排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
Shaoxia Wang Riitta Mahlberg Juha Nikkola Juha Mannila Saila Jämsä Anne‐Christine Ritschkoff Jouko Peltonen 《Surface and interface analysis : SIA》2012,44(5):539-547
Two hybrid coatings synthesized by using alkoxysilanes as precursors in a sol–gel process, differing from each other in terms of the organic components in alkoxysilanes, have been developed to improve the water repellent properties of base paper. The sol–gel‐coated base paper samples were characterized by scanning electron microscopy, atomic force microscopy, confocal laser scanning microscopy, X‐ray photoelectron spectroscopy, time‐of‐flight secondary ion mass spectrometry, and contact angle measurements. The sol–gel coatings were found to clearly change the surface properties of base paper. Thin coating layers were formed on base paper surfaces. The topographical data indicated the formation of discontinuous thin films; the time‐of‐flight secondary ion mass spectrometry analyses confirmed that the coatings were covering the fibres but only partially covered the fibre–fibre intersections. Water and the subsequent heat treatment used as a reference treatment reduced the surface roughness and porosity and slightly changed the surface chemistry of the base paper. The wettability and absorptivity of base paper was clearly reduced by the applied coatings. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
2.
Harri Härmä Anne-Maria Pelkkikangas Tero Soukka Petri Huhtinen Saila Huopalahti Timo Lövgren 《Analytica chimica acta》2003,482(2):157-164
The present study describes the development of a quantitative miniaturized single microparticle immunoassay. The main objective of the study was to evaluate the performance of a miniature heterogeneous immunoassay on a single microparticle in respect to assay kinetics, volume, and sensitivity, binding capacity of microparticles and sensitivity using europium(III) nanoparticle labels. The performance of the single microparticle assay of prostate-specific antigen (PSA) was investigated using different-sized microparticles (60-920 μm in diameter) and microtiter well as a solid-phase. Equilibration time of the assay was shown to be dependent in a linear manner on surface-to-volume ratio, i.e. larger surface-to-volume translated to a faster reaction. However, no correlation between PSA binding capacity and equilibration time was observed in these kinetic studies. Only moderate improvement in assay kinetics was found when PSA binding capacity was increased on a microparticle. Using europium(III) nanoparticle labels, 107 nm in diameter, coated with streptavidin a detection sensitivity of 30 ng l−1 (0.1 amol) was achieved in 1 μl total assay volume per microparticle. This was 50-fold higher compared to the same assay performed with intrinsically fluorescent europium(III) labels. 相似文献
3.
Summary Deoxynivalenol (DON) is one of the trichothecene mycotoxins produced byFusarium molds in grains. Polar cosolvents in supercritical carbon dioxide (SC-CO2) are needed to extract and isolate the polar DON moiety. This unfortunately results in the extraction of many interfering
compounds from the grains into the extracts obtained by supercritical fluid extraction (SFE). Analysis of DON by high performance
liquid chromatography (HPLC) using ultraviolet detection (UV) does not provide a specific detection method, although specific
detection of DON can be enhanced by using purification steps after SFE. Alternatively, combining SFE with an immunoaffinity
method can improve detection specificity and sample cleanup. In this study, SFE was employed to determine DON in grains and
cereal products. The effectiveness of the SFE method was compared with two different solvent extraction methods. The extracted
DON was quantitatively determined by HPLC-UV using external standardization or competitive enzymelinked immunosorbent assay
(ELISA). In some cases, extracts were purified prior to quantitative analysis of the DON by using solvent partitioning, and/or
solid phase extraction, or immunoaffinity columns. Therefore, this paper describes the analysis of DON in cereals using different
extraction, cleanup and analysis methods.
Names are necessary to report factually on available data: however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by USDA implies no approval of the products to the exclusion of others that may also
be suitable. 相似文献
4.
1