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1.
建立了一种基于CdSe/CdS量子点(QDs)标记技术测定微囊藻毒素-LR(MC-LR)的方法。MC-LR抗体经1-乙基-3(3-二甲基胺基丙基)碳二亚胺盐酸盐(EDC)活化,与经巯基乙酸修饰的CdSe/CdS量子点进行共价连接,获得的QDs生物共轭体在待测物MC-LR的作用下发生荧光猝灭现象,荧光猝灭程度与MC-LR的浓度呈线性关系。该方法操作简单、检测速度快、检出限低达6.9×10~(-11)mol/L。  相似文献   

2.
利用8-羟基脱氧鸟苷(8-OHdG)在酸性邻菲咯啉(Phen)-Cu化学发光体系中发光信号强的特点,建立了一种测定尿样中8-OHdG含量的方法。本方法的线性范围为1.67—333.33μg/L,检出限(S/N=3)为0.83μg/L。对167.00μg/L的8-OHdG平行测定11次,其相对标准偏差为1.2%。该法用于尿液中8-OHdG的测定,方法简便、灵敏、快速,分析结果令人满意。  相似文献   

3.
Fluorescence microscopy (FM) has recently been applied to the detection of airborne asbestos fibers that can cause asbestosis, mesothelioma and lung cancer. In our previous studies, we discovered that the E. coli protein DksA specifically binds to the most commonly used type of asbestos, chrysotile. We also demonstrated that fluorescent-labeled DksA enabled far more specific and sensitive detection of airborne asbestos fibers than conventional phase contrast microscopy (PCM). However, the actual diameter of the thinnest asbestos fibers visualized under the FM platform was unclear, as their dimensions were below the resolution of optical microscopy. Here, we used correlative microscopy (scanning electron microscopy [SEM] in combination with FM) to measure the actual diameters of asbestos fibers visualized under the FM platform with fluorescent-labeled DksA as a probe. Our analysis revealed that FM offers sufficient sensitivity to detect chrysotile fibrils as thin as 30–35 nm. We therefore conclude that as an analytical method, FM has the potential to detect all countable asbestos fibers in air samples, thus approaching the sensitivity of SEM. By visualizing thin asbestos fibers at approximately tenfold lower magnifications, FM enables markedly more rapid counting of fibers than SEM. Thus, fluorescence microscopy represents an advanced analytical tool for asbestos detection and monitoring.  相似文献   

4.
In recent years, the lipoaspirate collected from adipose tissue has been seen as a valuable source of adipose-derived mesenchymal stem cells for autologous cellular therapy [1, 2, 3]. For multiple applications, adipose-derived mesenchymal stem cells are isolated from the stromal vascular fraction (SVF) of adipose tissue. Because the fresh stromal vascular fraction typically contains a heterogeneous mixture of cells [4, 5], determining cell concentration and viability is a crucial step in preparing fraction samples for downstream processing. Due to a large amount of cellular debris contained in the SVF sample, as well as counting irregularities standard manual counting can lead to inconsistent results. Advancements in imaging and optics technologies have significantly improved the image-based cytometric analysis method. In this work, we validated the use of fluorescence-based image cytometry for SVF concentration and viability measurement, by comparing to standard flow cytometry and manual hemocytometer. The concentration and viability of freshly collected canine SVF samples are analyzed, and the results highly correlated between all three methods, which validated the image cytometry method for canine SVF analysis, and potentially for SVF from other species.  相似文献   

5.
Probe 1 was designed and synthesized as a new fluorescent molecular probe for thiols in PBS buffer at physiological condition. This fluorescent molecular probe consists of a thiol reaction moiety bound to a coumarin fluorophore. Its fluorescence quantum yield is low, but a drastic enhancement of fluorescence intensity was observed in the presence of thiols. Possible interference with other analytes was examined. Probe 1 displays a highly selective fluorescent enhancement with thiols, and the probe was successfully applied to thiols determination in intracellular, in human urine and blood samples.  相似文献   

6.
基于紫外吸收光谱的COD测量方法,尽管具有快速、实时、免试剂、无污染等优势。但该方法对于组分多变的水样适应性不强,构建的单一计算模型不能适用于所有待测水样类型,导致其在复杂环境下测量准确度较低,从而限制了其应用领域。本研究提出一种基于水样类型识别的测量方法。其过程包括:动态识别水样类型→自动选择相应的"吸光度(Auv)-COD"算法模型→计算COD。该方法有效提高了紫外光谱法COD测量的准确度和适用性。该研究在传统的光谱识别技术的基础上,针对COD实际测量的特点加以改进。选取水样吸光度曲线的形貌特征作为水样类型的表征参数,利用LM-BP神经网络作为识别算法。并引入了"历史数据队列"、"历史识别因子"的概念,在此基础上形成了级联的神经网络结构。该算法实现了COD测量应用中的高准确度的光谱识别,进而提高了复杂环境下COD测量的精度。大量实验测试和结果表明,与传统的光谱识别技术相比,该方法在COD测量应用中具有更好的鲁棒性和准确性。水样类型识别准确率达98%以上。同时算法结构简单,计算量小,适用于资源受限的小型化COD测量仪。当仪器在复杂多变的水环境中进行测量时,采用该算法测量得到的COD精度有显著的提高。该方法的提出为光谱COD测量法在水体组分多变场合的应用及提高其测量精度提供了技术保证,可望解决传统紫外光谱COD测量法难以适应变化和复杂水环境应用的问题。  相似文献   

7.
Optics and Spectroscopy - The possibilities of using fluorescence-based analytical methods and their advantages for visualization and identification of the type of programmed cell death in human...  相似文献   

8.
采用流动注射-分光光度法测定了环境水样中的硫化物.结果表明:其线性范围为0-0.6mg/L,方法的检出限为0.002mg/L,精密度RSD小于3%,对方法的回收率作了实验,所得结果在83.00%-95.33%之间.  相似文献   

9.
ICP-MS和AFS测定环境水样中的铅含量的比较   总被引:3,自引:0,他引:3  
张莹  顾锡龙  潭颖 《光谱实验室》2009,26(4):1000-1002
在选定的最佳条件下,样品经过前处理后采用ICP-MS和AFS两种方法测定环境水样中的铅的含量,最终ICP-MS与AFS测定结果一致。两种方法对环境水样中铅含量的测定都具有较好的应用,且ICP-MS简便、快速、线性范围宽、测量稳定、可多元素同时测定,AFS谱线简单,灵敏度高,检出限低。  相似文献   

10.
Atoms of several elements are produced when metal and certain silica refractory samples are heated in a flame. When concentrated HCL is then aspirated a signal enhancement occurs. The peak height of this signal can be used for the analysis of Mn and Cu in nails, Fe in brass and MgO in silica refractory. The technique is very matrix dependant and detection limits are poorer than for conventional atomic absorption.  相似文献   

11.
建立催化热解-AAS测定环境水及土壤样品中总汞的方法。采用DMA80型直接测汞仪测定水样及土壤中总汞含量,并采用有证标准物质验证方法的准确度、精密度。方法的线性范围为:低浓度系列0.01—0.3μg/mL,线性方程y=0.0116x+0.0012,R2=0.9997;高浓度系列0.50—4.00μg/mL,线性方程y=0.001x+0.0034,R2=0.9996,RSD为1.1%—1.3%。催化热解-AAS测定环境水及土壤样品中的总汞含量,方法简便,灵敏度高,适合环境水及土壤样品中总汞的测定。  相似文献   

12.
An equipment for the speed δ18O analysis of water samples is described. It used the equilibrium isotopic exchange reaction between water and CO2 gas. Outgasing of samples through capillary without freezing down the samples, together with shaking during the equilibrium time, reduced considerably time for sample preparation.

Apparatus is air termostated with hand valves. Measured δ values are not very sensitive to precision of preparation work and reaction conditions, except of temperature. With good temperature control the standard reproducibility of single measurement is better than 0,1‰  相似文献   

13.
采用TOC/TN法测定了环境水样中的总氮。结果表明:其线性范围为0-20mg/L时,具有良好的线性关系,精密度RSD小于2%,对方法的回收率作了试验,所得结果在85.3%—99.1%之间。  相似文献   

14.
本方导出了一种催化分光光度法计算公式,即二标样计算法,并进行了实验验证,结果良好。  相似文献   

15.
The deuterium content could be estimated in the low range by the infra-red method with an accuracy of ± 0.0005 mole% by using the suitable absorption band at 3·98 μ and a quartz cell of ≈0·3 mm thickness. The reproducibility of this method is tested by mass spectrometry and it is found that data of both methods are comparable.  相似文献   

16.
A novel fluorescent probe CR-ClO for detection of HOCl based on a carbazole fused rhodamine was designed and synthesized. The probe utilized a HOCl-promoted oxidation reaction, which lead to the ring opening of the compound with a strong enhancement of the fluorescent emission at about 587 nm.The new probe CR-ClO has excellent selectivity and high sensitivity to ClO?,whose detection limit to ClO? is 1.16 × 10?6 M. Furthermore, the new probe has been successfully applied in living cells for detection of ClO?.  相似文献   

17.
水样中总铬测定方法研究   总被引:2,自引:0,他引:2  
用石墨炉-原子吸收光谱法(GF-AAS)和高锰酸钾-二苯碳酰二肼分光光度法,对环境水中的总铬进行了比较测定.结果表明:两种方法测定总铬的各项指标均在要求范围内,两种方法测定结果的RSD值均≤4.7%,加标回收率在94.5%-110%之间;表明两种方法均可测定水中总铬;但是石墨炉-原子吸收光谱法操作简便快速,更稳定.  相似文献   

18.
激光雷达湍流大气探测   总被引:2,自引:0,他引:2  
基于湍流对激光束的扩散和漂移效应,提出了一种采用激光雷达观测湍流强度的方法。湍流对光束产生扩散和飘移作用,使激光光束偏离激光雷达接收视场,造成后向散射光能量损失。对比常规散射回波信号与畸变回波信号的差别可以测量湍流强度。实验表明该方法与其他方法的测量结果具有一致性,证明了该方法的有效性。  相似文献   

19.
建立了分光光度法测定水样中痕量磷酸盐的浊点萃取分离富集新体系。在酸性条件下,以抗坏血酸、钼酸铵作为磷钼蓝比色法测定磷含量的显色剂,酒石酸锑钾作为催化剂,形成稳定的磷钼蓝后,通过80℃水浴加热10m in,磷钼蓝被萃取到T rition X-100表面活性剂相并与水相分离。将表面活性剂富集相用0.5mL乙醇分散稀释,应用紫外-可见分光光度计进行400—1000nm范围内的波长扫描。在最佳条件下,测定的线性范围为0.3—180ng/mL,方法的检出限为0.73ng/mL,相对标准偏差(RSD)为2.8%。该法用于实际水样的富集和测定,结果令人满意。  相似文献   

20.
浊点萃取-分光光度法测定水样中微量钒   总被引:1,自引:0,他引:1  
提出了以5-Br-PADAP为络合剂、Triton X-114为表面活性剂的浊点萃取-分光光度法测定微量钒的新方法.探讨了溶液pH值,试剂浓度和平衡温度等实验条件对浊点萃取及测定灵敏度的影响.在优化的实验条件下,富集50mL样品溶液,钒的检出限为0.099 μg·mL-1,富集倍率为45.6.方法用于水样中测定微量钒的测定,结果满意.  相似文献   

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