流动注射-导数火焰原子吸收光谱测定植物油中的镍、锰、铬和铅

提出了流动注射－导数火焰原子吸收光谱测定植物油中微量镍、锰、铬和铅的新方法，流动注射进样技术克服了常规火焰原子吸收法耗样量大和基体干扰严重的缺点，导数技术应用于火焰原子吸收可提高方法的灵敏度和信号的选择性，流动注射与导数技术相结合应用于火焰原子吸收成功地测定了常规火焰原子吸收法和流动注射－火焰原子吸收法难以测定的植物油中微量镍、锰、铬和铅。镍、锰、铬和铅的特征浓度（μg/mL)，分别为0.0054、0.0034、0.0067、0.025，相对标准偏差在0.3%-2.8%的范围内。     

天女木兰油的分析鉴定

本文采用色谱质谱法分析了天女木兰油的化学成份,共鉴定出二十个组份,并对所得结果进行了讨论。     

脂肪酸量子化学特性对食用油脂生物学效应的影响

对一些食用油脂中的主要脂肪酸组份的量子化学参数进行计算，并与饲喂大鼠的相应生物学效应进行相关分析的结果表明，在各项大鼠血脂生化指标中，只有血清总胆固醇（TC）和低密度脂蛋白-胆固醇含量与脂肪酸各项量子化学参数间存在显著性相关（P＜0．05），其中单不饱和脂肪酸（MUFA）的效果优于多不饱和脂肪酸（PUFA）。MUFA还可有效降低机体丙二醛含量，增强生物膜的流动性（P＜0．01）．不饱和脂肪酸分子中烯键碳原子上量子化学参数的急剧变化是油脂产生显著生物学效应的基本条件．     

Fermentation and costs of fuel ethanol from corn with quick-germ process

The Quick-Germ process developed at the University of Illinois at Urbana-Champaign is a way to obtain corn oil, but with lower capital costs than the traditional wet-milling process. Quick-Germ has the potential to increase the coproduct credits and profitability of the existing dry-grind fuel ethanol process, but the fermentability of the corn remaining after oil recovery has not been tested. Therefore, a series of pilot scale (50 L) fermentations was carefully controlled and monitored with unique methods for standard inoculation and automatic sampling. It was found that the concentration of suspended solids was significantly reduced in the Quick-Germ fermentations. When compared at the same concentration of fermentable sugars, the fermentation rate and yield were not statistically different from controls. When Quick-Germ was integrated into a state-of-the-art dry-grind fuel ethanol process, computer simulation and cost models indicated savings of approx $0.01/L of ethanol ($0.04/gal) with the Quick-Germ process. Additional savings associated with the lower suspended solids could not be quantified and were not included. However, the savings are sensitive to the price of corn oil. Mention of brand or firm name does not constitute an endorsement by the U.S. Department of Agriculture over others of a similar nature not mentioned.     

蓖麻油基AB交联聚合物的介电性质

在-180℃至140℃范围内,用几个频率测定了蓖麻油基AB交联聚合物的介电松弛谱。对这些聚合物的多重松弛和相行为的研究表明,试样中的两组份在介电松弛谱上显现出相容的或近似互容的特征。试样中的次级松弛归因于聚氨酯组份中链段的局部运动。提出了一个描述界面极化的方法,计算了界面极化松弛活化能,它们同试样中组份间的相容性,界面相互作用大小以及分子链的柔曲性有关。     

Classification of edible and lampante virgin olive oil based on synchronous fluorescence and total luminescence spectroscopy

Total luminescence and synchronous fluorescence spectroscopies were tested as regards their ability to differentiate edible from lampante virgin olive oils. Total luminescence spectra were recorded by measuring the emission spectra in the range 350-720 nm at excitation wavelengths from 320 to 535 nm. The synchronous fluorescence spectra of 41 edible and 32 lampante virgin olive oils were acquired by synchronous scanning the excitation and emission monochromator maintained at an offset value of 80 nm. Classification of virgin olive oils based on their synchronous fluorescence spectra was performed by hierarchical cluster analysis and principal component analysis using the spectral range of 429-545 nm. Principal component analysis provided better discrimination between the two classes, without any classification error, while hierarchical cluster analysis allowed 97.3% correct classification. These results indicate the capability of fluorescence techniques to differentiate virgin olive oils according to their quality.     

Quantitative determination of toxic mono- and non-ortho polychlorinated biphenyls in cod liver oil after selective liquid chromatographic separation

Summary By application of chromatographic column filled with Supelclean ENVI-Carb/Celite and elution with three solvents of different polarity three PCB fractions were obtained. Fraction A contained poly-ortho PCBs, Fraction B mono-ortho PCBs, and Fraction C non-ortho PCBs. The Supelclean ENVI-Carb/Celite column was used in combination with a sample preparation procedure for pre-cleaning of acid-stable chlorinated hydrocarbons such as DDT and its metabolites, HCH isomers, and regulation-relevant PCB congeners. The method was optimized using standard solutions of 55 PCB congeners, 8 chlorinated pesticides and contaminated cod liver oil samples. The influence of traces of remaining matrix on the elution profile of the organochlorine compounds on Supelclean ENVI-Carb/Celite was observed. Quantitation was carried out by GC-ECD with fused silica capillary columns of different polarity.     

Fabrication of honeycomb-patterned cellulose films

This paper reports for the first time on the fabrication of honeycomb-patterned cellulose films by casting water in oil emulsion of cellulose acetate onto a glass substrate and subsequent deacetylation treatment. The honeycomb pore size could be controlled from 1 to 100 microm under a saturated water vapor condition. Both cellulose and cellulose acetate films with honeycomb-pattern are expected to be a two-dimensional model of plant cell walls as well as of micro-wells for single cell cultivation. Surface topographic image of a honeycomb-patterned cellulose film (scalebar: 50 microm).     

毛细管气相色谱法同时测定白酒中的甲醇和杂醇油

采用PEG20000石英毛细管柱直接进样、氢火焰离子化检测器检测,建立了毛细管气相色谱同时测定白酒中的甲醇和杂醇油的分析方法。甲醇和杂醇油的检出限均为2.0×10-4g/(100mL),回收率分别为96.4%~99.1%、91.2%~98.3%,相对标准偏差不大于4.3%。该方法适用于白酒中甲醇和杂醇油的同时分析测定。     

原子吸收法测定蔬菜罐头中铜含量的测量不确定度评定

对GB／T 5009．13－1996《食品中铜的测定方法》中火争原子吸收法测定蔬菜罐头中铜含量的测量不确定度进行评定，根据JJF1059－1999《测量不确定度评定与表示》技术规范的要求，分析了该测量过程的测量不确定度来源，建立了数学模型，并利用标准样品对测量不确定度的各个分量进行计算，计算得该测定水平下铜含量测定结果的扩展不确定度为0．2mg/kg.