of this work was to develop and assess a sensitive method, using the peculiar retention properties of graphitized carbon black, to extract natural free estrogens and their major conjugated metabolites, without any enzymatic cleavage, from yogurt, cheese, and butter. The free and conjugated estrogens were eluted in two distinct fractions from the solid‐phase extraction cartridge and analyzed separately by ultra high performance liquid chromatography coupled to tandem mass spectrometry. Recoveries were higher than 80% for all the three sample typologies. The highest matrix effects were observed for butter, which was richest in lipid content, but was below 30%. A survey on some commercial dairy products suggests that production processes decreased estrogen content. 相似文献
7.
Euterpio MA Cavaliere C Capriotti AL Crescenzi C 《Analytical and bioanalytical chemistry》2011,401(9):2977-2985
Pressurized hot water extraction (PHWE, also known as subcritical water extraction) is commonly considered to be an environmentally
friendly extraction technique that could potentially replace traditional methods that use organic solvents. Unfortunately,
the applicability of this technique is often limited by the very low water solubility of the target compounds, even at high
temperatures. In this paper, the scope for broadening the applicability of PHWE by adjusting the pH of the water used in the
extraction is demonstrated in the extraction of curcumin (which exhibits very limited water solubility) from untreated turmeric
(Curcuma longa L.) rhizomes. Although poor extraction yields were obtained, even at high temperatures when using degassed water or neutral
phosphate buffer as the extraction medium, yields exceeding those obtained by Soxhlet extraction were achieved using highly
acidic pH buffers due to curcumin protonation. The influence of the temperature, pH, and buffer concentration on the extraction
yield were investigated in detail by means of a series of designed experiments. Optimized conditions for the extraction of
curcumin from turmeric by PHWE were estimated at 197 °C using 62 g/L buffer concentration at pH 1.6. The relationships between
these variables were subjected to statistical analysis using response surface methodology. 相似文献
8.
Capriotti AL Caracciolo G Cavaliere C Crescenzi C Pozzi D Laganà A 《Analytical and bioanalytical chemistry》2011,401(4):1195-1202
The knowledge about the interaction between plasma proteins and nanocarriers employed for in vivo delivery is fundamental
to understand their biodistribution. Protein adsorption onto nanoparticle surface (protein corona) is strongly affected by
vector surface characteristics. In general, the primary interaction is thought to be electrostatic, thus surface charge of
carrier is supposed to play a central role in protein adsorption. Because protein corona composition can be critical in modifying
the interactive surface that is recognized by cells, characterizing its formation onto lipid particles may serve as a fundamental
predictive model for the in vivo efficiency of a lipidic vector. In the present work, protein coronas adsorbed onto three
differently charged cationic liposome formulations were compared by a shotgun proteomic approach based on nano-liquid chromatography–high-resolution
mass spectrometry. About 130 proteins were identified in each corona, with only small differences between the different cationic
liposome formulations. However, this study could be useful for the future controlled design of colloidal drug carriers and
possibly in the controlled creation of biocompatible surfaces of other devices that come into contact with proteins into body
fluids. 相似文献
9.
10.
Summary Based on a theoretical model worked out previously, an analysis is reported of triplet and double differential cross-section
of hydrogen atom ionization by electron impact in the presence of a single-mode, homogeneous, linearly polarized, off-resonance
laser field. In particular, calculations are carried out to investigatea) the dependence of the cross-sections on the field strength,b) the average number of exchanged photons,c) the limits of validity of a known sum rule. The reported results improve considerably the present knowledge of this kind
of elementary stimulated atomic process.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献