紫外可见分光光度计线性范围的校准

建立紫外可见分光光度计线性范围的校准方法。通过实验对紫外可见分光光度计线性范围的校准进行研究,提出了相应的校准方法和技术指标。采用重铬酸钾标准物质进行校准,测量波长为257 nm。线性范围下限不大于1.0×10–3 mg/mL,线性范围上限不小于0.10 mg/mL。该校准方法覆盖了JJG 178–2007 《紫外、可见、近红外分光光度计检定规程》中没有覆盖的吸光度范围,能够实现紫外可见分光光度计全范围吸光度的计量校准。     

原子吸收光光度法测定矿石中铁

运用石墨炉电热蒸发进行分子光谱研究,文献已有报道［１～３］,但用原子吸收光度计代替紫外－可见分光光度计进行溶液分子光谱分析报道较少［４,５］。本文以原子吸收分光光度计代替紫外－可见分光光度计用原子吸收光光度法研究了测定铁的条件并实测了铜矿中铁含量。实...     

紫外分光光度计标准溶液的制备及使用

介绍了紫外分乐光度计标准溶液的特性及其用于检定紫外分光光度计度准确度的优点和正确的使用方法 。     

紫外可见分光光度计的双向导数光谱法

紫外可见分光光度计的导数光谱法由于相移的存在,导致导数光谱中峰值、峰谷对应的波长位置与其真实的波长位置存在偏差以及复杂频率分量的物质吸收曲线发生群时延。基于零相移滤波器原理,双向导数光谱法能够有效地消除相移。实验采用紫外可见分光光度计扫描水杨酸溶液,并用导数光谱法和双向导数光谱法分析吸光度数据。结果表明,双向导数光谱法能克服相移,提供无群时延的更精确的吸收细节,从而提高紫外可见分光光度计的分析精度。     

在单波长紫外可见分光光度计上测定导数吸收光谱

在单波长紫外可见分光光度计上测定样品在不同波长（λ）下的吸光度（A），然后利用数学处理方法将λ-A转变为不同波长下的一阶、二阶及三阶导数关系，即λ-△A／△λ、λ-△^2A／△λ^2及,λ-△^3／△λ^3关系，并在计算机上利用EXCEL绘制出样品的各阶导数吸收光谱。实现了在单波长紫外可见分光光度计上测定导数吸收光谱的目的，扩大了单波长紫外可见分光光度计的应用范围。     

多功能酶标仪测定微量水体中总磷

依据钼锑抗分光光度法原理,使用多功能酶标仪测定水体中总磷(TP)的含量,并以紫外分光光度计测定的结果作为参考进行比较分析,探讨了一种新的批量测定TP的方法。结果显示,酶标仪法在显色55 min时吸光度值与浓度呈现最好的线性关系(R~2=0.9995,P0.001),加标回收率范围为98.1%~101.6%。酶标仪法较紫外分光光度计法的相对误差5%,相对平均偏差和相对标准偏差(n=6)2%。测定结果与紫外分光光度计法无明显差异,且样品量极少(单个仅200μL)。使用酶标仪法测定水体TP的方法可行。     

测定诺氟沙星胶囊的新方法

诺氟沙星(Norfloxacinium)是近几年合成的新抗菌素(图1)。具有抗菌谱广,疗效好,毒性低等优点。目前已广泛应用于临床。中国药典1990年版中对诺氟沙星胶囊的含量测定采用非水滴定法。本文改进了此法,采用紫外分光光度法测定该品种含量。实验表明该法简便、快速、重现性也较好。仪器与试药仪器:日本岛津UV-2100紫外分光光度计;日本岛津UV—260紫外分光光度计;751—GW(上海分析仪器厂)。     

氧化钬波长标准溶液的研制和应用

本文提出了一种紫外可见分光光度计波长检定用的氧化钬标准溶液,对其稳定性、均匀性和特征波长参考值进行了考察和研究,结果表明它是一种准确度高、稳定性好、使用方便的波长标准。在紫外可见光谱区(240～650nm)范围内,氧化钬波长标准溶液可适用于多种类型分光光度计的波长检定。     

联机系统获得导数光谱方法

目前,国外已报道了多种获得导数光谱的技术。如电子微分法、机械式转速计法、数值微分法、波长调制法、双波长分光光度法等,这些方法各具有优缺点。本文就自动记录式紫外-可见分光光度计波长扫描的特点和微计算机对模拟输入量采样时的固有方式,介绍应用计算机与自动记录式紫外-可见分光光度计联机进行实时数据处理而获得任意阶导数光谱的一种简单方法——数值差分法。     

用高温石墨管原子吸收法定量测定铅

使用自制高温石墨管原子化器,结合改装的紫外分光光度计安装成一台简易型高温石墨管原子吸收分光光度计,将溶液滴于石墨管内,在氮气流保护下用低电压大电流加热,方法简易,对某些样品不使用氢灯背景扣除器也能工作。     

日立U-2000型紫外可见分光光度计一例常见故障检修

日立U-2000型双光束紫外可见分光光度计,是日立公司20世纪80年代末90年代初的产品．采用了日立著名的凹衍射光栅和Scya—Namiota光学系统,配以6809CPU构成的专用计算机,确保了仪器稳定、可靠、便捷以及良好的性能,至今仍有不少单位使用．本文详细介绍了此机一例常见故障的检修、处理过程。供参考．     

标准溶液测量不确定度的评定

对标准溶液测量不确定度进行合理评定，充分估计分析不确定度的来源，从量值检验时考虑到影响不确定度的各种因素，测量方法的不确定度．配制时考虑到影响不确定度的各种因素以及标准溶液的不均匀性和在有效期内的变动性所引起的不确定度等方面进行综合分析，得出其扩展不确定度。并以镍标准溶液为例作实际分析。     

Study on adsorption of Th(IV) using surface modified dibenzoylmethane molecular imprinted polymer

The adsorption of Th(IV) was studied using a novel dibenzoylmethane molecular imprinted polymers, which was prepared using acryloyl-β-cyclodextrin as a monomer on surface modified functional silica gel. X-ray photoelectron spectroscopy and FTIR were employed to confirm the reliability of the synthetic polymer. Scanning electron microscope was used to analyze the surface properties of the experimental materials. UV-spectrophotometer was employed to investigate the adsorption property and the concentration of Th(IV). Adsorption kinetics and adsorption isotherm were carried out. In pH 3.5, the adsorption equilibrium could reach a balance in 45 min, the resultant adsorbing capacity was 30.8 mg g^?1, and the remove ratio of Th(IV) was 88.1 %.     

Comparison of various dilutions and solid-phase extraction cleanup on the determination of ephedrine-type alkaloids and internal standard recovery in ephedra botanical raw material and powdered extract

A study was conducted to determine the effect of 3 dilution levels on the precision of the ephedra alkaloid method when used in conjunction with a solid-phase extraction (SPE) column. For the dilutions studied, SPE column cleanup is necessary because it promotes a greater recovery of the internal standard. However, overall, target precision values were not obtained on the test materials. It was determined that the SPE column is not the cause of the lower recovery in the more concentrated solutions. Significant signal suppression of the internal standard occurs in more concentrated solutions within the mass spectrometer. It is hypothesized that this lack of performance on the part of the SPE column may be linked to its inability to fully clean contaminants from the higher concentration solutions and/or a mass spectrometer overload, which resulted in the internal standard not fully correcting for signal suppression in more concentrated solutions. An internal standard is necessary, especially for accuracy, for the determination of all alkaloids, and only dilute solutions can be accurately analyzed. Due to the sensitivity of the mass spectrometer, it is recommended that the determination of ephedrine alkaloids in dietary supplements and botanicals should be studied using a standard graph at a level 10 x less than the current method. It is also recommended that the SPE column used should be evaluated on its need for the sample dilutions made to fit the newly recommended standard graph.     

Development and supply system of reference materials based on the Measurement Law in Japan

 Analytical instruments used for measurements of air and water pollution are calibrated by using reference materials such as standard gases and standard solutions. In Japan, since the middle of the 1970s, those reference materials which are traceable to the national standards maintained at national research institutes have been supplied to users by reference material producers. In order to establish the primary standards and to secure the traceability from the working standards to the national ones, various analytical methods such as coulometric, titrimetric and gravimetric analyses for purity determination and highly sensitive atomic spectrometry for trace analysis have been developed as the primary methods and reference methods. The Japanese Measurement Law, revised in 1992, has introduced a new traceability system in which a public organization, a "designated calibration body", can also prepare and maintain the national standards under the advice and instruction of national research institutes. The designated calibration body can provide calibration services to reference material producers (accredited calibration bodies) by using the national standards. The reference materials supplied in conformity with the traceability system include standard gases, pH standard solutions, metal standard solutions and non-metal ion standard solutions. Received: 4 October 1996 Accepted: 2 December 1996     

Determination of zinc in aqueous solutions by a combined no-standard electrochemical method with preliminary electrolytic separation of copper

A combined method for no-standard determination of zinc in aqueous solutions (calibration of the device against standard solutions or use of standard additions is not required) is suggested. The method is based on principles of stripping voltammetry and potentiostatic coulometry.     

Stripping voltammetry using sequential standard addition calibration with the analytes themselves acting as internal standards

A novel two-step standard addition calibration procedure for stripping voltammetry, whereby the analytes under investigation act as internal standards for each other, is described. In this way, the benefits of an internal standard for improving precision are obtained, without the requirement to add internal standard solutions. Only the standard solutions used to perform quantification are required. The proposed methodology has been tested against the traditional standard addition method with no internal standardisation, for the measurement of Zn, Cd, Pb and Cu in synthetic and real ambient air sample digests. The new procedure is shown to improve substantially precision and accuracy compared to traditional standard addition without internal standardisation.     

具有抗凝性能的肝素化ε-己内酯/L-丙交酯共聚酯的合成及电纺丝加工

以辛酸亚锡为催化剂, 1,4-丁二醇为引发剂, 制备出ε-己内酯/L-丙交酯共聚酯(PLCL). 以1-(3-二甲氨基丙基)-3-乙基碳二亚胺/N-羟基琥珀酰亚胺为缩合剂将肝素连接在PLCL两侧端基上. 采用 1H NMR技术测定了共聚酯端基的肝素化率; 用XPS分析了肝素化后聚酯中N和S含量, 利用甲苯胺蓝紫外分光光度计法测定了表面肝素含量, 并根据静态接触角测定结果讨论了材料表面的亲水性变化. 凝血酶原时间、凝血酶时间和部分凝血活酶时间测试数据表明, 肝素化后PLCL的抗凝血性能得到明显改善. 探索了该共聚酯进行电纺丝加工的可行性.     

具有抗凝性能的肝素化ε-己内酯/L-丙交酯共聚酯的合成及电纺丝加工

以辛酸亚锡为催化剂,1,4-丁二醇为引发剂,制备出ε-己内酯/L-丙交酯共聚酯(PLCL).以1-(3-二甲氨基丙基)-3-乙基碳二亚胺/N-羟基琥珀酰亚胺为缩合剂将肝素连接在PLCL两侧端基上.采用1HNMR技术测定了共聚酯端基的肝素化率;用XPS分析了肝素化后聚酯中N和S含量,利用甲苯胺蓝紫外分光光度计法测定了表面肝素含量,并根据静态接触角测定结果讨论了材料表面的亲水性变化.凝血酶原时间、凝血酶时间和部分凝血活酶时间测试数据表明,肝素化后PLCL的抗凝血性能得到明显改善.探索了该共聚酯进行电纺丝加工的可行性.     

Sample preparation procedure for the determination of sulphur and trace metals in oil products by the ICP with a minitorch using emulsions

A quick sample preparation method was used for the determination of sulphur and trace metals in oil and oily products by the ICP with a minitorch. Stable aqueous emulsions of oils and oil products were made by using two kinds of emulsifiers (one with low sulphur content, the other sulfonated). Aqueous standard solutions can be used for the preparation of calibration solutions. The contents of S, Al, Cr, Cu, Fe, Mg, Ni and Pb in aqueous emulsions were determined and the results were in good agreement with the composition of oil standard solutions used for control analysis procedure.