二溴对甲基偶氮甲磺光度法测定钢中微量锶

研究了二溴对甲基偶氮甲磺与锶生成2:1兰色络合物进行钢中微量锶的测定.该法λ_(max)=638nm,摩尔吸光系数E_(638)=5.01×10~4,锶量在0.02～0.34μg/L范围内服从比尔定律.方法已用于钢中微量锶的测定,结果满意.     

黄曲霉毒素速测仪的模块化设计方法

为了快速准确地测定粮食和饲料中黄曲霉毒素的含量,设计了基于C8051F020单片机的黄曲霉毒素速测仪.速测仪采用免疫亲和柱-荧光分光光度法进行检测,克服了传统分析方法在标定标准物和样品预处理过程中的不足,显著降低了对操作人员的毒害和环境的二次污染,提高了分析速度.速测仪硬件电路使用模块化设计方法,以提高仪器运行的稳定性.光电转换元件使用具有极高灵敏度和超快时间响应的端窗式光电倍增管,测量线路使用高精度、低漂移集成电路,保证了仪器的灵敏度和测量精度.速测仪结构紧凑,仪器成本低,重复性好,适合现场速测和普及使用,实际应用效果良好.     

Determination of Analytical Wavelength in Derivative Spectrophotometry

Abstract

The work presents two methods for preliminary determination of analytical wavelength when a binary system is analysed by derivative spectrophotometry. “The method of disturbing effect” involves the recording of derivative spectra of a series of two-component solutions where the concentration of one component of the mixture remains unchanged, whereas the concentration of the other changes. “The method of sixteen solutions” involves the recording of derivative spectra of a series of 16 solutions, in which to four concentrations of the one component correspond four different concentrations of the other component of the mixture.     

采油微生物发酵液中各组分对原油量测定的影响

原油量的测定是原油及其产品分析的必要环节,根据芳香烃在255nm具有特征吸收峰,可以通过测定芳香烃量间接表征原油量。本研究采用紫外分光光度法测定原油量,分析采油微生物发酵液中各组分、pH和采油微生物细胞内含物对原油量测定的影响。结果表明,上述因素对该方法测定原油量均没有显著影响,采用紫外分光光度法可以快速、准确地测定微生物采油过程中的原油量。     

间接荧光光度法测定痕量铈

基于在无荧光性的铈（Ⅳ）体系中加入抗坏血酸后生成有特征荧光的铈（Ⅲ）离子,体系中再加入一定浓度的甲醛溶液后,新体系的荧光性得到更大强度的增敏．据此建立了一种间接测定痕量铈（Ⅳ）离子的新方法．利用该方法铈（Ⅳ）离子浓度在1×10^-6mol／L～1×10^-4mol／L范围内呈良好的线性关系,检出限为7．2×10^-6mol／L．此方法具有操作简便、灵敏度高、选择性好等优点．     

荷移分光光度法测定多杀菌素

建立一个新方法测定多杀菌素发酵液中多杀菌素含量.用分光光度法研究多杀菌素与碘在乙醇中的荷移反应,形成的络合物中多杀菌素与碘分子的摩尔比是2:3,生成的络合物在290 nm和360 nm处有2个吸收峰,表观摩尔吸光系数分别是3.89×103和2.35×103L/( mol·cm),当多杀菌素浓度为200 mg/L时,相对标准偏差(RSD)为0.712％(n=9).利用本法测定多杀菌素发酵液中有效成分多杀菌素的含量,并与文献报道的高效液相色谱法进行比较,两者结果基本一致,回收率为98.2％.     

1,2-萘醌-4-磺酸钠分光光度法测定甘氨酸

建立了用1,2-萘醌-4-磺酸钠测定甘氨酸的新方法。研究表明：1,2-萘醌-4-磺酸钠与氨基酸在pH为10.0的缓冲溶液中反应,生成组成比为1∶1的浅红色产物,最大吸收波长λmax=474 nm,表观摩尔吸光系数ε=2.8×103L.mol-1cm-1。甘氨酸浓度在0.4～80 mg/L范围内呈良好的线性关系,线性回归方程为A=0.017 64＋0.013 34c（mg/L）,线性相关系数r=0.999 3,检测限为0.12mg/L,R.S.D为0.64﹪,平均回收率为99.7%以上。本法用于测定药物样品中甘氨酸的含量,结果满意。     

U.v. absorbers in sun cosmetics 1978

A comprehensive survey has been carried out to establish which sun-screen agents are used by the cosmetics industry in Holland. During 1978, some 200 cosmetic sun preparations, composed of forty-eight brands, were purchased and analysed to determine which u.v. absorbing compounds were present. Most of those found were identified and quantified by means of thin layer chromatography and u.v. spectrometry. A basis for this work was the proposal by the European Cosmetic Manufacturers to produce a positive list of u.v. absorbers. It was felt that by carrying out this survey, some priority could be placed on the most popular materials used by the industry. When comparing those found with the European list of u.v. absorbers 1978, only twenty-four of the sixty compounds listed could be identified in the samples. The six most frequently used were found to be:

• 1 2-Ethylhexyl.p.methoxycinnamate (nineteen brands).
• 2 2-Phenylbenzimidazole.5-sulphonic acid (eleven brands).
• 3 2-Ethoxyethyl.p.methoxycinnamate (nine brands).
• 4 3 (4′Methylbenzylidene)D,D,L-camphor (seven brands).
• 5 3-Benzylidene.D,L-camphor (six brands).
• 6 2-Hydroxy.4-methoxy.benzophenone (six brands).

Usage levels varied from 0.4% up to 6.8%. Twenty-two products used a combination of two, and four products a combination of three sun-screens. Les filtres u.v. dans les produits anti-solaires 1978     

新型显色剂NPABST与镉的显色体系研究

以作者新合成的1-(5-硝基-2-吡啶)-3-(偶氮苯-4-磺酸)-三氮烯[1-(5-nitro-2-pyridyl)-3-(azobenzene-4-sulfonic acid)-triazene,简称NPABST]为显色剂,研究了它与镉的高灵敏显色体系。研究结果表明:在pH值为10~10.8的Na2B4O7-NaOH缓冲溶液中,NPABST在非离子表面活性剂Tween-80存在下可与Cd2+形成红色稳定的配合物,其最大吸收波长为525nm,摩尔吸光系数为1.8×105L.mol-1.cm-1。