Flame AAS determination of thallium in soils

The anion-exchange enrichment of TlCl(-)(4) coupled to flame AAS is applied to the determination of the total, pseudo-total (not bound in the silicate matrix) and mobile (plant available) content of thallium in soils. Ascorbic acid is used as a new efficient eluent of thallium. The limit of detection of the method is 0.04,mug/g, the relative standard deviation at the 1 mug/g level is about 3%. The method is rapid and simple.     

无火焰原子化-原子吸收光谱法测定不锈钢中砷量

在火焰原子吸收分光光度计火焰上方放置一只特制的不锈钢管作为原子化器,将不锈钢样品溶液定量滴加在不锈钢原子化管内,在乙炔-一氧化二氮高温火焰下对不锈钢样品中微量砷的含量进行无火焰原子化测定,以标准加入法进行定量分析.方法的特征质量为59 pg/1%,绝对检出限(3σ)为3.6 pg.     

火焰原子吸收光谱法测定电尘中高含量镉

对于高含量的镉,通常用EDTA滴定后加入碘化钾将镉从其EDTA的络合物中络合出来,再用锌标准溶液返滴定这部分EDTA。但当试样复杂时常会出现终点不明显,影响测定结果的准确性,若试样中含有较高含量的铅锌时,须沉淀过滤分离铅后再测定,操作手续较繁琐,且碘化钾用量大。     

Abatement of Trichloromethane by Using Nonthermal Plasma Reactors

This work investigated the destruction of a halogenated carbon (trichloromethane) using different types of nonthermal plasma reactors. Three reactors, i.e., a surface discharge reactor, a dielectric-packed bed reactor and a barrier discharge reactor with a perforated dielectric tube, were compared with respected to the trichloromethane destruction efficiency. The effect of oxygen content and input power on the trichloromethane destruction was examined, and the byproducts were analyzed to elucidate the destruction pathways. The dielectric-packed bed reactor was found to show better performance in the trichloromethane destruction than the other two reactors. The increase in the oxygen content decreased the destruction efficiency, and the highest destruction efficiency was obtained at oxygen content 0.5%. The calculations for electron-molecule collisions indicated that the most abundant reactive species initiating the destruction of trichloromethane are metastable nitrogen molecules. The major byproducts were CO and Cl₂, and the formations of NO₂ and N₂O were also significant.     

火焰原子吸收光谱法测定海水中微量铁和锌

海水中铁和锌为微量金属元素,在海水富营养化研究和赤潮调查的监测中,铁、锌是必测项目,但《海洋监测规范》中未见有关海水中铁的分析方法。     

火焰原子吸收光谱法连续测定锌精矿中锑钴镍

国标方法测定锌精矿中锑和镍，采用酒石酸王水溶样，萃取分离锌，比色法测定；钴的测定没有国标方法。比色法测定流程长，使用毒性有机物，工作强度大，有采用X-射线荧光光谱法测定，也有采用火焰原子吸收光谱法测定锑、钴和镍，但需将锑与钴、镍分开测定。本法用氟化氢铵、酒石酸、逆王水溶样可实现锑、钴和镍在同份样品溶液中快速连续测定，方法快速稳定、重现性好。     

火焰原子吸收法测定茶叶中的微量元素

使用同一消化液,溶解消化样品,以稀盐酸为底液,火焰原子吸收分光光度法对茶叶中Mn、Fe、Zn、Cu、Pb五种微量元素进行了测定。结果表明,标准曲线线性关系良好(r＞0．999)、精密度和准确度均较好,能够达到分析要求。     

色谱/原子吸收联用系统中卧管式微火焰原子化离子化同步检测器的研究与应用

 介绍了一种新型的卧管式微火焰原子化离子化同步检测器 ,对其结构、工作原理及性能进行了研究。将其应用到色谱 /原子吸收联用系统中 ,实现了有机金属化合物以及与其共存的有机化合物的同步检测。有机金属化合物 (二乙基汞 )的原子吸收信号检出限为 2 5× 10 -11g/s;有机化合物 (苯 )的离子化信号检出限为 1 0× 10 -11g/s。     

Determination of Cd and Li in U3O8 Powder by AAS With Carbon Cup Atomization

Abstract

The flameless atomic absorption spectrometric technique has been applied for determination of Cd and Li in U₃O₈ by direct atomization of the powder samples in the carbon cups. Results obtained indicate that Cd and Li can be estimated in the ranges 0.05–2 ppm and 1–25 ppm respectively using 1 mg sample, Precision of the method for the two elements varies between 7–9%. Trace concentrations of transition elements do not affect their estimation.     

Flame AAS determination of dopants and trace metal impurities in single crystals of potassium titanylphosphate

A flame AAS method is used for the determination of dopants and impurities in potassium titanylphosphate (KTP) single crystals. Sample digestion using sulphuric acid and hydrofluoric acid is proposed as being the most appropriate procedure. The effect of major and minor components in the sample solution on the analytical signal is studied. The content of the dopants Cr, Mn and Ni (at a level of about 1 mg g(-1)) as well as the content of the impurities Fe, Na, Mg, W and Al (from 4 mug g(-1), depending on the trace metal) in the KTP single crystals is determined. The precision of the method is characterized by a relative standard deviation of 3-10%. The accuracy is checked by comparison with ICP-AES data for the trace element content in the KTP single crystals.     

分光光度法与火焰原子吸收光谱法测定钢中硼的比较

提出了萃取-分光光度法和火焰原子吸收光谱法测定钢中硼的两种方法,比较了两者的线性范围、检出限、样品测定结果等.试验发现:分光光度法和火焰原子吸收光谱法在硼含量分别为0.11～3.2 mg·L-1和0.05～3.24 mg·L-1范围内时,吸光度与其质量浓度呈线性关系,检出限(3S/N)分别为0.033,0.036 mg·L-1.经检验,两种方法的测定结果之间无显著性差异.     

氧化氩氮-乙炔火焰原子吸收光谱法测定钛铝钒合金中铝

铝常用的测定方法有碱分离-EDTA络合滴定法、氟化钠分离-EDTA容量法、络天青S光度法、铜铁试剂分离-络天青S光度法、络天青S-氯化十六烷基吡啶光度法、偶氮氯膦Ⅰ光度法、苯甲酸铵分离-EDTA络合滴定法、氢氧化钠分离-六氟铝钾沉淀酸碱滴定法、原子吸收光谱法等。铝作为强抗氧化剂加入到钛铝钒合金中,具有细化晶粒、改善抗氧化和耐腐蚀性能的作用,但多了会对性能造成不良影响。因此必须对原材料中铝的量严格控制。化学法测定钛铝钒合金中铝含量,缺点是使用的试剂种类多,而且方法比较复杂繁琐,不便于掌握。用火焰原子吸收光谱法测定钛铝钒合金中铝,方法简单、快速、易于掌握、同时测定、精确度高,能满足原材料复检过程中分析的需要。     

火焰原子吸收法间接测定钢中硼和磷

提出了溶剂萃取-火焰原子吸收光谱法间接测定钢中硼和磷的分析方法.在弱酸性介质中硼酸、苯羟乙酸、铁(Ⅱ)以及邻二氮菲能形成稳定的多元离子缔合物,被1,2-二氯乙烷萃取后再用去离子水反萃取,然后测定水相化合物中的铁;在盐酸介质中,磷酸根与钼酸铵形成磷钼杂多酸,被甲基异丁基甲酮萃取后,测定有机相磷钼杂多酸中的钼.并可分别间接测定硼和磷.在优化的反应条件下,硼和磷的质量浓度分别在0.12～3.24及0.04～1.00mg/L范周内时,吸光度与质量浓度之间具有良好的线性关系,硼和磷的检出限分别为0.036和0.015mg/L.以8份样品空白进行测定,得硼和磷的标准偏差分别为1.2%和0.5%.方法用于钢样中微量硼和磷的测定,拓展了原子吸收分光光度计的应用范围.     

Flame AAS determination of lead in water with flow-injection preconcentration and speciation using functionalized cellulose sorbent

The on-line solid phase extraction of trace amount of lead in flow-injection system with flame AAS detection was investigated using cellulose sorbents with phosphonic acid and carboxymethyl groups, C(18) sorbent non-modified and modified with Pyrocatechol Violet or 8-quinolinol, commercial chelating sorbents Chelex 100 and Spheron Oxin 1000, non-polar sorbent Amberlite XAD-2 modified with Pyrocatechol Violet and several cation-exchange resins. The best dynamic characteristics of retention were observed for functionalized cellulose sorbents. For Cellex P assumed as optimum sorbent, elution with a separate fractions of nitric acid and ethanol allows the differentiation between tetraalkyllead and sum of inorganic lead and organolead species of smaller number of alkyl groups. The detection limit for the determination of inorganic Pb(II) was estimated as 0.17 microg/l. at preconcentration from 50 ml sample at a flow rate of 7 ml/min.     

Quantitative Relationship between the Rate Constant of Quadratic Chain Branching and the Rate of Nonthermal Flame Propagation

The pattern of the quantitative relationship between the rate constant of the quadratic branching of reaction chains and the rate of nonthermal flame propagation is determined by the example of the chain decomposition of nitrogen trichloride. It is shown that, due to this functional relationship, the values of the rate constants for the NCl₂ + NCl₂ = N₂ + 4Cl reaction determined by the stationary rate of the decay of the flame of the nitrogen chloride and, independently, by the spectroscopic kinetic study of NCl₂ radical consumption are almost the same.     

Decontamination of Polymeric Surgical Sutures Covered with Bacterial Biofilms Using Nonthermal Plasma

Plasma Chemistry and Plasma Processing - The objective of the study was to investigate the bactericidal effectiveness of atmospheric pressure nonthermal plasma (NTP) on biofilms of Staphylococcus...     

碳酸钙共沉淀原子吸收法测定天然水中锶

采用CaCO3共沉淀富集天然水中痕量锶后，再用空气-乙缺焰原子吸收法测定，使方法灵敏度提高一个数量级。本法简便，准确，最低检出限达0.0012mg/L。对0.10mg/L的锶水样，十次测定的标准偏差为0.0082，相对标准偏差为8.2%。