等离子体发射光谱法测定地质样品中的硼

用HF－HNO3－HCl－H3PO4混合酸分解样品，在氨性条件下，以元素的磷酸盐沉淀分离样品中大量的Fe、Al、Ca、Mg 等基体元素，然后用ICP－AES法测定，可用于地质样品中硼的分析。     

肿瘤患者血清中钴元素含量测定方法研究

本文建立了一种用石墨炉原子吸收光谱法测定肿瘤患者血清中微量钴的方法，血清以（１＋）硝酸沉淀消除蛋白后，加Ｔｒｉｔｏｎ Ｘ－１００和偏钒酸铵基体改进剂直接测定。     

微波微化—连续流动进样冷原子吸收法测定中成药中痕量汞

本实验室建立了用微波消化系统，消化中成药样品，用连续流动进样冷原子吸收法测定了中成药中痕量汞的方法，研究了硝酸－过氧化氢和硝酸－硫酸－高氯酸两种不同混合酸的消化体系及消化时间和压力对测定结果的影响。方法的相对标准偏差为4.9%，回收率在91％－116％之间，检出限为0.15ng/mL。     

微波消化-连续流动进样冷原子吸收法测定中成药中痕量汞

本实验室建立了用微波消化系统，消化中成药样品，用连续流动进样冷原子吸收法测定了中成药中痕量汞的方法。研究了硝酸－过氧化氢和硝酸－硫酸－高氯酸两种不同混合酸的消化体系及消化时间和压力对测定结果的影响。方法的相对标准偏差为４．９％，回收率在９１％—１１６％之间，检出限为０．１５ｎｇ／ｍＬ。     

基体分离ICP-AES法测定金属锇粉中的杂质元素

本文介绍了用浓硝酸在２００℃下溶解样品,同时把锇氧化成易挥发的氧化物离去并用氢氧化钠吸收,残液用ＩＣＰ－ＡＥＳ测定的方法。方法检测限为０．００５－０．１３４μｇ．ｍＬ＾－１,回收率为９１％－１１２％,精密度小于３％,同时测定１８种杂质元素,具有简单快速和准确度高的优越性。     

快速测定硅铁中铝和磷

试样以硝酸、氢氟酸溶解,用高氯酸冒烟驱除氟。铝的测定：于氢氧化钠溶液中将铁、锰、钛等元素与铝分离,加入过量EDTA与铝络合,以PAN为指示剂,用硫酸铜滴定计算铝含量;磷的测定：于硝酸介质中,用硫代硫酸钠还原砷,用抗坏血酸乙醇溶液还原成铋磷钼蓝,用分光光度计测量吸光度,计算磷含量。本方法采取一次溶样同时完成铝和磷的测定,方法快速、准确、可靠,适用于出口铁的日常检验。     

载体沉淀—原子吸收光谱法测定钢中微量锑

本文采用在硝酸介质中以二氧化锰为载体沉淀锑与大量基体铁分离，继而用火焰原子吸收光谱法测定钢中微量锑；该法测定锑的特征灵敏度为0.062微克／毫升／1％、工作线性范围6微克／毫升以下，测定含量为0.001－0.01％之间。该法在进行条件试验过程中采用正交设计。     

原子吸收光度法测定钢铁及合金中的铌量

本法叙述了一氧化二氮－乙炔火焰原子吸收光度法测定铌量，用鞣酸沉淀分离和在盐酸－氢氟酸介质中加入增感剂三氯化铝，灵敏度１２μｇ／ｍＬ／１％吸收，检出限６．１μｇ／ｍＬ。     

共沉淀预富集-火焰原子吸收法测定水中的铅和镉

在弱氧化剂存在下，二乙基二硫代氨基甲酸钠作为共沉淀剂预富集水中的铅和镉，加入饱和明矾溶液以加速沉淀物的生成和凝聚，虹吸除去上层清液（无需过滤），用硝酸溶解沉淀，火焰原子吸收测定铅和镉的含量。方法简便、实用，具有较高的准确度和精密度，适用于大体积水样预处理及重金属元素的测定。     

锰石墨炉原子吸收分析中氯化钙干扰机理研究

本文用时间分辨技术考察了氯化钙对锰测定过程的干扰情况。干扰包括三个方面：抑制效应，延迟效应和背景吸收。选用硝酸作为基体改进剂，ＨＣｌ的形成和挥发减少了锰的损失，消除了ＣａＣｌ２的分子吸收，硝酸的加入还改进了锰吸收峰形，改善了测定灵敏度。Ｃａ（Ⅱ）－Ｍｎ－ＨＮＯ３的共存体系使锰的原子化移向高温，原子化效率提高。镁，锶，钡具有类似钙的作用。     

ESR法研究龙胆酸在碱性溶液中的反应

本文用静态毛细管法研究了龙胆酸在醇钠-醇溶液中的反应,主要是氧化反应,发现了属于同一类型三种新的自由基物种,给出了它们的自由基结构模式;龙胆酸在氢氧化钠水溶液中的反应,不仅有氧化还有取代反应,氧化之后紧接着进行取代反应,本文都给予了解释。     

Selective synthesis of zeolitic phillipsite and hibschite hydrogarnet from lignite ash employing calcium hydroxide under mild conditions

A selective synthesis of zeolitic material, phillipsite, employing calcium hydroxide under mild chemical conditions is reported. This is to provide a potential method in reducing the amount of the waste from lignite power plant and the addition of economical value to the material. The fly ash was first activated by calcination at high temperature, and then fused with calcium hydroxide. The water was then added to the solid mixture before curing under saturated water vapour at low temperature. The treatment of as-received fly ash with either calcium hydroxide or a mixture of calcium and sodium hydroxide following as-described preparative procedure of phillipsite, but without prior calcination was also conducted, and led to the formation of Hibschite hydrogarnet, which was also evidentially selective. The following parameters, i.e. type and amount of alkali reagent, the amount of added water, fusion temperature and reaction time were investigated. Powder X-ray diffraction was used to identify type of crystalline solid products, and scanning electron microscope was employed to follow the alteration of solid morphologies. X-ray fluorescence (XRF) was used to trace the chemical composition of the solids. The heavy metal cation removal abilities toward lead ion of the prepared phillipsites were also investigated.     

电感耦合等离子体-原子发射光谱法测定铝合金中7种元素含量

采用基体匹配技术,相同牌号的铝合金标准样品绘制校准曲线,用氢氧化钠、过氧化氢和硝酸溶解铝合金试样,电感耦合等离子体-原子发射光谱法直接测定铝合金中Cu、Fe、Mg、Mn、Si、Ti、Zn 7种元素含量.方法简便、快速.回收率95.7%-102.4%,相对标准偏差0.45%-1.21%.     

微波辐射法合成4A沸石及表征

本文主要是采用微波辐照的方法合成4A沸石分子筛,并先后以纯化学原料,工业用高岭土为原料等进行合成,结果表明4A沸石合成的质量与微波功率及辐照时间密切相关,用高岭土为原料能合成出与化学法具有同等质量的4A沸石。     

An XANES study on the modification of single‐walled carbon nanotubes by nitric acid

X‐ray absorption near‐edge structure (XANES) spectroscopy has been applied to identify the modification process of single‐walled carbon nanotubes (SWCNTs) treated by nitric acid. The carboxyl groups created by the nitric acid treatment have been found to be formed on both the carbonaceous fragments and the side walls of SWCNTs. The carbonaceous fragments could be removed by a following washing treatment with sodium hydroxide. XANES spectra indicate that carbonaceous fragments are the result of the synthesis process and/or of the nitric acid treatment. Tube walls of SWCNTs are weakly oxidized by the nitric acid treatment although, after removing carbonaceous fragments, a direct oxidation process of SWCNTs is observed. Experimental data address the removal of carbonaceous fragments on SWCNTs as an efficient method for side‐wall modification of a SWCNT.     

Purification and fractionation of single-walled carbon nanotubes

This study presents the approach to the purification and subsequent metallic/semiconductive (M/S) fractionation of single-walled carbon nanotubes (SWCNTs) with diameter from 1.04 to 1.60 nm produced via laser ablation. SWCNTs were purified through 3-fold refluxing processes in nitric acid followed by the multiple washings with sodium hydroxide and hydrochloric acid. The purified-annealed SWCNTs sample was divided into seven batches. One batch was dispersed in acetone as a reference sample. Each of the remaining batches were dispersed in one of the following surface agents: sodium dodecyl sulfate, sodium cholate acid (SCA), sodium deoxycholate, cetrimonium bromide, cetylpyridinium chloride, and benzalkonium chloride (BKC). SWCNT suspensions were fractionated via free solution electrophoresis technique. The recovered fractions from electrode and control areas were analyzed via optical absorption spectroscopy in UV–Vis–NIR range to evaluate the efficiency of the separation process. Raman spectroscopy was applied to analyze the purity of the samples. The catalyst content was estimated by atomic absorption spectroscopy. The morphology of the investigated samples was observed via high-resolution transmission electron microscopy. This contribution clearly shows that among the investigated surfactants there are two promising candidates (SCA and BKC) which can efficiently enrich the bulk sample in one electronic type of carbon nanotubes when FSE is applied.     

分光光度法研究改性沸石对Fe2+的吸附性能

采用微波辐射技术结合酸、碱、盐分别对沸石进行活化改性处理,用分光光度法分析改性沸石对Fe2+的吸附性能及影响因素。结果表明:NaOH改性沸石对Fe2+的去除效果优于NaCl、HCl改性沸石,当微波功率为640W,微波时间为5min,NaOH浓度为0.8mol/L时,Fe2+去除率可达98.56%。经过对改性沸石再生,NaOH浸泡过的改性沸石再生性较好。     

ICP-AES法同时测定银锭中铋、锑、铅、铜、铁杂质元素

本文介绍ICP-AES法同时测定银锭中Bi、Sb、Pb、Cu、Fe杂质元素的方法。试样用稀硝酸溶解后测定,回收率为93.0%-105.0%,RSD为0.36-4.2%。     

pH-dependent color change of colloidal dispersions of gold nanoclusters: Effect of stabilizer

Gold nanoclusters protected by 3-mercaptopropionic acid (MPA-Au nanoclusters) were prepared by citrate-reduction of hydrogen tetrachloroaurate(III) in the presence of sodium 3-mercaptopropionate. Color of the dispersions of MPA-Au nanoclusters changed from red to purple by addition of hydrochloric acid and returned from purple to red by addition of an aqueous sodium hydroxide solution. This reversible response can be attributed to synchronized changes between dispersion and ordering of MPA-Au nanoclusters, determined by transmission electron microscopy. Gold nanoclusters protected by poly(acrylic acid) (PAA-Au nanoclusters) were prepared by UV irradiation of an aqueous solution of hydrogen tetrachloroaurate(III) in the presence of poly(sodium acrylate). The pH-dependent spectral change observed for MPA-Au was not observed for PAA-Au. UV-Vis absorption spectra of colloidal dispersions of PAA-Au nanoclusters after addition of hydrochloric acid and an aqueous sodium hydroxide solution were in good agreement with each other, suggesting the stability of PAA-Au nanoclusters to pH change. Received 18 October 2000 and Received in final form 10 April 2002