Determination of Atmospheric Ozone Using the Centrifugal Photometric Analyzer

Abstract

The production of formaldehyde from the selective cleavage of the double bond of 4-allyl-2-methoxyphenol (eugenol) by ozone permits the specific determination of ozone in air samples. The formaldehyde is determined by a modification of the West-Gaeke procedure for sulfur dioxide. Increased speed, accuracy, and reproducibility is achieved because of the parallel analysis technique of the centrifugal photometric analyzer.     

Applications of the GeMSAEC Centrifugal Photometric Analyzer in Environmental Analysis the Determination Of Phosphate

Abstract

The ORNL GeMSAEC Photometric Analyzer is described briefly. The use of a small computer with this instrument, for data acquisition and handling and for automatic printout of the analytical results, is also described. The determination of orthophosphate by the molybdenum-blue procedure has been utilized in a statistical evaluation of the GeMSAEC system, and the results are presented. This study illustrates the considerations that are important in designing procedures for the GeMSAEC type of analyzer, and the advantages that accrue.     

Catalytic Photometric Determination of Selenium by Flow Injection Analysis

A method is developed for the determination of trace amounts of selenium by flow injection analysis based on the catalytic effect of this element. Catalytic enhancement by selenium for the reduction of picrate ion by sodium sulfide was used and photometrically measured at the wavelength, 470nm. Optimum conditions were determined for temperature, pH, the concentrations of picrate and sodium sulfide, and also the conditions of the flow system; injection of sample volume, flow rate and mixing coil length. With these conditions a good linear relationship was obtained for selenium in the range from 0.1 ppm to 1.0ppm and the detection limit was about 5ppb (two times of the noise). Interference by the diverse ions can be avoided with the use of a precolumn cation exchanger (Dowex 50) and by masking with EDTA in the conditional stream.     

基于反射式光度传感器的自动光度滴定仪的研制及应用

研制了一种以颜色变化为滴定终点的自动光度滴定仪,仪器以光度传感器为核心,包括光度探头、滴定装置、AT89S52单片机、电磁阀、二极管和磁力搅拌器等部件。传感器采用开放设计,对溶液吸光度变化反应迅速。仪器用于红醋酸度的测定,所得结果与电位滴定分析法结果相符。     

生物样品中硒的测定方法研究进展

硒是生物体必需的微量元素,硒的毒性和营养功能与其总量有关,硒的测定具有重要意义。综述了生物样品中硒的测定分析方法研究进展,包括：样品预处理方法,荧光法,原子吸收光谱法,原子荧光光谱法,电感耦合等离子体发射光谱法,吸光光度法,化学发光法,电分析法,中子活化分析法,色谱法等。     

A New Kinetic‐Photometric Method for Determination of Carbimazole

A new kinetic photometric method for determination of carbimazole (CBZ) is described. The proposed method is simple, rapid, inexpensive and sensitive for the determination of CBZ in pure and tablet forms. This method is based on the inhibitory effect of carbimazole on the palladium(II)‐catalyzed reaction between neutral red (NR) and hypophosphite (HP) ions. The effect of various parameters such as dye, hypophosphite, and Pd(II) concentrations, pH, ionic strength, and temperature were optimized. The calibration graph was linear in the range 0.04–0.30 ppm (n = 9, r = 0.9972) and the detection limit was 0.02 ppm. The relative standard deviation of the developed method was 0.70% (n = 10). The proposed method was applied for the determination of carbimazole in pure and tablet forms.     

硅钼蓝光度法测定碳化硅中二氧化硅的含量

采用氯化钠-盐酸-氢氟酸溶解碳化硅样品,加钼酸铵使硅酸离子形成硅钼杂多酸,然后用1-氨基-2-萘酚-4-磺酸还原剂将其还原成硅钼蓝,在700nm波长处测定其吸光度,从而测得碳化硅中的二氧化硅含量。考察了称样量、水浴温度、水浴加热时间、样品储存容器、显色反应时间等因素对测定结果的影响,优化了测试条件。二氧化硅的质量浓度在0．25-12．5mg／（100mL）的范围内与吸光度呈良好的线性关系,线性相关系数r=0．99986。加标回收率为99．2％～100．9％,测定结果的相对标准偏差为0．76％（n=6）。     

半自动催化光度滴定法测定生物样品中的锰

报道了以催化光度返滴定法来测定锰含量的新方法 .以EDTA作络合剂 ,Mn(II)为返滴定剂 ,滴定终点由锰 (II)催化高碘酸钾氧化结晶紫的褪色反应来指示 .在体系中加入表面活性剂 (TritonX - 10 0 )可改善反应条件 ,使测定可在室温下进行 ,用半自动化装置使操作连续、快速、简便 .用该方法测定鸡肝、人发、啤酒中的锰含量 ,结果与原子吸收光谱法所得结果相吻合     

生物样品中硒的测定方法及形态分析研究进展

硒的毒性和营养功能不仅与其总量有关,而且与其存在的化学形态有关。因此,硒的测定及形态分析对于了解不同形态的硒化物在生物体和环境中的迁移转化规律具有重要意义。文章综述了生物样品中硒的测定分析方法以及形态分析研究进展。     

Determination of Low Level Sulfides in Environmental Waters by Automated Gas Dialysis/Methylene Blue Colorimetry

Abstract

A sensitive and rapid automated method has been developed for the selective analysis of acid extractable sulfide in environmental samples by combining gas dialysis separation techniques with methylene blue detection procedures. Acid extractable sulfide is separated from the sample matrix by the gas dialysis membrane and subsequently trapped in a dilute sodium hydroxide receiving stream. This stream is reacted with N, N-dimethyl-p-phenylenediamine and ferric chloride to produce methylene blue which is then quantitated colorimetrically at 660 nm. For standards and nonturbid environmental samples, there is good agreement between the results obtained by this procedure and the standard methylene blue method. The effect of interferences on the accurate determination of sulfide by both methods was also examined and it was found that cupric ions significantly interfered with sulfide estimation. To obtain adequate sulfide recoveries in tap water and environmental samples ascorbic acid must be added as an antioxidant. A detection limit of 2 μg/L of sulfide has been obtained using this procedure.     

铋盐-钼蓝示差光度法测定磷矿石中五氧化二磷

采用硝酸、盐酸溶矿,用高氯酸将偏磷酸氧化为正磷酸,在铋盐催化下磷与钼酸铵反应生成黄色磷钼酸铵,此磷钼酸铵能被抗坏血酸还原为磷钼蓝,以示差光度法直接测定.其最大吸收波长为700nm,表观摩尔吸光系数为1.60×10⁵L/(mol·cm),磷在3～5μg/mL范围内符合比耳定律,试样加标回收率为97.10%～100.86%,9次测定的相对标准偏差为1.08%～4.66%.适用于磷矿石中5%～38%五氧化二磷的测定.     

蛋白质快速检测仪测定乳及乳制品中蛋白质

采用研制的蛋白质快速检测仪,系统地考察了温度、时间和干扰物质等因素对蛋白质测定的影响及检测仪的重复性,并将检测仪应用于新鲜乳、纯牛奶、牛奶饮料(核桃、燕麦、红枣)、牛初乳、奶粉、豆奶粉、豆浆粉和鸡蛋等样品中蛋白质的定量测定.实验结果表明,在17～40℃条件下,蛋白质试剂与蛋白质在1 min内即可完成反应,整个蛋白质含量...     

光度分析法测定痕量硒的研究与应用

就目前研究较多的测定痕量硒的光度分析法进行了综述,着重介绍了分光光度法、荧光光度法、散射光谱法、原子吸收光谱法、电感耦合等离子体发射光谱等方法.     

催化光度法测定人发中微量碘的研究与应用

建立了催化光度法用于人发中微量碘的测定,研究了发碘的测试条件,重点研究了发样溶解条件对测试结果的影响,采用300 g/L的K2CO3溶液浸泡,105℃烘干后于550℃熔融分解。结果表明,该法的检出限为0.038μg/g,相对标准偏差为6.5%。用于儿童发碘分析,结果令人满意。     

气相色谱–火焰光度法测定进口天然气中4种形态硫

建立气相色谱–火焰光度法测定进口液化天然气中4种形态硫的方法。探讨了色谱柱、进样口温度、分流比、柱流速、升温程序和FPD检测器等对测定结果的影响。在优化的实验条件下,评价了方法的可靠性。4种形态硫化物的质量浓度在10.0~200.0μg/L范围内,其对数与峰面积对数呈良好的线性关系,线性相关系数r在0.983 3~0.999 2之间,检出限为1.7~7.7μg/L,测定结果的相对标准偏差为0.56%~0.68%(n=5)。用该法测定天然气形态硫标准气体,测定值与标准值相比,相对误差为–1.6%~–1.2%。该方法具有较高的准确度,可应用于进口天然气中4种形态硫的分析。     

溶剂浮选光度法测定痕量铜

提出了利用溶剂浮选富集ＤＤＴＣ－Ｃｕ（Ⅱ）体系测定水样中痕量铜的方法（ＤＤＴＣ为二乙胺二硫代甲酸钠）。质量浓度的检出限为０．０５ｎｇ·ｍＬ＾－１,线性范围为０．０￣６．０ｎｇ·ｍＬ＾－１,测定含Ｃｕ（Ⅱ）４．０ｎｇ·ｍＬ＾－１的样品,相对标准偏差为０．８５％,已用于天然水中Ｃｕ（Ⅱ）的测定。     

Determination of Beryllium in Natural Waters Using Atomic Absorption Spectrometry With Tantalum-Coated Graphite Tube

Abstract

In the present paper a method for direct determination of beryllium in natural waters, especially in surface waters, using atomic absorption spectrometry with graphite furnace is described. Two procedures are compared, using an ordinary graphite tube and matrix modifier Mg(NO₃)₂, and using a tantalum coated tube without any modifier added. The detection limit (3[sgrave]) of the proposed method using the tantalum-coated tube is proved to be 0.02 μgBe/1. With the developed method the Be content in natural water samples collected from highly polluted and reference regions of Bohemia were determined. A certified reference material (IAEA/W-4) was also analysed to prove the accuracy of proposed method.     

光度分析法在药物分析中的研究与应用

综述了国内近年来光度分析法在药物分析中的研究与应用情况.就分光光度法、荧光光度法、化学发光法3种重要的分析方法,从反应条件、线性范围、灵敏度等方面介绍了光度分析法对不同反应体系的研究现状,展望了光度分析法在药物分析中的发展方向.     

亚甲基蓝分光光度法测定锑浸出液中硫化钠

湿法炼锑中常采用硫化钠作为从锑矿中提取锑硫化物的浸出剂。准确测定锑浸出液中的硫化钠浓度对掌握和完善湿法炼锑工艺、提高生产效率有重要作用。将亚甲基蓝分光光度法用于锑浸出液中硫化钠的测定,考察了波长选择、体系酸度、显色时间、基质干扰等条件,测评、优化了方法;将方法应用于锑浸出液中硫化钠的测定,方法检出限为0.002mg/L,测定结果相对标准偏差≤3%,加标回收率≥90%。方法能较理想地应用于锑浸出液中硫化钠的测定,丰富了锑浸出液中硫化钠的测定方法,也为相关研究提供了支持与参考。     

亚甲基蓝分光光度法测定锑浸出液中硫化钠

湿法炼锑中常采用硫化钠作为从锑矿中提取锑硫化物的浸出剂。准确测定锑浸出液中的硫化钠浓度对掌握和完善湿法炼锑工艺、提高生产效率有重要作用。将亚甲基蓝分光光度法用于锑浸出液中硫化钠的测定,考察了波长选择、体系酸度、显色时间、基质干扰等条件,测评、优化了方法;将方法应用于锑浸出液中硫化钠的测定,方法检出限为0.002mg/L,测定结果相对标准偏差≤3%,加标回收率≥90%。方法能较理想地应用于锑浸出液中硫化钠的测定,丰富了锑浸出液中硫化钠的测定方法,也为相关研究提供了支持与参考。