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毛细管电泳法分离测定芦丁、槲皮素和连翘苷 总被引:6,自引:1,他引:6
用毛细管电泳紫外检测法同时测定了芦丁、槲皮素和连翘苷,研究了各种条件的影响,得到了优化的实验条件,在20mmol/L的Na2B4O7(H3B03调节至pH8.40)-30mmol/L十二烷基硫酸钠-10%乙腈(1 9)的缓冲溶液中,分离电压为12kV时,芦丁、槲皮素和连翘苷在10min内得到了良好的分离,检测波长为254nm,芦丁、槲皮素和连翘苷分别在0.01-1.0mg/mL,0.01-1.0mg/mL和0.05-1.0mg/mL质量浓度范围内与电泳峰高呈现良好线性关系,检测下限分别为0.005mg/mL,0.005mg/mL和0.01mg/mL,应用于实际样品的测定。 相似文献
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《分析试验室》2015,(11)
建立了高效液相色谱同时检测枸杞中槲皮素、山柰酚和异鼠李素的分析方法。样品经过甲醇超声提取后,用甲醇-25%HCl水解1 h,采用Inertsustain C18色谱柱进行分离,以甲醇-0.4%H3PO4溶液(48∶52,V/V)为流动相,进行等度洗脱,流速为1.0 m L/min,二极管阵列检测器检测,检测波长为360 nm,柱温为40℃。槲皮素,山柰酚,异鼠李素在40 min内实现分离,并分别在0.053~21.2μg/m L,0.053~4.24μg/m L和0.046~3.72μg/m L范围内具有良好的线性关系,相关系数为0.9972~0.9992,测得槲皮素、山柰酚、异鼠李素的加标回收率为99.2%~103.1%,95.6%~101.8%,93.2%~109.1%;相对标准偏差分别为0.95%~2.8%,0.55%~2.3%,0.81%~2.4%。对槲皮素、山柰酚和异鼠李素的检出限分别为0.04,0.05,0.03 mg/kg。方法可用来测定枸杞中3种黄酮苷元的含量。 相似文献
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《理化检验(化学分册)》2010,(9)
提出了反相高效液相色谱法同时测定布渣叶的3种水解黄酮苷元槲皮素、山奈酚和异鼠李素的含量。采用Kromasil C18色谱柱(250 mm×4.6 mm,5μm),以甲醇-0.4%(体积分数)磷酸溶液为流动相梯度洗脱,在368 nm波长处,对布渣叶的水解液进行了色谱分离测定。结果表明:槲皮素的质量浓度在1.97~19.7 mg.L-1,山奈酚在2.02~20.2 mg.L-1,异鼠李素在2.11~21.1 mg.L-1时分别与其峰面积呈线性关系。槲皮素、山奈酚和异鼠李素的加标回收率分别为93.0%~99.6%,92.6%~99.8%,92.5%~99.5%,相对标准偏差(n=6)分别为2.48%,2.80%,3.17%。 相似文献
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《化学研究》2015,(4)
研究了铁氰化钾与左旋多巴之间的氧化反应所引起的吸收光谱的变化.实验发现,碱性溶液中铁氰化钾氧化左旋多巴生成红色化合物,其最大吸收波长为475nm,铁氰化钾与左旋多巴的物质的量之比为2∶1.体系的吸光度与左旋多巴的浓度在3.2~54.4mg/L范围内呈良好的线性关系,线性回归方程A=-0.038 88+0.020 8c(mg/L),相关系数r=0.999 2,表观摩尔吸光系数ε=5.1×103 L·mol-1cm-1.该方法的检出限为2.32mg/L,对浓度为16.0mg/L的左旋多巴进行平行11次测定,其相对标准偏差为0.3%.据此建立了测定左旋多巴的新方法,能够直接用于市售的左旋多巴片中左旋多巴含量的测定,回收率为96.7%~104.4%. 相似文献
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原子吸收法测定污泥蚯蚓中的镉、铜、铬、锌、铅 总被引:4,自引:0,他引:4
研究用原子吸收法测定蚯蚓中的镉、铜、铬、锌、铅.将制备成粉状的蚯蚓用硝酸-高氯酸消解,在仪器工作条件下,金属离子含量与吸光度呈良好的线性关系.测定结果的相时标准偏差为1.3%~3.5%(n=7),加标回收率为93%~107%.测定镉、铜、铬、锌、铅离子的线性范围、线性相关系数、检出限依次为0~0.9 mg/L,r=0.9984,0.0r7 mg/L;0~10 mg/L,r=0.9989,0.05 mg/L;0~5 mg/L,r=0.999 1,0.13mg/L;0~0.7 mg/L,r=0.9997,0.02 mg/L;0~7.5 mg/L,r=0.9994,0.3 mg/L. 相似文献
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毛细管电泳紫外检测法测定莲须中的槲皮素、木犀草素、山萘酚、异槲皮甙 总被引:2,自引:0,他引:2
采用毛细管区带电泳紫外检测法(CZE-UV)同时测定中药莲须中槲皮素、木犀草素、山萘酚、异槲皮甙4种有效成分.研究了缓冲溶液的离子浓度、pH值和电压对分离度和迁移时间的影响,得到了最佳分离实验条件.在离子浓度为40 mmol/L Na2B4O7缓冲溶液(pH 9.0)中,分离电压为16 kV,波长为254 nm时,槲皮素、木犀草素、山萘酚、异槲皮甙4种物质在10 min内得到了良好的分离测定,其检出限分别为5.0、6.7、4.5和6.0 mg/L.本方法应用于实际样品的测定,结果令人满意. 相似文献
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The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
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Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared. 相似文献
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Stepkowska E. T. Perez-Rodriguez J. L. Jimenez de Haro M. C. Sayagues M. J. 《Journal of Thermal Analysis and Calorimetry》2002,69(1):187-204
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position. 相似文献
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The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations
were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples
were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of
hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the
best fitting experimental data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6. 相似文献