5—Br—PADAP一阶导数光度法同时测定钴和镍的研究

本文研究了５－Ｂｒ－ＰＡＤＡＰ与钴，镍反应的导数行为，利用一阶导数光度法同时测定钴和镍的新方法。用所建立的方法对化学试剂中的钴和镍的含量进行了同时测定，结果令人满意。     

一阶导数紫外分光光度法测定左旋舒必利片剂含量

报道用一阶导数紫外分光光度法测定左旋舒必利片剂含量,检测波长λ１＝２７５ｎｍ,λ２＝３００ｎｍ,线性范围为４０～２００μｇ／ｍＬ,相关系数γ＝０．９９９９,回收率高,此方法简单,结果可靠。     

分光光度法同时测定镀液中钴和镍

研究了在pH为8.0的氯化铵-氨水缓冲溶液中,以4-(2-吡啶偶氮)-间苯二酚为显色剂,应用双波长K系数分光光度法同时测定镀液中的钴和镍。钴以512 nm/482 nm为波长对,其线性范围为0.080~1.0μg/mL;镍以496 nm/526 nm为波长对,其线性范围为0.040~1.0μg/mL。此法用于合金镀液中钴和镍的同时测定,取得了较满意的结果。     

一阶导数分光光度法测定片剂中司帕沙星

建立了用一阶导数分光光度法测定司帕沙星的新方法,该方法具有操作简便、灵敏度高、选择性好等特点,用于测定司帕沙星片剂中司帕沙星的含量,结果令人满意。     

导数分光光度法测定布洛芬栓剂

<正> 布洛芬栓剂是由布洛芬、基质山苍子油脂和极少量的表面活性剂吐温80组成的,其解热、镇痛效果比一般剂型的好,临床疗效已有报道。布洛芬在波长265或273纳米处有吸收蜂,但由于基质在该两处也有少许吸收,因而测得的含量偏高(见图1),改用一阶导数分     

双波长分光光度法同时测定电镀液中的钴和镍

考察了以4-(2-吡啶偶氮)-间苯二酚(PAR)作为显色剂,用双波长分光光度法同时测定电镀液中的钴和镍的最佳实验条件.在pH=8.0的氯化铵-氨水缓冲溶液中,以λmax.Co=512nm,λ参比.Co=482nm为测定钴的波长对,Co的线性方程为y=0.0907x-0.0162,线性范围为8.00～22.00μg/25mL;以λmax,Ni=496nm,λ参比,Ni=526nm为测定镍的波长对,Ni的线性方程为y=0.363x 0.0197,线性范围为4.00～14.00μg/25mL.对电镀液进行加标回收实验结果表明,该方法精密度高,结果准确,令人满意.     

一阶导数紫外分光光度法测定地下水中硝酸盐氮

一阶导数紫外分光光度法是指硝酸盐氮的浓度与具有线性关系,利用这种线性关系建立一元线性方程,从而测定硝酸盐氮的方法。本实验用此方法测定国标样和地下水样,均取得了令人满意的效果。     

导数-双波长分光光度法测定镍

报告了应用一阶导数－双波长分光光度法测定钴、镍共存试样中的镍含量。在表面活性剂ＯＰ存在下形成Ｎｉ－５－Ｂｒ－ＰＡＤＡＰ三元配合物,对配合物吸光度的一阶导数曲线取波长组合５７２．５ｎｍ和５５３．５ｎｍ处的ｄＡ／ｄλ值进行测定,其Δ（ｄＡ／ｄλ）值对镍浓度的线性关系良好。对模拟样品和工厂排放水样进行了测定,结果说明该法灵敏度高,相对标准偏差为０．８％～２．２％,加标回收率为１００．２％～１０２．５％。     

一阶导数分光光度法测定几种制剂中氟罗沙星

用一阶导数分光光度法测定了氟罗沙星片剂、胶囊和粉针剂中氟罗沙星的含量。氟罗沙星的线性范围为0.4~20.0μg/mL,线性相关系数为0.9998,检出限为0.04μg/mL,对12μg/mL的氟罗沙星溶液测定10次的相对标准偏差为1.4%,回收率为98%~105%。该法简便、快速、准确,测定三种样品的结果令人满意。     

Electrocatalytic oxidation of urea by nanostructured nickel/cobalt hydroxide electrodes

The present paper describes the catalytic oxidation of urea performed by nickel hydroxide and nickel/cobalt hydroxide modified electrodes by using both electrodeposited films and nanoparticles. The incorporation of Co foreign atoms leads to a slight increase in sensitivity besides the shift in redox process, avoiding the oxygen reaction. Nanostructured Ni₈₀Co₂₀(OH)₂ was synthesized by sonochemical route producing 5 nm diameter particles characterized by high-resolution transmission electron microscopy (HRTEM) being immobilized onto electrode by using the electrostatic Layer-by-layer technique, yielding attractive modified electrodes for sensor development.     

5-Br-PADAP分光光度法测定环境水中微量锌

在pH 8.0的硼砂-硼酸缓冲溶液中,在非离子表面活性剂OP存在下,锌(Ⅱ)与5-Br-PADAP生成红色络合物,络合物的最大吸收波长为555 nm,表观摩尔吸光系数ε=1.44×105L/(mol·cm).测得络合物组成比为n[(Zn(Ⅱ)]:n(5-Br-PADAP)=1:2,锌质量浓度在0～0.6 m/L符合比尔定律.加入掩蔽剂后用该方法测定环境水中微量锌,结果满意.     

Structure and electrochemical properties of nickel hydroxide electrodes with cobalt additives

In this article,cobalt additives are introduced into nickel hydroxide electrodes by two incorporation methods—co-precipitated cobalt hydroxide during the nickel hydroxide synthesis or post-added CoO with nickel hydroxide. The results of X-ray diffraction, cyclic voltammetry, electrochemical impedance spectroscopy, and charge–discharge tests indicate that (i) the diffraction peaks show a decrease in intensity and increase in the half peak breadths for Ni(OH)₂ with co-precipitated cobalt hydroxide; (ii) the electrochemical activity of nickel hydroxide can be improved by both incorporated cobalt and the effects of post-added CoO are more notable; (iii) CoOOH derived from post-added CoO is not stable in the KOH electrolyte when the potential of the Ni(OH)₂ electrode is lowered and its reduction product may be inactive, thus results in an irreversible capacity loss of nickel-metal-hydride battery after over-discharge-state storage.     

微乳液增溶导数分光光度法直接测定水中可溶性磷酸盐

研究了在OP微乳液的作用下，用一阶导数磷钼蓝分光光度法直接测定水中可溶性磷酸盐的最佳条件。OP微乳液大大改变了磷钼蓝的最大吸收波长，并提高了测定的稳定性和灵敏度。本法可有效地消除硅、砷和悬浮物等的干扰，其服从比耳定律的线性范围为0-1.92mg/L，检出限为0.007mg/L，加标回收率在98％－101％之间，测定准确、快速。     

Biological leaching of nickel and cobalt from lateritic nickel ore of Sukinda mines

In the present study lateritic nickel ore was used for bacterial leaching using a mixed consortium of mesophilic acidophiles. The microorganisms were adapted to 1 gram nickel/L prior to leaching. For the experiments, lateritic ore in different forms such as raw, roasted, roasted ore presoaked in dilute sulphuric acid and palletized pretreated roasted (400 °C and 600 °C) ore were taken. The leaching experiments were conducted in 9 K+ with 40 L capacity bioreactor using 10% (v/v) inoculum concentration at 10% (w/v) pulp density. The aeration was maintained at 2–3 L/min and the speed of agitator and temperature at 400–500 rpm and 35 °C. The maximum extraction of nickel and cobalt was observed with pretreated ore (600 °C) at 10% pulp density (77.23% and 73.22%) respectively within 31 days at pH 1.5 and least extraction in case of raw ore i.e., 9.47% nickel and 41.12% cobalt respectively.     

5-Br-PADAP分光光度法测定微量铁

研究了 Fe( ) - 5- Br- PADAP体系的反应条件 ,在 p H=5.5时 ,Fe( ) -5- Br- PADAP能形成稳定的紫红色配合物 ,可用于试样中微量铁的快速测定 ,方法选择性好 ,灵敏度高 ,在波长 555nm处测量 ,表观摩尔吸光系数为 7.9× 1 0 P4。     

分光光度法测定光亮镀镍溶液中的钴

以硫氢酸铵络合钴离子，随后用乙酸丁酯进行萃取，利用分光光度法测量光亮镀镍溶液中的钴离子。探讨了测量波长、硫氢酸铵的加入量、温度、时间、酸度、共存离子对测量结果的影响。结果表明，当钴离子含量为0.04-0.1mg/mL，吸光度与钴离子浓度间的关系遵守比耳定律。加标回收试验结果表明，该方法回收率为96.4%，具有很好的实用价值和应用前景。     

Total and soluble chromium, nickel and cobalt content in the main materials used in the manufacturing of Spanish commercial cements

One of the problems that some industries, and more specifically cement industries, still have to deal with is the requirement to determine and control the content of some chromium, nickel and cobalt compounds due to their allergenic effects on human health (mainly cement dermatitis). This paper focuses on the quantification of total and soluble chromium, nickel and cobalt content in different materials used normally in the manufacturing of Spanish commercial cements (limestone, clay minerals, raws and clinkers). These materials belong to three different cement factories, which could be representative of Spanish Portland cements. This study is a follow-up of a previous research carried out by the same authors, which provides a valuable contribution to establish possible limitations of these allergenic compounds in future national as well as international standards.     

Stability of metal nanoparticles formed during reduction of alumina supported nickel and cobalt catalysts

The formation of nickel and cobalt nanoparticles in hydrogenation catalysts and their stability against sintering during the reduction of the oxidic precursors were investigated. The morphology of the catalysts was manipulated by varying the reduction conditions. The catalysts were characterized using temperature programmed reduction (TPR), hydrogen chemisorption, X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HREM). The transformation of the oxidic precursor into the active phase was monitored using quasi in situ HREM, which proved to be an excellent technique to visualize the formation of metal nanoparticles. For the nickel catalyst the reduction temperature plays a crucial role, whereas time is more critical for the cobalt catalyst. The sintering rate of cobalt is considerably lower than that of nickel during reduction. It is concluded that the activation energy for sintering is significantly higher for nickel than for cobalt. A model is proposed which depicts the structure of both types of catalysts in their oxidic and reduced state. TPR and XPS results indicate that the passivated catalysts contain approximately two oxygen atoms per surface Ni or Co atom.