Na_2EDTA滴定法测定复杂高铋物料中铅

复杂高铋物料中铋、砷、锑、锡4种元素含量高且共存时会影响铅的测定。特别是铋含量高时对铅的测定影响较大。实验用EDTA-酒石酸联合掩蔽铋、砷、锑、锡,在稀硫酸介质中以硫酸钾为沉淀剂,使铅生成硫酸铅钾复盐沉淀而与铋、砷、锑、锡、铁、铜、锌、铝、钴、镍等干扰离子分离,沉淀以乙酸-乙酸钠浸取,二甲酚橙为指示剂,Na2EDTA滴定法测定铅含量。实验进一步优化了测定条件,确定的最佳条件:硫酸(1+1)加入量为7mL、硫酸钾用量为5g、煮沸时为5min、沉淀陈化时间为2h、EDTA(50g/L)加入量为10mL、酒石酸用量为0.5g,铅的加标回收率99.7%~104%。将实验方法应用于测定复杂高铋物料中铅,标准样品BY0111-1的测定值与给定值一致,相对标准偏差(n=11)RSD 0.20%~0.23%,满足生产测定要求。     

Na2EDTA滴定法测定粗二氧化碲中铅含量

建立了用氢溴酸消除锑、砷、锡干扰,用硫酸将铅形成硫酸铅沉淀,再用EDTA络合滴定法测定粗二氧化碲中铅量的方法。试样用硝酸、盐酸溶解,用硫酸沉淀铅,氢溴酸消除锑、砷、锡的干扰后,过滤分离其他共存元素,以乙酸-乙酸钠缓冲溶液溶解硫酸铅沉淀,在pH=5.0～6.0时,以二甲酚橙作指示剂,用Na_2EDTA溶液滴定溶液中铅含量。实验结果表明,氢溴酸加入量为15mL,酒石酸加入量为10mL,沉淀体积为50～60mL,沉淀时间1h以上时,方法相对标准偏差(RSD)在0.10%～1.1%,加标回收率为97.1%～102%,满足粗二氧化碲中铅量的生产控制检测要求。     

硝酸铅沉淀/ICP-MS法测定高纯铅中18种杂质

通过硝酸铅沉淀分离基体铅、有效富集高纯铅中镁、铝、钙、铁、镍、钴、锰、铜、锌、砷、硒、镉、铟、锡、锑、碲、铊、铋等18种杂质,通过电感耦合等离子体质谱测定高纯铅中18种杂质,测定下限在0.04～0.32μg/mL,加标回收率为80%～108%,测定精密度(RSD)为2.5%～14%。     

易熔合金中铋的测定

本文研究了易熔合金中铋的直接滴定条件。用盐酸-硝酸分解试样,加过量酒石酸络合锡、锑、铋等,既消除了锡、锑的干扰,又防止了铋的水解。由于锡、锑的酒石酸络合物较铋的酒石酸络合物稳定,控制硫脲加入量。在pH1—2时用EDTA直接滴定铋,终点变化敏锐。在拟定条件下,由于控制滴定的pH较低,     

硫酸铅分离-EDTA滴定法测定铜闪速冶炼烟尘中的铅

建立了用硫酸形成硫酸铅沉淀加以分离,再用EDTA络合滴定法测定铜闪速冶炼烟尘中铅量的方法。试样用盐酸、硝酸、硫酸、氟化氢铵和高氯酸溶解,用硫酸沉淀铅与其它干扰元素分离,沉淀溶解于乙酸-乙酸钠缓冲溶液中,以巯基乙酸掩蔽铋,抗坏血酸掩蔽铁,二甲酚橙作指示剂,用Na2EDTA标准滴定溶液滴定溶液中铅含量,采用火焰原子吸收光谱法测定滤液中铅含量加以补正。实验结果表明,沉淀时硫酸(1+24)加入量为50mL,无水乙醇加入量为10mL,乙酸-乙酸钠缓冲溶液加入量为30mL。方法相对标准偏差(RSD)在0.35%～1.5%,加标回收率为在99.0%～101%。完全满足生产控制分析的要求,同时也可以作为类似物料中铅分析的参考方法。     

硫酸铅分离-EDTA滴定法测定铜闪速冶炼烟尘中的铅

建立了用硫酸形成硫酸铅沉淀加以分离,再用EDTA络合滴定法测定铜闪速冶炼烟尘中铅量的方法。试样用盐酸、硝酸、硫酸、氟化氢铵和高氯酸溶解,用硫酸沉淀铅与其它干扰元素分离,沉淀溶解于乙酸-乙酸钠缓冲溶液中,以巯基乙酸掩蔽铋,抗坏血酸掩蔽铁,二甲酚橙作指示剂,用Na2EDTA标准滴定溶液滴定溶液中铅含量,采用火焰原子吸收光谱法测定滤液中铅含量加以补正。实验结果表明,沉淀时硫酸(1+24)加入量为50 mL,无水乙醇加入量为10 mL,乙酸-乙酸钠缓冲溶液加入量为30 mL。方法相对标准偏差(RSD)在0.35%~1.5%,加标回收率为在99.0%~101%。完全满足生产控制分析的要求,同时也可以作为类似物料中铅分析的参考方法。     

EDTA滴定法测定分银渣中的铅含量

采用氟化铵-盐酸-硝酸-高氯酸溶解样品,加入氢溴酸除去样品中的砷、锑、锡等共存元素,加入硫酸将样品中的铅转化为硫酸铅沉淀,通过过滤与其它元素分离,滴定前加入巯基乙酸掩蔽铋,在乙酸-乙酸钠缓冲体系下,以二甲酚橙为指示剂,建立了采用EDTA络合滴定法测定分银渣中铅含量的方法。实验方法用于测定分银渣中的铅含量,测定结果的相对标准偏差(RSD,n=11)为0.32%～0.90%,加标回收率为100%～102%。能够满足日常测定需求。     

电感耦合等离子体原子发射光谱（ICP-AES）法测定高铋铅中的杂质元素

采用硝酸+酒石酸溶解试样,电感耦合等离子体原子发射光谱(ICP-AES)法测定高铋铅中的铜、铁、镍、镉、砷、锑和铋的含量。测定范围为ωCu(0.10%～5.00%)、ωF e(0.001%～0.10%)、ωNi(0.001%～0.10%)、ωCd(0.001%～0.050%)、ωAs(0.50%～7.00%)、ωSb(0.50%～5.00%)、ωBi(1.00%～7.00%)。经加标回收实验,各元素的加标回收率为91.5%～115%。方法准确简单,适用于高铋铅中铜、铁、镍、镉、砷、锑和铋量的同时测定。     

电感耦合等离子体发射光谱法测定粗二氧化碲中 铜、铅、锑、铋、砷和硒

粗二氧化碲作为碲精炼或碲化工产品生产的重要原料,其中共存元素铜、铅、砷、锑、铋、硒含量的准确测定对于生产过程质量控制和贸易结算具有重要意义,但目前没有粗二氧化碲中铜、铅、砷、锑、铋、硒含量检测的标准分析方法。采用王水和饱和氟化氢铵分解试样,在王水和酒石酸介质中,选用Cu 327.393 nm、Pb 220.353 nm、Sb 217.582 nm、Bi 223.061 nm、As 193.696 nm、Se 196.026 nm为分析谱线,采用电感耦合等离子体发射光谱(ICP-AES)法测定粗二氧化碲中铜、铅、锑、铋、砷和硒含量。各元素校准曲线的相关系数均大于0.999;铜、铅、锑、铋、砷和硒的检出限分别为0.0004%、0.0005%、0.0006%、0.0007%、0.0004%和0.0007%,定量检出限分别为0.0012%、0.0016%、0.0020%、0.0025%、0.0013%和0.0025%。按照实验方法测定5个粗二氧化碲样品中铜、铅、锑、铋、砷和硒,测定结果的相对标准偏差(RSD,n=7)为0.79%~4.8%,加标回收率为96.0%~103%。方法简单,精密度和准确度较高,可用于测定粗二氧化碲中铜、铅、砷、锑、铋、硒含量。     

电感耦合等离子体原子发射光谱法(ICP-AES)测定高铋铅的杂质元素

采用硝酸+酒石酸溶解试样,电感耦合等离子体原子发射光谱法测定高铋铅中的铜、铁、镍、镉、砷、锑和铋的含量。测定范围: ω(Cu)：0.10%～5.00%,ω(Fe)：0.001%～0.10%,ω(Ni): 0.001%～0.10%,ω(Cd): 0.001%～0.050%,ω(As)：0.50%～7.00%,ω(Sb)：0.50%～5.00%,ω(Bi)：1.00%～7.00%。经加标回收实验,各元素的加标回收率为91.5%~114.6%。该方法准确简单,适用于高铋铅中铜、铁、镍、镉、砷、锑和铋量的同时测定.     

Determination of silver, antimony, bismuth, copper, cadmium and indium in ores, concentrates and related materials by atomic-absorption spectrophotometry after methyl isobutyl ketone extraction as iodides

Methods for determining ~ 0.2 mug g or more of silver and cadmium, ~ 0.5 mug g or more of copper and ~ 5 mug g or more of antimony, bismuth and indium in ores, concentrates and related materials are described. After sample decomposition and recovery of antimony and bismuth retained by lead and calcium sulphates, by co-precipitation with hydrous ferric oxide at pH 6.20 +/- 0.05, iron(III) is reduced to iron(II) with ascorbic acid, and antimony, bismuth, copper, cadmium and indium are separated from the remaining matrix elements by a single methyl isobutyl ketone extraction of their iodides from ~2M sulphuric acid-0.1M potassium iodide. The extract is washed with a sulphuric acid-potassium iodide solution of the same composition to remove residual iron and co-extracted zinc, and the extracted elements are stripped from the extract with 20% v v nitric acid-20% v v hydrogen peroxide. Alternatively, after the removal of lead sulphate by filtration, silver, copper, cadmium and indium can be extracted under the same conditions and stripped with 40% v v nitric acid-25% v v hydrochloric acid. The strip solutions are treated with sulphuric and perchloric acids and ultimately evaporated to dry ness. The individual elements are determined in a 24% v v hydrochloric acid medium containing 1000 mug of potassium per ml by atomic-absorption spectrophotometry with an air-acetylene flame. Tin, arsenic and molybdenum are not co-extracted under the conditions above. Results obtained for silver, antimony, bismuth and indium in some Canadian certified reference materials by these methods are compared with those obtained earlier by previously published methods.     

Influence of volatile hydride-forming elements on antimony determination by atomic-absorption spectrometry with hydride-generation

A study was undertaken to determine the interfering effects of arsenic, bismuth, germanium, lead, selenium, tin and tellurium on trace determination of antimony by atomic-absorption spectrometry with hydride-generation. A 1% NaBH(4) solution was used as reductant and a small amount of oxygen was added to the hydrogen produced, to support the combustion and atomization of SbH(3). The interference from selenium in the determination of antimony is removed if potassium iodide-ascorbic acid solution or copper sulphate is added to the sample solution. The interference of tin and tellurium can also be avoided by adding potassium iodide-ascorbic acid solution. A possible interference mechanism is discussed.     

碘酸钾滴定法测定铜阳极泥分银渣中的锡

建立了碘酸钾滴定法测定铜阳极泥分银渣中锡的含量。通过硝酸溶解,过滤除铜,还原铁粉置换分离锑、铋、砷等元素,消除了铜阳极泥分银渣中的铜、锑、砷等杂质元素对锡测定的干扰。方法加标回收率在99.7%~100%。精密度实验结果表明,相对标准偏差(RSD,n=11)小于1.1%。操作过程简单,能满足生产的需要。     

Spectrophotometric determination of bismuth in copper and cartridge brass by the iodide method

An improved spectrophotometric method is proposed for the determination with iodide of trace amounts of bismuth in copper and cartridge brass. The sample is dissolved in nitric acid and the bismuth is separated from the copper by an ammoniacal precipitation in the presence of iron(III) hydroxide as a gathering agent. The hydroxide precipitate is dissolved in hydrochloric acid, sulfuric acid is added, the solution is evaporated to a few ml, hydrobromic acid is added to volatilize the antimony and tin, and the solution is evaporated to fumes of sulfuric acid. The bismuth iodide color is then developed with a composite potassium iodide—sodium hypophosphite reagent. Factors affecting the bismuth iodide color are investigated.     

氢化物发生-原子荧光光谱法(HG-AFS)测定特硬铅合金中硒和碲

建立了氢化物发生-原子荧光光谱法(HG-AFS)测定特硬铅合金中硒和碲的分析方法。试样经硝酸和酒石酸溶解,硫酸沉淀分离基体铅元素。移取部分试液,在40%盐酸介质中直接用氢化物发生-原子荧光光谱法(HG-AFS)测定样品中的硒;另移取部分试液,加入氢溴酸挥发除去砷、锑、锡、硒等元素,在40%盐酸介质中用氢化物发生-原子荧光光谱法(HG-AFS)测定样品中的碲。考察了测定的最佳条件、铅及共存元素对测定的影响。测定硒和碲的相对标准偏差分别为7.5%～9.3%和3.6%～13.0%,加标回收率分别为88%～92%和98%～102%。准确度和精密度均能满足分析需要,具有较强的实用性。     

The determination of traces of antimony,tin and arsenic in cadmium by pulse polarography

Traces of antimony, tin and arsenic in cadmium products were determined by pulse polarography. Arsenic was distilled, while antimony and tin were precipitated as hydroxides with manganese dioxide as carrier; some lead was coprecipitated with tin, hence these elements were further separated by distillation. In all cases quantitative recoveries were obtained. Antimony(III) was determined in a hydrochloric acid-sodium hypophosphite mixture, tin(IV) in a hydrochloric-hydrobromic acid mixture and arsenic(III) in sulphuric acid as supporting electrolytes; for arsenic(III), methylene blue had to be added. A sample weight of 10 g and an end volume of 10 ml allowed the determination down to about 0.004 p.p.m. antimony, 0.006 p.p.m. tin and 0.003 p.p.m. arsenic in cadmium. Several synthetic samples and commercially available cadmium products were analysed.     

氢化物发生–原子荧光光谱法同时测定锌锭中砷和锑

建立用氢化物发生–原子荧光光度计同时测定锌锭样品中砷和锑含量的方法。采用硝酸一次溶样,加入酒石酸防止锑水解。加入硫脲–抗坏血酸混合溶液作为还原剂和掩蔽剂,消除干扰元素的影响,对实验条件进行了优化。砷和锑的负高压分别为220,200 V,灯电流分别为80,60 mA,还原剂为1%硼氢化钾溶液(含0.5%KOH),载流为10%盐酸溶液,还原时间为30 min。测定砷的线性范围为0~80 ng/mL,相关系数r=0.999 8,检出限为0.35μg/L,测定结果的相对标准偏差为3.18%(n=11);测定锑的线性范围为0~80 ng/mL,相关系数r=0.999 6,检出限为0.42μg/L,测定结果的相对标准偏差为4.32%(n=11),砷和锑的加标回收率在97.46%~100.30%之间。用该方法对标准样品进行测定,测定结果与标准值相符。该方法基体干扰少,灵敏度高,适合于锌锭中砷和锑的日常测定。