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1.
本文介绍了提取吉如很阿嘎如-8中水溶性多糖的方法,并用硫酸-苯酚法测定了该药中水溶性多糖的含量。回收率为99.3%-100.5%,RSD为0.90%。用气相色谱法测定了吉如很阿嘎如-8的水溶性多糖,它是由阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖等组成。它们的摩尔比为:1.00:0.76:3.61:2.88:5.00。  相似文献   

2.
氢化物-原子荧光光谱法测定建筑用粘合剂中汞   总被引:1,自引:0,他引:1  
用硝酸-硫酸-高锰酸钾在高压锅中溶样,采用氢化物发生原子荧光光谱法测定建筑用粘合剂中汞。相对标准偏差为4.3%,回收率为87.6%-106%。该方法快速、简单、准确。  相似文献   

3.
ICP-AES法同时测定茶叶中的锌、铁、锰、铜、镍、镁   总被引:6,自引:0,他引:6  
研究了用硝酸+硫酸+高氯酸消解样品,用ICP-AES法同时测定茶叶中锌,铁,锰,铜,镍,镁的新方法,在选定的最佳条件下,测锌,铁,锰,铜,镍,镁的检出限分别为4.2,7.8,0.4,7.3,7.6,4.8ng.mL^-1,回收率为94.7%-104.2%,RSD为0.3%-4.7%,该法准确,快速,简便,适用于茶叶样品的测定,结果令人满意。  相似文献   

4.
硫酸酯化螺旋藻多糖的制备与IR表征   总被引:1,自引:1,他引:0  
陈金娥  张海容 《光谱实验室》2005,22(6):1322-1324
微波法提取的螺旋藻多糖,经十六烷基三甲基溴化铵盐溶液分级,得不同级分螺旋藻多糖S1、S2、S3。通过浓硫酸法和氯磺酸甲酰胺法合成了螺旋藻硫酸酯化多糖SL1、SL2和SL3,用IR对产物结构作了表征。  相似文献   

5.
微量化提取结合毛细管柱气相色谱法测定茶叶中六六六,滴滴涕残留量,对六六六,滴滴涕8种异构体都能得到满意的分离效果,采用外标法定量测定,且用此方法检测滴滴涕4种异构体的平均回收率在92.5%-103.2%之间,相对标准偏差在1.6%-3.1%之间,检出限可达0.04μg/kg.  相似文献   

6.
原子吸收光谱法间接测定硫酸阿托品   总被引:2,自引:0,他引:2  
张雨青  王伟 《光谱实验室》2002,19(5):665-667
研究了原子吸收光谱法间接测定硫酸阿托品的方法。在pH为5.0的溶液中,当四苯硼钠过量时可完全沉淀硫酸阿托品,在滤液中加入过量的氯化钾沉淀剩余的四苯硼钠,再测定过量的钾可以计算得到硫酸阿托品的含量。方法简单、快速,回收率在97%-101%之间,相对标准偏差为1.1%。  相似文献   

7.
本文采用和LI2B4O7熔样、MgO基体匹配、ICP-AES法同时测定出口镁质耐火材料的主要成分及杂质元素。RSD<2.7%,加标回收率为97.6%。方法快速、简便,结果准确。  相似文献   

8.
免疫亲和柱HPLC荧光检测酒中黄曲霉毒素B1、B2、G1、G2   总被引:17,自引:0,他引:17  
采用单隆抗体免疫样和技术作为直接从样品分离提纯黄曲霉素素的特效手段,提出液挥发干后,经衍生用HPLC荧光检测器测定,本法在样品中添加2.5μg/kg黄曲霉素素时进行10次测定,平均回收率分别为G178.3%、B197.3%、G261.7%、B290.5%;2.5μg/kg10次测定的精密度分别为:G4.50%、B13.805、G23.68%、B24.77%,本方法在25-1250pg范围内呈线性,相关系数分别为G1:r=0.9990,B1:r=0.9994,G2:r=0.9995,B2:r=0.9992 ,测定的最低检出限为6.25pg.  相似文献   

9.
溶胶-凝胶法合成Sr2CeO4及其发光性能的研究   总被引:15,自引:5,他引:10  
采用Pechini溶胶-凝胶法合成了Sr2CeO4粉末。利用X射线衍射(XRD)、扫描电镜(SEM)、热重及差热分析(TG-DTA)以及发光光谱等测试手段对Sr2CeO4的结晶过程、发光性质进行了研究。XRD结果表明,用Pechini溶胶-凝胶法合成的样品800℃时已开始结晶,900℃时可得到三斜晶系的Sr2CeO4多晶粉末。扫描电镜照片可以看出颗粒大小不均匀,粒径约为1-5μm。发光光谱测试表明Sr2CeO4粉末的激发光谱是一个宽带双峰结构,分别位于310nm和340nm。这个宽带属于Ce^4 的电荷迁移带。用340nm激发样品,其发射光谱也是一个宽带,最大峰位于475nm,这个峰属于Ce^4 的f→t1g跃迁。用310nm激发得到的发射光谱与用340nm激发得到的发射光谱相同。  相似文献   

10.
研究了用火焰原子吸收光谱法在同一溶液体系中直接快速测定金川铜镍矿浮选产品中铜、镍、镁含量新的新方法。考察了产品中高含量的SiO2对测定镁的干扰情况,并提出了排除这项干扰简便方法,根据各元素的标准溶液系列的测定数据,推算出了铜、镍、镁3元素的线性回归方程及线性相关系数,特征浓度铜为0.40mg.L^-1/1%,镍为0.48mg.L^-1/1%,Mg为0.018mg.L^-1/1%;线性浓度范围铜,镍均为0-10mg.L^-1,镁为0.2-1.2mg.L^-1。相对标准偏差铜为2.5%(n=6),镍为2.3%(n=6),镁为2.8%(n=6),加标回收率铜为96.5%-102.5%,镍为98.8%-103.5%,镁为98.2%-102.5%,这种方法操作简便,快速,实用,具有较好的精密度和准确度,实际产品分析结果与外检单位及金川公司测定的结果吻合。  相似文献   

11.
光催化剂SO2- 4/TiO2和TiO2 的光谱行为比较   总被引:3,自引:0,他引:3  
用IR、Raman和DRS光谱研究了SO^2-4/TiO2光催化剂和TiO2光催化剂的光谱行为差别。结果表明,TiO2光催化剂的表面只有L酸中心,而SO^2-4/TiO2光催化剂表面既有L酸中心也有B酸中心。TiO2的硫酸化有效地抑制了晶相转变和晶粒度的增加。与TiO2相比,SO^2-4/TiO2光催化剂的锐钛矿相含量较多、晶粒较小、光谱吸收边蓝移,从而增大了光吸收阈值,增强了光生空穴和电子的氧化  相似文献   

12.
采用溶胶‐凝胶法制备了Ce掺杂 T iO2,经 H2 SO4处理得到酸化Ce掺杂 T iO2。利用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、吡啶吸附红外光谱(Py‐FTIR)、紫外‐可见光漫反射光谱(UV‐Vis)及X射线光电子能谱(XPS)技术对样品的性质进行了表征,以罗丹明B(RhB)在样品上的可见光催化降解为模型反应,评价了所制备样品的光催化性能。XRD测试结果表明,铈掺杂使 TiO2产生晶格缺陷、粒径减小,有利于光生电荷的转移,继而提高催化剂的活性;FTIR谱图说明SO2-4以桥式双齿配位吸附形式存在;Py‐FTIR谱图显示,酸化铈掺杂TiO2样品表面同时存在Br?nsted和Lewis酸位,但以Lewis酸为主。Lewis酸中心的缺电子性质有利于样品表面的光生电子与光生空穴分离,从而改善催化剂的活性;UV‐Vis结果表明,Ce掺杂减小了TiO2的带隙能,引入的杂能级能够捕获导带上的光生电子和价带上的光生空穴,降低光生电子‐空穴对的复合几率;同时还可以使能量较小的光子激发杂能级上捕获的电子,拓宽光响应范围;XPS分析表明SO2-4/Ce‐TiO2样品上同时存在Ce3+/Ce4+的混合价态,Ce3+/Ce4+氧化‐还原转换有助于TiO2受光激发后产生的光生电子和空穴的分离,从而提高光量子效率。酸化Ce掺杂TiO2对RhB的可见光催化降解反应有很好的活性,实验结果证明,H2 SO4酸化和Ce掺杂的协同作用改善了样品的可见光响应,促进了其可见光催化反应活性。  相似文献   

13.
Staining methods applied to glycol methacrylate embedded tissue sections   总被引:2,自引:0,他引:2  
The use of glycol methacrylate (GMA) avoids some technical artifacts, which are usually observed in paraffin-embedded sections, providing good morphological resolution. On the other hand, weak staining have been mentioned during the use of different methods in plastic sections. In the present study, changes in the histological staining procedures have been assayed during the use of staining and histochemical methods in different GMA-embedded tissues.

Samples of tongue, submandibular and sublingual glands, cartilage, portions of respiratory tract and nervous ganglion were fixed in 4% formaldehyde and embedded in glycol methacrylate. The sections of tongue and nervous ganglion were stained by H&E. Picrosirius, Toluidine Blue and Sudan Black B methods were applied, respectively, for identification of collagen fibers in submandibular gland, sulfated glycosaminoglycans in cartilage (metachromasia) and myelin lipids in nervous ganglion. Periodic Acid-Schiff (PAS) method was used for detection of glycoconjugates in submandibular gland and cartilage while AB/PAS combined methods were applied for detection of mucins in the respiratory tract. In addition, a combination of Alcian Blue (AB) and Picrosirius methods was also assayed in the sublingual gland sections.

The GMA-embedded tissue sections showed an optimal morphological integrity and were favorable to the staining methods employed in the present study. In the sections of tongue and nervous ganglion, a good contrast of basophilic and acidophilic structures was obtained by H&E. An intense eosinophilia was observed either in the striated muscle fibers or in the myelin sheaths in which the lipids were preserved and revealed by Sudan Black B. In the cartilage matrix, a strong metachromasia was revealed by Toluidine Blue in the negatively-charged glycosaminoglycans. In the chondrocytes, glycogen granules were intensely positive to PAS method. Extracellular glycoproteins were also PAS positive in the basal membrane and in the region occupied by the lamina externa and reticular fibers surrounding each smooth muscle cells of the blood vessels. In the epithelial cells of the respiratory tract, acid and neutral mucins were histochemically detected by AB and PAS methods, respectively. Moreover, granules containing acid and neutral mucins were revealed in purple by AB and PAS concomitantly. In the sublingual gland sections, a distinct affinity of acid mucins by AB (in turquoise-blue) and collagen fibers by Picrosirius (in red) was obtained when these methods were combined. Although some routine dyes used in paraffin sections have showed a weak stain in historesin sections, our results showed that different dyes could be applied in GMA sections if modified staining procedures were assayed. Therefore, appropriate staining contrast and, thus, detection of one or different substances in a same section can be acquired in association to the good morphological resolution provided by GMA.  相似文献   


14.
In view of follow up, survey and development of therapeutic strategies for osteoarthritis where cartilage deterioration plays an important role, a non invasive, reliable and quantitative assessment of the articular cartilage is desirable. The currently available high resolution T(1)-weighted (T1-w) 3D FLASH pulse sequences with frequency selective fat suppression are very time consuming. We have 1) optimized a high resolution T1-w 3D FLASH water excitation (WE) sequence for short acquisition time and cartilage visualization, and 2) validated this sequence for cartilage volume and thickness quantification. The spectral fat presaturation was replaced by selective water excitation. The flip angle of the WE sequence was optimized for the contrast to noise (C/N(cart)) ratio of cartilage. Sagittal datasets (voxel size: 0.31 x 0.31 x 2 mm(3)) of the knees of nine healthy volunteers were acquired both, with the 3D FLASH WE (17.2/6.6/30 degrees ) sequence (WE) and a previously validated 3D FLASH fat saturated (42/11/30 degrees ) sequence (FS). For validation of the WE sequence, cartilage volume, mean and maximal cartilage thickness of the two sequences were compared. Reproducibility was assessed by calculating the coefficient of variation (COV %) of 4 consecutive WE data sets in the volunteers. The acquisition time was reduced from 16'30" (FS) down to 7'14" for the WE sequence. Image contrast and visualization of the cartilage was very similar, but delineation of the basal layer of the cartilage was slightly improved with the WE sequence. A flip angle of 30 degrees provided the best C/N(cart) ratios (WE). Reproducibility (COV) was between 1.9 and 5.9%. Cartilage volume and thickness agreed within 4% between FS and WE sequence. The WE sequence allows for rapid, valid and reproducible quantification of articular cartilage volume and thickness, prerequisites for follow-up examinations. The reduced acquisition time (50% of FS) enables routine clinical application and thus may contribute to a broader assessment of osteoarthritis.  相似文献   

15.
Vu  Tam  Taylor  M. Joan  Singh  Harprit  Bilmoria  Jay  Bottrill  Andrew  Sahota  Tarsem 《Journal of fluorescence》2022,32(2):569-582

Fluorescently labelling proteins such as insulin have wide ranging applications in a pharmaceutical research and drug delivery. Human insulin (Actrapid®) was labelled with fluorescein isothiocyanate (FITC) and the synthesised conjugate identified using reverse phase high performance liquid chromatography (RP-HPLC) on a C18 column and a gradient method with mobile phase A containing 0.1% trifluoroacetic acid (TFA) in Millipore water and mobile phase B containing 90% Acetonitrile, 10% Millipore water and 0.1% TFA. Syntheses were carried out at varying reaction times between 4 and 20 h. Mono-labelled FITC-insulin conjugate was successfully synthesised with labelling at the B1 position on the insulin chain using a molar ratio of 2:1 (FITC:insulin) at a reaction time of 18 h and confirmed by electrospray mass spectroscopy. Reactions were studied across a pH range of 7–9.8 and the quantities switch from mono-labelled to di-labelled FITC-insulin conjugates at a reaction time of 2 h (2:1 molar ratio) at pH?>?8. The conjugates isolated from the studies had biological activities in comparison to native insulin of 99.5% monoB1, 78% monoA1, 51% diA1B1 and 0.06% triA1B1B29 in HUVEC cells by examining AKT phosphorylation levels. MonoB1 FITC-insulin conjugate was also compared to native insulin by examining cell surface GLUT4 in C2C12 skeletal muscle cells. No significant difference in the cellular response was observed for monoB1 produced in-house compared to native insulin. Therefore mono-labelled FITC-insulin at the B1 position showed similar biological activity as native insulin and can potentially be used for future biomedical applications.

  相似文献   

16.
离子色谱法测定清洗液废酸中的4种阴离子   总被引:1,自引:0,他引:1  
介绍了清洗液废酸中F-、Cl-、SO42-和NO3-的测定方法,通过一定的前处理,减少清洗液废酸中金属离子及残留酸液的干扰,有效去除了对色谱柱带来的污染。利用优化的实验条件,准确测定了清洗液废酸中F-、Cl-、SO42-和NO3-的含量,检出限分别为0.04、0.09、0.71、0.27mg/L,回收率为94%—109%。  相似文献   

17.
Here, the nanometer anatase and rutile titanium dioxide (TiO(2)) powders were introduced to act as the sonocatalysts during the ultrasonic degradation of azo dye-acid red B which was chosen as model compound. The ultrasound of low power was used as an irradiation source to induce TiO(2) particles performing catalytic activity. It was found that the processes of sonocatalytic degradation were different between nanometer anatase TiO(2) and nanometer rutile TiO(2). For nanometer anatase TiO(2) catalyst, the acid red B was mainly oxidated by the holes on the surface of nanometer anatase TiO(2) particles, so that the decolorization and degradation happened at the same time. For the nanometer rutile TiO(2) catalyst, the acid red B was mainly oxidated by the *OH radicals from the ultrasonic cavitation, so that the decolorization of azo bond takes place primarily, and then the degradation of naphthyl ring does. The intermediates of acid red B in the presence of nanometer anatase and rutile TiO(2) powders have been monitored by UV-vis spectra and high performance liquid chromatography (HPLC), respectively. All experiments indicated that the degradation effect of acid red B in the presence of nanometer anatase TiO(2) powder was obviously better than that in the presence of nanometer rutile TiO(2) powder. Hence, the method of sonocatalytic degradation for organic pollutants in the presence of nanometer anatase TiO(2) powder is expected to be promising as an advisable choice for the treatment of organic wastewaters in future.  相似文献   

18.
Sulfated and phosphated titania (TiO2) were obtained by the sol-gel method. The sulfation was prepared in situ using sulfuric acid as hydrolysis catalyst, or by impregnation with ammonium sulphate. Phosphated sol-gel titania was synthesized with phosphoric acid. Long thermal treatments were carried out from 100 to 1000 °C to study the crystallization process of titania. All present phases were nanocrystalline, and the anatase-rutile polymorphic transformation was dependent on the crystallite size of the materials and on the preparation method. The smallest crystallite values were obtained for the phosphated samples. Titania sulfated by impregnation was found to be an efficient and selective catalyst towards propene, whereas di-isopropylether was obtained only in the catalyst prepared in situ with H2SO4.  相似文献   

19.
Depth and orientational dependencies of microscopic magnetic resonance imaging (MRI) T(2) and T(1ρ) sensitivities were studied in native and trypsin-degraded articular cartilage before and after being soaked in 1 mM Gd-DTPA(2-) solution. When the cartilage surface was perpendicular to B(0), a typical laminar appearance was visible in T(2)-weighted images but not in T(1ρ)-weighted images, especially when the spin-lock field was high (2 kHz). At the magic angle (55°) orientation, neither T(2)- nor T(1ρ)-weighted image had a laminar appearance. Trypsin degradation caused a depth- and orientational-dependent T(2) increase (4%-64%) and a more uniform T(1ρ) increase at a sufficiently high spin-lock field (55%-81%). The presence of the Gd ions caused both T(2) and T(1ρ) to decrease significantly in the degraded tissue (6%-38% and 44%-49%, respectively) but less notably in the native tissue (5%-10% and 16%-28%, respectively). A quantity Sensitivity was introduced that combined both the percentage change and the absolute change in the relaxation analysis. An MRI experimental protocol based on two T(1ρ) measurements (without and with the presence of the Gd ions) was proposed to be a new imaging marker for cartilage degradation.  相似文献   

20.
Sulfated glycosaminoglycans (GAGs) were isolated and characterized in thoracic muscle, fat body, whole digestive tract (stomach+intestine) and reproductive tract of adult male cockroaches, Periplaneta americana. Heparan sulfate (HS) was the predominant sulfated GAG species in the tissues analyzed, corresponding to more than 90% of the total sulfated GAG content. In both the thoracic muscle and fat body it was the only sulfated GAG species detected. We also determined the location of sulfated GAGs in most of these organs by histochemical analysis using 1,9-dimethylmethylene blue. In the thoracic muscle, sulfated GAG metachromatic staining was detected only in the connective tissue that surrounds the muscle bundles or fascicles. In the intestinal tract, metachromatic staining was observed in both epithelial and lining columnar cells. Only spermatozoa presented metachromatic material in the male reproductive tract. Since, HS corresponds to 90-100% of total sulfated GAGs in these tissues, the metachromatic staining specifically reflects the location of this particular sulfated GAG in these organs. In conclusion, the present study extends previous observations on the GAG composition in cockroaches providing new information on the tissue distribution and location of HS in several internal organs of adult males of the cockroach P. americana.  相似文献   

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