分光光度法同时测定人发中的钙、锌

将多元线性回归分析用于分光光度法同时测定人发中钙、锌元素的含量,讨论了该方法的原理,考察了最佳实验条件,建立了回归方程和线性方程。对6个模拟发样和2个人发样品进行了测定,结果令人满意。     

人发中锌、铜、铅含量的测定与评价

本文用极谱络合吸附波同时快速测定人发中的微量锌、铜、铅。测定了青岛市区不同年龄的人发样品336例,并对统计分析结果进行了评价。     

校正矩阵同时分光光度法测定人发中钙、镁、锌

将校正矩阵计算法应用于分光光度法中,同时测定了人发中的钙镁锌含量。讨论了方法原理和最佳实验条件,对４个发样和模拟样进行了测定,取得满意结果。     

极谱配合吸附波测定人发微量锰和铁

采用浓硝酸-高氯酸消化法结合锰铁-乙二胺极谱配合吸附波方法测定人发微量猛铁。对各种预处理方法进行了比较研究。测定了模拟人发、混合人发、国家一级标准物质人发样品以及某些肿瘤患者的发锰铁含量,均获得了满意结果。     

悬汞电极阳极溶出伏安法测定人发中的铜、铅、镉、锌

从人发中了解重金属对于人的危害有其重要的作用。阳极溶出伏安法对于测定重金属来说其价格/收益比例是最好的。Chittleborough等用悬汞电极上的微分脉冲阳极溶出伏安法测定了人发中的铜、铅、镉、锌。但所用仪器较昂贵,我们实验了用悬汞电极的线性扫描阳极溶出伏安法测定人发中的这四种元素,结果是满意的。     

高频感耦等离子体光谱法测定人发中铁、锰、铬、铜、钛和锌等元素的研究

人发微量元素分析在医学,环境科学,法医学等方面具有极其重要的意义。ICP-AES法具有快速简便,检测极限低,精密度高,干扰少,多元素同时测定等优点,用于人发中微量元素的分析具有突出的优越性,本文研究了ICP-AES摄谱法同时测定发样中铁、锰、铬、铜、釱、锌的最优化条件,拟定了测定方法,取得了满意的结果。实验部分 (一)仪器与试剂 1.ICP装置:GP_(3.5)-D_1型高频发生器。功率3.5KW,频率35MHz,耦合线圈φ6mm紫铜     

洗洁精-金试剂吸光光度法测定人发中微量铜

利用洗洁精为增敏、增溶剂试,以金试剂为显色剂,拟定了吸光光度法测定了人发中微量铜的方法,方法简便快速,准确度高,人发中常见离子不干扰铜的测定。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定人发中铜、锌、钙、镁、铁

样品经硝酸-高氯酸消化溶解,高氯酸冒烟,盐酸溶解盐类后,在盐酸(5%)介质中,在选定的测定条件下,用电感耦合等离子体原子发射光谱(ICP-AES)法测定人发中微量元素铜、锌、铁、镁、钙。选择Cu 327.3、Zn 206.2、Fe 238.2、Mg 279.5、Ca 315.8nm分别作为铜、锌、铁、镁、钙的分析线与混合标准溶液同时测定;方法加标回收率为98.6%～101%,铜、锌、铁、镁、钙的精密度(RSD,n=8)为0.37%～2%,准确度(RE)为-3.4%～1.15%,检出限分别为0.002 3、0.001 6、0.004 6、0.003 0、0.001 4μg/mL。方法克服了分光光度法和原子吸收光谱法操作繁琐、周期长、成本高、灵敏度低等缺点。用于测定人发样品中的铜、锌、铁、镁、钙元素,测定结果与原子吸收光谱法测定值基本一致。经GBWO7061标准物质和自制标样分析验证,测定值与标准值吻合,结果准确可靠。     

分光光度法同时测定人发中的钙,锌

将多元线性回归分析用于分光光度法同时测定人发中钙，锌元素的含量，讨论了该方法的原理，考察了最佳实验条件，建立了回归方程和线性方程。对６人模拟发样和２个人发样品进行了测定，结果令人满意。     

锌、铜元素与优生优育

郑州市第一人民医院对185例分娩前健康孕妇与足月正常新生儿作发锌、铜测定，其中85人作血清锌、铜测定，10月后随访62例母婴发锌、铜含量．以探讨微量元素锌、铜与优生优育的关系。     

Determination of Vanadium with Chlorosubstituted Hydroxamic Acids for Photometric and Atomic Absorption Spectrophotometric Determination

Abstract

The eight newly synthesized chlorosubstituted hydroxamic acids are described for the extraction and spectrophotometric determination of vanadium. The sensitive and selective reagent, N-m-Chlorophenylpalmito hydroxamic acid, (m-CPPHA), which gives violet coloured vanadium complex was extracted with chloroform from 6M HCl. The violet coloured complex thus obtained has a maximum absorbance at 520 nm and molar absorptivity 4.9 ± 10³1mol^?1cm^?1. The Beer's law obeyed in the region 0.50-12.0ppm. Effects of acidity, reagent concentration, diverse ions have also been investigated. A comparison has been made with atomic absorption spectrophotometric method. Vanadium has been determined in the environment, e.g. plant, soil, rock, etc.     

消毒剂产品中三氯新的测定及其稳定性研究

 采用反相高效液相法测定消毒剂产品中的三氯新。在KromasilC18柱 (2 0 0mm× 4 6mmi d )上 ,以甲醇 乙腈 水 (含 0 0 2mol/LKH2 PO4,pH 2 7) (体积比为 4 0∶4 0∶2 0 )溶液为流动相 ,2 80nm波长下检测 ,样品用流动相超声溶解。三氯新的回收率为 94 2 %～ 10 2 2 % ,相对标准偏差 (RSD)为 2 2 %～ 3 0 %。方法操作简便 ,精密度和准确度高 ,适合三氯新的快速分析。在 5 4℃时保存 14d和 37℃时保存 90d后 ,标准品和样品的含量没有明显变化 ,证明三氯新具有良好的稳定性。     

Determination of Mn and Na in geological samples

Neutron activation technique using a low intensity²⁵²Cf source has been applied for Mn and Na analysis in geological samples. The series of samples tested in the present work were collected from the boreholes Nádudvar-9, Hajdúböszörmény-1 and Nagyecsed-1 in Hungary, from different strata.     

Determination of isotopic uranium in food and water

The U.S. Food and Drug Administration (FDA) conducts surveys of foods both domestic and imported for the presence of radioactivity. It does not routinely analyze for the actinides, specifically uranium, as it has been shown by previously by studies as reported by WELFORD and others that the concentration in food is very low. This was the result of a "Tri-City" study. However, at specific sites, the FDA has been requested to analyze for uranium. The concern is that either 'enriched' or 'depleted' uranium has been introduced into the environment and possibly contaminated the food supply. In addition some concern has been raised that water from wells or other sources used for processing food may contain uranium, both natural, depleted or enriched. This paper will discuss the methodology for the determination of isotopic uranium, specifically for uranium-238 (depleted) and/or uranium-235 (enriched) in the analyses of food and water samples and the results of these surveys.     

Determination of ammonia in tobacco and smoke

A gas chromatographic method has been developed for the determination of ammonia in tobacco and smoke. Ammonia is liberated from tobacco by a microdiffusion technique using a Conway diffusion cell. Bubbler traps containing dilute sulphuric acid are used to collect the ammonia from smoke.     

Determination of energizers in energy drinks

The method of UV/VIS derivative spectrophotometry for the determination of caffeine and B vitamins in energy drinks after solid phase extraction has been developed. Caffeine has been determined in the mixture with B₂ vitamin with zero-crossing technique from the I derivative spectra (λ = 266.8 nm), and B₃ in mixture with B₆ vitamin from the II derivative spectra (λ = 280.1 nm). B₁₂ vitamin has also been determined in a three-component mixture with vitamins B₃ and B₆. Taurine in drinks has been determined from the basic spectra after derivatization with ninhydrin (λ = 570 nm).     

Collection and Determination of Mercury in Air

A method has been developed for the determination of low concentrations of mercury in air (nanograms/m³), i.e. in the range of the believed natural levels of mercury in the atmosphere (20 ng/m³). Mercury vapour has been collected from up to 200 1 of air in glass tubes containing thin films of gold on sieved ceramic powder. In the laboratory the absorbed mercury was then released into a quartz-window cell by heating the tube in an oven at 500°C.

In this paper it is demonstrated that, by using extremely thin films of precipitated gold, quantitative recovery is obtained and memory effects, which result from the use of thicker films, are avoided.     

Determination of the absolute stereochemistry of Etzionin

The absolute configuration of Etzionin, a marine peptide-like compound isolated in 1989 from a red tunicate collected from the Red Sea has been determined by a combination of synthetic and spectroscopic procedures. Finally, its absolute stereochemistry has been established as 3S,3′R.     

Determination of counting losses and pile-up rejection in ionizing radiation spectrometry

The spectrometric system for ionizing radiation measurement with pile-up rejection and counting losses correction has been described. The results for HpGe, Ge(Li), Si(Li) and surface barrier detectors have been presented. The total count rate ranged from 500 to 10⁵ cps and different radioisotopes have been used. The counting losses correction accuracy has been within ±1% with tenfold reduction of background from pile-up pulses. The possibility of the system application for radiation intensity measurement of the mixture of short- and longlived radioisotopes has been discussed.