共查询到17条相似文献,搜索用时 78 毫秒
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硫胺经紫外光照射后的低温磷光分析法 总被引:3,自引:8,他引:3
硫胺在酸,水,碱中经紫外光照射后产生强的磷光,以酸中照射的磷光最强。观察了最佳光化学反应条件,建立硫胺经光化学反应后的磷光分析方法,适用于制剂分析 相似文献
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紫外光催化氧化在环境水质分析中的应用 总被引:3,自引:0,他引:3
紫外光催化氧化是近年来环境水质分析中采用的一种样品预处理新技术,目前在国内环境监测领域还应用得不多。本文结合笔者近期的工作,介绍了紫外光催化氧化的原理、特点、设备及其在环境水质分析中的应用,并简介了微波辅助紫外光催化氧化和超声波-紫外光氧化两种最新技术。 相似文献
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María T. Rodriguez-Estrada Maria F. Caboni Arianna Costa Giovanni Lercker 《Journal of separation science》1998,21(9):509-512
The performance of a fused silica column coated with 50% phenyl-/50% dimethyl-polysiloxane, characterized by a high thermal stability, was evaluated for the gas chromatographic determination of cholesterol oxidation products. A silylated mixture of eighteen oxysterol standards (0.1 mg/ml of each compound) was injected into the gas chromatographic system. The temperature was programmed from 230 to 260°C at 2.5°/min and then to 290°C at 1°/min; the injector and detector temperatures were set at 325°C, and the gas linear velocity was 22.8 cm/s. The column gave a fast (15 min) and satisfactory resolution of the main cholesterol oxides. Good separation of the hydroxy from the epoxy derivatives was achieved.The suitability of the method for the determination of oxysterols in food matrices was successfully tested on a saponified lipid extract from egg yolk powder, previously enriched and purified by NH2 solid phase extraction. 相似文献
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本文采用光离子化和热导池两个检测器串联,以5A钙型分子筛填充柱与Chromesorb 104+2%KOH填充柱并联方式,成功地定量分离分析了N2,O2,NO或NO_2,N_2O和NH_3的混合气体。 相似文献
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Birgit Rossmann Karin Thurner Wolfgang Luf 《Monatshefte für Chemie / Chemical Monthly》2007,138(5):437-444
Summary. This study was aimed at analyzing the daughter ion spectra of 7 toxicologically relevant cholesterol oxidation products (COPs) i.e. cholestanetriol (cholestane-3β,5α,6β-triol), 7-ketocholesterol (cholest-5-en-3β-ol-7-one), 7α-hydroxycholesterol (cholest-5-en-3β,7α-diol),
7β-hydroxycholesterol (cholest-5-en-3β,7β-diol), 25-hydroxycholesterol (cholest-5-en-3β,25-diol), α-epoxycholesterol (cholestane-5α,6α-epoxy-3β-ol)
and β-epoxycholesterol (cholestane-5β,6β-epoxy-3β-ol). In addition, 19-hydroxycholesterol (cholest-5-en-3β,19-diol) was analyzed
as this serves as internal standard in COPs determination by HPLC-MS.
Mass spectrometry was performed using a triple quadrupol mass spectrometer that was equipped with an APCI ion source.
Our results indicate a common fragmentation pattern for COPs. The main breaking sites identified were in the sterol ring system between the carbon atoms with the position numbers 11–12,
12–13, and 8–14. Typical daughter ions of m/z = 81, 95, and 195 were used for multiple reaction monitoring analysis. 相似文献
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- hydroxybenzaldehyde,vanillin and syringaldehyde etc. were separated on a Novapak C18 column (5μ 3. 9mm i. d.× 150mm) and eluted with MeOH-H2O (25:75, V/V) at a flow rate of 0. 6mL/min and detected at 254nm. Quantitative analysis was performed with piperonal instead of synthetic product . m-meconin,as the internal standard. Recoveries are 95%-98% and CV≤1%. The method is simple,rapid and reliable. 相似文献
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The oxidation of hydrobenzoins to the corresponding benzils was carried out in excellent yield by ammonium chlorochromate (ACC) supported on montmorillonite K10 in CH2Cl2 at room temperature under ultrasound irradiation. 相似文献