催化裂化汽油光化学氧化脱硫

以水为萃取剂、空气中的O2为氧化剂、500W高压汞灯为紫外光光源,研究了催化裂化(FCC)汽油光化学氧化反应的机理和氧化产物,考察了反应条件对FCC汽油脱硫率的影响。实验结果表明,FCC汽油中的极性含硫化合物首先部分溶于水相中,然后在水相中被氧化。在空气通入量为150mL/min、水与FCC汽油的体积比为1.0的条件下,反应5h后FCC汽油脱硫率达40.6%,加入0.45g4A分子筛作为O2的吸附剂后FCC汽油脱硫率提高到70.2%。FCC汽油的光化学氧化反应为一级动力学反应,加入4A分子筛时的反应速率常数为0.217 4h-1,半衰期为3.18h。FCC汽油光化学氧化反应的主要产物为亚砜和砜,并进一步生成CO2、草酸、SO24-等。     

Histamine determination in tears as an index of safety in use of cosmetic products

To assess ocular irritancy caused by chemical and cosmetic products a reliable method based on evaluation of histamine (Hm) in tears is presented. Hm is measured at picomole levels by HPLC and fluorimetric detection after fluorescamine-HM derivatization. In order to avoid any uncontrolled irritation and stimulation of the conjunctiva during sample collection, a procedure of conjunctiva lavage was developed. A balanced salt solution (50 μl) containing a known amount of Hm-fluorophore as reference standard is instilled in the conjunctiva fornix. After a few seconds 20 μl of tear fluid is collected: 10 μl are immediately analysed and 10 μl after derivatization reaction. In this way it is possible to evaluate tear dilution and to assess Hm content in less than 10 minutes.
In a group of 20 normal subjects Hm has been determined in comparison with that of two volunteers after topical application of 50 μ of 0.2% and 0.4% sodium lauryl sulphate solution. A contact of 30 seconds of the cosmetic ingredient caused an immediate dose-dependent Hm release through a direct cytotoxic damage of cell membranes due to the surfactant action.
Évaluation de l'irritation occulaire due aux cosmétiques par la détermination de l'histamine lacrimale     

Validation of a Gas Chromatography-Mass Spectrometry Method for the Measurement of the Redox State Metabolic Ratios Lactate/Pyruvate and β-Hydroxybutyrate/Acetoacetate in Biological Samples

The metabolic ratios lactate/pyruvate and β-hydroxybutyrate/acetoacetate are considered valuable tools to evaluate the in vivo redox cellular state by estimating the free NAD+/NADH in cytoplasm and mitochondria, respectively. The aim of the current study was to validate a gas-chromatography mass spectrometry method for simultaneous determination of the four metabolites in plasma and liver tissue. The procedure included an o-phenylenediamine microwave-assisted derivatization, followed by liquid-liquid extraction with ethyl acetate and silylation with bis(trimethylsilyl)trifluoroacetamide:trimethylchlorosilane 99:1. The calibration curves presented acceptable linearity, with a limit of quantification of 0.001 mM for pyruvate, β-hydroxybutyrate and acetoacetate and of 0.01 mM for lactate. The intra-day and inter-day accuracy and precision were within the European Medicines Agency’s Guideline specifications. No significant differences were observed in the slope coefficient of three-point standard metabolite-spiked curves in plasma or liver and water, and acceptable recoveries were obtained in the metabolite-spiked samples. Applicability of the method was tested in precision-cut liver rat slices and also in HepG2 cells incubated under different experimental conditions challenging the redox state. In conclusion, the validated method presented good sensitivity, specificity and reproducibility in the quantification of lactate/pyruvate and β-hydroxybutyrate/acetate metabolites and may be useful in the evaluation of in vivo redox states.     

新型光化学反应器及二氧化碳光解反应研究

研究设计了可产生波长小于200 nm真空紫外光的光化学反应器,首次利用该波段的光在该反应器中进行了CO2光解反应的研究。用氮气为发光介质对其进行光强标定,实验表明主要产生120、149、174 nm波长的光(N原子谱线);实验条件下CO2光解后生成产物CO,结果表明光源电流一定时产生CO的量与光源工作气体的压力有关,在CO2和N2反应物系中,光源内发光介质N2的压力在2 500 Pa左右时CO的产率最大,而在该反应物系中加入甲烷后,CO的产率明显增大。     

Female sex pheromone components ofHeliothis peltigera (Lepidoptera: Noctuidae)

Ten compounds were found in the sex pheromone glands ofHeliothis peltigera (Schiff) and identified as tetradecenal, (Z)-9-tetradecenal, (Z)-9-tetradecenol, (Z)-9-tetradecenyl acetate, hexadecanal, (Z)-7-hiexadecenal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-11-hexadecenol, and (Z)-11-hexadecenyl acetate. Behavioral tests in a wind tunnel and subsequent trapping studies conducted in the field indicated that (Z)-11-hexadecenal and (Z)-9-tetradecenal are the main pheromone components ofH. peltigera. Addition of (Z)-11-hexadecenol to the binary blend did not enhance the capture of males ofH. peltigera, but it decreased the number of males of the sympatricH. armigera. Rubber septa impregnated with a mixture of 2 mg (Z)-11-hexadecenal + 1 mg (Z)-9-tetradecenal + 0.6 mg (Z)-11-hexadecenol are recommended for monitoringH. peltigera. Contribution from the Agricultural Research Organization (ARO), No. 2454-E, 1988 series.     

二硝基芘异构体在模拟大气条件下的光化学反应

本文研究了二硝基芘异构体在模拟大气条件下的光化学反应，结果表明反应速率呈二级动力学关系，除光源变化的影响外，二硝基芘异构体在不同气氛中，反应速率不同，存在着氧的猝灭和氧化作用，而不同的异构体之间，相应的反应速度也不同。光解产物中存在硝基羟基类化合物、醌类和二聚体。毒理实验表明，光解产物致突变性下降。     

Analysis of epoxidized soybean oil by gas chromatography

A fast and cost-effective procedure to quantitate epoxidized soybean oil by means of an external standard method is reported. This procedure is applicable to commercial epoxidized oils, polymer additive packages and polymers—polyvinyl chloride (PVC)—containing epoxidized oils. The epoxidized soybean oil is converted into fatty acid methyl esters with tetramethylammonium hydroxide, and analyzed by capillary gas chromatography with flame-ionization detection. In PVC samples, the epoxidized soybean oil was extracted with toluene and followed by derivatization prior to analysis. The methyl esters of monoepoxyoctadecanoic, diepoxyoctadecanoic and triepoxyoctadecanoic acid were separated with a short capillary column.     

在可溶性聚合物体系中光化学法制备Pd纳米粒子的研究

研究了在可溶性聚合物体系中Pd纳米粒子的光化学合成.Pd(Ⅱ)-PEG-丙酮溶液以紫外波长300nm光辐照,获得了胶体Pd纳米粒子并对其进行TEM表征.结果表明,Pd粒子的平均粒径为1.8～5.7nm,具有好的分散性.研究了各种组分的影响,探讨了体系中Pd(Ⅱ)的快速光化学还原和纳米Pd粒子的稳定性机理.     

Photochemical synthesis of bimetallic Au-Ag nanoparticles with "core-shell" type structure by seed mediated catalytic growth

The colloidal Au core/Ag shell structure composite nanoparticles were synthesized in PEG-acetone solution by photochemical route. The monodispersed Au nanoparticles with average diameter of 3.9 nm were used as growth seeds. The optical property of colloids and the sizes of composite nanoparticles were characterized when the molar ratio of Au to Ag ranges from 4 : 1 to 1 : 4. The results show that a composite nanoparticle structure similar to strawberry shape is formed at the molar ratio of Au to Ag from 4 : 1 to 1 : 1; the composite nanoparticles consisting of a core of Au and shell of Ag were generated at the 1: 4 molar ratio, having a striking feature of forming interconnected network structure.     

Magnetic field-assisted photochemical machining (MFAPCM) of SS316L

In this paper, a new technique of photochemical machining (PCM) process has been described. The objective of this study is to investigate the effect of applying a magnetic field on the PCM of AISI 316?L stainless steel. The experiments were planned and conducted using a Full Factorial Design (FFD) approach. The control parameters selected were magnetic field, temperature, concentration and time. The analysis of the results shows significant improvement in the etch rate due to the application of a magnetic field. The highest etch rate was achieved at a concentration of 700?g/l, at the temperature of 60°C in a static magnetic field. The improvement of the etch rate is 2.5 times with the application of magnetic field as compared to the conventional PCM process.