稀土元素在LD30铝合金真空钎焊中的作用

研究了添加La和Ce的Al-Si基钎料真空钎焊LD30铝合金接头的力学性能，微观组织形貌和EDS，并与未添加稀土元素的Al-Si基钎料真空钎焊接头进行对比。结果表明，添加稀土元素的LD30铝合金真空钎焊接头抗拉强度为288MPa，达母材抗拉强度的97．6％，明显高于未添加稀土的LD30合金真空钎焊接头。其机制在于La,Ce能够明显提高Al-Si基钎料与LD30铝合金的润湿性能，改善LD30铝合金真空钎焊接头焊缝及其基体中杂质元素的分布，促进钎料和母材中各元素的均匀扩散，从而提高真空钎焊接头的力学性能。     

电感耦合等离子体原子发射光谱法测定镍基钎料中Cr,Si,B,Fe

建立了电感耦合等离子体原子发射光谱法测定镍基钎料中Cr,Si,B,Fe含量的新方法。以硝酸–氢氟酸溶解样品,分别选择267.716,288.158,249.677,259.940 nm作为分析谱线,不用进行基体匹配,可直接测定镍基钎料中Cr,Si,B,Fe含量。在优化的实验条件下,测定结果的相对标准偏差为0.71%~1.43%(n=11),加标回收率为97.0%~102.0%。该方法可满足日常分析对镍基钎料中Cr,Si,B,Fe含量的检测要求。     

镧对钛基钎料钎焊Ti3Al和GH536的影响

研究了La的添加对Ti-Cu-Ni基钎料的性能,以及对Ti3Al和GH536钎焊接头的显微组织和机械性能的影响.研究结果表明： 采用添加La的钎料,可显著提高钎焊接头的拉伸强度,其原因在于La能明显提高钎料与母材的润湿性能,促进母材和钎料中元素的扩散.     

用铍试剂Ⅲ光度法测定钒

偶氮类化合物是钒的重要显色试剂,但是用铍试剂Ⅲ光度测定钒的方法尚未见报导。作者在研究钛的铍试剂Ⅲ多元络合物时发现,钒和铍试剂Ⅲ的反应灵敏,而且络合物形成后加入EGTA对吸光度无影响。本文对这一反应作了进一步研究,并拟定了铁矿石中钒的测定方法,获得了良好的结果。     

抗坏血酸-铍试剂Ⅲ光度法测定钛

抗坏血酸能与钛形成黄色络合物,并已用于钛的光度测定。当在钛(Ⅳ)-VC络合物中引入铍试剂Ⅲ时,则能形成钛(Ⅳ)-VC-铍试剂Ⅲ三元络     

石墨炉原子吸收分光光度法测定空气中的铍

对300余个样品进行监测,选择灵敏度高的石墨管和最佳基体,提高灰化、原子化的温度,确立了石墨炉原子吸收法测定空气中铍含量的实验条件。样品采用干灰化消解法,最佳溶剂为质量分数l％的硝酸溶液,利用仪器内置的样品浓度计算程序,绘制工作曲线直接获得样品中铍的含量。方法检出限为0．021μg／L,测定结果的相对标准偏差小于2％（n=6）,线性范围为0～6．5μg／L,加标回收率为91．6％～107％。     

ICP—AES法直接测定富钇稀土中钇量

采用ＩＣＰＳ－１０００Ⅱ型单道扫描光谱仪直接测定南方离子型稀土矿料中的Ｙ量，其Ｙ含量为３０％以上。采用正交设计试验对仪器有关工作条件进行优化，研究了共存稀土元素和非稀土元素的光谱干扰，酸度影响加料回收率为９６．５％￣９９．２％。不同方法进行对照，结果相符。     

石墨炉原子吸收法测定水系中的铍

用石墨炉原子吸收法测定水系中的铍，以Mg(NO3)2为基体改进剂，提高了测定铍的灵敏度，增强了测定铍的抗干扰能力。方法的线性范围为0－1．0μg/L，检出限为0．05μg/L。用于水库水、黄河水、饮用水和地下水等水中铍的测定，回收率为95％－110％。     

电感耦合等离子体原子发射光谱法测定Cu-Ni-Mn钎料中铝、钽元素含量

采用电感耦合等离子体原子发射光谱法测定Cu-Ni-Mn钎料中的铝和钽元素含量。实验探讨了Cu-NiMn钎料中基体元素及共存元素对铝、钽元素分析谱线的光谱干扰情况,确定了合适的分析谱线和背景校正方法。铝、钽元素的分析谱线分别为396.152 nm和240.063 nm。根据Cu-Ni-Mn钎料中铝、钽元素含量范围,合成系列标准溶液,建立标准工作曲线,工作曲线的线性范围为0.05%~0.20%,线性相关系数分别为0.999 6和0.998 8,此方法用于测定铝、钽元素的检出限分别为0.001 2%和0.008 4%,相对标准偏差为2.43%~4.55%(n=8)。标准加入回收率为100%~119%。该法可用于测定Cu-Ni-Mn合金中的铝和钽含量。     

载体沉淀-苯基荧光酮-CTMAB光度法测定合金钢中锡

钢铁合金中基体及掺杂元素钨、钼、钛的存在，严重影响了苯基荧光酮对锡的显色。通常采用碘化物与锡反应，以苯为萃取剂；或采用硫酸铍作载体沉淀剂，苯萃取的方法进行分离富集。但这两种方法不仅麻烦，而且工作流程长。本文以EDTA-H2O2络合，硫酸铍为载体沉淀，将钨、钼、钛等     

Determination of beryllium in urine by graphite-furnace atomic absorption spectrometry

A method has been developed for the determination of beryllium in urine by graphite-furnace atomic absorption spectrometry. Ammonium 12-molybdophosphate and ascorbic acid were employed as a matrix modifier. The tolerable charring temperature for beryllium in both aqueous solution and urine was raised to 1400 °C in the presence of a matrix modifier. The sensitivity for the determination of beryllium was also improved by a factor of 1.5 in comparison with that obtained by using magnesium nitrate as a matrix modifier. The mechanism of the enhancement effect of ammonium molybdophosphate was ascribed to the effectiveness of the formation of gaseous BeO, which is a precursor of free beryllium. Beryllium in urine can be determined simply by dilution with ascorbic acid solution. The relative standard deviation for seven replicate determinations of beryllium was 1.9% for a urine sample containing 0.029 μg ml^?1 of beryllium.     

固相萃取-石墨炉原子吸收法光谱分析铝合金中痕量铍的研究

建立了固相萃取-石墨炉原子吸收光谱法测定铝合金中铍的方法。利用偶氮砷酸类试剂7-(2′-胂酸基-5′-羧酸)苯偶氮-8-羟基喹啉-5-磺酸(H2L)与Be2+形成螯合物,该螯合物可用C18固相萃取柱富集,而Al3+则不被保留。采用石墨炉原子吸收光谱法(GF-AAS)测定C18柱洗脱液中的Be2+的螯合物,从而实现铝合金中铍的分离检测。最佳实验条件为:采用pH=3.0的5%H2L水溶液螯合Be2+,水相上柱,用2mL体积比为50%的甲醇/水溶液作为洗脱液。结果表明:经过C18柱固相萃取可以去除Al3+的干扰,Be2+的测定范围为0.05～16μg/L,检出限为0.025μg/L,加标回收率为92%～108%。应用该法于铝合金标样中铍的测定,结果与认定值相符。     

Simultaneous kinetic determination of beryllium and aluminium by spectrophotometric H-point standard addition method.

The H-point standard addition method (HPSAM), based on spectrophotometric measurements for simultaneous determination of beryllium and aluminium, is described. This method is based on the difference between their rates of reactions with Chrome Azurol S (CAS) in cetyltrimethylammonium bromide (CTAB) micellar media. The results showed that beryllium and aluminium could be determined simultaneously in the ranges of 10-200 and 10-300 ng mL(-1), respectively. Under working conditions, the proposed method was successfully applied to the simultaneous determination of beryllium and aluminium in environmental, geochemical and alloy samples.     

石墨炉原子吸收分光光度法测定固体废物中铍和钼

建立了石墨炉原子吸收法测定固体废物中铍和钼的方法。采用盐酸–硝酸–氢氟酸–高氯酸消解样品,钯盐作基体改进剂,消除了基体干扰。铍、钼的质量浓度分别在0~4.0,0~50.0μg/L范围内与吸光度呈良好的线性,线性相关系数均为0.999 6,检出限分别为0.03,0.2μg/g。实际样品加标回收率为82.5%~117.0%,测定结果的相对标准偏差为6.6%~10.4%(n=6)。该方法选择性强、灵敏度高,测定结果准确,满足固体废物全量分析要求。     

Preconcentration of trace amounts of beryllium in water samples on octadecyl silica cartridges modified by quinalizarine and its determination with atomic absorption spectrometry

A simple method has been developed for rapid and selective extraction, preconcentration and determination of trace amounts of beryllium. The extraction is carried out by octadecyl silica cartridge, modified with quinalizarine as a chelating agent. The effect of different parameters, such as sample matrix, flowrates of sample solution and eluent, pH, type and least amount of eluent for elution of Be(+2) ions from cartridge, breakthrough volume and limit of detection, were evaluated. Also, the effects of various cationic and anionic interferences on percent recovery of Be(+2) were studied. Be(+2) was extracted from solution at pH 6-6.6 and was eluted from modified cartridge with 5 ml of 0.5 M HNO(3). Extraction efficiencies >99% were obtained by elution of the cartridges with minimal amount of eluent. A preconcentration factor of 200 and a detection limit of 200 ng per 1000 ml were obtained. The method was applied to the recovery and determination of Be(+2) in different water and alloy samples.     

石墨炉原子吸收法测定土壤中铅、镉、钴、锑、铍

建立石墨炉原子吸收法测定土壤中铅、镉、钴、锑、铍含量的方法。优化了石墨炉原子吸收光谱法测定条件,在最佳实验条件下,采用硝酸-盐酸-氢氟酸-双氧水混合酸体系微波消解土壤样品,选用抗坏血酸-硝酸镁混合溶液为基体改进剂。铅、镉、钴、锑、铍的质量浓度在各自的范围内与吸光度成良好的线性关系,相关系数均大于0.999,各元素的检出限为0.008~0.06 μg/g。样品加标回收率为90.5%~104.0%,测定结果的相对标准偏差均小于2.5%(n=6)。该方法样品前处理简便,灵敏度高,检出限低,测定结果准确、可靠,可用于土壤中铅、镉、钴、锑、铍的测定。     

Resin phase spectrophotometry of beryllium by an optical fiber and beryllon II

We have developed a resin phase spectrophotometric method to determine the amount of beryllium by detecting a change in absorbance of the resin phase. 8-Hydroxynaphthalene-3,6-disulphonic acid-(1-azo-2')-1',8'-dihydroxynaphthalene-3',6'-disulphonic acid tetrasodium salt (beryllon II) immobilized by a strong base anion-exchange resin on the end of a bifurcated optical fiber bundle was chosen as a material sensitive to beryllium. Experiments were made using a home-made optical fiber spectrophotometer. The properties of the resin phase proved to be good for continual use of 350 times during a month. The reaction order between immobilized beryllon II and beryllium in solution was determined by kinetic theory and experiments. This method was also used to determine the amount of beryllium in beryllium-copper alloy; the response was linear from 0.43 to 2.60 mug/ml at pH 12.5 and 676 nm. The effect of interfering ions on the determination of beryllium was studied at the same time.